On a bread board, there is no heatsinking for the h bridge. You will
need to add.

Check the freewheel diodes - don't rely on any internal diodes.

Aaron

Sent from my iPod


On Nov 23, 2009, at 8:18 PM, "jeffdayman" <jeffdayman@...>
wrote:

> Hi Ben,
>
> I have the fourth printing of the book. I am not using a supplied
> PCB, I wired a breadboard PCB. It does pass all tests in the book.
>
> The servo up and down switches do already have 1K resistors inline
> with them, R15 and R16 on the circuit diagram.
>
> I have had a 33 Ohm resistor in series with my gearhead motor during
> the entire first burn tryout. Without the 33 Ohm resistor the motor
> winding is roughly 120 Ohms.
>
> I have checked the motor operation using a separate bench power
> supply and at 12 VDC it runs fine, there is lots of torque and it
> runs equally well in both directions. I checked my leadscrew system
> and it takes almost no torque to turn it. It is a plated steel screw
> in a bronze block, both threads clean and smoothly finished.
>
> No idea why I am blowing servo IC's.
>
> Anybody have any ideas?
>
> Is there a way to install current limiter to prevent blowing the
> servo IC?
>
> Is there a more robust servo chip out there we could use?
>
> Happy I achieved the first burn, but I want to do lots more now and
> can't!
>
> Best regards Jeff Dayman
>
> --- In EDMHomeBuilders@yahoogroups.com, Benjamin Nathan Fleming
> <bnf@...> wrote:
>>
>>
>> Yes two 1K resistors in each switch leg.
>>
>> Jeff you are building from the PCBoard right?? The instructions for
>> that board and the latest printing of the book have that change.
>>
>> Ben
>>
>> ----- Original Message -----
>> From: Aaron Pasteris <aarons_groups@...>
>> Date: Sunday, November 22, 2009 9:38 pm
>> Subject: Re: [EDMHomeBuilders] First burn plus problems
>> To: "EDMHomeBuilders@yahoogroups.com" <EDMHomeBuilders@yahoogroups.com
>> >
>>
>>> Ben
>>> Did you update the schematic?
>>>
>>> As I remember, pressing both the up and down together would short
>>> the
>>> power rails.
>>>
>>> Aaron
>>>
>>> Sent from my iPod
>>>
>>>
>>> On Nov 22, 2009, at 9:43 PM, Benjamin Nathan Fleming <bnf@...>
>>>
>>> wrote:
>>>
>>>>
>>>> Jeff when operating properly you should be able to push the up
>>> and
>>>> down buttons at any time with out experiencing any problems.
>>>>
>>>> Yes it sounds like you blew a motor driver chip!! do you have a
>>> heat
>>>> sink on the chip. I know that there has been a problem with this
>>>> chip blowing. It is suppose to have over current and thermal
>>>> protection on board but I am not sure how effective it is.
>>> Thought
>>>> the chip works well in most situations with these small motor I
>>>> would not say it is really robust, and I have been a little
>>>> disappointed in it reliability.
>>>>
>>>> You could put a low ohm resistor in series with your motor lead
>>> to
>>>> reduce the current drawn by your present motor. Perhaps others
>>> might
>>>> chim in her on their experiences.
>>>>
>>>> Allied Electronics sells Pittman motors  They use to carry the
>>>> Pittman GM8712-31 Allied Stock number 388-0004.
>>>>
>>>> A check a few mins ago indicate that they have drop that motor!!
>>>> Electronic suppliers appear to change the stock they carry
>>> Making
>>>> it very difficult to keep current  for plans built type items
>>> such
>>>> as this EDM, It is very frustrating for me.
>>>>
>>>> I don't have an a source at the present time since Allied appears
>>> to
>>>> have dropped that motor.
>>>>
>>>> I would suggest you check other Electronics supply houses and
>>> keep
>>>> an eye on EBay. The latter would be my choice as the motors in my
>>>
>>>> opinion are steep in price if bought new.
>>>>
>>>> The meter should deflect to the right during a burn. Did you
>>> adjust
>>>> the 100K Pot. (R13) for deflection prior to operation?? if so did
>>> it
>>>> deflect to the right?
>>>>
>>>> Hope this helps
>>>>
>>>> Ben
>>>>
>>>>
>>>>
>>>>> Couple of questions for Ben Fleming:
>>>>>
>>>>> 1. Is it OK to push the ram up and ram down buttons at any time or
>>>>> are there times when they could cause a high current situation and
>>>>> should not be pushed?
>>>>>
>>>>> 2. Do you have a source for the exact Pittman motor gearhead you
>>>>> used? I think part of my problems are that the gearhead I'm using
>>>>> is different than the Pittman and draws more current than it
>>> should.>>
>>>>> 3. During the burn the DC meter needle did not move at all. Is it
>>>>> supposed to? Not that it matters to the machine function, but I
>>>>> feel a bit stupid buying and fitting it if it doesn't do something
>>>>> useful.
>>>>> Best regards Jeff Dayman
>>>>>
>>>>>
>>>>
>>>>
>>>> ------------------------------------
>>>>
>>>> Yahoo! Groups Links
>>>>
>>>>
>>>>
>>>
>>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

I believe the method is called out in the data sheet.

Parallel channel 1 with 4 and 2 with 3

Make sure you heatsink if the board doesn't have one built into the
pattern. It's a good idea even if there is a few square inches of
copper heatsink on the four ground pins.

Aaron

Sent from my iPod

On Nov 23, 2009, at 8:06 PM, "jeffdayman" <jeffdayman@...>
wrote:

> Me too Cary - I am running out of driver IC's and Allied says they
> are now backordered.
>
> I see how the piggybacking method works but for your method to use
> both H bridges "wiring it to use both of them" exactly how would I
> wire them? Can you give us a pinout or sketch? Forgive me if it's
> obvious but I am from a machining background rather than electronics.
>
> Best regards Jeff Dayman
>
> --- In EDMHomeBuilders@yahoogroups.com, Benjamin Nathan Fleming
> <bnf@...> wrote:
>>
>>
>> Cary I would be interested in seeing your data.
>>
>> Thanks
>>
>> Ben
>>
>> ----- Original Message -----
>> From: cary heestand <c.hhestand@...>
>> Date: Monday, November 23, 2009 10:32 am
>> Subject: Re: [EDMHomeBuilders] First burn plus problems
>> To: EDMHomeBuilders@yahoogroups.com
>>
>>> The motor driver chip can be made more effective by doing this;
>>> http://www.acroname.com/robotics/info/ideas/stacking/stacking.html#c
>>> It can be made even more effective by using both haves of the
>>> chip.  There are two H-bridges in the chip and by wiring it to use
>>> both of them you double the amperage available to the motor.
>>>
>>> Also the over heating of the chip is increased by the comparator
>>> circuit.  Ben, I know you disagree with me on this but I did the
>>> math on it and there is no "window" on the comparator.  In fact
>>> there is a overlap.  The Comparator is trying to move the ram up
>>> and down at the same time, right where the "window" should be.
>>>
>>> If you want I will post a chart showing what I mean.  I found this
>>> out when I was doing research on my comparator circuit.  I was
>>> comparing all of the available plans to see how they work in theory
>>> and found this.
>>>
>>> Cary
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> --- On Sun, 11/22/09, Benjamin Nathan Fleming <bnf@...> wrote:
>>>
>>>
>>> From: Benjamin Nathan Fleming <bnf@...>
>>> Subject: Re: [EDMHomeBuilders] First burn plus problems
>>> To: EDMHomeBuilders@yahoogroups.com
>>> Date: Sunday, November 22, 2009, 9:43 PM
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> Jeff when operating properly you should be able to push the up and
>>> down buttons at any time with out experiencing any problems.
>>>
>>> Yes it sounds like you blew a motor driver chip!! do you have a
>>> heat sink on the chip. I know that there has been a problem with
>>> this chip blowing. It is suppose to have over current and thermal
>>> protection on board but I am not sure how effective it is. Thought
>>> the chip works well in most situations with these small motor I
>>> would not say it is really robust, and I have been a little
>>> disappointed in it reliability.
>>>                                                    < SNIP >
>>>
>>> Ben
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

It turns out I have an older version of the book and the resistors for the up
and down switches are not listed on the circuit diagram. I had planned on using
a spring loaded two postion toggle switch in place of the individual push button
switches anyway. That way it's one less part to install, gives me more room to
work with on my control panel layout and prevents me from activating both
switches at the same time. Also I like the idea of pushing the toggle up to go
up and down to go down. Sorry I don't have the switch number handy, I got it in
a grab bag of switches from somewhere years ago and most didn't have any specs
with them.

Brad Necker

--- In EDMHomeBuilders@yahoogroups.com, Aaron Pasteris <aarons_groups@...>
wrote:
>
> Ben
> Did you update the schematic?
>
> As I remember, pressing both the up and down together would short the
> power rails.
>
> Aaron
>
> Sent from my iPod
>
>
> On Nov 22, 2009, at 9:43 PM, Benjamin Nathan Fleming <bnf@...>
> wrote:
>
> >
> > Jeff when operating properly you should be able to push the up and
> > down buttons at any time with out experiencing any problems.
> >
> > Yes it sounds like you blew a motor driver chip!! do you have a heat
> > sink on the chip. I know that there has been a problem with this
> > chip blowing. It is suppose to have over current and thermal
> > protection on board but I am not sure how effective it is. Thought
> > the chip works well in most situations with these small motor I
> > would not say it is really robust, and I have been a little
> > disappointed in it reliability.
> >
> > You could put a low ohm resistor in series with your motor lead to
> > reduce the current drawn by your present motor. Perhaps others might
> > chim in her on their experiences.
> >
> > Allied Electronics sells Pittman motors  They use to carry the
> > Pittman GM8712-31 Allied Stock number 388-0004.
> >
> > A check a few mins ago indicate that they have drop that motor!!
> > Electronic suppliers appear to change the stock they carry  Making
> > it very difficult to keep current  for plans built type items such
> > as this EDM, It is very frustrating for me.
> >
> > I don't have an a source at the present time since Allied appears to
> > have dropped that motor.
> >
> > I would suggest you check other Electronics supply houses and keep
> > an eye on EBay. The latter would be my choice as the motors in my
> > opinion are steep in price if bought new.
> >
> > The meter should deflect to the right during a burn. Did you adjust
> > the 100K Pot. (R13) for deflection prior to operation?? if so did it
> > deflect to the right?
> >
> > Hope this helps
> >
> > Ben
> >
> >
> >
> >> Couple of questions for Ben Fleming:
> >>
> >> 1. Is it OK to push the ram up and ram down buttons at any time or
> >> are there times when they could cause a high current situation and
> >> should not be pushed?
> >>
> >> 2. Do you have a source for the exact Pittman motor gearhead you
> >> used? I think part of my problems are that the gearhead I'm using
> >> is different than the Pittman and draws more current than it should.
> >>
> >> 3. During the burn the DC meter needle did not move at all. Is it
> >> supposed to? Not that it matters to the machine function, but I
> >> feel a bit stupid buying and fitting it if it doesn't do something
> >> useful.
> >> Best regards Jeff Dayman
> >>
> >>
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>

The problem I found is the price of parts when ordering from more than one
company can cost more in shipping and handling than the parts are worth. Those
20uf capacitors are a good example. Although I could find them at reasonable
prices, I found the shipping and handling for them cost double or more than what
the parts cost. Some companies have a minimum order and that prohibits ordering
the odd item at times. I think anyone that had to scrounge up the parts from
several different vendors like I did would agree that a parts kit would have
been a welcomed addition had they been availible.

Brad Necker

--- In EDMHomeBuilders@yahoogroups.com, "luslugger" <agm@...> wrote:
>
> Has anyone put together a bag of parts for this circuit?  As I build mine
should I get a dozen of each part and make a kit?
>

Thanks for the information, also thanks to David for his input as well. I'll
take your information and go ahead and try that meter I have and I'll go for the
recommended transformers. I walked down to Radio Shack today to find they only
cary one transformer at a time in stock. I bought the one they had and will have
to hit another Radio Shack or wait two weeks for the store to order another one.

Brad Necker



--- In EDMHomeBuilders@yahoogroups.com, Donald H Locker <dhlocker@...> wrote:
>
> A VA is a "volt-amp", related to the power that the unit can handle.  A 24Volt
transformer with at 2.4VA rating can deliver 0.1A RMS at 24V RMS.
>
> This VA is different than the watt because the amps only generate watts when
they are in phase with the volts, while the amps heat the transformer whether
they are in phase or not.  Many loads are non-linear and will draw current that
is out of phase with the voltage.  These loads require more amps than the watts
would indicate.  A 2.4Watt load with a 50% power factor will require up to 0.2
amps (therefore a 4.8VA transformer) to work.
>
> I can't help with the capacitors; 22uF should work as well as 20.
>
> All meters with a needle are basically current meters, usually 50 uA; put an
appropriate resistor in series and you have a volt meter.  As a starting point,
figure the 9V/250 ohms indicates the meter requires 36 mA to drive full scale,
so has an internal shunt to make it a current meter.  I'd put enough resistance
in series to make that work (e.g. desire 70V full scale: 70V/0.036A = 1944.44444
ohms (call it 1950)  The meter already has 250, so you need 1700 ohms in series
to make 70V read full scale.  Power = current squared * resistance, so the
resistor must be rated at least (0.036A * 0.036A * 1700 ohms) = 2.2 Watts so as
to not catch fire/blow up/whatever - use a 2.5W or 4 or 5W unit to be safe. 
P.S.  a 1700 ohm resistor is an odd value; you might have to use 1500 + 210 or
1500 + 180 (and calculate the power for each; that doesn't divide evenly) to
give you the requred value.
>
> HTH,
> Donald.
>
> ----- Original Message -----
> From: "camden_blue" <camden_blue@...>
> To: EDMHomeBuilders@yahoogroups.com
> Sent: Saturday, November 21, 2009 4:43:50 PM GMT -05:00 US/Canada Eastern
> Subject: [EDMHomeBuilders] I'm unclear on transformer lingo.
>
> Hi edm builders,
>
> I've been researching the labeling on a couple of transformers I have laying
around. One is labeled 120v 60hz primary with a 25 volt center tap secondary. It
also says class 2-3 VA and that's the mystery, does that mean 3 amps? Another I
have is printed 24 VAC class 2 and 4.8 VA and I'm not sure if that means 4.8
amps or something else. I was thinking of just trying them, the worse that I
could think might happen is I might let the magic smoke out of them. It wouldn't
be the first time I've fried a transformer. Another question I have concerns the
20uf capacitors. I've looked high and low for the correct parts at a cheap price
and ended up getting a pair of electrolitic versions. Since the rough cut cap.
is an electrolitic I figured they should work here too as long as I put them in
with the poles correct. Anybody see any problems here? Anyone using 22uf caps.
instead as these are availible everywhere at a cheap price? My last question
concerns the volt meter. I have a couple of meters out of an old tape recorder.
These were used to adjust the volume levels during recording. I'm not sure if
they are volt meters or amp meters? Is there any way to tell the difference? I
can put an ohm meter across the leads and it reads about 250 ohms. My volt meter
has a 9 volt battery in it and while measuring for ohms that's just about enough
voltage to peg the meter and reversing the ohm meter leads does change the
direction the mystery meter swings. Since my multimeter measures both amperage
and voltage using the same meter maybe there's no difference in meters, only in
the way they are hooked into a circuit? I could probably rig up a voltage
divider to get me in the right range to get full travel out of this meter in my
circuit but I'm not sure if would be of any use to me. Anyone using their volt
meters while burning? I realize it's a lot of questions in one letter but the
group sometimes needs a few questions to get information flowing within. I'm
looking forward to your answers and I'll be completing this thing one way or
another. I've got the circuit board built and the bottom of the case drilled to
hold most of the components. The only other change I've made so far is in
regards to the hole pattern for venting heat from the resistors. My last name is
"Necker" so I drilled my last name using a series of holes for the letters. I've
got a Terco CNC machine I've converted to run off a laptop and I generated the
hole pattern using the free version of CamBam software. It turned out great.
When I get the rest of it done I'll put a few photos in the photo section to
show how it comes out.
>
> Brad
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>

The semiconductor failure is likely not from heat and the relays will be too
slow to protect the H-bridge.  I'll try to get a look at the circuit and see if
I see anything that jumps out to me.

I'd be a little  reluctant to try paralleling the sections of the driver. 
Likely better to go to a higher rated device instead.  Semiconductors don't
often like to share current evenly.  One will play hero while the other starves.
In this case, it will probably be better than one section only, because the load
should not exceed the capability of one of the device sections, but in general
it's not such a good idea.

Donald.
----- Original Message -----
From: "mike maxim" <mammike@...>
To: EDMHomeBuilders@yahoogroups.com
Sent: Monday, November 23, 2009 9:10:47 PM GMT -05:00 US/Canada Eastern
Subject: Re: [EDMHomeBuilders] Re: First burn plus problems


I use 4 n/o relays but the type I use can go either way.  2 relays are for the
+ side and 2 are for the - side. 
 
dont know what the temp should be I only use one small fan for cooling never had
a problem.
 
mike m

Forgot to mention I am using the book-specified heatsink, heatsink grease, and 3
cooling fans. There is lots of cool air in the box, I checked internal temps
with a thermocouple and the box air just above the PCB is 55-60 deg F.

Best regards Jeff Dayman

--- In EDMHomeBuilders@yahoogroups.com, "jeffdayman" <jeffdayman@...> wrote:
>
> Hi Ben,
>
> I have the fourth printing of the book. I am not using a supplied PCB, I wired
a breadboard PCB. It does pass all tests in the book.
>
> The servo up and down switches do already have 1K resistors inline with them,
R15 and R16 on the circuit diagram.
>
> I have had a 33 Ohm resistor in series with my gearhead motor during the
entire first burn tryout. Without the 33 Ohm resistor the motor winding is
roughly 120 Ohms.
>
> I have checked the motor operation using a separate bench power supply and at
12 VDC it runs fine, there is lots of torque and it runs equally well in both
directions. I checked my leadscrew system and it takes almost no torque to turn
it. It is a plated steel screw in a bronze block, both threads clean and
smoothly finished.
>
> No idea why I am blowing servo IC's.
>
> Anybody have any ideas?
>
> Is there a way to install current limiter to prevent blowing the servo IC?
>
> Is there a more robust servo chip out there we could use?
>
> Happy I achieved the first burn, but I want to do lots more now and can't!
>
> Best regards Jeff Dayman
>
> --- In EDMHomeBuilders@yahoogroups.com, Benjamin Nathan Fleming <bnf@> wrote:
> >
> >
> > Yes two 1K resistors in each switch leg.
> >
> > Jeff you are building from the PCBoard right?? The instructions for that
board and the latest printing of the book have that change.
> >
> > Ben
> >
> > ----- Original Message -----
> > From: Aaron Pasteris <aarons_groups@>
> > Date: Sunday, November 22, 2009 9:38 pm
> > Subject: Re: [EDMHomeBuilders] First burn plus problems
> > To: "EDMHomeBuilders@yahoogroups.com" <EDMHomeBuilders@yahoogroups.com>
> >
> > > Ben
> > > Did you update the schematic?
> > >
> > > As I remember, pressing both the up and down together would short
> > > the
> > > power rails.
> > >
> > > Aaron
> > >
> > > Sent from my iPod
> > >
> > >
> > > On Nov 22, 2009, at 9:43 PM, Benjamin Nathan Fleming <bnf@>
> > >
> > > wrote:
> > >
> > > >
> > > > Jeff when operating properly you should be able to push the up
> > > and
> > > > down buttons at any time with out experiencing any problems.
> > > >
> > > > Yes it sounds like you blew a motor driver chip!! do you have a
> > > heat
> > > > sink on the chip. I know that there has been a problem with this
> > > > chip blowing. It is suppose to have over current and thermal
> > > > protection on board but I am not sure how effective it is.
> > > Thought
> > > > the chip works well in most situations with these small motor I
> > > > would not say it is really robust, and I have been a little
> > > > disappointed in it reliability.
> > > >
> > > > You could put a low ohm resistor in series with your motor lead
> > > to
> > > > reduce the current drawn by your present motor. Perhaps others
> > > might
> > > > chim in her on their experiences.
> > > >
> > > > Allied Electronics sells Pittman motors  They use to carry the
> > > > Pittman GM8712-31 Allied Stock number 388-0004.
> > > >
> > > > A check a few mins ago indicate that they have drop that motor!!
> > > > Electronic suppliers appear to change the stock they carry
> > > Making
> > > > it very difficult to keep current  for plans built type items
> > > such
> > > > as this EDM, It is very frustrating for me.
> > > >
> > > > I don't have an a source at the present time since Allied appears
> > > to
> > > > have dropped that motor.
> > > >
> > > > I would suggest you check other Electronics supply houses and
> > > keep
> > > > an eye on EBay. The latter would be my choice as the motors in my
> > >
> > > > opinion are steep in price if bought new.
> > > >
> > > > The meter should deflect to the right during a burn. Did you
> > > adjust
> > > > the 100K Pot. (R13) for deflection prior to operation?? if so did
> > > it
> > > > deflect to the right?
> > > >
> > > > Hope this helps
> > > >
> > > > Ben
> > > >
> > > >
> > > >
> > > >> Couple of questions for Ben Fleming:
> > > >>
> > > >> 1. Is it OK to push the ram up and ram down buttons at any time or
> > > >> are there times when they could cause a high current situation and
> > > >> should not be pushed?
> > > >>
> > > >> 2. Do you have a source for the exact Pittman motor gearhead you
> > > >> used? I think part of my problems are that the gearhead I'm using
> > > >> is different than the Pittman and draws more current than it
> > > should.>>
> > > >> 3. During the burn the DC meter needle did not move at all. Is it
> > > >> supposed to? Not that it matters to the machine function, but I
> > > >> feel a bit stupid buying and fitting it if it doesn't do something
> > > >> useful.
> > > >> Best regards Jeff Dayman
> > > >>
> > > >>
> > > >
> > > >
> > > > ------------------------------------
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > >
> >
>

Thanks for this Mike. I am thinking about how I can maybe try this with some
relays I have. However the car relays I have don't have the same wire colours as
yours. On your diagram, which wires are to the relay coils and which are to the
contacts? and to which contacts, NC or NO?

Thanks and best regards, Jeff Dayman

--- In EDMHomeBuilders@yahoogroups.com, mike maxim <mammike@...> wrote:
>
> This is why I came up with the relay circut,(can be seen in pics section
under mikes edm) It Isolates the computer form the motor and makes the load on
the computer constant and low, which means a cool computer but just to be safe I
added a fan and heatsink.  Also, it allows me to use any dc motor that I like,
giving me as much power to move the ram of any size.
> mike m 
>

Hi Ben,

I have the fourth printing of the book. I am not using a supplied PCB, I wired a
breadboard PCB. It does pass all tests in the book.

The servo up and down switches do already have 1K resistors inline with them,
R15 and R16 on the circuit diagram.

I have had a 33 Ohm resistor in series with my gearhead motor during the entire
first burn tryout. Without the 33 Ohm resistor the motor winding is roughly 120
Ohms.

I have checked the motor operation using a separate bench power supply and at 12
VDC it runs fine, there is lots of torque and it runs equally well in both
directions. I checked my leadscrew system and it takes almost no torque to turn
it. It is a plated steel screw in a bronze block, both threads clean and
smoothly finished.

No idea why I am blowing servo IC's.

Anybody have any ideas?

Is there a way to install current limiter to prevent blowing the servo IC?

Is there a more robust servo chip out there we could use?

Happy I achieved the first burn, but I want to do lots more now and can't!

Best regards Jeff Dayman

--- In EDMHomeBuilders@yahoogroups.com, Benjamin Nathan Fleming <bnf@...> wrote:
>
>
> Yes two 1K resistors in each switch leg.
>
> Jeff you are building from the PCBoard right?? The instructions for that board
and the latest printing of the book have that change.
>
> Ben
>
> ----- Original Message -----
> From: Aaron Pasteris <aarons_groups@...>
> Date: Sunday, November 22, 2009 9:38 pm
> Subject: Re: [EDMHomeBuilders] First burn plus problems
> To: "EDMHomeBuilders@yahoogroups.com" <EDMHomeBuilders@yahoogroups.com>
>
> > Ben
> > Did you update the schematic?
> >
> > As I remember, pressing both the up and down together would short
> > the
> > power rails.
> >
> > Aaron
> >
> > Sent from my iPod
> >
> >
> > On Nov 22, 2009, at 9:43 PM, Benjamin Nathan Fleming <bnf@...>
> >
> > wrote:
> >
> > >
> > > Jeff when operating properly you should be able to push the up
> > and
> > > down buttons at any time with out experiencing any problems.
> > >
> > > Yes it sounds like you blew a motor driver chip!! do you have a
> > heat
> > > sink on the chip. I know that there has been a problem with this
> > > chip blowing. It is suppose to have over current and thermal
> > > protection on board but I am not sure how effective it is.
> > Thought
> > > the chip works well in most situations with these small motor I
> > > would not say it is really robust, and I have been a little
> > > disappointed in it reliability.
> > >
> > > You could put a low ohm resistor in series with your motor lead
> > to
> > > reduce the current drawn by your present motor. Perhaps others
> > might
> > > chim in her on their experiences.
> > >
> > > Allied Electronics sells Pittman motors  They use to carry the
> > > Pittman GM8712-31 Allied Stock number 388-0004.
> > >
> > > A check a few mins ago indicate that they have drop that motor!!
> > > Electronic suppliers appear to change the stock they carry
> > Making
> > > it very difficult to keep current  for plans built type items
> > such
> > > as this EDM, It is very frustrating for me.
> > >
> > > I don't have an a source at the present time since Allied appears
> > to
> > > have dropped that motor.
> > >
> > > I would suggest you check other Electronics supply houses and
> > keep
> > > an eye on EBay. The latter would be my choice as the motors in my
> >
> > > opinion are steep in price if bought new.
> > >
> > > The meter should deflect to the right during a burn. Did you
> > adjust
> > > the 100K Pot. (R13) for deflection prior to operation?? if so did
> > it
> > > deflect to the right?
> > >
> > > Hope this helps
> > >
> > > Ben
> > >
> > >
> > >
> > >> Couple of questions for Ben Fleming:
> > >>
> > >> 1. Is it OK to push the ram up and ram down buttons at any time or
> > >> are there times when they could cause a high current situation and
> > >> should not be pushed?
> > >>
> > >> 2. Do you have a source for the exact Pittman motor gearhead you
> > >> used? I think part of my problems are that the gearhead I'm using
> > >> is different than the Pittman and draws more current than it
> > should.>>
> > >> 3. During the burn the DC meter needle did not move at all. Is it
> > >> supposed to? Not that it matters to the machine function, but I
> > >> feel a bit stupid buying and fitting it if it doesn't do something
> > >> useful.
> > >> Best regards Jeff Dayman
> > >>
> > >>
> > >
> > >
> > > ------------------------------------
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> >
>

Me too Cary - I am running out of driver IC's and Allied says they are now
backordered.

I see how the piggybacking method works but for your method to use both H
bridges "wiring it to use both of them" exactly how would I wire them? Can you
give us a pinout or sketch? Forgive me if it's obvious but I am from a machining
background rather than electronics.

Best regards Jeff Dayman

--- In EDMHomeBuilders@yahoogroups.com, Benjamin Nathan Fleming <bnf@...> wrote:
>
>
> Cary I would be interested in seeing your data.
>
> Thanks
>
> Ben
>
> ----- Original Message -----
> From: cary heestand <c.hhestand@...>
> Date: Monday, November 23, 2009 10:32 am
> Subject: Re: [EDMHomeBuilders] First burn plus problems
> To: EDMHomeBuilders@yahoogroups.com
>
> > The motor driver chip can be made more effective by doing this;    
> > http://www.acroname.com/robotics/info/ideas/stacking/stacking.html#c 
> > It can be made even more effective by using both haves of the
> > chip.  There are two H-bridges in the chip and by wiring it to use
> > both of them you double the amperage available to the motor.
> >  
> > Also the over heating of the chip is increased by the comparator
> > circuit.  Ben, I know you disagree with me on this but I did the
> > math on it and there is no "window" on the comparator.  In fact
> > there is a overlap.  The Comparator is trying to move the ram up
> > and down at the same time, right where the "window" should be.
> >  
> > If you want I will post a chart showing what I mean.  I found this
> > out when I was doing research on my comparator circuit.  I was
> > comparing all of the available plans to see how they work in theory
> > and found this.
> >  
> > Cary
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >  
> >
> >
> > --- On Sun, 11/22/09, Benjamin Nathan Fleming <bnf@...> wrote:
> >
> >
> > From: Benjamin Nathan Fleming <bnf@...>
> > Subject: Re: [EDMHomeBuilders] First burn plus problems
> > To: EDMHomeBuilders@yahoogroups.com
> > Date: Sunday, November 22, 2009, 9:43 PM
> >
> >
> >  
> >
> >
> >
> >
> > Jeff when operating properly you should be able to push the up and
> > down buttons at any time with out experiencing any problems.
> >
> > Yes it sounds like you blew a motor driver chip!! do you have a
> > heat sink on the chip. I know that there has been a problem with
> > this chip blowing. It is suppose to have over current and thermal
> > protection on board but I am not sure how effective it is. Thought
> > the chip works well in most situations with these small motor I
> > would not say it is really robust, and I have been a little
> > disappointed in it reliability. 
> >                                                    < SNIP >
> >
> > Ben
> >
> >
> >
> >
> >
> >
> >
>

Cary I would be interested in seeing your data.

Thanks

Ben

----- Original Message -----
From: cary heestand <c.hhestand@...>
Date: Monday, November 23, 2009 10:32 am
Subject: Re: [EDMHomeBuilders] First burn plus problems
To: EDMHomeBuilders@yahoogroups.com

> The motor driver chip can be made more effective by doing this;    
> http://www.acroname.com/robotics/info/ideas/stacking/stacking.html#c 
> It can be made even more effective by using both haves of the
> chip.  There are two H-bridges in the chip and by wiring it to use
> both of them you double the amperage available to the motor.
>  
> Also the over heating of the chip is increased by the comparator
> circuit.  Ben, I know you disagree with me on this but I did the
> math on it and there is no "window" on the comparator.  In fact
> there is a overlap.  The Comparator is trying to move the ram up
> and down at the same time, right where the "window" should be.
>  
> If you want I will post a chart showing what I mean.  I found this
> out when I was doing research on my comparator circuit.  I was
> comparing all of the available plans to see how they work in theory
> and found this.
>  
> Cary
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>  
>
>
> --- On Sun, 11/22/09, Benjamin Nathan Fleming <bnf@...> wrote:
>
>
> From: Benjamin Nathan Fleming <bnf@...>
> Subject: Re: [EDMHomeBuilders] First burn plus problems
> To: EDMHomeBuilders@yahoogroups.com
> Date: Sunday, November 22, 2009, 9:43 PM
>
>
>  
>
>
>
>
> Jeff when operating properly you should be able to push the up and
> down buttons at any time with out experiencing any problems.
>
> Yes it sounds like you blew a motor driver chip!! do you have a
> heat sink on the chip. I know that there has been a problem with
> this chip blowing. It is suppose to have over current and thermal
> protection on board but I am not sure how effective it is. Thought
> the chip works well in most situations with these small motor I
> would not say it is really robust, and I have been a little
> disappointed in it reliability. 
>                                                    < SNIP >
>
> Ben
>
>
>
>
>
>
>

Yes two 1K resistors in each switch leg.

Jeff you are building from the PCBoard right?? The instructions for that board
and the latest printing of the book have that change.

Ben

----- Original Message -----
From: Aaron Pasteris <aarons_groups@...>
Date: Sunday, November 22, 2009 9:38 pm
Subject: Re: [EDMHomeBuilders] First burn plus problems
To: "EDMHomeBuilders@yahoogroups.com" <EDMHomeBuilders@yahoogroups.com>

> Ben
> Did you update the schematic?
>
> As I remember, pressing both the up and down together would short
> the
> power rails.
>
> Aaron
>
> Sent from my iPod
>
>
> On Nov 22, 2009, at 9:43 PM, Benjamin Nathan Fleming <bnf@...>
>
> wrote:
>
> >
> > Jeff when operating properly you should be able to push the up
> and
> > down buttons at any time with out experiencing any problems.
> >
> > Yes it sounds like you blew a motor driver chip!! do you have a
> heat
> > sink on the chip. I know that there has been a problem with this
> > chip blowing. It is suppose to have over current and thermal
> > protection on board but I am not sure how effective it is.
> Thought
> > the chip works well in most situations with these small motor I
> > would not say it is really robust, and I have been a little
> > disappointed in it reliability.
> >
> > You could put a low ohm resistor in series with your motor lead
> to
> > reduce the current drawn by your present motor. Perhaps others
> might
> > chim in her on their experiences.
> >
> > Allied Electronics sells Pittman motors  They use to carry the
> > Pittman GM8712-31 Allied Stock number 388-0004.
> >
> > A check a few mins ago indicate that they have drop that motor!!
> > Electronic suppliers appear to change the stock they carry
> Making
> > it very difficult to keep current  for plans built type items
> such
> > as this EDM, It is very frustrating for me.
> >
> > I don't have an a source at the present time since Allied appears
> to
> > have dropped that motor.
> >
> > I would suggest you check other Electronics supply houses and
> keep
> > an eye on EBay. The latter would be my choice as the motors in my
>
> > opinion are steep in price if bought new.
> >
> > The meter should deflect to the right during a burn. Did you
> adjust
> > the 100K Pot. (R13) for deflection prior to operation?? if so did
> it
> > deflect to the right?
> >
> > Hope this helps
> >
> > Ben
> >
> >
> >
> >> Couple of questions for Ben Fleming:
> >>
> >> 1. Is it OK to push the ram up and ram down buttons at any time or
> >> are there times when they could cause a high current situation and
> >> should not be pushed?
> >>
> >> 2. Do you have a source for the exact Pittman motor gearhead you
> >> used? I think part of my problems are that the gearhead I'm using
> >> is different than the Pittman and draws more current than it
> should.>>
> >> 3. During the burn the DC meter needle did not move at all. Is it
> >> supposed to? Not that it matters to the machine function, but I
> >> feel a bit stupid buying and fitting it if it doesn't do something
> >> useful.
> >> Best regards Jeff Dayman
> >>
> >>
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>

Ben
Did you update the schematic?

As I remember, pressing both the up and down together would short the
power rails.

Aaron

Sent from my iPod


On Nov 22, 2009, at 9:43 PM, Benjamin Nathan Fleming <bnf@...>
wrote:

>
> Jeff when operating properly you should be able to push the up and
> down buttons at any time with out experiencing any problems.
>
> Yes it sounds like you blew a motor driver chip!! do you have a heat
> sink on the chip. I know that there has been a problem with this
> chip blowing. It is suppose to have over current and thermal
> protection on board but I am not sure how effective it is. Thought
> the chip works well in most situations with these small motor I
> would not say it is really robust, and I have been a little
> disappointed in it reliability.
>
> You could put a low ohm resistor in series with your motor lead to
> reduce the current drawn by your present motor. Perhaps others might
> chim in her on their experiences.
>
> Allied Electronics sells Pittman motors  They use to carry the
> Pittman GM8712-31 Allied Stock number 388-0004.
>
> A check a few mins ago indicate that they have drop that motor!!
> Electronic suppliers appear to change the stock they carry  Making
> it very difficult to keep current  for plans built type items such
> as this EDM, It is very frustrating for me.
>
> I don't have an a source at the present time since Allied appears to
> have dropped that motor.
>
> I would suggest you check other Electronics supply houses and keep
> an eye on EBay. The latter would be my choice as the motors in my
> opinion are steep in price if bought new.
>
> The meter should deflect to the right during a burn. Did you adjust
> the 100K Pot. (R13) for deflection prior to operation?? if so did it
> deflect to the right?
>
> Hope this helps
>
> Ben
>
>
>
>> Couple of questions for Ben Fleming:
>>
>> 1. Is it OK to push the ram up and ram down buttons at any time or
>> are there times when they could cause a high current situation and
>> should not be pushed?
>>
>> 2. Do you have a source for the exact Pittman motor gearhead you
>> used? I think part of my problems are that the gearhead I'm using
>> is different than the Pittman and draws more current than it should.
>>
>> 3. During the burn the DC meter needle did not move at all. Is it
>> supposed to? Not that it matters to the machine function, but I
>> feel a bit stupid buying and fitting it if it doesn't do something
>> useful.
>> Best regards Jeff Dayman
>>
>>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

Jeff when operating properly you should be able to push the up and down buttons
at any time with out experiencing any problems.

Yes it sounds like you blew a motor driver chip!! do you have a heat sink on the
chip. I know that there has been a problem with this chip blowing. It is suppose
to have over current and thermal protection on board but I am not sure how
effective it is. Thought the chip works well in most situations with these small
motor I would not say it is really robust, and I have been a little disappointed
in it reliability.

You could put a low ohm resistor in series with your motor lead to reduce the
current drawn by your present motor. Perhaps others might chim in her on their
experiences.

Allied Electronics sells Pittman motors  They use to carry the Pittman GM8712-31
Allied Stock number 388-0004.

A check a few mins ago indicate that they have drop that motor!! Electronic
suppliers appear to change the stock they carry  Making it very difficult to
keep current  for plans built type items such as this EDM, It is very
frustrating for me.

I don't have an a source at the present time since Allied appears to have
dropped that motor.

I would suggest you check other Electronics supply houses and keep an eye on
EBay. The latter would be my choice as the motors in my opinion are steep in
price if bought new.

The meter should deflect to the right during a burn. Did you adjust the 100K
Pot. (R13) for deflection prior to operation?? if so did it deflect to the
right?

Hope this helps

Ben



> Couple of questions for Ben Fleming:
>
> 1. Is it OK to push the ram up and ram down buttons at any time or
> are there times when they could cause a high current situation and
> should not be pushed?
>
> 2. Do you have a source for the exact Pittman motor gearhead you
> used? I think part of my problems are that the gearhead I'm using
> is different than the Pittman and draws more current than it should.
>
> 3. During the burn the DC meter needle did not move at all. Is it
> supposed to? Not that it matters to the machine function, but I
> feel a bit stupid buying and fitting it if it doesn't do something
> useful.
> Best regards Jeff Dayman
>
>

On Friday night I made my first burn (see photos in Jeff's EDM directory)

The machine worked well during the burn, very smooth and not much adjustment
required at all to get a good 'frying bacon' sound. Servo was working well back
and forth, and LED was bright green bright yellow when ram was rising and
falling and flickering during burn. However, after the burn I pushed the ram up
button, to raise the electrode for a look at the cavity. It raised OK, but after
that, the ram would not descend either by pushing the button or rotating R5 as
it had before. The ram LED would not glow bright green, it was a very faint
green. The ram would raise at first and then would not. I think I have again
blown the servo chip.

Couple of questions for Ben Fleming:

1. Is it OK to push the ram up and ram down buttons at any time or are there
times when they could cause a high current situation and should not be pushed?

2. Do you have a source for the exact Pittman motor gearhead you used? I think
part of my problems are that the gearhead I'm using is different than the
Pittman and draws more current than it should.

3. During the burn the DC meter needle did not move at all. Is it supposed to?
Not that it matters to the machine function, but I feel a bit stupid buying and
fitting it if it doesn't do something useful.

Best regards Jeff Dayman

camden_blue wrote:
> Hi edm builders,
>
> I've been researching the labeling on a couple of transformers I have laying
around. One is labeled 120v 60hz primary with a 25 volt center tap secondary. It
also says class 2-3 VA and that's the mystery, does that mean 3 amps? Another I
have is printed 24 VAC class 2 and 4.8 VA and I'm not sure if that means 4.8
amps or something else.

Volt-Amperes are similar to Watts, the biggest difference is that Watts
accounts for the phase, Volt-Amperes don't.  If you measure 100 Volts at
1 Ampere, it is 100 Volt-Amperes.  However, it could be 100 Watts
(current in phase with the voltage), -100 Watts(current 180 degrees out
of phase with the voltage) or even ZERO Watts (Current and Voltage 90º
out of phase.)  It is sort of like batteries, two in series can be the
sum of the voltages (+ to -) or the difference in voltages (+ to +).

--
David G. LeVine
Nashua, NH  03060

A VA is a "volt-amp", related to the power that the unit can handle.  A 24Volt
transformer with at 2.4VA rating can deliver 0.1A RMS at 24V RMS.

This VA is different than the watt because the amps only generate watts when
they are in phase with the volts, while the amps heat the transformer whether
they are in phase or not.  Many loads are non-linear and will draw current that
is out of phase with the voltage.  These loads require more amps than the watts
would indicate.  A 2.4Watt load with a 50% power factor will require up to 0.2
amps (therefore a 4.8VA transformer) to work.

I can't help with the capacitors; 22uF should work as well as 20.

All meters with a needle are basically current meters, usually 50 uA; put an
appropriate resistor in series and you have a volt meter.  As a starting point,
figure the 9V/250 ohms indicates the meter requires 36 mA to drive full scale,
so has an internal shunt to make it a current meter.  I'd put enough resistance
in series to make that work (e.g. desire 70V full scale: 70V/0.036A = 1944.44444
ohms (call it 1950)  The meter already has 250, so you need 1700 ohms in series
to make 70V read full scale.  Power = current squared * resistance, so the
resistor must be rated at least (0.036A * 0.036A * 1700 ohms) = 2.2 Watts so as
to not catch fire/blow up/whatever - use a 2.5W or 4 or 5W unit to be safe. 
P.S.  a 1700 ohm resistor is an odd value; you might have to use 1500 + 210 or
1500 + 180 (and calculate the power for each; that doesn't divide evenly) to
give you the requred value.

HTH,
Donald.

----- Original Message -----
From: "camden_blue" <camden_blue@...>
To: EDMHomeBuilders@yahoogroups.com
Sent: Saturday, November 21, 2009 4:43:50 PM GMT -05:00 US/Canada Eastern
Subject: [EDMHomeBuilders] I'm unclear on transformer lingo.

Hi edm builders,

I've been researching the labeling on a couple of transformers I have laying
around. One is labeled 120v 60hz primary with a 25 volt center tap secondary. It
also says class 2-3 VA and that's the mystery, does that mean 3 amps? Another I
have is printed 24 VAC class 2 and 4.8 VA and I'm not sure if that means 4.8
amps or something else. I was thinking of just trying them, the worse that I
could think might happen is I might let the magic smoke out of them. It wouldn't
be the first time I've fried a transformer. Another question I have concerns the
20uf capacitors. I've looked high and low for the correct parts at a cheap price
and ended up getting a pair of electrolitic versions. Since the rough cut cap.
is an electrolitic I figured they should work here too as long as I put them in
with the poles correct. Anybody see any problems here? Anyone using 22uf caps.
instead as these are availible everywhere at a cheap price? My last question
concerns the volt meter. I have a couple of meters out of an old tape recorder.
These were used to adjust the volume levels during recording. I'm not sure if
they are volt meters or amp meters? Is there any way to tell the difference? I
can put an ohm meter across the leads and it reads about 250 ohms. My volt meter
has a 9 volt battery in it and while measuring for ohms that's just about enough
voltage to peg the meter and reversing the ohm meter leads does change the
direction the mystery meter swings. Since my multimeter measures both amperage
and voltage using the same meter maybe there's no difference in meters, only in
the way they are hooked into a circuit? I could probably rig up a voltage
divider to get me in the right range to get full travel out of this meter in my
circuit but I'm not sure if would be of any use to me. Anyone using their volt
meters while burning? I realize it's a lot of questions in one letter but the
group sometimes needs a few questions to get information flowing within. I'm
looking forward to your answers and I'll be completing this thing one way or
another. I've got the circuit board built and the bottom of the case drilled to
hold most of the components. The only other change I've made so far is in
regards to the hole pattern for venting heat from the resistors. My last name is
"Necker" so I drilled my last name using a series of holes for the letters. I've
got a Terco CNC machine I've converted to run off a laptop and I generated the
hole pattern using the free version of CamBam software. It turned out great.
When I get the rest of it done I'll put a few photos in the photo section to
show how it comes out.

Brad



------------------------------------

Yahoo! Groups Links

Has anyone put together a bag of parts for this circuit?  As I build mine should
I get a dozen of each part and make a kit?

Hi edm builders,

I've been researching the labeling on a couple of transformers I have laying
around. One is labeled 120v 60hz primary with a 25 volt center tap secondary. It
also says class 2-3 VA and that's the mystery, does that mean 3 amps? Another I
have is printed 24 VAC class 2 and 4.8 VA and I'm not sure if that means 4.8
amps or something else. I was thinking of just trying them, the worse that I
could think might happen is I might let the magic smoke out of them. It wouldn't
be the first time I've fried a transformer. Another question I have concerns the
20uf capacitors. I've looked high and low for the correct parts at a cheap price
and ended up getting a pair of electrolitic versions. Since the rough cut cap.
is an electrolitic I figured they should work here too as long as I put them in
with the poles correct. Anybody see any problems here? Anyone using 22uf caps.
instead as these are availible everywhere at a cheap price? My last question
concerns the volt meter. I have a couple of meters out of an old tape recorder.
These were used to adjust the volume levels during recording. I'm not sure if
they are volt meters or amp meters? Is there any way to tell the difference? I
can put an ohm meter across the leads and it reads about 250 ohms. My volt meter
has a 9 volt battery in it and while measuring for ohms that's just about enough
voltage to peg the meter and reversing the ohm meter leads does change the
direction the mystery meter swings. Since my multimeter measures both amperage
and voltage using the same meter maybe there's no difference in meters, only in
the way they are hooked into a circuit? I could probably rig up a voltage
divider to get me in the right range to get full travel out of this meter in my
circuit but I'm not sure if would be of any use to me. Anyone using their volt
meters while burning? I realize it's a lot of questions in one letter but the
group sometimes needs a few questions to get information flowing within. I'm
looking forward to your answers and I'll be completing this thing one way or
another. I've got the circuit board built and the bottom of the case drilled to
hold most of the components. The only other change I've made so far is in
regards to the hole pattern for venting heat from the resistors. My last name is
"Necker" so I drilled my last name using a series of holes for the letters. I've
got a Terco CNC machine I've converted to run off a laptop and I generated the
hole pattern using the free version of CamBam software. It turned out great.
When I get the rest of it done I'll put a few photos in the photo section to
show how it comes out.

Brad

I like the Gas tank idea, I hope no-one tries to run an outboard motor on it's
contents though !

--- In EDMHomeBuilders@yahoogroups.com, "gst338lm" <gst338lm@...> wrote:
>
> W.ell, my EDM is coming along slowly.  Today I got a notice from parts-express
explaining that they messed up the shipping on my caps, so they're delayed. 
That's the last bit to the electronics that I have to do.  My oil filter mount
is coming from Jeg's, and I need a tap to tap the holes for my loc-line. 
Otherwise, I think I have most everything gathered and am making headway.
>
> I uploaded photos of progress thus far - I just glued the tooling plates into
the tank, built the structure for the ram holder.  My thru-hull connector had a
screwdriver slot in it, so I had to turn a chamfer in the lathe to get rid of
that, or my ping pong ball would never create a seal.  (I may dispense with the
ping pong ball and machine an acetal plug in any case).
>
> For those looking for a reservoir tank - I was having trouble finding a gas
can bigger than 5 gallons until I visited the local marine shop, where 6 gallons
appears to be a standard size.  The shape of the tank is ideal given that I will
be building a stand for the entire unit as well.
>
> Who else has a machine in progress?
>
> GsT
>

Photos to date are now in Jeff's photos

--- In EDMHomeBuilders@yahoogroups.com, "jeffdayman" <jeffdayman@...> wrote:
>
> I have one in progress, but I have changed the tank and machine design quite a
bit so it is taking longer than expected to build. Will post photos when done.
>
> Cheers Jeff Dayman
>
> --- In EDMHomeBuilders@yahoogroups.com, "flyppc" <bnf@> wrote:
> >
> > Gene that is a GREAT looking setup I think you will be pleased.
> >
> > Ben
> >
> >
> > --- In EDMHomeBuilders@yahoogroups.com, "gst338lm" <gst338lm@> wrote:
> > >
> > > W.ell, my EDM is coming along slowly.  Today I got a notice from
parts-express explaining that they messed up the shipping on my caps, so they're
delayed.  That's the last bit to the electronics that I have to do.  My oil
filter mount is coming from Jeg's, and I need a tap to tap the holes for my
loc-line.  Otherwise, I think I have most everything gathered and am making
headway.
> > >
> > > I uploaded photos of progress thus far - I just glued the tooling plates
into the tank, built the structure for the ram holder.  My thru-hull connector
had a screwdriver slot in it, so I had to turn a chamfer in the lathe to get rid
of that, or my ping pong ball would never create a seal.  (I may dispense with
the ping pong ball and machine an acetal plug in any case).
> > >
> > > For those looking for a reservoir tank - I was having trouble finding a
gas can bigger than 5 gallons until I visited the local marine shop, where 6
gallons appears to be a standard size.  The shape of the tank is ideal given
that I will be building a stand for the entire unit as well.
> > >
> > > Who else has a machine in progress?
> > >
> > > GsT
> > >
> >
>

Simple Manual EDM Machine -in progress, pics uploaded
Not speak English,Google English Translation

I have one in progress, but I have changed the tank and machine design quite a
bit so it is taking longer than expected to build. Will post photos when done.

Cheers Jeff Dayman

--- In EDMHomeBuilders@yahoogroups.com, "flyppc" <bnf@...> wrote:
>
> Gene that is a GREAT looking setup I think you will be pleased.
>
> Ben
>
>
> --- In EDMHomeBuilders@yahoogroups.com, "gst338lm" <gst338lm@> wrote:
> >
> > W.ell, my EDM is coming along slowly.  Today I got a notice from
parts-express explaining that they messed up the shipping on my caps, so they're
delayed.  That's the last bit to the electronics that I have to do.  My oil
filter mount is coming from Jeg's, and I need a tap to tap the holes for my
loc-line.  Otherwise, I think I have most everything gathered and am making
headway.
> >
> > I uploaded photos of progress thus far - I just glued the tooling plates
into the tank, built the structure for the ram holder.  My thru-hull connector
had a screwdriver slot in it, so I had to turn a chamfer in the lathe to get rid
of that, or my ping pong ball would never create a seal.  (I may dispense with
the ping pong ball and machine an acetal plug in any case).
> >
> > For those looking for a reservoir tank - I was having trouble finding a gas
can bigger than 5 gallons until I visited the local marine shop, where 6 gallons
appears to be a standard size.  The shape of the tank is ideal given that I will
be building a stand for the entire unit as well.
> >
> > Who else has a machine in progress?
> >
> > GsT
> >
>

Gene that is a GREAT looking setup I think you will be pleased.

Ben


--- In EDMHomeBuilders@yahoogroups.com, "gst338lm" <gst338lm@...> wrote:
>
> W.ell, my EDM is coming along slowly.  Today I got a notice from parts-express
explaining that they messed up the shipping on my caps, so they're delayed. 
That's the last bit to the electronics that I have to do.  My oil filter mount
is coming from Jeg's, and I need a tap to tap the holes for my loc-line. 
Otherwise, I think I have most everything gathered and am making headway.
>
> I uploaded photos of progress thus far - I just glued the tooling plates into
the tank, built the structure for the ram holder.  My thru-hull connector had a
screwdriver slot in it, so I had to turn a chamfer in the lathe to get rid of
that, or my ping pong ball would never create a seal.  (I may dispense with the
ping pong ball and machine an acetal plug in any case).
>
> For those looking for a reservoir tank - I was having trouble finding a gas
can bigger than 5 gallons until I visited the local marine shop, where 6 gallons
appears to be a standard size.  The shape of the tank is ideal given that I will
be building a stand for the entire unit as well.
>
> Who else has a machine in progress?
>
> GsT
>

W.ell, my EDM is coming along slowly.  Today I got a notice from parts-express
explaining that they messed up the shipping on my caps, so they're delayed. 
That's the last bit to the electronics that I have to do.  My oil filter mount
is coming from Jeg's, and I need a tap to tap the holes for my loc-line. 
Otherwise, I think I have most everything gathered and am making headway.

I uploaded photos of progress thus far - I just glued the tooling plates into
the tank, built the structure for the ram holder.  My thru-hull connector had a
screwdriver slot in it, so I had to turn a chamfer in the lathe to get rid of
that, or my ping pong ball would never create a seal.  (I may dispense with the
ping pong ball and machine an acetal plug in any case).

For those looking for a reservoir tank - I was having trouble finding a gas can
bigger than 5 gallons until I visited the local marine shop, where 6 gallons
appears to be a standard size.  The shape of the tank is ideal given that I will
be building a stand for the entire unit as well.

Who else has a machine in progress?

GsT

The Group meets on the third Sunday each month (this month Sunday 15th NOVEMBER,
2009) - at:

McDonalds McCafe
Corner Canning Highway and Berwick Street
Victoria Park
Western Australia

at about 7.00 pm

Turning, milling, welding, CNC, EDM, laser cutting, casting, electroplating,
anodising, group projects, bring show-and-tell, suggest group projects, etc

BYO (buy your own) coffee & cakes.

Phone me on 0412 768 348 if you need more info

All welcome
Jack

Hi,

has anyone here build a wire edm before ?
I'm looking for a suitable power source schematic.
Or can i use the power stage of any sinker EDM ?


Thank you

Frank