Just as Robert mentioned, looking at the photograph, it looks as if you're using three solid shafts with the toothed pulley / wheels freely spinning on each,...
Another possibility is to use smooth belts to drive the center wheels. That way it can slip a bit and you avoid removing all the center mechanics. Charlie...
Hi Robert, I *think* it's the belts making the popping sound on the timing belt pulleys. Not sure what else could make that noise. The torque would increase,...
Alan, I have not observed this behavior with jBot. Basically the timing belts/pulleys/motors are strong enough to twist up the original plastic driveshafts...
Hi Andy, That's an interesting idea! My 'bot is 20" long, and 16" between outside two centers (8" each belt run). Tires are QUITE soft. How much suspension...
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twcarroll@...
Jan 25, 2013 11:15 pm
In a message dated 1/25/2013 2:56:58 P.M. Pacific Standard Time, davida@... writes: Alan, I have not observed this behavior with jBot. Basically the...
We typically have zero suspension. I hadn't looked at your photos closely enough to notice that yours do. You might try the lighter springs on the outer...
Hi Tom, Yeah, I was just considering "lightening" the springs on the center two wheels in the last post. Maybe removing them as you suggest is a good ...
Alan, maybe it is just the tires. Check out the video of jBot getting unstuck, the first segment it has the larger, knobbier tiers, and listen to the tires as...
Sand might work! I'm going to try the springs and tape on the wheels first. Alan KM6VV...
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twcarroll@...
Jan 25, 2013 11:40 pm
Alan, Ackermann steering will be a bear to implement with your present arrangement. The model race cars and off road car people use Ackermann steering as...
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Peter Balch
peterbalch@...
Jan 26, 2013 12:11 am
... My experience with skid steering is that the length of the vehicle matters. Imagine turning on the spot. The front and back wheels must slide sideways ...
Hi David! Good of you to jump in! I remember you mentioned twisting your axles before. That's why I've been careful, I'm not ready to replace them (or new...
Alan If the belts ping they shouldn't ever slip unless something bad is happening, they should loose teeth first. Looking at the photos the chassis looks very...
Hi Andy, you're saying reduces the springs on the four outside tires, not the middle two as I had thought. That makes sense. Yeah, it all goes back to belt...
David, I heard the burst of "pops" or "crackles"; as the 'bot first strikes the wire. I'm not sure it's the same noise. I guess I could try to record MY pops....
Hi Tom, I can certainly try pulling off the two center wheels. Yeah, Ackermann steering will be hard to build in. As I said, I have the servo, horns and links...
Hi Peter, My wheelbase is 16" long by 17" wide. To bad I didn't think of that and try to make it square. I think DPA's J-bot is pretty close to that. Alan...
Hi David, I agree, the chassis looks quite flimsy, that is until it's "boxed up" with the 7 2" high bearing blocks between the two. I can detect NO deflection...
Alan How about you run it on the bench and grab hold of the wheels then you could be up close to see which belt slips and when. Something has to be flexing. ...
Hi David, I did that, I pinned the motor, and turned the wheel closest to the motor. I could see the belt on the little pulley end jump. I'm going to work on...
Alan, I ran into this problem with tensioning arms, even when I had two tension arms (one for each direction). The motor would change direction too fast and...
EZ-B is a great board, DJ has done a fantastic job with the software! I'd highly recommend it to anyone that is starting a new robot. I did not look deeply...
Xandon, I can see how a sudden reversal of direction could cause problems. You had two spring-loaded tension arms? I just have one fixed tensioning idler...
This is probably obvious, but be careful. I once got my eyes burned working with a strong UV lamp. Since a lot of the brightness is not in the human range,...
Nothing to flex that I can see. Box construction. I made it ratchet (jump) by slowly increasing a static load, I pinned the motor down, and turned the wheel....
