Team MedBots

[Max]

Re: Team MedBots

I've been working on trax (fw tracked robot) today which uses wiper motors . The problem is I am not sure how to attach anything onto the output shaft (small threaded shaft) currently I have a bit of steel rod with a tapped hole to screw onto the shaft and then a horizontal hole for a split pin to go through and a corresponding hole on the wiper shaft. But my split pin keeps snapping and I've tried a small bolt and that just snapped as well. How do most people attach anything to these shafts?

[plargen]

Re: Team MedBots

have you seen the way they attached the wheels to the motors in the real robots books in rex's section

[Max]

Re: Team MedBots

Just had a little look at that but I can't see how he stops the wheel unscrewing when the motor is reversed?

[jonny]

Re: Team MedBots

i drilled a hole through the shaft and used a bolt to hold the wheel to it.

[plargen]

Re: Team MedBots

the hole in the lever arm that's attached to the motor has lots of grooves like on the shaft so it doesnt spin so if u can imitate that or modify the original lever arm and attach it

[Max]

Re: Team MedBots

Jonny what sized bolt did you use?

[jonny]

Re: Team MedBots

M4

[Max]

Re: Team MedBots

I've got it working now. Annoyingly the batteries don't last very long. It not going to be used in combat, more as a remote control off road vehicle so I'd like it to last longer so I may try and get some big capacity sla's, anyone got any suggestions?

[RogueTwoRobots]

Re: Team MedBots

Wiper motors being a pain to attach wheels to? Batteries not lasting very long? Sounds just like my Rex's Robot Challenge experience all over again

I'm assuming you're currently using 12V SLAs but what Ah rating are they? I found something around the 7Ah mark gave a decent run-time, and a quick search threw up these:

http://www.screwfix.com/p/sealed-lead-a ... 0x%20151mm

No idea what they're like compared to other brands but I doubt there'll be much of a difference. If you need something that'll last longer still, just type 12V SLA and the desired Ah value into Google; there seems to be a pretty decent selection for all Ah values.

[Max]

Re: Team MedBots

Currently I'm using 2 12v 2200mah nicds in series to give 24v. it means the motors and batteries get very hot! Can you mount sla's on their side?
Annoyingly just a few months ago my dad found a load of 12v sla's powering our new houses alarm, thought they were useless so through them out! Can't believe it

[Bodge Job]

Re: Team MedBots

I used a 7ah lead acid battery in armerdillo (the worlds slowest robot) and that used windscreen wiper motors, so that would be fine, they are fine on there side, that's how I used it in bruiser, an those Nicds may be enough, just see if it runs for 3 or more.

[Max]

Re: Team MedBots

Ive had a fun day messing around with Trax, here are a couple of photos:
[attachment=2:2wnwvzeq]Trax pic 1.jpg[/attachment:2wnwvzeq]
[attachment=1:2wnwvzeq]trax pic 2.jpg[/attachment:2wnwvzeq]
[attachment=0:2wnwvzeq]trax pic 3.jpg[/attachment:2wnwvzeq]

here is a test video:
http://www.youtube.com/watch?v=C1u6ZHG1sE8

[Max]

Re: Team MedBots

I've been playing around with my pneumatic system and I can't get my 5/2 valve working it makes a clicking sound when I connect it to a battery but it seems to stay in the same state, I don't have it hooked up to the full pressure (10 bar) instead I am just blowing down the pipe would that make a difference? Does anyone know what might be wrong?

[jonny]

Re: Team MedBots

It won't work unless it's hooked up to a compressed gas supply at atleast the minimum pressure.

[Max]

Re: Team MedBots

I've got the valve working but my Trevor regulator is still leaking! I connected it to a fire extinguisher bottle and put on the gas slowly but it started leaking out of the thread between the end cap you twist to change the pressure and the rest of the reg. I don't think the gas is even supposed to get to that bit if the reg. the pressure also seemed to rise a lot, my pressure gauge only goes upto 11bar and it went way past that despite the end cap being screwed up most the way.
Hope that makes sense a that someone can help and diagnose the problem!