Is there any Edu beval gears, or anyone have a sugestion on how to jimmyrig this Coaxial Crab module
Could you take another tire and have them run perpendicular to eachother, and the friction would transmit the power?
*Originally posted by Kevin A *
**Could you take another tire and have them run perpendicular to eachother, and the friction would transmit the power? **
Hmm. Not a bad idea. I found these:
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDE95&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDE95&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFU85&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXFU85&P=7
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKK04&P=7
All of them do come in larger sizes too but I thought you would want something small.
SWEET!
Any chance of a copy of the plans?
Niiiice…
I made an similar crab-drive edubot, only problem is the wheels won’t turn, it appears like there is way too much friction- do yours successfuly rotate?
it spins like crazy dude, don’t even start
I still need a beval
You crab system looks much like my large scale design, Tytus, cool! I just screwed the wheel assemblies into 2 servos for my crab drive
The only prob. is that the servos only range 100deg, I need 180. I’m lookin into some new ones. But for now, that’s what I’m doing.
I actually built a edu prototype of my full crab drive, and just stuck 2 of the gears together at 90 deg. They worked OK. But, I would look into getting some nice beveled gears. I think there’s an easy way to mod up lego beveled gears to fit the edubot’s shafts… I did it last year. I’ll try and dig up that project…
edu is realy anoying me, there are only so many parts in the kit and there are only chains and sprockets. I used a Victor an FP motor on my hoverbot
as far as crab goes my turntables just came in from Pitsco and i built a coax lego crab with arakeen correction, i hope my Legoleague kids wont tear it apart for the motors untill i take a picture tho
Berg sells miter gears that can be made to work with the EDU kit.
It will not be pretty but it can be done.
I recommend a 1 to 1 ratio with a relatively small diameter to keep “tilt” from disengaging your teeth ( like the pair M72N-1A for example).
This gear set is aluminum and has a 1/8 inch bore. You will have to make the hole square. To do that, I recommend the following broach from McMaster.com 3156A11 – the problem is that it costs a bit more than I like – but I have used it and they are beautiful for making EDU compatible square holes in aluminum parts).
Also, the pitch of these gears is a bit danty (72DP – that means . You will likely have issues trying to get these gears to stay engaged reliably – the teeth are only a little more than a half mm tall!)
To be honest, I suppose that for the most part, you could modify something from another toy set (Lego maybe) and have better success.
Good luck just the same.
Joe J.
