View Single Post
  #2   Spotlight this post!  
Unread 22-12-2015, 15:31
GeeTwo's Avatar
GeeTwo GeeTwo is online now
Technical Director
AKA: Gus Michel II
FRC #3946 (Tiger Robotics)
Team Role: Mentor
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Slidell, LA
Posts: 3,531
GeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond reputeGeeTwo has a reputation beyond repute
Re: pic: Octocanum Module

Quote:
Originally Posted by Ari423 View Post
Yeah I messed up my math when calculating the torque needed to lift the robot. I will probably end up increasing the cylinder to 2" diam. which should be more than enough torque even with the piston where it is. I would go for a 1.75" pancake cylinder, but Bimba doesn't offer that and they're the only pneumatic company I've ever worked with.
You shouldn't need 2" - Bimba does have 1.5" cylinders in both square and round pancake styles. Remember that force goes up as the square of the diameter, so 1.5" provides twice the force of a 1.0625" cylinder (to within 1%).


Quote:
Originally Posted by Ari423 View Post
Since the mecanum wheel is AndyMark and the pulley is Vex, there's no easy way to attach them and make it a dead axle. Sadly, AndyMark doesn't make an 18t pulley and Vex's 4" mecanum wheel doesn't support dead-axle drive. If you have another way to do this dead-axle, I would be interested in hearing about it.
You could pivot on the mecanum, which would make the cantilevered wheel the traction wheel which has a 42 tooth sprocket, if I did my math correctly. This would be easy to mount sprocket to wheel on a dead axle. This solution would also require a change in gear ratio of your gearbox - in the direction that it will probably get simpler and lighter. This would also make high-speed mecanum your "default" drive if the pressure goes out, which may be a good or bad thing depending on your game strategy/style.
__________________

If you can't find time to do it right, how are you going to find time to do it over?
If you don't pass it on, it never happened.
Robots are great, but inspiration is the reason we're here.
Friends don't let friends use master links.

Last edited by GeeTwo : 22-12-2015 at 15:34.
Reply With Quote