WCD-Belt Driven CAD practice

[DampRobot]

Originally Posted by Cash4587

http://prntscr.com/1m24bi

I was doing some more messing around and found that if WCP would have made their gearbox a little more than an 1/8th of an inch wider maybe more like 1/4", we could have fit 5mm gt2 pulleys in there that are 9mm wide. It is so close. I wish WCP would just make a version of their gearbox for people like us who like to use belts...

Talk to RC about this. He's typically very responsive about design requests like that. It might even end up as one of the models for next year.

We did a very similar mod to the DS last week, except we were going from a Standard type to one that could fit one VP sprocket. It's quite simple. You just need to turn a few spacers and one 3/8" shaft.

[Brian Selle]

Originally Posted by Cash4587

http://prntscr.com/1m24bi

I was doing some more messing around and found that if WCP would have made their gearbox a little more than an 1/8th of an inch wider maybe more like 1/4", we could have fit 5mm gt2 pulleys in there that are 9mm wide. It is so close. I wish WCP would just make a version of their gearbox for people like us who like to use belts...

It can be made to work. We used stock WCP gearboxes with 9mm GT2 pulleys this year. Loved it. Two double flanged pulleys won't fit within the transmission so you need to create a double pulley with one flange between them. It fits just barely. We modified pulleys from sdp-si and used 060 flanges. Using pulley stock would have probably been easier/better.

[Cash4587]

Originally Posted by btslaser

It can be made to work. We used stock WCP gearboxes with 9mm GT2 pulleys this year. Loved it. Two double flanged pulleys won't fit within the transmission so you need to create a double pulley with one flange between them. It fits just barely. We modified pulleys from sdp-si and used 060 flanges. Using pulley stock would have probably been easier/better.

Attachment 15158

Oh man. You are going to have to go into more detail of how you made it work. I am really interested.

[Akash Rastogi]

Originally Posted by Cash4587

Oh man. You are going to have to go into more detail of how you made it work. I am really interested.

Cooper, you can buy pulley stock and cut it to size on a lathe. You can also remove flanges from Gates pulleys pretty easily and add in your own shim to act as a center flange.

[Mk.32]

Originally Posted by Cash4587

http://prntscr.com/1m25qt

Yet again, I did some more updating to make the bumper mounts legal (the distance between them was not <= 8in.) and I made their flanges beefier. Lastly, I widened the frame an inch and a half on each of the end tubes to better use all of the frame perimeter rule except 1 inch of it. so the frame perimeter is now 111" vs 108"

We did the almost did the same thing, belt drive WCD with WCP gearboxes.

We were able to fit 9mm GT2 pulleys in there no problem.
http://31.media.tumblr.com/624ace34b...cgvo7_1280.jpg I personally machined the pulleys out of 3/8 alum plate.

[Akash Rastogi]

Originally Posted by Mk.32

We did the almost did the same thing, belt drive WCD with WCP gearboxes.

We were able to fit 9mm GT2 pulleys in there no problem.
http://31.media.tumblr.com/624ace34b...cgvo7_1280.jpg I personally machined the pulleys out of 3/8 alum plate.

Haha Mark I've been showing him your stuff the entire time for this project

[Cash4587]

OHHHH. This is the team with that drive that pushed that robot the whole field length. That was sick.

[DampRobot]

Originally Posted by Akash Rastogi

Haha Mark I've been showing him your stuff the entire time for this project

Yeah, that was kind of an uncanny resemblance...

But I suppose once you decide to use belts and colsons in a WCD, they're not many choices left to make.

[roystur44]

Cooper,

You should ask your sponsor if they have the proper brake dies to bend your bumper brackets from one piece. They would need to use a large goose neck die or make a window in the die set for the return flange. Otherwise great design. You could bend in hat sections into the belly pan for air lines and wiring. I haven't seen many designs that incorporate access from the bottom of the robot.

[ablatner]

Originally Posted by Cash4587

http://prntscr.com/1m25qt

Yet again, I did some more updating to make the bumper mounts legal (the distance between them was not <= 8in.) and I made their flanges beefier. Lastly, I widened the frame an inch and a half on each of the end tubes to better use all of the frame perimeter rule except 1 inch of it. so the frame perimeter is now 111" vs 108"

I can't quite tell from the angle, but is there enough room for mounting hardware on the bumper mount flanges? The sets of holes on the inside of the flange look really close to the bend. You may not be able to get a rivet gun in there.

[Mk.32]

Originally Posted by Akash Rastogi

Haha Mark I've been showing him your stuff the entire time for this project

Oh awesome
We were really happy with how our 2013 drive came out. Let me know if you have any questions.

[Cash4587]

Originally Posted by roystur44

Cooper,

You should ask your sponsor if they have the proper brake dies to bend your bumper brackets from one piece. They would need to use a large goose neck die or make a window in the die set for the return flange. Otherwise great design. You could bend in hat sections into the belly pan for air lines and wiring. I haven't seen many designs that incorporate access from the bottom of the robot.

Oh yeah they have plenty of ways to get it done, they use multiple cnc pan and brakes in their shop and have tons of capabilities to do things like this. I will be sure to check again. I have been in constant contact with them and I am always talking with the shop and company owner. Since I am out of Houston, Texas, we have some of the finest shops in the world due to the large oil industry just south of us in the gulf and surrounding area.

[Cash4587]

Originally Posted by ablatner

I can't quite tell from the angle, but is there enough room for mounting hardware on the bumper mount flanges? The sets of holes on the inside of the flange look really close to the bend. You may not be able to get a rivet gun in there.

I did some re-work to address that problem, you are right there is no way to fit a riveter in there. especially the 3/16th" pneumatic riveter we are going to use. Here is the product with the new bumper mounts.

http://prntscr.com/1m618o


Also, For anyone who cares, there definitely is plenty of room in the standard WCP-WCDS for 9mm wide pulleys if you do some reworking of them. I took off the existing flanges and made my own. I don't know if it is a good idea to set it up the way I did but, they fit. I put the pulleys over the bearing on what I think is the low gear? Anyways that means it will need a recessed hole on that side of the pulley so the bearing can be "inside" the pulleys. Also there is no flange on that side, since the pulley is against that gear. Here are some screen shots of the outcome.

http://prntscr.com/1m622x
http://prntscr.com/1m63s6
http://prntscr.com/1m63y3

[ptitchener]

The weight seems a little low to me - you should check if your CIMs are set to 2.5 lbs each/wheels etc. If it is right, how did you get it so low?

[Cash4587]

Originally Posted by ptitchener

The weight seems a little low to me - you should check if your CIMs are set to 2.5 lbs each/wheels etc. If it is right, how did you get it so low?

Sorry that was the weight not including the wheels hubs pulleys or gearboxes. The updated weight is 36.78lbs including everything.