WCD-Belt Driven CAD practice

[Cash4587]

Originally Posted by jb1403

This looks great. We went to a belt WCD this year and loved it. My big question is with the WCP dual speed. Did you have to increase the size of the spacers and the hex shafts in the gearbox or did the 2 9mm pulleys fit into the basic gearbox. Also did you use the regular or the WCD model.

Due to the belt pulleys being larger than sprockets, the gearbox will have to be widened by about half an inch +/- .125". Although it will take some machining to get this done, (some very basic machining) I see it as a benefit rather than a hassle. With belts rather than chains, after they are set since it is exact c-c you never have to touch them again unless something bad goes wrong. like thrown belt or ratcheting occurs or other issues caused usually by human error. I forgot to mention I added .003" to the c-c distance to get the tight fit on the belts. But I have seen some very good and bad things said about belts. Mainly good. So I am giving them a shot. I put the WCP WCD gearbox in there because it was built for the type of frame I designed so it was basically a plug and play. I guess you could try and use the regular WCP shifter but I didn't. Glad I could help.

[Akash Rastogi]

To be clear, Damprobot, this is all for a prototype to test out some sponsors we found for Cooper's fantastic team.

I have high hopes for their team, Cooper is awesome at absorbing information from all over and learning very quickly. They are also backed by some former mentors of 57 and 624.

[Cash4587]

Originally Posted by Akash Rastogi

To be clear, Damprobot, this is all for a prototype to test out some sponsors we found for Cooper's fantastic team.

I have high hopes for their team, Cooper is awesome at absorbing information from all over and learning very quickly. They are also backed by some former mentors of 57 and 624.

We are also backed by people like you who are always willing to help

[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...

[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"

[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.

[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.

[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.

[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.

[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?