pic: 2016 Offseason Drive Gearbox

[Chris is me]

Originally Posted by Michael Corsetto

I think I see a snap ring right in the middle of your output shaft. This snap ring will be close to, if not entirely, impossible to install.

Other options:

E-Clip - Ok in this application, but not recommended. I don't like transferring torque through any sort of groove, especially the deep grove required for this application

Shaft Collar - Not the best, but could work in this spot

Change up your shaft retention locations. Review other team's CAD's to see their arrangement of shaft retention on a typical output shaft.

Please post results.

-Mike

I didn't even notice this when I first commented. This is a huge problem because a snap ring groove between loads (between gears and direct drive wheel) is a stress riser. With some bad luck you could fail your shaft here.

If you are looking to prevent the shaft from sliding out in that direction, you can turn the far end of the shaft to 1/2" round (or 3/8" round) and use a 1/2" round (or 3/8" round) bearing on the inner plate. That, combined with a snap ring groove on the outside of the inner plate, will fully retain your output shaft.

[Sperkowsky]

Originally Posted by Chris is me

I didn't even notice this when I first commented. This is a huge problem because a snap ring groove between loads (between gears and direct drive wheel) is a stress riser. With some bad luck you could fail your shaft here.

If you are looking to prevent the shaft from sliding out in that direction, you can turn the far end of the shaft to 1/2" round (or 3/8" round) and use a 1/2" round (or 3/8" round) bearing on the inner plate. That, combined with a snap ring groove on the outside of the inner plate, will fully retain your output shaft.

Oh yea I don't even need that snap ring. I was not thinking when I put it there. It's been removed but I didn't feel like re rendering. The shaft is turned down on the back to 1/2 round and it's tapped so it wont fall off.

[Sperkowsky]

Here is the 'finished' version

http://i.imgur.com/fBHiik0.jpg


Here is how the output shaft is actually held in. (spacer, bearing, and plate hidden) https://gyazo.com/7331d2fcb0f597dad4bb6db74bdbd5d2

and here is it on the WCD itself which should answer the question about what its mounting to
https://gyazo.com/cc8580fe4a5277e981f19836fc12c0c6

The WCD is a WIP. I still have to model the belts and shafts on the outer wheels and figure out how I want to layout the frame with the shooter. Before anyone says there is not enough support with the corner gussets I should mention there will be a belly pan.

Even building the rest of that WCD will be really cheap. All we have to buy is the Versablocks and CAMs.

So.. yes we are building an entire drive train for $166. The only parts I am not 100% sure on is hardware but in the end that's pretty negligible and I am pretty happy what I was able to make with our stockpile of parts.

Also, I may be attempting a flipped CIM gearbox soon with the same goals. Due to the crazy thickness of the pulley there is room. If that works out we will probably build that.

[Chris is me]

The corner brackets might be robust enough, but I'm mostly concerned about how you're going to mount a belly pan with pulleys that are bigger than the tube?

The pulleys are sized well for this drive, I'm not saying go smaller on those, just that you'll have challenges mounting a belly pan without going through belt loops.

The same criticisms about the lightening pattern still apply.

[Sperkowsky]

Originally Posted by Chris is me

The corner brackets might be robust enough, but I'm mostly concerned about how you're going to mount a belly pan with pulleys that are bigger than the tube?

The pulleys are sized well for this drive, I'm not saying go smaller on those, just that you'll have challenges mounting a belly pan without going through belt loops.

The same criticisms about the lightening pattern still apply.

Yea the belly pan won't be that fun but it's almost a necessity with me only having 2inches where I can mount gussets. If I got rid of the versa blocks I could get away without it but I don't think I want to do that. I am exploring the possibility of custom versablocks and if I did that I could size them such that I could get a gusset underneath

I changed up the lightening pattern on the bottom and I am still learning how to get the other one to work. Chak made it look good (I gave him the plate file) but when I tried to do what he did I broke Solidworks and he was sleeping.

[Chris is me]

Originally Posted by Sperkowsky

Yea the belly pan won't be that fun but it's almost a necessity with me only having 2inches where I can mount gussets. If I got rid of the versa blocks I could get away without it but I don't think I want to do that. I am exploring the possibility of custom versablocks and if I did that I could size them such that I could get a gusset underneath

Compare these gussets to the length of the VersaChassis gussets. They aren't that different. I'm not saying you dont' need a belly pan or other cross support, but having to take apart your frame to change a belt (not that you should ever have to do that) is gonna be a nightmare.

[JesseK]

Could you post a photo of the gearbox mounted to the 2x1 rail, without the direct-drive wheel?

Curious what the bearing situation is there, and if there are tips that may help with machining the rails w.r.t. the direct drive wheel's shaft alignment.

[bkahl]

Originally Posted by Chris is me

The same criticisms about the lightening pattern still apply.

Yup.

I would, again, recommend a web going to the "6 o'clock" directly down from the output bearing or something a bit less extreme on the angles to the corners. The pocket directly below the bearing is concerning to me.

Also, a web going to the "3 o'clock" and "9 o'clock" from what appears to be the top mounting holes to the outside of the plate.

[ASD20]

Originally Posted by Sperkowsky

Here is the 'finished' version

http://i.imgur.com/fBHiik0.jpg

What changed from the original? I can't seem to find any differences.

[Sperkowsky]

Originally Posted by ASD20

What changed from the original? I can't seem to find any differences.

Extra support at the bottom fixed all the fillets and deleted the circlip.