Cheap Ass 6x2 Pneumatic Belt Setup. 3D printed Pulley/ Vex Versa Pulley. Thingiverse link in post #534

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So… I got a little issue here. This is the Pulley Adapter from this link (From orig link at the top) https://drive.google.com/drive/folders/14AF8h_PFzBTdH6JRkKynJ70I3WzezC0N

There appears to be like a 3mm gap where the pulley adapter does not fit flush to the wheel. I bought these 6x2 pneumatic wheels from the original link at top. I am assuming that they have changed their milling process. [This thread is getting so long…]

Has anyone else had this issue. Does anyone have any thoughts on this???

Thanks.

I didn’t have a gap when I assembled it, but that gap will not cause any issue. All the load is taken by the bolts and the force is exerted by the belt in the radial direction.

Bought 8 new bearings for these wheels, gonna test how much of a difference that makes.

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@mishrasubhransu , Thanks for the quick reply. I absolutely love these parts… Great Job! I looked further - It appears that these wheels are not machined the same as the ones that would fit the pulley adapter. (Although they look same, and are the 6x2’s)

  1. The pulley adapter lip is a greater diameter than the inner diameter of the wheel hub.
  2. The bolt pattern for the hub is a few mm narrower than the adapter. I measured my bolt pattern to be 40mm. I measured the Pulley Adapter to be 41.57mm.

I am going to try and take your hub, and gear - fill in the bolt holes, then recreate my own bolt pattern. Then I will have to bring in the lip about 3mm so that the wheel adapter flange is flush with the wheel.

Let me know if you have any further thoughts. Thanks so much.

it is possible that you didnt import the file the right way.

@Benjamin899 , Great thought! I was thinking the same thing… So I imported the SLDPRT files into Fusion 360 so I could measure them in the file, and sure enough - Its a 41.57mm bolt pattern (unless you have in your files a 40mm bolt pattern)… Not sure if I am making sense. I can send pics. Thanks so much for your help.

By the way. I printed them in PETG at 80% - They turned out fantastic, and feel super tough… Just gotta get em to fit… haha. I have Nylon, and PC shipping to me at the moment. I am hoping to try both filaments to do a comparison.

strange. maybe yours are different, but 41.57 is correct

@Benjamin899, Wellp. I got the bolt holes removed, and added the new ones at 40mm. I am printing a test right now to see if it matches up. I am having a little trouble moving the lip. Fusion 360 is having trouble with all the rounded corners and fillets. (by the way, I like rounding and fillets - improves strength).

Any chance you have a model saved without the fillets, and rounding. That would be easier to modify. If not - thats totally Ok. Don’t go to any extra trouble.
Thanks :slight_smile:

You could ship the rim to me for $3.5 with usps (I’ll send it back)or take necessary measurements with a caliper and post it here. I’ll see what’s different and modify accordingly.

You could hand draw a sketch and dimension it. It’s easier to imagine the issue that way.

I’ll upload a model without fillets

@mishrasubhransu , I hope you haven’t done to much work on this. I think I got it.
I was able to remove the fillets. I am printing some basic prototypes now.

@mishrasubhransu , Can I send the finished files to you when I get them done? That way - anyone with a similar issue to mine will be able to easily find a fit.

Or - Do you have a better idea? Thanks

I was wondering about mounting on TB trucks. Using only speed rings means small offset and the nut is wayyy too far from the rim. Using the included spacer instead of the internal speedring makes the thread too short. Using a bearing->speedring->rim combo makes the thread still too short. Wot in tarnation?

Any suggestions?

Should I just slap a ridiculous amount of speedrings?

I cut down the spacers to get it in the Goldilocks zone… a shit ton of speedrings will work too.

More speedrings = more speed. Sonic the Hedgehod always wanted to go fast, he loved rings. What’s also rings and go fast? That’s right. Speedrings.

But in all seriousness, I will do what you did(cutting the spacers) most likely. :slight_smile:

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i don’t get it, why wouldn’t it fit with the 6x2 rims. Btw installed the bearings with a press, and they run smooth. Now comes the final test on my axles. Hope they roll better now.

The axle is too long, the spacer is also too long, so there’s no medium available. :slight_smile:

Whatever this has to do with cheap ass 6x2 pneumos…

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i moded my old axles to 47mm, and my 6x2 fit perfectly and 218TB have the same, weird.