Frc131, CHAOS CAD Release

Hi Everyone,

In preparation for the 2022 season, we have decided to do a CAD release of old materials rather than follow our usual path of rebuilding everything from the ground up.

Here is are a few of Chassis options we have been looking at using for the 2022 season:
https://cad.onshape.com/documents/01503d258b4b6dd85c17994c/w/a3f11a2be94a4d56151fe0da/e/b5fdaafdc59fa10533c2a8da
https://cad.onshape.com/documents/c15a6138833bbf75d3201ab1/w/50fbab057932fa642d9976d6/e/7c3834dcabf046bb5f74621f
https://cad.onshape.com/documents/a97d06afb9623a36e66b711f/w/1268afdb17850e620cf22394/e/5db513b42d04ca27da71e6ff?renderMode=0&uiState=61cbde69589d13443b0f7f94

Here is CHAOS 131’s 2020/2021 FRC Robot:
https://cad.onshape.com/documents/02538995346edd67775cef68/w/d2995268c1f35b38f07a16d8/e/1274aa3a10e8502bf2c4f618

Here is CHAOS 131’s 2019 FRC Robot (previously released):
https://cad.onshape.com/documents/67d645910674540fc8d929d8/w/9af70d3a2ae75260f9b46662/e/f8f4d77154cf540d44ef17d4

Let me know if you have any questions,

FRC 131, CHAOS

9 Likes

It looks like you explored a chain design. What are your team’s thoughts on using chain vs belt (like y’all did in 2020)?

Super impressed with your 2020 robot, especially this off-season you guys killed it. 2019 was very impressive engineering, even if it was a bit complex for my taste :slight_smile: Honestly though keep it up, I can’t wait to play with y’all again this year.

In 2020/2021 we used a heavily modified Kit-bot. The holes that Andymark has for the bolts were opened up to be 1.125" for a hex bearing on a CNC router. That change allowed us to move the drive rails inwards so we could mount the wheels outside the rail in a sudo west coast drive design. The belt spacing worked well in that application and we did not look into chain at that time.

Here are my general thoughts on the chain vs belt conversation:

  • Belts are clean and unlubricated and stay that way for the most part
  • Belts can be lighter if the pulleys are plastic and even if they are aluminum in some cases
  • Belts are easier to install the first time in build season
  • Belts are quieter
  • Chain is easier to do maintenance on and reinstall
  • Chain is more space efficient
  • Chain results in lower cantilever distances to the pulley/sprocket
  • Chain is more tolerant to deviations in length
  • Teams that I have worked with have has similar numbers of thrown chain vs damaged belts in the drive train (1 of each in the last 10 years)
  • They are both similarly difficult to add tensioners to after the fact if there is a machining error.

I am not sold on the way the belts work on the 2022 chassis.

Thanks!

We will hopefully get some good time together in the upcoming season.

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One more with some updates:

https://cad.onshape.com/documents/00b7c3ad73ca62125a6bc6f0/w/c52b492c01533b80bf60b40f/e/83bf87453c5ae8c2f33b2221?renderMode=0&uiState=61d844723522d2373d2e00e9

1 Like