![]() |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Not to say it couldn't be done with chain. 846 ran without issue through Buckeye, Silicon Valley, Champs, Chezy, and CalGames without any provision for changing chain tension. We nailed the C-C right the first time and never looked back.
Just my own experience. I would be comfortable running chain with the versablocks locked in place after the right chain tension was found. Just make sure your gearbox pilots into the frame. |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
I know that this system uses two 3-CIM transmissions but with only 2 motors each. Do you think that with the back-and-forth, high impact motion that a typical FIRST drive train will go through, the 9mm belts might not be strong enough? Would 15mm belts be a better choice for a drive train, especially for those who want to add on that third motor to each side?
|
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
You absolutely definitely do not need tensioners for a belt driven WCD, provided you can machine bearing holes in your drive tube with reasonably good accuracy. Our past three years of robots will attest to that. Quote:
To me there's basically no benefit to not going 15mm, and the reliability is *much* higher. Even if it does work, why would you want to gamble on the edge of a safety factor with your drivetrain? All of our 15mm setups have been rock solid. By the way, a good calculator for belt center distance is here. http://www.wcproducts.net/how-to-belts/ We have had good results with zero center distance added. Your mileage may vary based on your tolerances. |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
449 ran 9mm belts last year without any issue on their WCD.
Looking at the belt specs (which are conservative - you can get more than the rated torque out of them given how short the lifespan is in FRC compared to industrial applications), if I were running an 8WD I'd probably be happier with 15mm between the two lower wheels. For a 6WD, where the vast majority of the robot's weight is on the center wheel to begin with, I don't think it's a likely problem. As for why bother with 9mm, it allows one to use the WCP gearboxes with pulleys-in-gearbox just as one would do with chain. Personally, I'm not a huge fan of that setup - if a belt does break (admittedly unlikely but it's better not to tempt Murphy if you can avoid it) it's a royal pain to fix - but even in other setups it's nice and much more compact to be able to fit 2 9mm belts on one pulley than have two pulleys. |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
|
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
|
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
|
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Small request on this guide (which is amazing by the way)
Would you consider updating it with an estimate on pricing for both materials required for just the drive, and what any parts you feel are the minimum requirements to make a quality drivetrain? I think the combination of this guide and sufficient budget might allow some teams that would traditionally use the KoP drivetrain to venture out to a slightly more difficult drivetrain. It would be helpful for them to be able to compare the cost of the VEX drivetrain versus the $450 voucher. Either way, I'll probably make sure a few teams in our area (rookie and otherwise) are aware of this guide. It was excellently written. |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
http://www.chiefdelphi.com/forums/sh...ght=wcd+vexpro From our experience this is not a harder drive train to build than the KOP drive train. We are very familiar with KOP drive train because we used it in our competition and practice robot for aerial assist. We feel that the Versachassis is very easy to build and configure. There is not a whole lot of difference in cost between the two drive train for just the chassis. However the KOP drivetrain uses the single speed toughbox mini which one can adapt to the Versachassis, but it requires a custom build plate. http://www.chiefdelphi.com/forums/sh...=129576&page=2 The ideal gearbox for the Versachassis for team with low manufacturing capability is the 3 sim ball shifter which is more expensive than the toughbox mini. Obviously for the added cost you now have a 2 speed drivetrain. I will post a spreadsheet with all the parts number and cost when I have a chance. |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
|
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
|
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
You do need a lathe to make custom 30+mm wide pulleys if you don't want two 15mm ones, and you may need to modify the outer wheel shafts a bit (may not be enough room for the standard locking collar retension, haven't checked). |
Re: paper: Belt Driven VersaChassis WCD - Step by Step guide
Quote:
|
| All times are GMT -5. The time now is 04:46. |
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi