pic: 649 Offseason Hexagonal Chain-in-Tube WCD

[RobotsThatWork]

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[asid61]

Very neat. I assume the bumpers will form the hexagonal sides? Very clever, and it performs the same function.
What made you opt for screw+washer and eclips to secure the shafts over circlips everywhere?
Is it just me, or are there 4 wheels on the far side and only 3 on the close side?

EDIT: Did you add any extra spacing for the chain? Apparently that's a problem according to these tests.

[RobotsThatWork]

Originally Posted by asid61

Very neat. I assume the bumpers will form the hexagonal sides? Very clever, and it performs the same function.
What made you opt for screw+washer and eclips to secure the shafts over circlips everywhere?
Is it just me, or are there 4 wheels on the far side and only 3 on the close side?

EDIT: Did you add any extra spacing for the chain? Apparently that's a problem according to these tests.

yeah the bumpers form the sides we probably need a bit stronger bracing for the bumpers though, as these supports only touch the bottom of the bumper. And we used bolts and washers last year without too much problem, and its easier to machine for us than e-clip grooves are. we may do only e-clips or only only bolt and washers. we still haven't decided.

Chain spacing is .1835 for the 6W config and .2 for the 8W config (cuz both designs share the outer holes, we couldn't make everything a nice .186 like we would have liked)

[Boe]

Originally Posted by asid61

Very neat. I assume the bumpers will form the hexagonal sides? Very clever, and it performs the same function.
What made you opt for screw+washer and eclips to secure the shafts over circlips everywhere?
Is it just me, or are there 4 wheels on the far side and only 3 on the close side?

EDIT: Did you add any extra spacing for the chain? Apparently that's a problem according to these tests.

It appears that the sides are set up so the near one would be for a 6 wheel drive and the far one would be for a 8 wheel drive

EDIT: just read the original post lol...

[Scott Kozutsky]

Going by the 2014 rules (as well as 2010-2013 I believe, don't quote me) the bumper corners need to be supported. Because there are unsupported corners that overhang the wheels this drive base would not pass inspection in 2014.

Cool design otherwise.

[KohKohPuffs]

I'm not sure what's going on the bumpers, but we will definitely take that into consideration.

Meanwhile, we have uploaded a .STEP file to grabCAD for anyone who wants to see this drivetrain closeup on their CAD software. Link is found here: https://workbench.grabcad.com/workbe...3ckfPNf6IoZmc9

[Sohaib]

Originally Posted by Scott Kozutsky

Going by the 2014 rules (as well as 2010-2013 I believe, don't quote me) the bumper corners need to be supported. Because there are unsupported corners that overhang the wheels this drive base would not pass inspection in 2014.

Cool design otherwise.

Assuming 2016 game rules are similar to 2014, you can just have plates that touch the bumper in the corners for the required distance (1/2" in 2014 IIRC) to satisfy the bumper rules.

[jagoldman]

I think that is a nice design especially with the option for both 6 and 8 wheel drive. I was wondering why your side bumper supports are oriented horizontally instead of vertically. Additionally, it is pretty easy to cut a hole in the top of your change (where the chain is running) and put in a basic chain or belt tensioner if your end up having that problem. In the past, I have found 3D printer parts with a bolt to be great for tensioning.

[RobotsThatWork]

Originally Posted by jagoldman

I think that is a nice design especially with the option for both 6 and 8 wheel drive. I was wondering why your side bumper supports are oriented horizontally instead of vertically. Additionally, it is pretty easy to cut a hole in the top of your change (where the chain is running) and put in a basic chain or belt tensioner if your end up having that problem. In the past, I have found 3D printer parts with a bolt to be great for tensioning.

Thanks!

Since the bumpers have to be 2 inches off the ground according to 2014 bumper rules, the bottom half of the boxtubing wouldn't actually contact the bumper. so we turned it sideways to get some more contact area. But the bumper system is still a work in progress, so we may change it again if we think of something nicer.

and actually the design can be used with versablocks if we need to (the drop center is the same). we are just hoping to avoid spending money (and robot weight) on them.

[lewislongbottom]

I believe you will also be able to get a 4wd out of that system too!

[first_newbie]

Is this slightly better at turning due to the wheel that is on the outside (wider track width)

[KohKohPuffs]

Originally Posted by first_newbie

Is this slightly better at turning due to the wheel that is on the outside (wider track width)

I think that is correct, but the main intentions of this drivetrain is to have the ability to work around t-bones.

I believe you will also be able to get a 4wd out of that system too!

Yup. However I don't see any advantages of a 4wd as opposed to a 6wd or a 8wd, and I think the reason is because how many wheels are in contact with the ground (probably 99.99% wrong because of drop center).

Also, one time I saw a 4wd FTC chassis, and when it turns the entire thing shook, and I think that was because of the rubbing of the wheels. I think if we use a 4wd on this drivetrain, we will see the same thing happen, although I am not entirely sure.

[first_newbie]

why aren't the two gearboxes parallel?

[KohKohPuffs]

Originally Posted by first_newbie

why aren't the two gearboxes parallel?

It's just for show: we are trying to demonstrate that our system can be easily switched from a 6wd and a 8wd. That's why the gearboxes aren't parallel because of the position of the outputs shaft, but when we actually make this, both gearboxes will be parallel

[jagoldman]

This rendering is demonstrating a 8wd on the far side and a 6wd on the nearside. As a result, the gearboxes are in different places.