[FW] Wedge Spinner in time for Robo Challenge champs!

**Giles** · 9th March 2016, 11:37

Myself and team mate Dave have been slowly tinkering away at a crusher bot for the champs.... but we've realized the champs are VERY CLOSE now and our hydraulics isn't going to be sorted in time. So, we're going to work our asses off to make a more simple design - a wedge/small spinner.

Dave has been working on a custom ESC for the last month or so, and will continue to do so for the coming weeks. We wanted to do this as a challenge, and considering the work we've done on it so far, we don't wanna quit! If this turns out to be an epic failure, we will fall back on more tried and tested ESC's. Will post more about this later.

I've been doing a bit of CAD work, with hopes to get the whole bot designed by the weekend and have parts being ordered early next week.

First I started off with a simple box with a pair of Ellis' mighty fine gear motors and some castor wheels:
f6458b9f9f08ee52cc333dbad1f44c88.png

Then I designed & balanced a single tooth disc:
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Then I made some mountings for it, which will hold the weapon motor, belt drive and dead shaft axle:
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At this point I realised it was rather long and making bad use of space, so I took it into photoshop and sliced it up into a more appealing layout. Will implement these changes in my cad file soon:
383da1c99c5b3877c2d44a8ae631819c.png

As you can see, we don't have much, but hopefully that will change in the coming weeks! This is technically my second ever build (disregarding the half-started crusher), so I will no doubt need to ask some annoying questions to you all along the way!

**Eventorizon** · 9th March 2016, 13:04

Any reason why you are running another reduction off the Saturns? I don't know your wheel size or voltage but I can see that being very slow given direct drive off the Saturns is fine as it is.
Aside from that, doesn't look bad :-)

**Giles** · 9th March 2016, 13:31

I was thinking about this on the train to work this morning

I think the belt drive will actually be a 1:1 ratio, using HTD5 timing belts. The belt drive is just so the wheels aren't directly attached to the motors, to offer some protection.

Edit:
I just realized you have been replying to my facebook posts! Thanks for all the input so far mate.

**Rapidrory** · 9th March 2016, 18:27

It would be easier to just drive the rear wheels directly from the Saturns, and then have a single belt drive either side from the rear wheels to the front wheels; the saturns are built for combat, and unless you're using solid metal wheel hubs or something, the wheels will likely give way before the gearbox if they get clipped by a spinner. Plus at the rear of the robot, they're usually fairly well protected by the front of the robot :L

**Giles** · 9th March 2016, 19:01

I agree with you if i'm honest. But the biggest problem I can see is the making of the hubs. I don't have much in the way of machinery/tools, so I'm pretty limited to 2D laser/watercut parts or 3D printed nylon parts, or whatever I can cobble together from bits and bobs. Unless I can think of an easy way to make/find a hub with a keyway and grub screw that fits the saturn drives, its easier for me to do a belt drive. For the belt drive I can order a timing pulley from belting online, have them bore it out to size and add a keyway and then make a nylon/alu hub for the castor wheels myself.

Extremely open to suggestions on alternatives btw, I'm just trying to be resourceful with what I have access to!

**daveimi** · 9th March 2016, 20:33

I have been wondering if there are any off the shelf wheel solutions for the saturn motors...

**Eventorizon** · 9th March 2016, 20:52

Originally Posted by Giles

I just realized you have been replying to my facebook posts! Thanks for all the input so far mate.

No Problem

So far as I know there is no off the shelf solution for the Saturns right now, which is a problem for you but I know Ellis is on it. Aside from making your own wheels from HDPE, Bike Tyre and then either filing a keyway in the plastic or going with grub screws I cant think of any fast and dirty solutions... then again I don't really do fast and dirty.