10-08-2008 18:58

RMS11

Re: pic: Good overall view

I designed this 6WD in solidworks over the past few days. Most gears are just circles and stuff. Right now it weighs a bit over 20 pounds without the CIM's and chain with banebots 4 7/8 inch wheels or 24 pounds with custom aluminum wheels. Both sides are identicle and can be removed by pulling 4 easy to access cotter pins for changing out sides on the fly if needed. Please leave feedback. Go WiredCats and check out other pics.

10-08-2008 19:49

R.C.

Re: pic: Good overall view

Love the Cad and what is the thickness/material on that back panel "WiredCats 2415". Also on the middle beams that have that CNC pattern, you can save a lot of weight by CNCing the top and bottom of it too. You won't lose too much, it will still be sturdy.

10-08-2008 20:40

RMS11

Re: pic: Good overall view

The back plate is 1/8, and there just for looks, not support. The middle beams are C channel and the walls are 1/8 inch thick. I did not want to take weight/support off the top piece because i wanted it bo be strong since it will be the main support holding the beams together. I might if we do use this for competition and need to save more weight, but right now it is less than half the weight on ours from last year.

10-08-2008 21:20

R.C.

Re: pic: Good overall view

The back panel could be a 1/16 of an inch, that's only if you want to.

10-08-2008 21:22

RMS11

Re: pic: Good overall view

Ya it could, and i guess we could make multiple ones, because if somebody hit us from behind then it would easily get bent and we would either have to ditch it or replace it. Depending on weight, we might change it.

10-08-2008 22:01

R.C.

Re: pic: Good overall view

If i remember right, the pink team used a 16th inch CNC cutout of 6061 for their back. They said it worked fine and never had to replace it. The key thing is, that it will be protected by bumpers.

11-08-2008 01:52

AdamHeard

Re: pic: Good overall view

I would recommend changing the C channel of the cross supports to rectangular/square tubing. The Significant increase in strength is worth the minor weight increase.

As for the back panel, 1/8" or 1/16" will be both be bent very easily if not covered by bumpers in the current setup. If they are covered correctly by bumpers that are well supported, neither would be an issue. As for cutting the name and number into it, those letters are big, and will reduce the strength a good deal. Since it'll be covered by bumpers, really no reason to write that.

11-08-2008 08:33

RMS11

Re: pic: Good overall view

This year we used C channel and it was pleanty strong enough. Also if we dont want it to bend, would you recommend 1/4? We would like it to show if it is there because otherwise it is just extra weight.

11-08-2008 09:06

AdamHeard

Re: pic: Good overall view

If C channel was strong enough in the same application, then I guess go with it again. I just prefer Box tubing over C channel because it is stronger for not much more weight (and the strength gains outweigh the weight gains).

For that outer plate, if you really want to do it, I would use some C channel or box tubing instead. Just going to 1/4" plate would be rather inefficient. Using C channel how 488 did on this base is a much stronger option than just using plate. Once again I would prefer box tubing for the extra rigidity, but that's just me.

As for the gearing, you'll find that the cost of AndyMark gears is very nice (same for their quality).
The 14T pinion for the CIM motors
The 40T gear
The 14T gear with a hex bore
The 50T gear

You can probably even find a way to use AndyMarks various shafts (from their gearboxes) to eliminate even more custom parts from the design.

11-08-2008 10:06

vivek16

Re: pic: Good overall view

Yeah, thats how I design my gearboxes. I usually find an easy way to use AM gears. They come prebroached and the service is great! They even did a custom gear for me.

You could probably pull off that 10-1 reduction gearbox with 2 globe motors by putting these hub things on the shafts of the globes, using these gears on those hubs, driving a 50 tooth gear with that, having a 14 tooth gear on the same shaft as that 50 tooth gear, and then having a 50 tooth output gear.

That would be a 10.5:1 reduction. You could swap that output gear for a 48 to get a 10.1:1 reduction.

-Vivek

11-08-2008 11:49

ducttapedude

Re: pic: Good overall view

We did use 1/16" aluminum for our back and front, we never replaced it, but, it was supported by 2 pieces of angle attaching it to the bottom plate, riveted at the ends of 4x4, and at the top had a piece of 2x1 tubing supporting it.