01-01-2009 19:23

chris31

Re: pic: 6wd - revised - feedback requested

Those bottom plates could very well be where you under up mounting your electronics and battery. If you are going to make this is would originally leave the bedpan out and layout the electronics and batteries and determine what material you can cut out after these components have been mounted.

01-01-2009 19:24

gorrilla

Re: pic: 6wd - revised - feedback requested

why omni's in all four corners?

you could probobly get away with just having them in the back(and not have to drop the center wheels)

01-01-2009 20:09

R.C.

Re: pic: 6wd - revised - feedback requested

I like it but:

-40 lbs is a lot with cnc work in it, supershifter are about 18 lbs if you don't lighten them.
-Why omni's, use 2 in the front. If you put the ones in the back you'll get pushed around and levered.

Otherwise, nice design.

01-01-2009 20:59

Vikesrock

Re: pic: 6wd - revised - feedback requested

I will pt in the siggestion here to see what the game is before deciding on a drivetrain.

Last year my team went with a 4 omni 6WD setup and we were not spun or turned at all during our regional. As I recall 488 also uses the 4 omni 6WD setup and is generally happy with it.

We felt that with the 2008 field layout it would be difficult for a team to get into a position to try and spin us and we wanted our turn center to be centered so we went with the 4 omni 6 WD.

01-01-2009 21:29

R.C.

Re: pic: 6wd - revised - feedback requested

I have never been a fan of omni's and i have seen a lot of teams getting turned with them. But if it works for you guys then ok, sounds great then.

01-01-2009 22:04

GUI

Re: pic: 6wd - revised - feedback requested

You might not want to put the lightening holes in the bellypan, it would be easier to mount the electronics without them, and you only save about 2 1/2 pounds. Also, I would be wary of using this design withoug adding gussets on the top corners, it will be a lot stronger with them. You may want to lighten the super shifters a little, if you're concerned about weight.

01-01-2009 22:23

JHSmentor

Re: pic: 6wd - revised - feedback requested

Thx for the suggestions.

We used the 4 omni's last year and it worked very well - although I am definitely keeping options open to use only 2 in the front. obviously the game may make this whole design not very good anyway.

The gussets have been suggested often and it's probably something we will strongly consider. Just worried about them getting in the way. We didn't use them last year but our whole chassis was 3/16" rather than 1/8" so maybe that made the difference. Plus we didn't have any huge impacts.

All of the lightening holes will be dependent on if we can find a shop to help us. Otherwise we have ZERO ability to do anything this fancy. I would love to lighten the Super Shifters as well but that's way beyond our abilities as well.

this design is already 20+ lbs lighter than last years so even if we couldn't do everything shown here then we are a little ahead already.

thx,

02-01-2009 02:51

DonRotolo

Re: pic: 6wd - revised - feedback requested

Make sure there are places at the top edge to mount superstructure (i.e., manipulator), perhaps turn the top edge of the inner rails inward. Maybe make them a little taller too, so the top is just above the tops of the wheels - your manipulator team will love you for giving them a perfectly flat surface the size of the whole robot (your maintenance work will be from the bottom looking up). Also, count on using your bumpers as structural elements, which means only the mounting points on the outer rails need to be strong, the rest can be weak because you have that 3/4" plywood holding it all together. For the bottom plate, consider fewer and smaller lightening holes, as mentioned above so you can easily mount your electronics and gear there. Last, line up the shift pistons and use just one to shift both at the same time. There's a thread here somewhere that shows how one team did that.

02-01-2009 07:42

TVan

Re: pic: 6wd - revised - feedback requested

Are the standoff bolts in the path of the chains ? maybe just one bolt
in the center will be ok, Or you could put a slot in this area to mount chain
tensioners, A shaft with tapped holes in the ends and a small roller
on it may work as a stand off and a chain tensioner.
Caution this is a untested idea, just a quick thought
thank you for posting your chassis it looks great,
Tim

03-01-2009 03:32

bmarick

Re: pic: 6wd - revised - feedback requested

This looks Great Brian.
I would disagree this will be enough to mount our electonics and phenumatics.
One worry that I agree with is the bumbers. Thanks for doing this.
From what I hear form jordan, Crossbracing the cornors would be a good ideal it would give some solid regidity. This can be ssen in our cornors of last years bot.
To finish it off it we can't decide what we will use for wheels until the game is anounced.

See you tomorrow.

03-01-2009 03:59

Re: pic: 6wd - revised - feedback requested

Talk to Madison from 488 about their experience using Omni's in a traction 6 wheel drive. She's got some GREAT insight and experience there.

Otherwise, looks pretty good. Might want to work on using less material by means of design instead of CNC pocketing... I'm SURE you can achieve a lighter, stronger base with less machine time. Keep at it!