Chassis CAD Drawings

First drawing, as of 15 January:

Transmission mounting leaves us with the same problem as last year. We will have to either have a tang welded on to the chassis or we make stand offs like Michael Robinson is using on the test bot this year. Especially in the back where I would still like to see if we can get a kicker. In the planning last night I moved the front wheels back 10 inche and the rear wheels back 8 inches. We may have to adjust this as we add stuff.

I was seriously looking at Andymark modulus transmissions bhy iR3 especially the Pandoras box kit. They provide so much versatility that I would love to use them. I could see having the wheel mounted as far to the right of one as possible ( long ways on the plate) and have room on the left side for the pick up roller. ( I'm @ work so I can't draw this out right now). It would make mounting much more simple for the trans and the roller all in one. However we could use a "transmission engineer" to look at the gear ratios and figure out if they are going to be close to the nano box trans, which ships with Overall Ratio: 12.75:1 (standard). I cannot find any information on the gear ratios for the modulus trans. So someone needs to look into this for me please.

Should we go to hex shafts on the nano box trans? I am suggesting a conscious decision to run with hex shafts. Pro's no more keyways, Cons: adjustment of wheel on shafts.
Should we change out and order all aluminum gearing for the nano box transmissions?

Now is the time to talk about this stuff. Comments? Transmission gear engineers what say you? Ratios? feet per second on the floor?

Interesting thought. I would really have no problems going with those transmissions, aside from the fact that the Pandora is a lot more expensive. Form a quick glance it would seem like you could get the same (or at least very similar) gear ratios as the Nano.

Another thought I had: What if we still went with the Toughbox Nano Tube, but cut it in half? That basically makes your gearbox 16 inches long (or shorter, depending on if you cut more than half), so you could mount it vertically and be able to attach it to the chassis without making a plate like last year - the standoffs are essentially "built in". Food for thought.

Also, I'm kind of hesitant to switch the gears to aluminum - the Toughboxes on last year's robot had a habit of turning the aluminum gear on the CIM into powder. I don't know how much of that was due to interfacing aluminum gears with steel (probably a lot), but I would be more comfortable taking the slight weight penalty to go with all steel gears and know we wouldn't have to worry about the gears getting stripped and having to replace them like we did last year.

I like all that's being discussed except I would be much more comfortable with all steel gears in our gearboxes this year.

Admin wrote:

Also, I'm kind of hesitant to switch the gears to aluminum - the Toughboxes on last year's robot had a habit of turning the aluminum gear on the CIM into powder. I don't know how much of that was due to interfacing aluminum gears with steel (probably a lot), but I would be more comfortable taking the slight weight penalty to go with all steel gears and know we wouldn't have to worry about the gears getting stripped and having to replace them like we did last year.

I thought we have been using all steel gears in the nano boxes? I am suggesting that we go all aluminum and hex shafts. Then we cover the ends of the nano tube to keep them free of "shavings" etc. I think this combo can save weight and still provide reliability. I could be swayed, if someone could show me the grind-age on the gears. I didn't know about this as an issue from last year.

r3p0 wrote:I thought we have been using all steel gears in the nano boxes?

We were using mostly steel gears last year - except on the CIM, which was aluminum. That combination caused the gear on the CIM to wear completely down, to the point where the gearbox seized up and we had to replace the gear. Again, I don't know how much of that was the fact that it was aluminum gears and steel ones, but I'd certainly feel more at ease with all steel.