pic: Team 30 Dual-Motor Transmission

[CD47-Bot]

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[Rickertsen2]

<sarcasm>I don't think it's beefy enough. It looks rather fragile, almost as it it might spontaneously fall apart at any second.</sarcasm>
Really though, good job. Looks great!

The only problems as far as i can see are:
1.)a bit heavy

[Veselin Kolev]

Wowie.
Hey, one question.. where did you get the .7 mod gears to match with the drill? And.. how fast did you get them? Thanks

[Elgin Clock]

Let me guess, they each weigh approximately 7-8 lbs each?

[Ryan Curry]

We didn't use the .7mod gears, the gear on the drill is a 20 DP that we put on it. As for the weight im not sure how heavy it is, but it is sturdy to say the least. Not too expensive to make either, ~$100 per side.

-Rc

[sanddrag]

A few Questions:
What is the 20P gear on the drill, how did you put it on, how did you get the old one off, and where did the new one come from? Thanks.

EDIT: I see some potential problems, you have a shaft collar riding right up against the Oillight bushing, and it looks like you may have gears with the same problem. Also, I assume you are supporting the end of that output shaft, if you weren't planning on it, please do.

[Cory]

Sanddrag: you can get the new gear from pretty much anywhere. I ordered oen from Motion Industries yesterday. Im guessing they press fitted it onto the shaft of the drill motor. As to how they got it off, search. I remember Paul Copioli posting a neat little machined piece that you made, then screwed an M5 screw through, eventually popping the pinion off the shaft.

Cory

[Rob Colatutto]

What speed did you calculate that to drive your robot at with the 12.5 inch wheels your using? I looked and took some educated guessed and calculated it to be about 15.8ft/s. Did you run any numbers on that to obtain your current draw at that speed? How about how well the robot will turn with 4 pneumatic wheels? Also from the drawings it doesn't appear like the bosch is held into the gearbox with anything, is it connected at the bottom in an unseen way? I also share the concern about that output shaft, I would not recommend to have something that long as a cantilever shaft. It also looks like you are planning to have the gearbox slide into the chassis and be bolted in. I have had experiance with mounting gearboxes like that and I would suggest against it, espescially with a more than 2 wheel drive robot. Under the highest stress situations, the gearbox will be sliding around on you and the bolts will try to loosen.

[AlexR]

You can take the gear off the drill motor with a good old fashioned dremel. Just don't let shavings get in the motor. It's good fun, really.

[Ryan Curry]

I'm not sure what speed the wheels will be turning, becuase we can adjust what sizze sprockets we have the chains going to. If we want more speed we can lower the ratio. As for turning we were concerned that it might have the "jumping" problem but we ran it and had no issues, turned just fine. We never cantilever drive shafts, there is a pillowblock that the output shaft goes into already on the frames. I'm not sure how they bolted it on however becuase I'm at college ~100+ miles away.

The gear that is on the drill we ordered through motion industries, it is made by boston gear. It was press fit on. The drill motor is held in place by the giant shaft collar that was machined for it, it was run for about 20min at full speed with no slipping.

-Rc

[Rob Colatutto]

The calculation I did was with a 12:60 sprocket reduction and thats the biggest possible with ordering from mcmaster and such. What are those gear reductions in there? From observation it appears you might have the numbers wrong with your bosch motor, but knowing the actual teeth numbers would be nice.

[SarahB]

Originally Posted by AlexR

You can take the gear off the drill motor with a good old fashioned dremel. Just don't let shavings get in the motor. It's good fun, really.

We’ve been through this many times before. Do NOT Dremel off the drill pinion, and if you do, don’t encourage others to repeat your mistake. This can cause many problems including: damaging the output shaft, getting shavings in the motor, damage the motor in other ways, and just generally cause problems. Besides, if you’re removing the pinion, you’re going to need a press to put on the new gear anyway so why not just do the right thing from the beginning. If you don’t have access to a press, you can always use the mod 7 gears from PIC, as long as you order far enough in advance.

[Landon]

How many of those are you using?

[AlexR]

Originally Posted by SarahB

We’ve been through this many times before. Do NOT Dremel off the drill pinion, and if you do, don’t encourage others to repeat your mistake. This can cause many problems including: damaging the output shaft, getting shavings in the motor, damage the motor in other ways, and just generally cause problems. Besides, if you’re removing the pinion, you’re going to need a press to put on the new gear anyway so why not just do the right thing from the beginning. If you don’t have access to a press, you can always use the mod 7 gears from PIC, as long as you order far enough in advance.

Ok, lets think about this for a second. How many times have you tried to dremel the pinion off the drill motor and failed personally. 0. In fact, how many times have you actually tried to dremel the pinion off of a drill motor? 0. So, you have no right to say it shouldn't be done. If you do it carefully and cover the motor, you will have no problems. It's really very simple. You are basing your opinion off of zero evidence. So please stop talking.

[RobDeCotiis]

sarahb,
dremeling off the gear only poses a threat to the motor of you're lazy. Make sure you don't get shavings inside the motor and i see no reason dremeling the gear off would cause harm. Cutting into the drill motor shaft slightly won't cause problems, unless you hack it to bits. Some people don't have presses, and honestly, you don't need one. The dremel works fine for removing the gear, and simple expansion/contraction properties of the metals will allow you to put the gear on. freeze the motor(or just the shaft, assuming you have liquid nitrogen in your chem lab ) and heat up the gear with a blowtorch and you'll be able to get it on, and when it cools down, good luck getting it off. Try to think a little more about reasoning before you post. You yourself have seen the motor ryan put the gear onto, you know it works fine, the motor isn't damaged, i don't really see what the problem is. anyway. beautiful looking gearbox, ryan. nice job

Team 30 forever
Rob DeCotiis