Need help with mini motors
 

Couple questions? How did you use this? Can you press or put any pinions or spur gear on this? Is there any way to use these? We have a lot because teams have given us these and we have about 12 of them.

Re: Need help with mini motors
 

If I recall correctly, they have two threaded holes on the face for mounting.

As for a pinion, You can press a gear onto the shaft if it has the right bore size for a press fit. I think that would be just a few thousandths undersize, but I'm no expert in that. You can buy a gear with bore below that and open it up on a lathe, or you can turn a custom one from gear rod.

You could also buy a gear with a hub and set screw with a bore size the same as the shaft. Although set screws are not a good way to mechanically fasten the pinion to the shaft.

As for usage, I've only seen teams use them as a tachometer and I have to see a team power a system with them. I'm sure some have, I just haven't seen it. It's not terrible powerful, so there aren't many applications for it.

Re: Need help with mini motors
 

i'm sorry i just remembered that banebots has all the small mini motors in a planetary gearbox

Re: Need help with mini motors
 

Yes, they do. You can only get the gearboxes with them already in.

They make for good rollers I hear. :)

-Vivek

EDIT: At 2 dollars a pop, they are pretty cheap.

Re: Need help with mini motors
 

We used this little motors for our drive base. They offered plenty of power and made us one of the fastest robots on the field. We never had trouble with them. They're strong enough to pull my car! This little motors really amaze me with their efficiency, strength, and weight. There has never been a better motor in FIRST.








All jokes aside... yea... I'm not sure what use these motors could have. Possibly put a small fan on the end of them to keep something cool? We've never used the large fans they provide in the kit either, nothing ever gets hot enough to need them. We did use a small muffin fan to cool a FP motor down.

Re: Need help with mini motors
 

BaneBots with their gearboxes are plenty strong enough for light applications. 330 used a pair in 2007 for ramps. No penalties for expansion, and one case of pulling the ramps up to go block a spoiler.

Re: Need help with mini motors
 

Those were the 36mm gearboxes with the much more powerful RS-540 motors though.

Re: Need help with mini motors
 

Exactly... The applications for these little motors in the real world are limitless, but in the FIRST world, I don't see very much use. These are the motors that can probably be found in a lot of children's toys (not that the big scooter motor cannot be found in children's scooters, and I actually had one of these motors before they came in the kit).

But with what EricH said, the motors on the small BaneBots are very strong. In fact we used this motor for our arm last year (2007). However, we did manage to burn it out a few times when we accidently stalled it in the pit and in the workshop. This year's fork mechanism involved a more complex and intricate system involving a FP motor, its gearbox, a muffin fan, a servo, and the tread that came with our test AM Performance wheel, some aluminum tube, 1/4" aluminum plate, a 10 turn potentiometer and about ten hours or more of work.

What we ended up with was a very nice wench system that worked flawlessly all season.
Attachment 6727

Re: Need help with mini motors
 

I'm telling you, these things look like they would make wicked rollers.

With a reduction to around 800 rpm, they have 190 oz-in of torque and with the 28mm gearbox, they end up at a weight of 5.1 oz with the gearbox!

These would be really useful in a manipulator because of their relatively high power density.

-Vivek

Re: Need help with mini motors
 

I agree with this point with the caveat that it really depends on the game piece. Sure, you can pick up any game piece using this motor on a roller when you're sitting still. However when you're in motion the roller needs to move at a speed greater than your robot's speed, otherwise the game piece will be kicked away or forced to slide with the bot (which greatly increases your chance to be defended against). Combine that with the needed torque to pick up the game piece of the year and you should see that there are many years where a small intake motor like this just isn't feasible. Use the "Intake Mechanism" tab of JVN's 2008 Design Calculator.

The conclusion I've derived is that with a 20:1 gearbox this motor was ideal enough to pick up the tubes in '07 and 1-2 poof balls at a time in '06 if your bot drove 6ft/sec or less. I agree that they're great power for the small size and weight in these years.

Re: Need help with mini motors
 

I was contemplating using a 16:1 or 20:1 reduction with a 4" diameter wheel on the end of the shaft as a roller. Our robot moves at 12 fps or so.
With the 16:1 reduction, it is at 1000 rpm or 16.7 rps. 4*Pi=12.5" or one foot. So that is a surface speed of 16 fps easily right?

We have supports under the ball and these rollers on the sides of the ball (near the middle) so it is not like the rollers would be supporting the weight of the ball directly. We pick up off the ground.

All of your points are valid though.

-Vivek

Re: Need help with mini motors
 

Keep in mind a roller system will slow down when it makes contact, I guess how much would all depend on what the object is, if it is being compressed, etc...

We had a roller this year with two sides, one side powered by a 540 and one by a 550. It slowed down a significant amount when a ball was contacted.

I would use these motors in an application you might use a servo, but need more power. Maybe a little blocker to block the ball path of a conveyor for a shooter in 06.

They might work as a roller, but they game piece would have to be much less formidable than a trackball.