Banebots Doubt
 

Re: Banebots Doubt
 

We're using a 20AMP on our, and it hasn't tripped yet! You must remember that this is stall current, and when it stalls, it burns the motor up.... So better be safe than sorry and use the 30AMP. We used a 20AMP to save weight on the wiring.

Re: Banebots Doubt
 

i would use the 40 amp

Re: Banebots Doubt
 

Why? Do you want to start a fire!?

Re: Banebots Doubt
 

If you're worried about the motor then use a smaller fuse!! Better the fuse blow than the motor or wire burning!!

Re: Banebots Doubt
 

we have a 20 amp in ours, I sure hope it never sees more than 10 amps

Re: Banebots Doubt
 

Banebots lists the current at peak efficiency at 6+ amps. The 20 amp breaker should work for most designs. However, be aware that many teams are reporting that this motor is smoking when under heavy loads. It is essential for these motors to be operated in a range where the fan has adequate RPM to cool the internals. Plan accordingly.

Re: Banebots Doubt
 

Now I'm really curious...where is this "fan" you speak of?

(yes, I have a 36mm BB gearmotor right here and I've been looking at it)

Re: Banebots Doubt
 

If you look at the slots in the side of the motor, you will see a white fan. The blades are on edge. When the motor runs the fan "throws" the air out through the slots and draws air in through the other holes in the motor.

Re: Banebots Doubt
 

When I look in the motor of my new Craftsman cordless drill, I see a white plastic fan, as you describe. But when I look at a BB RS540 motor, I see no fan at all. Here are some pics taken thru the slot in the motor.

Re: Banebots Doubt
 

Jim,
I could have sworn there was a fan. I will try to check tonight, we are not using the Banebot motors. The Fisher Price motors are a similar design and have an internal fan.

Re: Banebots Doubt
 

The FP motor will fit the BB gearbox, eh? might be a worthwhile swap. Then again, I just ordered 4 more RS540 motors and pinions from BB, for $20 for all 4, plus postage.

Re: Banebots Doubt
 

We are using the FP in a custom transmission. We have used these motors for many years and are happy with the performance if you keep the fan turning and the ventilation holes open. We have smoked a few over the years. This years motor has an internal circuit breaker though. I am still researching this, we found it by accident over the weekend.

Re: Banebots Doubt
 

heh....I guess it's better to find a breaker, than to find the magic smoke!

Re: Banebots Doubt
 

Not when the arm is half way up! We solder wires to the motor for best reliability but I may have damaged it when I performed the solder operation. It trips pretty easily and has a slow recovery. We will be testing our backup tonight (I hope) or tomorrow.

Re: Banebots Doubt
 

There is no fan in the banebots motor. If the holes in the front
of the motor where the output shaft are open the spinning
armature does cause some air flow through the motor. Nothing like you
get from the little white fan from the FP motor, however.

If your FP motors are not used elsewhere, you can easily put these
on the banebots gear box. You can use the longer motor shaft to
allow a 1/8 inch thick spacer between the motor and the gearbox that
allows air flow into the cooling holes that air is drawn into. The FP
motors are much more robust, so you should use them on your banebots
gear boxes if they are not used elsewhere.

Eugene

Re: Banebots Doubt
 

Well, I guess the last week of build is showing. It's a good thing I don't have to inspect this weekend.

Re: Banebots Doubt
 

Thanks for the tip! looks like a great idea. I brought an FP motor home, maybe I'll tinker on the lathe in the morning.

Re: Banebots Doubt
 

I did get a chance to look at the FP motor, removed the gear, and the shaft is knurled...which looks like a potential problem when using the BB 36mm 125:1 trans, which has a very small pinion gear, that might break when pressing over the knurled shaft. Also the spacer needs to be about .325" thick, as best I can tell.

Anyways....I have taken apart a KOP 64:1 gearbox, and discovered that it uses 3 gear planets for the first and second stages, and a 4 gear planet for the third stage. Not much interchangeability there. And then I took apart a 125:1 gearbox and discovered that it has 4 gear planets in all stages, but the sun gear (pinion) in the second two stages is pressed into the planet carrier of the previous stage, while the final stage has the typical DD joint to the output shaft. Not much interchangeability there, and it also seems to prevent mixing stages to get custom gear ratios, which I had hoped we could do.

Also the team ran the robot today some more, and the 125:1 gearbox was showing noticeable backlash.....like maybe the output carrier plate is getting bowtied.....

Maybe we'll go back to the Globe plan B.

Re: Banebots Doubt
 

We can testify to the fact that if you try to press the BaneBots pinion gear for a 5:1 stage directly onto the FP motor shaft, the pinion gear will crack. We broke about 4 last year before we finally learned how much we needed to turn down the FP motor shaft. Alas, I don't have the specs that the machinist finally determined (empirically) to have the pinion pressed safely onto the FP motor shaft.

Best Regards,

--ken

Re: Banebots Doubt
 

Huh, I guess my intuition was right that time :)

the non-knurled part of the FP shaft is the same diameter as the BB motor, 0.125", while the knurled part of the FP shaft is about .004" larger.

My guess is that if you turn the knurl down to .125-.126" it would be fine.