Re: Number of FP Motors
 

How did you JB Weld the motor pinion to the first planetary stage and make sure everything was concentric? I'm trying to do this with one of our globe motors now, and was going to leave the first stage planetary gears in for concentricity alignment purposes, and then just dremel off the outer teeth so they don't mesh with the ring gear.

Re: Number of FP Motors
 

Richard,

57 had this done at LSR by the welder. Twice. We had an extra globe about, so we laid a degreased first planetary stage on top of the pinion and had him tack the gears in place from the top side, then grinding the outsides of the planets off and grinding the top of the carrier smooth. Grounding through the globe chassis wasn't particularly nice to it, thus the having extra globes. We haven't had a chance to run with it yet, but it looks fairly promising. Also, don't lose the washer you need between that stage's planets and the motor face. One of the students assembled one without that and it wasn't very happy with him.

Re: Number of FP Motors
 

is there any chance to do this to a globe motor without having to weld or mill or lathe???

We don't have those tools, and have run into the same problem as previously mentioned.

Re: Number of FP Motors
 

I'm using JB Weld (a strong form of epoxy for metal/metal contact), which you can get at any local hardware store for $5 or so.

According to Andy L (a little further up in this thread), it was strong enough for him. Mine is still drying right now, so I'll let you know how it holds up when it's done.

Re: Number of FP Motors
 

I believe you can pull it off with just JB Weld or a similar metal filled epoxy. It would be easiest to degrease the first and second stages and JB Weld them together with the planet gears in place for alignment, then grind off the outside teeth of the now frozen planet gears. I as I understand the gearings, this would give you approximately 5.5 times more speed with the requisite drop in torque. I'm a little antsy about this mod because that stage could be under as much as 7 in-lbs of torque. It's not a whole lot if you get the parts well cleaned and bonded, but I don't know if the JB Weld will hold up under it with poor bonding.

Better would be if you could JB Weld the first planetary stage to its sun gear, or atleast fix the first stage's planet gears in place with JB Weld. I think this would require a little more care, but the first stage is dealing with lower torques , so I think it would hold up better. Plus it's only a ~3.8x change in speed and torque, which might suit you better.

Re: Number of FP Motors
 

We removed the planetaries
Generously applied JB Weld
Put the gears together(Sun and plate thingy)
Put the motor back in the gearbox and the planetarys of the next stage put it in the right place