15T CIM Shaft Pinion Gear (DeWalt project)

[Jack Jones]

How would one go about turning down the CIM output shaft? Can that be done reliably without damaging the motor?

IDK - I'd hate to give bad advice, not having done it and knowing I'd probablly lose a CIM or two in the learning process.

FYI - We got about 8 fps with the 4" wheels locked in low gear. We attempted shifting in '06, but it was too unreliable and wasn't worth the hassle.

Attached are the DXF files for the adaptors we use. They are ready for watercutting - on an Omax, and maybe a Flow (since they're now the same company). The meaning of the layers (colors) are as follows:
0: Traverse
3: Cut w/ quality = 3 (normal)
5: Cut w/ quality = 5 (slow precise cut)
9: Lead In/Out

Good luck...

EDIT: use 0.25 - 0.27" stainless or TI for the adaptors

[craigboez]

I got some advice via PM from Teched3 on how they turn down the CIM shafts. To summarize what that message said:

* To turn down CIM shaft on the lathe, disassemble the CIM and secure the tail end of the shaft in a collet.
*Centerdrill the other end of the shaft (transmission side) using a bushing to center a 5/16" centerdrill. Now that end can be supported by the lathe tailstock with a BB center.
*Turn the shaft end down where it is supported by the tailstock. It has worked well for us for about 4 years.

This process sounds fairly straight forward, but also a little complicated for what I'm trying to do. I'm really looking for an easier solution to this DeWalt/CIM interface issue. Any other suggestions?

EDIT - I'd also really like to keep all the parts un-modified, or at least as close to COTS items as possible.

[JDNovak]

I know you are looking for someting simple but just to add another tested solution. . .

We interfaced a CIM to the first stage of the Dewalt by milling the CIM shaft into a hex. I believe it was done by chucking the end of the shaft in an index head and milling the exposed part. After the hex was complete the end of the shaft was cut to the insertion depth. I don't think the motor was even dissassembled.

The pinion (taken from another gearbox) was EDM'd to a mating hex. No fastener to the shaft was needed.

We put extreme pressure on the resulting gearmotor by driving the first joint of an 8' arm. The backdrive pins failed a time or two but the motor interface survived the whole season and still looked good. During the offseason we even used it to pick up chairs and stack them as a demonstration.

[Greg Needel]

I was thinking about this and if you want a direct drive solution why don't you get the interfacing gear and mount it to a shaft which can then be coupled with a flexible coupler (spider) to the cim motor. It would require the use of another bearing set, but could be done without modification of the cim motor or transmission. The only downside I see is that it would not be a compact package.