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Carlton 1A Arm Elevating Motor Inoperative - Worth Acquiring Complete Drill for$300


Mar 30, 2011
western pa
I have the opportunity to acquire a Carlton 1A RAD for almost nothing: half the fuel cost from central WI to western PA.

The current owner has said that his fuel cost per run is around $600; so, my acquisition cost would be around $300.

However; the arm elevating motor on this Carlton 1A was removed years ago, SUPPOSEDLY because it just stopped working.

I’ve seen one poorly illuminated cell phone picture of this unit; some of the radials on eBay look much more haggard to me.

Here is what I’ve been told about this 1A unit–
1) This unit was acquired in a company buyout and the new owner (my partner’s employer) has no interest in having a RAD
2) This unit has sat largely unused in the previous owner’s factory for at least the last 10 years
3) An ex-employee of the previous owner has said this Carlton had very little use after the year 2000
4) At some point (perhaps prior to the year 2000 – this date is indeterminate) the arm elevating motor quit working
5) The arm elevating motor was removed (but it was saved and would be included in the “sale”)
6) A large socket was then used to turn the nut on top of the arm elevating screw to raise and lower the arm
7) The previous owner was evidently the original purchaser of this Carlton
8) An employee of my partners firm sent out to appraise the machinery watched the arm being moved with a 24” breaker bar
9) Then a few 1-inch holes were drilled in mild steel without issue (but evidently a Carlton doesn't sound much like a CNC machine)

Theoretically, I assume the problem could actually be an electrical control system issue(s) and the arm elevating motor is fine.

In searching for guidance on how to resolve this issue I came across the following informative PM thread:

However, the issue being discussed in this thread appears to be separate from the issue I am facing –
i.e. worn arm elevating nut(s)/screw vs inoperative arm elevating motor

As the arm is moveable 'manually' I assume this rules out a mechanical problem in the elevating assembly gear-train/etc.

Would the presence and correct orientation of the safety nut to the main nut conclusively point to a motor related issue?

Are there any details available that would enable me to determine if the lifting screw and nuts are within specification(s)?

None of the downloadable Carlton manuals on the internet provide details about rebuilding any of the Carlton drive motors.

ASSUMING I've been told the truth, and the motor is indeed faulty, is a Carlton arm elevating motor readily rebuildable?

Is this a job that any reputable electric motor rebuilder could do; or is specialist Carlton motor expertise required?

If so, who would forum members suggest I contact?

If a used arm elevating motor is necessary, how much would one for a 1A likely cost (and who would be the best source)?

Dumb idea perhaps: could the Carlton 1A arm lifting screw assembly tolerate being driven with an air or hydraulic motor?

So; for $300 is this too good of an opportunity to pass up, or do the potential headaches/costs negate any winning outcome?

As I’ve never operated, much less owned, a Carlton RAD, any advice from those with hands on experience would be helpful.

Many thanks to any forum member who takes the time to respond and share their insights/thoughts.

Bill D

Apr 1, 2004
Modesto, CA USA
For $300 I think that is a deal. I am no expert so take care with that opinion.
Depending on use how often would you need to raise/lower the arm? Would an air impact wrench do the job. I assume the arm motor is 3 phase. If so it can be re wound if needed.

Looking at the 3rd link below it looks like a standard motor. Not a gear motor. I would suggest using a VFD to control it.
Bill D.