Assuming one has a fairly straight 4.5" OD x 10" long round motor with smooth surface, what would be a good way to get some heat sink type of deal ?

I am thinking about

A) getting say 3/8 or 1/2 alum channel, cutting it into pieces the length of the motor and attaching the "strips" flat bottom toward the motor around the circumference. 3-4 zip-ties holding the Us against the motor

B) doing something with copper or alum sticky foil, where you create as many folds as possible in a "pleaded" fashion

Is this DC brushed or DCBL? as the later can be cooled by a heat sink on the case, often these come finned already.
With the DC brushed, you do not achieve a lot by heat sinking the stator, as the stator will either have the low current field winding or the P.M. field, in both case the source of the heat is from the armature, which in the majority of cases, is reduced by a forced air fan solution.
Al.

Brushed DC . I do understand it is the rotor coils that generate the heat. Don't see an ez way to get a flow of air streaming across the stator-rotor gap, unless I go with compressed air ... which might not be a bad idea ... I have a dirt cheap low-psi low-volume uber-quiet air compressor from HF and may be I can get that hooked up somehow.

I also had an imagination breakthrough here on how to attach an effective HS.

Use 2"-wide alum sticky foil. Overlap few strips till you get (for 4x10 round motor) a (3.14x4) by 10 rectangular, sticky side up. Pi times D

Cut enough pieces of 1/8" thick 3/4 or 1 wide alum strips - these are our fins.

Attach enough of these to "fill" the said sticky surface. The idea is to have the sticky tape hold the strips.

Now gently lift the whole thing and wrap it around the motor. The curvature of the circumference will "fan out" the fins in radiating fashion.

Now to get the contraption to stay put may be drop some crazy glue or epoxy in between the fins here and there ?

Al,

The brushed permanent magnet DC servo motor I am using has a completely sealed case. Does this mean that the manufacturer has determined that no external cooling is necessary? The maximum armature heat is listed as 155c.

Thanks,

Bill

Is this DC brushed or DCBL? as the later can be cooled by a heat sink on the case, often these come finned already.
With the DC brushed, you do not achieve a lot by heat sinking the stator, as the stator will either have the low current field winding or the P.M. field, in both case the source of the heat is from the armature, which in the majority of cases, is reduced by a forced air fan solution.
Al.

The majority of DC servo's are TENV, Totally Enclosed Non-Ventilated.
These are designed to run at their Continuous torque rating without further cooling.
Usually the characteristics of a servo is it will briefly run into peak torque, high inrush, and then will run at less than max continuous torque, so the mean current level will generally not overheat the motor.
Al.