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[Edward Pinniger]

I picked up these 3 motors on a sales stand last month - I'd no idea what they were at the time, but they were cheap, about the right size (I thought) for a couple of my projects, and looked good quality! After doing some web searches, I found that they're produced by the Swiss company Portescap (the name printed on the motor is "Escap"). These appear to be very high quality, expensive motors and are popular for model railway locomotives, though I couldn't find any reference to them being used in model boats.

The motors I have (photos below) are a pair of 26s and a 28 (the latter is the one with wires attached) - the numbers refer to the motor's diameter in mm, all 3 are a bit over 40mm long. They are brushed motors (Portescap also make brushless ones, but these look quite different) but run extremely smoothly, especially the 28.

My questions - to anyone here who's more familiar with this brand of motor - are:

- Are these motors suitable for use in R/C model boats - if so, what type? ((fast electric, slower scale boats, tugs, etc.). I'd imagine they'd be quite effective in a tug, with high torque and smooth running at low speeds, but this is just a guess.
- If so, what battery voltage and ESC type would be the optimum for one of these motors (or two of the 26 type)?
- Do they need suppressor capacitors to be fitted? (The casing appears to be stainless steel, which is quite difficult to solder to)

[stallspeed]

Most likely they are coreless motors which are popular for locos due to the smooth running at low speed.
You can tell coreless and motors with laminated iron cores apart by the lack of cogging on hand cranking.
Coreless motors are not noted for high torque but the characteristic you can benefit from is the high efficiency peak.

The down side is coreless brush gear is optimised for low friction which means it is less rugged and you particularly want to avoid brush arcing on metal brushed types.The higher the esc frequency,the less brush arcing you get but the ideal for coreless is in the region of 50kHz or more anyway.

The best application in boats is where you are not pushed for weight or space and you only prop them such that they are only light loaded and they run at their efficiency peak.

Just forget about soldering to the motor case.Should you get data on the motors,the nominal voltage may turn out to be 24v or 36v.

[andrewh]

Edward,

I do not have the data on these specific motors, but yes, they are coreless.  They are used for servos and very high quality industrial and instrumentation drives  - motors like this move the Mars lander.

So:  Do not ever run them unloaded to high speeds.  This is generally terminal on a coreless because the windings are a thin cylinder of rotor windings in the form of a cylinder and if spun too fast they bulge under centrifugal force and kiss the magnets.

And as stallspeed says they will have low friction low current brushgear - often gold-plated fingers.
So fabulous quality, but use them for light loads or high gear ratios
andrew

[Edward Pinniger]

Thanks for the advice. If these motors are intended for very light loads and are also quite sensitive/easily damaged then it looks like they're probably not much use to me, most of my current and future projects will be fine with standard 545/550-type motors, or 385s for the smaller ones. I am looking for a low-speed/geared motor suitable for a paddle steamer, and a high-torque model suitable for a tug (for when I get round to upgrading my Dickie/Seaport tug with proper radio) - but it looks like the Portescap motors aren't suitable for either. I'm also not very experienced or knowledgeable at setting up props, shafts etc. for optimum efficiency - generally, as long as the model runs at a reasonable scale speed, and has no problems with motor overheating, battery life etc., then I'm happy!

Looks like my best option with these would be to sell them on eBay and put the money towards some more usable motors/components. I suspect I'll end up wrecking them if I attempt to use them in any of my models. I didn't pay much for them in the first place (and I bought a number of more practical 540- and 385-type motors in the same lot), so it's not any great disappointment.

[stallspeed]

Edward,I think you are reading more information in the replies than has been given.
They may actually be superior replacements for 385 motors.

[malcolmfrary]

If you just figure out if they are happy at your chosen voltage, they will work fine.  Smooth, very reliable starting.  Looking at the size, probably a very superior 385.  For suppression, a 470pF across the motor terminals will do the job - with the quality of engineering in there, the other capacitors to the case will not be needed.  Mount the capacitor close, but do not trim its legs - use these as wiring terminals and remember to twist the motor wires as a pair.

[Edward Pinniger]

What's the maximum size of model the Escap 26s would be "safe" in? Would they be OK in a 1/96 destroyer (about 3" long) driving a 30-35mm prop each (and run at scale speeds only) or is this too big/heavy?