Epoxy filling method for brushless motors

I have 3D printed temporary casings with Water Soluble PVA (Polyvinyl alcohol) filament to assist in encapsulation of the motor windings and magnet housing for brushless motors with epoxy. These parts are slip fit and no post machining required. Some touchup required with brush. This PVA material is somewhat pliable and has a bit of give. This is in evaluation phase.  Water test to start next week 1/20.  Material list:
Epoxy West System 105 and 205 hardener (looking at different potting compounds)
Water Soluble PVA (Polyvinyl alcohol) filament http://www.matterhackers.com

Pins from Molex connector 1.14mm dia gold over nickel plate

Printer MakerBot Replicator 2 with standard setting @ 215 C extrusion temperature no support


Views: 2728


You need to be a member of OPENROV to add comments!


Comment by Matthew Valancy on May 4, 2014 at 7:36am

The motor bell? I think the magnets rust too but the motor core is the most important part, starting with replacing the bearings. 

Comment by Tom-Vidar Salangli on May 3, 2014 at 2:36pm

great job...I have a though...is it actually necessary to epoxy the outrunner part?

Comment by Tom-Vidar Salangli on May 3, 2014 at 9:33am

What is the inner and outer measurements of the original bearings to the motors in the V2.6 kit?
I am looking for bushings for the motors.

Comment by Matthew Valancy on April 15, 2014 at 9:59pm

For people following along with Marks motors there are two new related posts available here(part 3) and here(part 2 with video playlist).

Comment by Matthew Valancy on February 22, 2014 at 7:10pm

Just received my first 2 mark motors today and am upgrading an ROV with some pretty critical salt water motor damage. The top motor is altogether missing the bottom bearing and the prop is no longer removable. Hoping for the best with these after I get 1 more to be salt resistant and explore the kelp forests trouble free! 

Comment by Darcy Paulin on February 21, 2014 at 2:13am


Comment by Mark P on February 20, 2014 at 10:08pm

Two of the epoxy coated motors are still running.
230 hours of fresh water mixed speed operation reverse-stop-forward full motor speed. The teardown has shown galling present at front bearing surface at rear slight wear .001mm and retaining ring failure by corrosion.  The white paint was also having adhesion problems will omit next test.
The replacement 3mm stainless steel retaining rings have just arrived from Maryland Metrics.
Next run in salt water not to exceed ROV recommended RPM 1600 and also trying different epoxy. 

Comment by Mark P on February 10, 2014 at 2:26pm

The fit is controlled by holes size in support material nominal shaft clearance is approximately .005mm. Both bearnings have been replaced.  Planning on using one thrust washer at rear clip. Waiting on stainless steel clips.  

Comment by quantumquark on February 10, 2014 at 1:19pm


You mentioned using the Ingus bushing material.  How was the fit for the 

H370SM-0304-03 ?  And what did you use to replace the 3x8x4 bearing?

Are you using thrust washers as well? 

Comment by Michael Labonne on February 9, 2014 at 9:43am

I was thinking about replacing the metal bearings with 3D printed plastic. Just a simple friction bushing. The bearings corrode very quickly and ceramic bearings are several times more expensive than the motors, especially when bought in small quantities. I see you have a nice solution - Iglidur bushing inside a brass ring (the outer bushing). I was looking for the outer ring, but I didn't find anything with the outer diameter. Maybe I don't have the right dimensions... according to my measurements, the first metal bearing is 7 x 2 mm and the other is 8 x 3 mm. Am I correct?

© 2015   Created by Eric Stackpole.   Powered by

Badges  |  Report an Issue  |  Terms of Service