logo Heading




























































































How To Convert A Diesel Free Flight Vintage Model To Brushless.

This is very simple and quite easy to do.

Here we have a Tomboy model that used to fly on a Mills .75 diesel.

1. Remove diesel engine and mounting bolts.

Nose section

2. Use a Perma-Grit tool and sand off the nose to make a new end face.


3. Sand a couple of degrees of right thrust into the new face and you should end up with something looking like this.

Right Thrust

4. The picture below shows what the nose looks like after being faced off with the Perma- Grit tool.

Face Off

5. Drill two holes into the original beech engine bearers as shown. An oversized piece of scrap light ply should now be screwed into the face end beech bearers using 2 wood screws.

6. Roughly carve and sand a new light ply nose plate in situ on the model. Here is a top view.

Top View

Another view of the new nose and motor mount plate after carving.

Another view

Rear view

Rear View

7. Screw the new nose plate and brushless motor mount onto the front of the model.

New nose plate

8. Drill a couple of access holes in the fuselage for the Peterborough Fet timer and ESC speed controller wiring and it is all finished.

My brushless motor set up consists of a cheap 10 gram outrunner from Micron, a 5x3 APC propeller and a 2 cell 450 mA lipo stuffed securely into the engine bay where the Mills used to be.

Fet timer position shown underneath model.

Access Holes

This picture shows a home made ESC controller on the side as I like building my own circuits.

For those new to brushless electric flight you could of course just buy the readily available KP brushless timer from SAMS Models or KP aero and it will work.

Tomboy flies consistently well in left hand circles followed by a smooth left handed glide.

Home made ESC controller

The finished model.

Should I ever to revert to diesel again all I need do is remove 2 woodscrews holding the brushless light ply mount, remove the battery and then reinstate the Mills engine.


For details of the brushless wiring circuit used in this Tomboy click the following link:- Peterborough Model Flying Club technical article dated August 2011 at the club website.

Click for details of KP timer.(It is a .pdf file).

It is also here at SAMS models.

Ted Szklaruk
Peterborough Model Flying Club

February 2012