RC Boat Motor Mount

Want plans for this project? Get them at the Plan Store.

RC boat motor mount

An RC boat motor can be mounted in as many ways as there are model boat builders. I've seen everything from a glob of hot-melt glue to slick and colorful anodized aluminum brackets to hold that power plant.

Personally, I've always been in favor of a simple solution that gets the job done. That's not to say I'd glue my motors into my boats. I do appreciate the option to be able to remove or replace the motor easily, if need be.

Surplus Mabuchi RE-280 to the left and Aristo-Craft RE-280 with a simple motor mount to the right.
photo of rc boat motor options - surplus motor vs aristo craft

Another thing to note is that I don't build high performance boats, so copy my rubber-band mount for your Mega Power output brushless motor at your own peril.

My two favorite mounts are:

  • A homemade motor bed with the motor held in place with a rubber band.
  • A commercial but inexpensive motor bracket that can be bolted down from the top

I don't like face mounting my motors. Most RC boats have a direct-drive where the motor face is pointing down towards the bilge at a shallow angle. It makes it very difficult to access the screws and almost impossible to see what you're doing if you need to remove or reattach the motor.

A scratch built motor mount installed in the RC cabin cruiser prototype. Installing the motor before the bottom was planked made alignment a lot easier.
photo of rc boat motor mount after installation

For the prototype RC Cabin Cruiser I built, I ended up making the motor mount from scratch. If I had to do it over again, I'd get the Aristo-Craft motor with the simple, but perfectly adequate motor mount included. I would have made a simple flat piece of 1/8" (3mm) plywood with a cut-out for the keel spanning between bulkhead 2 & 3 for the mount to sit on.

Motor Coupling Efficiency

Between the motor and propeller shaft a compliant coupling should be used. There are several different commercial types, but my three favorites are (from low to high torque):

  • A piece of silicone rubber tubing
  • A rubber coupling with metal inserts in each end
  • Universal joint

One of the most overlooked aspects when installing a motor in a model boat is the alignment of the motor and propeller shaft. Too many builders believe that because a compliant coupling is used having an angle between the two shafts is OK. This is a misunderstanding.

Proper alignment between the motor and propeller shaft is paramount in model boat building. Note the scratch-built motor mount.
photo of rc boat motor mount after installation

The purpose of the compliant coupling is to relieve the motor from strain and side loads due to misalignment. No motor installation is perfect, so the misalignment that does occur should be kept to a minimum.

A model boat with a misaligned motor will suffer unnecessary power loss and shorted life of the motor and coupling. The more power the motor generates the more important the alignment becomes. That means:

The bigger the boat, the more important alignment becomes

In effect, most effected motor types are: high performance brushed motors, all brushless and gas motors

Secure Motor Mounting

Just as important as the coupling is making sure the motor is mounted securely. If the motor can wiggle loose, the wires may get twisted and break or short out.

A homemade motor mount for the RC cabin cruiser.
photo of rc boat motor mount before installation

The reason I like rubber bands for small motors is that they have high friction against the motor can and prevent the motor from twisting. They also are compliant and hold the motor with spring pressure. Compliance helps dampen shock loads and is very resilient to vibrations compared to a more positive type of mounting.

Return to Simple RC Model Boats

Return from RC Boat Motor Mount to Homepage

Share this page:
Enjoy this page? Please pay it forward. Here's how...

Would you prefer to share this page with others by linking to it?

  1. Click on the HTML link code below.
  2. Copy and paste it, adding a note of your own, into your blog, a Web page, forums, a blog comment, your Facebook account, or anywhere that someone would find this page valuable.
model boat plans store thumbnail image