3X13mm

[Stewart32]

Anybody make a 3X13mm motor mount for a BT55?

Thanks

 

[Elapid]

what RU making?

 

[phaar]

Most likely not. But, you can definately get them made custom.

 

[Fore Check]

I don't know - but I have an idea.

If you stack your three motor tubes together (glued to each other) you have a cluster diameter of 1.172" (per RockSim). The inside diameter of a BT55 coupler is 1.212 (per BMS and Totally Tubular catalogs.) That leaves a gap of 0.02" between the motor tube and the coupler if the tubes are mounted within the coupler.


So, I'd assemble the motor mount like a scaled down Astron Cobra of Richter Recker (no centering rings.) I'd put a 1.5 - 2" piece of BT55 coupler in the airframe. Then I'd put on a nice layer of epoxy inside the BT55 coupler, and slide the motor tubes in. The epoxy *should* fill in and make up that 0.02" on the outsides of the tubes. Then fill in the gaps using glue-soaked wadding (again, like the Cobra or Richter Recker.)

If you aren't liking the epoxy to fill that 0.02" between the inside of the coupler and the motor tubes, here's an alternate solution.

0.02" is approximately the thickness of a BT55 tube. You could take a piece of BT55 tube the same lengthe of the coupler you'll be using, take about a 1/4" wide slice out of it *lengthwise* so you can squeeze it down to a smaller diameter, and glue this tube inside the coupler. Then slide the motor tubes inside the whole shootin' match for a nice snug fit (just make sure that one of the three contact points for the motor tubes is *not* the same spot where the lengthwise slice was taken out of it.

 

[sandman]

You don't really need a pre-made mount.

Just make 3 13mm motor tubes (2" lengths of BT-5's) with bulkheads and engine hooks (if desired) and glue them together.

After the glue drys on your "cluster" wrap the assembly with about two wraps of masking tape and check the fit in a BT-55 tube coupler. It should be pretty close. Glue it into the coupler.

Glue the assembly into place. You can then Fifl in the gaps between the motor tubes with tissue soaked in glue. you're all set.

sandman

 

[Stewart32]

Yeah...

after a bit of research I have decided that Gorilla glue will fill in the gaps nicely


Thanks guys

 

[Stewart32]

I want to take a Custom Satelite Drone and modify it to take 3X13mm motors. I'm looking for a slow and majestic take off.

I think this model has a BT55 sized fueslage...but it may be BT60.

 

[rabidsheeep]

be careful about gorilla glue... the stuff expands quite a bit

 

[bsexton]

Originally posted by sandman
You don't really need a pre-made mount.

Just make 3 13mm motor tubes (2" lengths of BT-5's) with bulkheads and engine hooks (if desired) and glue them together.

After the glue drys on your "cluster" wrap the assembly with about two wraps of masking tape and check the fit in a BT-55 tube coupler. It should be pretty close. Glue it into the coupler.

Glue the assembly into place. You can then Fifl in the gaps between the motor tubes with tissue soaked in glue. you're all set.

sandman

Now where have I heard that before? Oh yeah, the Mini Astron Cobra...and it works great!