Guys,
I have been a fan of front mount motors since I started with electric. Several friends have used rear mount and find they are just a good as the front mount and much easier to change props (no shaft slippage when tightening). I am thing about switching my S1 over and wondering how others have done the rear mount on a profile fuse ships?

Best,   DennisT

I've done both. It isn't worth changing an existing installation IMO. Both have advantages and disadvantages. The biggest advantage of front mount is that moderate crashes tend to just bend the motor shaft. A new shaft and front bearing fixes it. Rear mount exposes the bell to impact and if the bell takes the hit it can render the motor trash if the bell gets bent. The ringmaster has a pretty good shnog out front and may protect it. Rear mount is probably a better cooling choice in a profile and front better in a full fuse. Most motors want to airflow from the stator to the end of the bell. The ports on the end of the bell act as a centrifugal pump. That pumping action is weak though and can be overcome though. For a full fuse and front mount, the incoming air naturally pumps the motor in its preferred direction. Rear mount the air has to either overcome the basic pumping action or enter the cowl and reverse direction. As long as there is enough air coming in and passing through, those details aren't truly that significant. A profile airplane the motor is usually exposed and there is plenty of air for cooling. 

I make that decision based upon how motivated I am. A simple Square piece of 1/4 plywood is enough to hold the motor and a bamboo skewer used as a pin through the mount is sufficient to hold the motor. That generally takes around 30 minutes if it includes band sawing out the front of the airplane. The mount is an existing part in my laser so that is a minimal effort. Front mounting is a bit more complicated and needs a few more steps. I have boxes and stuff for them as well. With all the parts handy the front mount takes about an hour. Ultimately its more about what you like. I do both.

My PathFinder seems happy.
I 3D printed the mount.

Quote from: Paul Taylor on September 06, 2026, 01:45:27 PMMy PathFinder seems happy.
I 3D printed the mount.

That's pretty slick. My Pathfinder was done rear mount as well. The motor was destroyed in the crash and front mount may not have faired much better as hard as it hit. The mount bearer for the engine will likely help in the event that there is ground strike. What material did you use Paul?

Hey Mark,
Sometimes you win, sometimes you lose.

Its PETG+

I've used PETG for mounts. It's a bit marginal temperature wise. Keep your eye on it. As long as the motor isn't pushed hard it can work.

Well most of the mounts Tom Morris use to sell were all PLA.
PETG+ is a lot stronger and heat resistant and it's better at 60-70 % infill rather than 100%.
And my mounts utilize the aluminum bracket that comes with the motor and it dissipates the heat better.

The one in this plane is a copy of the one that Lucian's sells at Innov8te.

This is my front mount utilizing the aluminum mount.

Quote from: Paul Taylor on September 06, 2026, 04:28:51 PMWell most of the mounts Tom Morris use to sell were all PLA.
PETG+ is a lot stronger and heat resistant and it's better at 60-70 % infill rather than 100%.
And my mounts utilize the aluminum bracket that comes with the motor and it dissipates the heat better.

The one in this plane is a copy of the one that Lucian's sells at Innov8te.

Tom's mounts were PC polycarbonate. At least the ones I have are. I used to make most of mine with PC. I glues very nicely. I also use Nylon X or PA (nylon) but nylon doesn't glue very well. PLA won't stand up to the temperatures. PLA is actually stronger than PETG until it get warm. Your mount design looks like it will work with PETG. I like it.

Paul,
Nice mount design for both. On the rear mount how are you installing it to the fuse? I have seen a design that clips around the fuse sides and is glue there with a bolt or screw in the center to a hardwood cross member with angle gussets on the back (kinda like the old 1/2A mounts). Also seen "L" clips with bolts through the fuse and an "X" mount on them (with cooling holes drilled in the clips to match the X mount).

Best, DennisT

On the Pathfinder I attached it to a plywood "firewall" like it's done on a RC plane. If my memory serves me correctly I put a small piece of hardwood between the doublers and put a small wood screw in it. Epoxy too. I also printed a small angle bracket for my grandsons 1/2a. I'll post a picture of it also.

1/2a on a Ron Burns Spitfire.

Here is my front mount. Using the aluminum mount that comes with all motors I mount that in the 3D printed part. It provides more cooling and heat dissipation as compared to a solid material. Part is lighter too. It should out live the balsa parts in a landfill.

Plywood, balsa, and fiberglass makes a strong, clean motor mount, unless you have a need to utilize 3D printing.  Plastic mounts still need some structure to screw onto.
This leaves the option of adding shim plates and longer bolts to adjust the balance.

Paul,
Very nice. That was what I was thinking (the first or last photo). I'm thinking one could use some thicker strip brass (K&S stock) to make "L" clips that bolt through the fuse with the "X" mount bolted to it. Might add a shim piece to adjust the motor offset (I like 3 - 4 deg) or just take the time to bend it in when making the clips, might need to add hardwood dowels through the fuse at the bolt mount points to prevent crushing. Thanks for the photos!!

Best,   DennisT

Roger Kramar's Pathfinder demonstrates a very clean rear mount method. It's light. His fiberglass cowl shells give a very finished look.

Quote from: Dennis Toth on September 08, 2026, 10:29:55 AMPaul,
Very nice. That was what I was thinking (the first or last photo). I'm thinking one could use some thicker strip brass (K&S stock) to make "L" clips that bolt through the fuse with the "X" mount bolted to it. Might add a shim piece to adjust the motor offset (I like 3 - 4 deg) or just take the time to bend it in when making the clips, might need to add hardwood dowels through the fuse at the bolt mount points to prevent crushing. Thanks for the photos!!

Best,   DennisT

I put one washer under the x mount to give motor offset. What ever method to hold on the wood firewall. Glue and a screw works for me. If it comes out it's because I drove it into the ground.

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