Mystery plane with DC motor

[dylanbeaudette]

A friend gave us a sweet model recently, but it uses a (brushed) DC motor with a very narrow drive shaft. We attached a 3S LiPO and the motor seemed to run a little too fast. With a 2S battery it seemed a little less frantic. The geared drive was incredibly noisy, but after a cleanup and oiling it quoted down a little. Servos and ESC seem fine.

We’d like to get this plane in the air but can’t quite figure out an appropriate propeller and battery configuration. Any suggestions?

The propellor drive shaft is quite short at exactly 10mm; diameter is about 3mm.

 

[quorneng]

The Wattage IC 380AS is apparently good for 30A although I doubt the 350? brushed motor would last very long at that level of Amps.
It was probably intended for a 9.6 V (8s NiHM or NiCd).
Without a positive identification of the plane and its original prop size you really need a Watt meter so you can size the prop to draw a maximum of say 20A using a 2s LiPo.

 

[bisco]

or replace the motor/controller with something appropriate for the w/s and weight

 

[Tench745]

It looks to me like that gearbox is a little short in length to clear the cowling I'm picturing on this model. It might need a collet style prop adapter like some of our brushless motors take. https://www.amazon.com/dp/B000BOF104/?tag=lstir-20 (link is an example, not an endorsement)
Or, maybe a prop-saver type attachment. https://www.gravesrc.com/bp-hobbies-prop-saver-for-1-5mm-shaft.html

Any printing on the balsa or identifying marks anywhere to help identify it? I'd place the vintage as late 90's to mid 2000s based on that motor and ESC.

 

[dylanbeaudette]

Thanks for the advice. We decided to install a power pack B motor and ESC. After sawing off the old motor mount, we were able to mount the new motor with a spare firewall, hot glue, and some screws.
CG seems reasonable, right near the middle of the wing. With a 3s lipo and 10x4.5 prop it wants to leap out of my hand at 1/2 throttle. Maybe it will fly?

 

[RossFPV]

Thanks for the advice. We decided to install a power pack B motor and ESC. After sawing off the old motor mount, we were able to mount the new motor with a spare firewall, hot glue, and some screws.
CG seems reasonable, right near the middle of the wing. With a 3s lipo and 10x4.5 prop it wants to leap out of my hand at 1/2 throttle. Maybe it will fly?

View attachment 230105

Normally cg around a third of the way back on the wing, if the cg is in the center of the wing it may be tail heavy.

 

[bisco]

beautiful! i hope you have a successful maiden!

 

[dylanbeaudette]

Normally cg around a third of the way back on the wing, if the cg is in the center of the wing it may be tail heavy.

Thanks! At the point there is nothing else to slide foreword. Would adding some weight to the nose be a good idea? The plane is balsa and weighs about the same as our fully loaded Tutor.

 

[dylanbeaudette]

beautiful! i hope you have a successful maiden!

She is a cute little plane, but very different than any of the FT models we are familiar with. I’m a little concerned that a hard crash will shatter the balsa.

 

[RossFPV]

Thanks! At the point there is nothing else to slide foreword. Would adding some weight to the nose be a good idea? The plane is balsa and weighs about the same as our fully loaded Tutor.

I think adding nose weight is a good idea because a heavy plane is better than a crashed plane

 

[dylanbeaudette]

Well maiden wasn’t great, even after adding nose weight. She will make a fine decoration. Scrapping the electronics for a new FT model!