I wonder if this HobbyKing geared starter motor could be used as the basis for a small glider winch:
https://www.hobbyking.com/hobbyking/s...dProduct=16197

Neil.

I flew with a crazy smart guy years ago who built a hand launch sized winch from a cheapo speed 600 motor. Worked like a charm too! He said he had considered using a starter motor but had the 600 laying around the house.

The problem with geared winch motors is that much more line tension is needed to pull the chute back for the next launch.

Hi Neil,

How small of a glider?

Some of the things that go into the formula for a winch motor include the size of the line drum (both in terms of mass and the diameter of the spool portion that the line winds up on), the RPM of the drum, how long the line is going to be, how many amps will the motor draw versus how many amps do you have feeding into it, and how much line tension will the motor have to pull against without stalling.

I'm going to venture to say that this starter motor is geared so that it can turn the larger nitro and smaller gas powered engines. Without knowing the gear ratio, I'm going to say that you may not have enough RPM to tow a plane, but that depends on the other factors above. I don't know how much experience you may have with a launch winch, but it does take a lot of power from the motor to get a good launch. Here in the U.S., it is not uncommon for the Ford Longshaft motor to pull over 600-amps during a launch, and this motor originated in Ford trucks. Despite this massive amount of power, there are more than a few guys out there who can stall one out.

There was a nice, compact winch out there, I think called the little big winch, or something like that, and it was nice, but not real powerful. You would get a decent launch and it was dependable, but nothing like a competition type ping off the line.

Mike L

...

I've got this "really mini winch" which has two 1/5 hp motors.. It will pull up a Bubble Dancer or AVA, but it could use more, since the Super AVA will almost stall it.... I used 100 yards of braided string attached to 100 yards of 130 lb. mono filament... To launch, you tighten up the line, then stretch the mono filament until you can't hold it... Then release... The motors are running 4,000 rpm (unloaded)...
Cheers,
JR

If you were using a geared motor, perhaps you could incorporate a clutch of drive pin to use when pulling it back out.

Originally Posted by superskeg

https://www.rcgroups.com/forums/show...8&postcount=59

Does anyone know the details?

I have photos somewhere of a mini winch made from an aircraft starter motor. I'll try to dig them out.

I've never used a winch, so sorry for the newbie question, but why is this a problem?

Neil.

Originally Posted by rogerflies

The problem with geared winch motors is that much more line tension is needed to pull the chute back for the next launch.

Hi Mike,

I have DLGs up to a 4m Hyper AVA. All electric apart from the DLGs, but I would like to try flying the larger models as pure gliders (with new fuses of course). Also I have an old Graupner Cirrus 3m, which I would rebuild if I could be sure I could launch it.

I lot of things that you mention in your design parameters could be fixed by changing the voltage and/or drum diameter. I guess the motor could operate at a higher voltage than HobbyKing are recommending. Also if necessary the brushed motor could be changed for a brushless. The real value is in the belt reduction drive.

In order to design a winch I guess the two main parameters are
a) No load wind-in velocity.
b) Stalled max pull.

Do you have any numbers you can share for these?

TIA,

Neil.

Originally Posted by mlee8249

Hi Neil,

How small of a glider?

Some of the things that go into the formula for a winch motor include the size of the line drum (both in terms of mass and the diameter of the spool portion that the line winds up on), the RPM of the drum, how long the line is going to be, how many amps will the motor draw versus how many amps do you have feeding into it, and how much line tension will the motor have to pull against without stalling.

I'm going to venture to say that this starter motor is geared so that it can turn the larger nitro and smaller gas powered engines. Without knowing the gear ratio, I'm going to say that you may not have enough RPM to tow a plane, but that depends on the other factors above. I don't know how much experience you may have with a launch winch, but it does take a lot of power from the motor to get a good launch. Here in the U.S., it is not uncommon for the Ford Longshaft motor to pull over 600-amps during a launch, and this motor originated in Ford trucks. Despite this massive amount of power, there are more than a few guys out there who can stall one out.

There was a nice, compact winch out there, I think called the little big winch, or something like that, and it was nice, but not real powerful. You would get a decent launch and it was dependable, but nothing like a competition type ping off the line.

Mike L

page 14 January 2003 RCSD has winch made from a model starter motor.
http://www.rcsoaringdigest.com/pdfs/...SD-2003-01.pdf

Originally Posted by mhodgson

page 14 January 2003 RCSD has winch made from a model starter motor.
http://www.rcsoaringdigest.com/pdfs/...SD-2003-01.pdf

Thanks, that is very interesting.

Neil.

The gear reduction starter has a low-torque motor running at high speed turning the output at low speed with more torque. The motor has a certain amount of drag because of the brushes and bearings.

When you pull the chute back, the winch drum will be turning at a moderate speed, but the motor will be turning much faster. The torque and the line tension will be pretty high to overcome the brush and bearing drag of the motor.

You'll also have to overcome the inertia of the motor armature, which will also be multiplied by the gear train. That will make the retrieve very "jerky" as the motor accelerates and slows down.

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