I am taking the first tentative steps looking to build an electric glider launching winch.
First thing is get an idea of a few affordable motor/controller combos.
A glider winch typically has used something like a 6 - 7+ liter V8 through an auto gearbox to a truck diff with a cable drum on one or both ends. Usually the diff is welded locked. Power in decent winches is around minimum 180kW+ (250hp).
To give an idea, a stock Ford 351 cu in (5.8 L) V8 is underpowered. It launches light gliders OK, is adequate with modest two seaters in reasonable conditions, but is run absolutely flat out to achieve that. With a modern fully laden high performance two-seater it is completely inadequate.That all points to:
A stock 455 cu in (7.5 L) V8 is sufficient, but is probably maxed out with a heavy glider.
Heat can be an issue. With an efficient system and crew you can launch a glider every few minutes. Motor basically goes 35 seconds full power, couple of minutes cooling, then full power again. Usually on a hot summer day. Basically a drag race every few minutes.
A lighter single seat glider achieves flying speed (75-80 kmh) within low 10's of meters and is established on climb at over 100kmh in a few seconds.
The bottom line is you need to lift an up to 800kg glider 600m high in about 35-40 seconds.
My target is:
Cable speeds up to 100 kmh (28 m/s).
Cable tension up to 800 kgf at Max speed.
Drums benefit from being large & narrow (less growth in diameter as cable winds in, & easy self level winding). A fairly typical narrow drum might be around 800mm dia core.
That all points to:
Power: 220 kW
Shaft torque: 3100 N.m
RPM: 670
To give some ideas:
German guidelines require minimum 180kW.
A very nice looking (spare no expense) winch under development at present is using a BorgWarner HVH 250-115 (330 kW, 409Nm) motor.
A commercially available unit quotes peak power at 205kW
A club in Denmark with experience building a good performing ICE winch previously is in the process of building a winch using a Tesla S motor and Y battery.
While weight and size are considerations, I could probably cope with a motor up to say 250kg, so maybe industrial motors are another option, although when I look at induction motors in that power they are HUGE! I've also no idea about cost effectively controlling them.
Currently I'm inclined to think the Tesla S LDU is the most appropriate option. Sufficient power, reasonably available, not stupidly large or expensive, includes the inverter, OpenInverter provides a likely sensible route to controlling it.
Only real downside I can see so far is that it will still need a second reduction drive to get to the required RPM/torque.
Any comments and suggestions that might clarify my thinking welcomed.
First thing is get an idea of a few affordable motor/controller combos.
A glider winch typically has used something like a 6 - 7+ liter V8 through an auto gearbox to a truck diff with a cable drum on one or both ends. Usually the diff is welded locked. Power in decent winches is around minimum 180kW+ (250hp).
To give an idea, a stock Ford 351 cu in (5.8 L) V8 is underpowered. It launches light gliders OK, is adequate with modest two seaters in reasonable conditions, but is run absolutely flat out to achieve that. With a modern fully laden high performance two-seater it is completely inadequate.That all points to:
A stock 455 cu in (7.5 L) V8 is sufficient, but is probably maxed out with a heavy glider.
Heat can be an issue. With an efficient system and crew you can launch a glider every few minutes. Motor basically goes 35 seconds full power, couple of minutes cooling, then full power again. Usually on a hot summer day. Basically a drag race every few minutes.
A lighter single seat glider achieves flying speed (75-80 kmh) within low 10's of meters and is established on climb at over 100kmh in a few seconds.
The bottom line is you need to lift an up to 800kg glider 600m high in about 35-40 seconds.
My target is:
Cable speeds up to 100 kmh (28 m/s).
Cable tension up to 800 kgf at Max speed.
Drums benefit from being large & narrow (less growth in diameter as cable winds in, & easy self level winding). A fairly typical narrow drum might be around 800mm dia core.
That all points to:
Power: 220 kW
Shaft torque: 3100 N.m
RPM: 670
To give some ideas:
German guidelines require minimum 180kW.
A very nice looking (spare no expense) winch under development at present is using a BorgWarner HVH 250-115 (330 kW, 409Nm) motor.
A commercially available unit quotes peak power at 205kW
A club in Denmark with experience building a good performing ICE winch previously is in the process of building a winch using a Tesla S motor and Y battery.
While weight and size are considerations, I could probably cope with a motor up to say 250kg, so maybe industrial motors are another option, although when I look at induction motors in that power they are HUGE! I've also no idea about cost effectively controlling them.
Currently I'm inclined to think the Tesla S LDU is the most appropriate option. Sufficient power, reasonably available, not stupidly large or expensive, includes the inverter, OpenInverter provides a likely sensible route to controlling it.
Only real downside I can see so far is that it will still need a second reduction drive to get to the required RPM/torque.
Any comments and suggestions that might clarify my thinking welcomed.
