Wire Drive Experiment

[dr gary turner]

Thanks

 

[PaulHail]

No reason to scratch build a collet when you can get precision ground collets from machinery supply houses at quite reasonable cost. A DA300 or ER 11 would be about the right size, just need to machine a body to screw onto the crankshaft.

 

[RaceMechaniX]

we are using DR11/ER11 collets for the new couplers.

 

[longballlumber]

we are using DR11/ER11 collets for the new couplers.

Tyler, are the other parts commercially available? The threaded motor side and the capture nut?

 

[RaceMechaniX]

Not yet Mike, the smooth bore ones are available for electric motor and I am testing tapered couplers for gas motors, but still working on the Nitro versions.

 

[Christian Lucas]

Hi,
we have used wire drive since over 45 years. We Hans Lehner and i, start wire drive when i was 18 years old. We see the first who used such drive by British Daniel Holder under 1 kg speed boat. He used this 1mm pianowire to drive the full submerged propeller. The motor has a hole wher the wire was klamped by a grub screw and he used a small propschaft bearing strut holder in front and one strut after the propeller. The propeller hub has a hole and also a grub screw to fix it , a little flat made by a rund diamond file give the spot to get better grip. We messured such drives witch run in small brass tubes with plenty gap of 0,2mm The brass tube was 2mm outer dia and 1,2mm inside hole for the 1mm pianowire. This dirves are the most efficancy drives that we need with electric drives at this time as every watt count. This was good for about 1000 watt.For higher power we rise dia, at last for the under 1 kg boats we run 1,2 mm wire in a 1,5 mm brass tube. For the bigger boats i run up to 3000 watt a 2mm wire in w 2,2 mm brass tube and over such power i use 3mm wire but then with very slittly bend. And with the 3 mm wire i use a carbon tube with insert no swirrl brass ring. This are short brass tube pices that have a hole gap of 0,2 - 0,3 mm and are place by looking where the most sinus wave output will occer. I notice such the the tethered line boats used such brass no swirrl bearing they glue inside a rubber pice they can easy slide for and back to find the best position to prevent the wire from swirrl acction. The German Jag´s team use a very precision made cuppling made by Jürgen Zander. This look like a very easy , but very precision drilled hole in an aluminium rund part one front sided has the motor shaft dia and other side has the pianiwire dia . On both frontside it has a small slot and on every side it has two setscrew to presfit the shaft and the wire. The have a lot of such cupplings as the use allways a extra one for 1 hundredt of a millimeter diverent wire size. So all has exactly to fit to get the most surface to get in contact together. This run up to 18 kilowatt at 70000 rpm with a 2,5mm pianowire. For the secure in the propshaft i do not know exactly but as i know they drill a precision hole over the full lengh of the shaft and than clean both parts realy best and glue the parts toghter with Loctite anerobe 648 or better super high fixing glue.No flat spot or other on the wire .
In the 1990 we run a 10 minutes endurance race boat with surface propeller that used a spezial way of wire drive a very thin 0,8mm wire that drove a Octura X467 propeller at about 1200 watt and 10000 rpm. To handle the power of such thin wire we bend a short par at the end of the wire 90 degree that fit in a grove inside the couping and using an insert that hold the wire inside the cuppling . With a smart start contoller to limit the torque it handles the power with no problem .
An othe way to fix a wire in a propshaft was,
Insert the spring steel wire through the hole in the propeller shaft so that it protrudes a little to the rear and tap the wire with a hammer on the spring steel wire on an anvil. Then drive the wire back into the hole in the propeller shaft with a hammer. This results in a very strong torque connection.No glue ore solder needed. I never solder pianowire and if only soft solder with low temperature use. Hard silver solder will make the pianowire brittle after cooling in air and it will breake easy like glas. This is the reason many soldered wire break short to the propshaft or motor cuppling.
Hope it helps , combustion motor need allways a little moore dia than electric motors .

Happy Amps Christian

 

[Andrew Coppolino]

I have been using wire drive in my gas rigger now for a couple of years that I got from Brent Byers
I picked up an extra 500 rpm or so over the conventional shaft
Highly recommended