Piano wire drive

[dahodevil]

Anyone have any suggestions on piano wire drives. I'm building a small rigger with a 110 watt motor and trying to decide on .062 wire drive or .098 flex. I have no experience with wire drives but I know I will need as little resistance in the shaft as possible. How should the wire be supported? Is it worth the trouble?
David

[Jeff Wohlt]

Forget the 098. Yes wire is the way to go on a rigger. I have 1/8" shaft now with 062 and 3/16 prop shafts with 062 or 078. Go with a 062 with 1/8" prop stub for smaller props.

[Jeff Wohlt]

The 1/8" shaft will be on my site shortly if you want to order one.


Forget the 098. Yes wire is the way to go on a rigger. I have 1/8" shaft now with 062 and 3/16 prop shafts with 062 or 078. Go with a 062 with 1/8" prop stub for smaller props.

[dahodevil]

Jeff'
Could you suggest a strut for the wire drive and some props to go with it. Also, how do I secure the wire,(stuffing tube?) I need all the parts except rudder. This is a homemade 16" rigger. 1/8" motor shaft.
Thanks David

[Jeff Wohlt]

I think I have one mini strut left for 1/8" shafts. Props? I would get some plastic ones to try out first. Octura has some or maybe Steven does on this site. See how it goes then get an Octura 432 or one of those and dial it in. Will never know until you check heat and get her set up right first. You may be able to go with 435 or even a 632 once you get it set up right. you can email me at [email protected] if you want more info.

[NativePaul]

In the Naviga Mini Hydro class we have around 140W average to play with, my boat before last had a .98" flex in it and I ran it for approx 4 years (3 sport, 1 race) without ever breaking it, I built a new boat for racing and put a 1.2mm /.047" wire in it and raced that for 2 years without breaking it, I now run a .130" cable as it is what came with the minisprint I have been running for the last year but it is way heavier than it needs to be (both the hull and the drive), and I am in the process of building a new lighter boat along the same lines which will have another 1.2mm/.047"wire. There is not that much harm in it as it will still be a heck of a lot lighter than a .098" flex, but to my mind 1.6mm/.062" wire is needlessly big for minis with such little power, I use it up to around 1KW average.

You have not supplied enough information for us to give you any meaningful suggestions as to props, we need to know the KV of the motor and the voltage/cell count you will be running to get a safe prop, and the capacity of the cells and the run time you want to get in order to get it close to what you want.

[dahodevil]

Thanks Nativepaul, That is the info I was looking for. Where do you get .047 wire drive from and what kind of stuffing tube do you use? What props to start with? (110watt 1080 kv on 3s.) What speeds might I get?

[NativePaul]

A friend with a machine shop made me the .47 wire drive, Jeff who posted above may be willing to make you one (or maybe not as I was told it was a PITA compared to bigger sizes), for a stuffing tube I use a brass tube just as I would use for a flex (but of much smaller diameter to suit the wire), and instead of having the stuffing tube the full length of the flex for a wire you just put a short length in where it goes through the hull, leave just enough on the inside to slip a piece of silicone tube over to seal it. Its the stuffing tube that really saves the weight over a flex so if you cant get or make a .47" one get don't be afraid of a .62", while heavier than you need it will still be much lighter than the alternative.

I hate to be a bearer of bad news but that motor is a long way from being optimal, on 3s we normally run around 3000kv with 27-32mm props, I would guess with 1000kv you would be looking at 45-50mm, we were seeing speeds in the high 20s set up for oval racing when we had 110w, but I would be surprised if prop walk or torque roll did not limit the power you can put down with a little boat and a prop that size.

[Jeff Wohlt]

Yes...the 047 wire is easy to make...a good coupler is not. I can do it but hate them so I gave up on that. 062 is easy and small.