What overall length 2.5mm (.098) wire drives would you like to see?

[CornelP]

Hi guys,

Wires are almost standard here in Europe, you rarely see a flex in a racing boat, with the exception of some small eco boats. Two of the suppliers I found for stub shaft material are:

http://www.rigamonti-obr.it/index.php/en/tubes/tubes-inox.html

and

http://www.motionco.co.uk/shafts-c-29.html

Rigamonti produces a stainless tube (4mmODx2mmID) that is very good for the small applications (mono1, mini mono) or the larger 5 and 6mm OD. The big advantage is the full length bore: very strong bond to the wire.
I am sure you can find an equivalent producer in the US, mainly in the medical sector.

Talking about wire support, we did some calculations and we found that a teflon bearing (just a 10mm piece of teflon tube with the ID 0.1 larger than the wire) placed at every 80mm for the 2mm wire or 90-95 for the 2.5mm will eliminate the whipping tendency. I use a 4mmODx2.2mmID teflon tube that I cut to size for the support bearing and a 4mmODx3mmID as a spacer in the tube.

Cornel

[RaceMechaniX]

Thanks Cornell.

What are people using on the motor side? MBP collet or the simple set screw sleeve couplers?

[CornelP]

Probably over 90% are using the MBP collet, it's an elegant and smart solution. The only drawback is that if you use it once without tightening enough on the wire end you can throw it away... it will never grip properly.
Normal couplers are used in Mini classes or small eco where they go down to 1-1.2mm wire and you have a lack of space.

Cornel

[NativePaul]

Although I am not in the market, I voted for 24" as the 2.5mm wire in my P sized JAE is roughly 20" of wire and 23" overall, I like a forward mounted motor and a gentle bend with wires. Here in the UK nearly all monos run straight or very nearly straight wires with the motor in the step, but most hydros run flexies, the ETTI collet couplers are probably the most popular for both, though I prefer old fashioned set screws and flat spots for wires as they don't get chewed up by the screws the way flexies do.

[RaceMechaniX]

Cornel, I have used the MBP collets with some success but as you say one slip and you throw it out. With the power I am putting to a 2.5mm wire, the MBP collets do not hold up and slip often. I have been drilling and tapping the old collets after they slip to pinch with set-screws in addition to the normal squeeze. Still it is problematic. I also add flat spots to the cable.

Tyler

[jwohlt]

Tyler, sure I make shafts longer and almost any size. I understand the coupler situation. I have used many and have drilled a few of the mvp or whatever they call it. Good coupler but very expensive. I also use TFL couplers and drill them to fit the wire such as 093 and they have worked well. One thing I do like about Octura is their couplers are hardened. Once you spin one in a SS or these others they are shot because of the soft material.

There is a way to mech connect the wire in to the stub but you can't use long stubs. I have built these for SAW racing.

The other option is using surgical SS tubing and gluing all the way thru it. This is what Jorge did for his 140 mph record. Then you can mech connect it as well.

[RaceMechaniX]

Jeff,

I like the Octura collets when they are straight. Unfortunately, they don't make a 8mm to .125/.098/.093 coupler. 5mm motor shafts don't hold up to SAW RPM's. I could machine down a 8mm shaft to 5mm, but would prefer not to.
I have been using the 5x2.5mm stainless tubing like Joerg does.

Can you expand on your proposed connection technique for the stub shafts?
Can you make .098 shafts?

TG

[dmitry100]

Tyler, have you used these "old" MBP collets? They're apparently the best (better) than the ones being sold right now for some reason.

Have you considered just loctite 648 the wire into the collet if it doesn't hold? Especially if its spun inside the ruined collet...
or maybe even some Thread Locker (the blue stuff that flows too well) to improve overall grip inside/outside the collet


wire1.jpgwire2.jpg

[RaceMechaniX]

I have both old and new style, what you have pictured is the lesser one to use. The cross section is too thick around the wire side and it cannot compress enough. The ones with the two different outside diameters are the better ones.
Yes, I have tried Loctite. It only holds to a certain point especially when the length is limited. Longer couplers would work better.