Wire drive slippage

[Darin Jordan]

Ive tried a number off collet couplings for wire & flex ie various stainless ones, Etti & Octura,

Yeah... the Etti's I've used have to be tightened down with care. They get all twisted up inside if tightened too much. Just soft material. I've had an Octura or two over the years that weren't quite "true", but it's pretty rare. I've used them for years without issue...

[TheShaughnessy]

i'm using a .78 wire drive with the octura long coupler. It has two set screws on the motor shaft side and cinches down nice and tight on the wire drive, plenty of issues with the boat but the wire drive slipping isn't one of them.

The octura couplers are HARD i was trying to drill a hole in one so i could install a magnet, used for the rpm sensor I have. I ended up just opening up one of the set screw holes because i couldn't get a dril bit to bite into it.

[martin]

Yes the Octuras are hard but also strong, ive had to machine the hex on a couple to miss the mounting screws on a couple of small motors & just got away with it with a new carbide tip tool. The Ettis are very soft indeed & you can twist them off centre with some of the smaller ones when tightening & undoing.

[Basstronics]

Billy beat me to the link.

I see the topic of hardness was brought up. As you may or may not know, when you harden steel it also becomes more brittle. Ive had two octrua couplings now break and finger off.

Another point about the hardness. If its hard it will only grip on the high spots of the flex. The softer materials such as the brass inserted collets will give in turn providing more holding power. The 3 piece collets are more of a compression system over a pure clamp.

Now when it comes to a wire drive, its sorta different but sorta the same. The wire is pretty much round (maybe minor oval). Now think of how the collet works. There is an oversized hole, slots cut into the material to make room for it to be wedged down onto the material by a cone. So what you are doing is applying a lot of clamping force into a small area at the sharp point of the hole. Harder material wont give much, maintaining a small area with a lot of pressure. Softer material will give slightly allowing the pressure to be distributed more.

Just saying. Food for thought.

[Basstronics]

The couplers I twisted off were 5mm to .130 cable.

A bit back someone mentioned grinding the point type surface off the setc screw. FWIW thats called a "dog point" and it is designed to dig into the surface.

[detox]

In addition to using the Octura coupler I would also use Blue Loktite. You could also roughen up (crosshatch) the wire end with sandpaper by chucking propeller shaft in a drill and spinning.

[detox]

One bad thing I noticed when using collet couplers with wire drives is excessive woble or runout at wire after tightening collet.

The Wohlt aluminum couplers have almost zero runout. I used Blue Loktite with these to prevent slipping. You can heat slightly to remove for greasing.

[T.S.Davis]

Octura makes a coupler for .078? I did not know that.

I've tried a bunch of different methods. I like the Octura collet on .062 myself.

The collet I dislike with a passion is the the Octura 5mm x .187. That thing is misserable. Have to crank the poo out of them to get a good grip and then they're hard to get apart because.....well, I just cranked the poo out of it.

On some of my set screw types I ditched the grub screw and ground down 2 cap screws of the right thread size so that when torqued down the head is almost all the way down to the coupler. The screws need to be very close to the same length for balance. With a cap screw instead of a grub screw you can really reef on a 6-32 thread to hold wire or cable in place. I use that on 1/4" cable even.

[Darin Jordan]

Octura makes a coupler for .078? I did not know that.

I don't think they make them... I think that Jeff Wholt has figured out a way to machine a .062 out to fit .078. I have a couple of them and they work great.

[properchopper]

Octura makes a coupler for .078? I did not know that.

I've tried a bunch of different methods. I like the Octura collet on .062 myself.

The collet I dislike with a passion is the the Octura 5mm x .187. That thing is misserable. Have to crank the poo out of them to get a good grip and then they're hard to get apart because.....well, I just cranked the poo out of it.On some of my set screw types I ditched the grub screw and ground down 2 cap screws of the right thread size so that when torqued down the head is almost all the way down to the coupler. The screws need to be very close to the same length for balance. With a cap screw instead of a grub screw you can really reef on a 6-32 thread to hold wire or cable in place. I use that on 1/4" cable even.

Since I started using this stuff on the Octuras, no poo-cranking. Helps even out the torque-tightening and un-tightening. Ex-wife said it tastes funny 'tho.

DSC03227.JPG

Never had a problem with Oct collet wire couplers either. Just lucky I guess

[martin]

Darin Octura make a 5mm - .078", Steven has them in the OSE store

[martin]

Tony do you use the anti seize on just the collet nut or on the flex as well. thanks Martin.

[properchopper]

Tony do you use the anti seize on just the collet nut or on the flex as well. thanks Martin.

Just the collet nut. Jay Turner gave out this tip.

[JIM MARCUM]

Since I started using this stuff on the Octuras, no poo-cranking. Helps even out the torque-tightening and un-tightening. Ex-wife said it tastes funny 'tho.
[ATTACH=CONFIG]77186[/ATTACH]

Never had a problem with Oct collet wire couplers either. Just lucky I guess

Thanks Tony!!! Now I have a few thoughts that I can't share. JIM

[TheShaughnessy]

I assume mine is an octura but it actually came with a boat I picked up from Tony so he may be able to elaborate.

Slightly unrelated but i was using the collet without the nut to tighten it on an airplane. The plane props would thread right onto it and it seemed to spin more true then an actual plane prop adapter. it survived multiple nose dive crashes and found its way back into my Vegas. Perhaps this is just Tony's lucky collet though.