5mm to .078" Couplers...

[Simon.O.]

Darin, it looks like you will get the help you need for the coupler and I can help with losing your shaft. I know only too well how much props cost in time and money. I am not a fan of donating them to the pond bottom.

On my exposed shaft hulls Anything except a mono I have a stub saver. This is a wheel collar with a nose cone that sits on the wire infront of the strut. If I blow a wire then the boat stops and I get it all back just need to cut a new wire for it.
Another good reason to run that wire out in the open.

Set screw couplers need a flat on the wire, well mine do.
For 5mm to 062 I use the Octura collet coupler.

[paulwilliams]

Losing shafts and props led me to making this design of wiredrive:





The aluminium "silver bullet" is loctited to the wire and shaft and rotates with the shaft. This not only stops you losing props, but it increases the amount of the wire that is loctited in place - the wire is loctited into the stub shaft, then the silver bullet is loctited to both wire and shaft.

The only drawback to this design is that you must remove the strut from the boat to get the wire out, obviously less than ideal as you risk changing the setup if you put it back in a different position. I scribe a line on the strut bracket to allow me to put it back in the same place each time.

Regarding the issue of supporting a wiredrive, I built this 'rigger with a tunnel to allow me to run a wiredrive entirely unsupported:



As expected, the wire resonated, so I made a small support in the shape of a length of 3/8ths" aluminium bar, cross-drilled to take a length of brass tube, with the ends dimpled to take some epoxy glue. The drive now spins at full speed (5000kv motor on 2S) with no vibration.

Paul

[Jesse J]

Darin, I feel your anger. I even went swimming in the duck *!***!***!***!** pond after loosing my second one ($50 was my minimum loss to convince me to take the slimy plunge).

I have since done 4 things and have not lost a single drive for either 1/16th nor .078"
1) as stated here make two flat spots on wire drive
2) use lots of (probably too much) loctite and a good allen wrench
3) get some wheel collars at your wire size, they make .078 also and use loctite on this too
4) ALWAYS recheck tightness of set screws before and after first run. If you go more than 20 seconds, you may be risking, but wheel collar in step 3 will save your bacon and reduce your anger to just a retrieval.

I also make sure to wipe off any lube on the wire before inserting into coupler, minimize the chance, eh?

The main thing is to quit loosing these dang drive lines and keep wining lots of races!
cheers,
J

[Darin Jordan]

The main thing is to quit loosing these dang drive lines and keep wining lots of races!
cheers,
J

I hear that! It does make me feel a little better knowing that, each time I lost a shaft... I was WAY out front!

Paul... that's a nice system you designed there... Looks like if you made the bullet removeable, which is how Fuller's system like that works, it would be a nice setup and pretty easy to work with...

Sounds like Jeff will have me hooked up with some Octura style shortly... I've had about enough of having to deal with set screws for now...

[paulwilliams]

ILooks like if you made the bullet removeable, which is how Fuller's system like that works, it would be a nice setup and pretty easy to work with...

That's the next thing to do - I have a prototype version made for ball-race bearings which has a detachable bullet.

I have thought about trying to thread the end of 78thou wire M2, but this would entail annealing the wire to cut a thread, then re-tempering, plus you would need to cut the wire to length at the bullet end then loctite - more trouble than it's worth

Paul

[AndyKunz]

Darin,

One of the things I have been doing on flex cable (gag!) and wire drives is putting a wheel collar between the stuffing box and motor coupler. Even if I lose the heat due to a loose motor coupling, I don't lose the prop because the wheel collar keeps it from going out the back.

Andy

[Darin Jordan]

Darin,

One of the things I have been doing on flex cable (gag!) and wire drives is putting a wheel collar between the stuffing box and motor coupler. Even if I lose the heat due to a loose motor coupling, I don't lose the prop because the wheel collar keeps it from going out the back.

Andy

Andy... I'm going to do that as well... just to be safe...

Once I get the lathe that my Grandfather left me setup (was my GREAT Grandfathers... Craftsman Atlas... nice OLD lathe!)... I'll be able to really fix these types of issues myself!

[Jeff Wohlt]

Darin, I can assure you it is because you did not use a flat on the wire. Everytime you crank it that wire moves a slight bit...after enough is will take the wire down in dia or the cups off the set screw and release.

It is the only explanation there is as these have been tested all over the world.

[Simon.O.]

Paul... that's a nice system you designed there... Looks like if you made the bullet removeable, which is how Fuller's system like that works, it would be a nice setup and pretty easy to work with...

Sounds like Jeff will have me hooked up with some Octura style shortly... I've had about enough of having to deal with set screws for now...

Darin you are right, Paul's setup is very nice.
My stub saver bullet is removeable, so I do not have to remove the strut to pull the wire. It also means I can use the one bullet on all of my exposed wire setups.

For those still using set-screw couplers (me too) put a flat on the wire !

The Octura ferule coupler is the ticket.

[Darin Jordan]

Thanks Guys... Jeff has me hooked up on some new Octura style couplers and some replacement wires (I already have two at home, but I hate being without spares...)...

I'll see how things look and decide then if I want to try the set-screw style again... If the Octura ones work out fine, then that's the way I go... Just simpler to deal with all the way around!

[paulwilliams]

Once I get the lathe that my Grandfather left me setup (was my GREAT Grandfathers... Craftsman Atlas... nice OLD lathe!)

Darin,

Is it one of these?

http://www.lathes.co.uk/craftsman/page5.html

More:

http://www.lathes.co.uk/craftsman/index.html

Paul

[Darin Jordan]

Darin,

Is it one of these?

http://www.lathes.co.uk/craftsman/page5.html

More:

http://www.lathes.co.uk/craftsman/index.html

Paul

Yup... that top one looks about like it...

[Darin Jordan]

Got my 5mm to .078 Octura style couplers from Jeff Wohlt this afternoon. They look great. The .078 wire shafts he made me look great as well.

I'm put a flat in the replacement shafts, and also made a .078 catch collar to put just aft of the motor. I'm going to give these screw type couplers one more shot to verify that it was indeed the lack of a flat that was causing the problem. Hopefully the catch-collar prevents another prop loss should the coupler fail to grip again.

I'll find out tomorrow.

[detox]

Wouldn't a lighter weight allen screw work best on your catch coller (balance). Good idea BTW

I'm still waiting on my Octura 5mm x .078 couplers................


...

[Darin Jordan]

Wouldn't a lighter weight allen screw work best on your catch coller (balance). Good idea BTW

I honestly don't think it would make any difference, given where this is in the driveline...

Plus... this collar started life as a 1/16" wheel collar... I don't think they make a set-screw small enough to fit in there... the smallest I have (on the drive-dog) use the smallest allen wrench I have, and these are considerably bigger... It'll work fine...