5mm to .078" Couplers...

[Darin Jordan]

OK... I KNOW there is a way to get these stinking 5mm to .078" set-screw style couplers to work... but after loosing THREE different shafts... AND the props associated with said shafts... I'm ready to throw them in the dumpster and find something better...

I KNOW, however, that people have success with these things, so if you don't mind, could someone please tell me HOW they do it? I KNOW that I had the set-screws as tight as I could get them.. and yet... the shafts just keep falling out the back. WHAT could be the deal? Am I suppose to put "flats" on the wire? I'm getting REALLY tired of losing props...

And, for the second part of my question... Does ANYONE make a collet style or Octura style coupler for 5mm to .078" wire?

Thanks Guys... After winning Heat 1A of 1/10th scale today... I was out front in heat 2A when the shaft and prop just disappeared... Then, after changing couplers and putting in a new shaft... Prop two and the shaft dropped out again... And, again, I had them as tight as I could get them.

Help!

If no one makes a collet style coupler... They SHOULD! Enough people are using .078" wire that these should be standard parts...

[Boatman]

http://www.rcraceboat.com/

I got TWO from him

[properchopper]

www.rcraceboat.com [Jeff Wohlt]

[bustitup]

Jeff has what your looking for....5mm to .078 collet style
I got one from him

[Boatman]

http://www.rcraceboat.com/

Jeff has great couplers. nice prices too

[Darin Jordan]

http://www.rcraceboat.com/
Jeff has great couplers. nice prices too

Doesn't help... They are his couplers and wire-drives I'm using... I have to be doing SOMETHING wrong... because there is NO WAY these set screws... on TWO separate couplers... weren't tight... The second coupler was one of the newer ones with the higher tolerance wire-drive hole... and I assure you it was as tight as one could get it...

[Darin Jordan]

Alright... I'll look into Jeff's collet-style couplers... Something needs to be made to work...

[johnnyoverkill]

Darin,

I use the .078 from Jeff too. Grind a small flat on one side of the wire, it WILL hold. Until I cut a flat spot, I had the same trouble.

Good luck, and get back out front!

John

[Boatman]

Darin, at he very bottom of his page he has "modded" coupler type for wire drive. 14.00 each

[Jeff Wohlt]

Darin, sorry to hear about the loss in drives...that really sucks! A flat spot is the key. Also, some couplers that even I have made (set screw style) must be checked well. I have found that even with mine if I do not really check the set screw threading to make sure they actually go to the wire then they feel tight but are not. It fakes you out and you think it is tight...but it is because threads are not all the way thru the coupler.

So I make a slight flat spot and put the wire in and slightly tighten to find that flat. Or even easier is to make a mark on the wire drive where the flat is and then set them down. The opposing set screws are to push the wire to the flat as well. This way it is not putting pressure on the alum coupler but holds the opposing side with steel...if not the alum will wear and the set screws will not hold it. I have never had one slip in my boats or the 100s I have sold...or at least they have not written back to tell me. Also thread locker is a must.

The smaller the coupler (062 and 78) is the hardest to make. Big couplers are easy to make.

As of now I am modifying the Octura version but some new 078 versions are on the way. What is the one you mention about the high tolererance hole you stated? You have never gotten anything from me as far as couplers.

They are tight so when you get them I take my grinder or wheel and make taper point on the wire so it will push in. You actually have to twist using your prop to twist them in but once tightened...they are solid.

I can assure you the set screw style does not slip unless whomever is making the couplers are not threading them well enough.

[Jeff Wohlt]

Darin, I see you posted on RRR that the couplers were also mine. Unless Steve has some really old couplers I have not sold any couplers to him for a long long time. I figured David (HFC) was making them. I have only sold drives to him for the last year or more. I double check my couplers for this.
Just wanted that cleared up.

These are not mine...

http://www.offshoreelectrics.com/pro...per_medium.JPG

These are mine:

http://www.geocities.com/jwohlt5362/Tapercoupler.JPG

[Darin Jordan]

Jeff... I might have been mistaken... I got them from OSE, but just assumed they were yours....

Here's the deal... on the first set of couplers I purchased... One went in my Miss Oberto, and the other in my DeWalt... The Oberto has never dropped a shaft while I owned it... The DeWalt during it's second test run...

When I got the DeWalt home that day... I took the coupler out... and, after resisting the urge to beat it to death with a hammer, I looked it over and let reason and logic set it...

I ran a tap through the 4-existing set screw holes to make sure they were tapped all the way through... THEN, I drilled another pair of set-screw holes at 90-degrees from the existing 4, giving me a total of 6 set screws... All tapped all the way through and and having verified through visual inspection that the screws were extending into the hole plenty far to grip the wire...

THIS is the coupler that let go this weekend... RIGHT after I had verified that all of the screws were very tight...

I then switched to a newer coupler from OSE, which Steven told me had been improved from the first set by a tighter tolerance on the .078 hole... it's VERY snug...

Two laps in... this one let go...

SO, my only conclusion at this point is that I need to put flats on the wire to make this style of coupler work for me. I haven't been doing that, and now, 3-shafts and 3-props down, I think that's what I need to do... I still don't understand how 4 or even SIX set screws wouldn't be enough to hold that round wire in place... but I'll give the flats a try and see if that helps...

Honestly, I REALLY HATE this style coupler... it's a pain to deal with... BUT, I do know that they are truer than the Octura style... I can see that on the bench and I'm sure that can make a difference in how long the system holds up...

I'll give it another try... but I may figure out a way to put in a wheel collar in the system to prevent the shaft from falling out, coupler or not... Just to be safe!

[detox]

Steve at OSE had a few Octura style couplers that were modified to accept the 078" wire. Mine has worked perfect so far in my UL-1. Tighten collet on coupler until you poot...if you crap you have tightened too far.


.............

[detox]

BTW...if the Octura style coupler is centered and machined true, vibration will not be a problem. I feel the tried and true Octura Collet style is the best for now. I feel VERY LITTLE vibration by spinning motor and Octura coupler in hand.


...

[Jeff Wohlt]

Thanks for clearing that up. Well looks like you made every effort to make sure it was right and knowing you I was pretty sure you took every precaution.

Can't really do any more than you have except for the flat spot. That is plenty of set screws to hold it. Do you lock tight the set screws?

Sorry to hear about it. Yes, you can get a 1/16" collar wheel and drill it to 78 and use that at the stuffing tube/coupler in case it would let go. Not sure about balance on something like that but it was used in straight hard shafts long ago.

I will have more modified Octuras shortly and yours will go out.