8mm Neu Coupler spy shot

[Steven Vaccaro]

We will be testing a new coupler design for a Neu 8mm motor shaft. Here is a picture of the coupler.

[Doozie870]

There is not near enough set screws J/K

[DuckOfDeth]

I would have to agree with Mon Signor Doozie.....it appears that there is room for another 12 set screws, slightly offset from the existing set screws.

[Eyekandyboats]

come one guys. 12 please 14 maybe 16 for sure !
lmao! just kidding.
looks nice Steve Should hold tight for those neu's

[kck741]

Is there a need for that many set screws?Do Neu motors put that much of a beating on the couplers?

[Darin Jordan]

Steven,

Have people been having issues with the 8mm Octura stuff that would warrent and new coupler design???

[Steven Vaccaro]

Steven,

Have people been having issues with the 8mm Octura stuff that would warrent and new coupler design???

No but I aways disliked having to wrench down on the Octura flex hex. Plus its quite a weight savings in the drive line.

[Steven Vaccaro]

Steven,

Have people been having issues with the 8mm Octura stuff that would warrent and new coupler design???

No but I aways disliked having to wrench down on the Octura flex hex. Plus its quite a weight savings in the drive line.

[Eyekandyboats]

No but I aways disliked having to wrench down on the Octura flex hex. Plus its quite a weight savings in the drive line.

Tell me about it. I have some motors way down deep in boats and i find it hard to get the wrenches in there.
I like this idea! thanks for posting

[Fluid]

There is no need for so many screws, and the engineering behind this design is faulty, IMO anyway. You should never have opposing set screws applying force to the flex cable; there is limited contact and high stress risers on a non-solid surface. I could live with with screws 90 degrees apart forcing the cable against the coupler, and non-functioning screws opposite to maintain balance.

Still, the best method to secure any round rotating body is with a collet. This method has proven its reliability in automotive applications for many decades. A good collet does compress the cable with time, but set screws cause damage to the wires. The solution for both is to use silver solder on the cable end for strength and durability - and the knowledge that the cable is an expendible item, eventually.

The angular momentum difference of a steel collet versus an aluminum coupler is very small compared to the motor magnets/armature/flex cable. You would never notice it under anything resembling normal running.

That all said, having more choices in this rather rare size is still good. :)

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[Steven Vaccaro]

There is no need for so many screws, and the engineering behind this design is faulty, IMO anyway. You should never have opposing set screws applying force to the flex cable; there is limited contact and high stress risers on a non-solid surface. I could live with with screws 90 degrees apart forcing the cable against the coupler, and non-functioning screws opposite to maintain balance.

Still, the best method to secure any round rotating body is with a collet. This method has proven its reliability in automotive applications for many decades. A good collet does compress the cable with time, but set screws cause damage to the wires. The solution for both is to use silver solder on the cable end for strength and durability - and the knowledge that the cable is an expendible item, eventually.
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I read that on the other forum. Thanks for the info. I can cut down on the setscrews

I more than value your opinion, but on this one I'm going with my experience. The ONLY flex shafts I have lost have been with Octura hex's. I lost two. Both different boats. After that Ned S made me some straight couplers and I never looked back. I try to use a straight coupler in all the builds I do. So far so good, all of them have had opposing screws. The largest motor I have run with a coupler of that design is a Lehner 2250/12t with 32 cells. Its been a couple of seasons and its still holding like a champ.

Someone will be testing the Neu coupler in a week or so. We will post the results.

[properchopper]

Still, the best method to secure any round rotating body is with a collet. :)

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For what it's worth, my vote is for the collett. I've had to bend some wrenches to fit into tight spaces, and I solder the ends of my cables. I remove and lube after each day's running & I don't beleive setscrews and cables can sustain their integrity after frequent uses. [One of our members stripped a setscrew at the THC and was out of the race for that day]. Just my 2 cents.

[Doozie870]

You could strip 3 or 4 on this one and still be ok
It looks good to me, I dont know if Ned made this one, but he makes some great stuff that holds up really really well! :D

[Darin Jordan]

We have guys in the club that use both with equal success...... I think it all boils down to how you use what you have... If care is taken, either can work fine...

One nice thing about the set-screw style is that a person with the right tools actually could make these themselves... to any tolerance and spec they desire...

I wish I had the tools...

[Steven Vaccaro]

You could strip 3 or 4 on this one and still be ok
It looks good to me, I dont know if Ned made this one, but he makes some great stuff that holds up really really well! :D

Ned did not make this one. But he does make nice stuff.