Cable collet runout.

[Brad Christy]

Did what Brad described and faced off the flywheel. That got the runout at the wire down to about 0.0015" Not bad!

Bob,

It's amazing how much a little runout on the face of the flywheel can translate into a lot of runout at the end of a collet, huh? It's all about that trig.....

I figured this out when I made my first collet. I KNEW I had taken every measure possible to ensure as little runout as possible, and STILL had runout at the shaft end of the collet when mounted to the flywheel. The only possible source of the error WAS the flywheel.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Brad Christy]

There ya go Bob! A thou runout is excellent, it also verifies that the Octura collets are very good.

I would mark the flywheel, collet and crank somehow so you can re-assemble them in the same position when you need to take off the flywheel. I use a small ball cutter in the dremel and mark where the slot in the collet goes on the inside of the flywheel. I then orient that with the crank pin ATDC.

Terry,

Repeatability. It's a thing.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Terry Keeley]

Terry,

Repeatability. It's a thing.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

And as my Consigliere says, "everything moves".

 

[Jim Allen]

"Note to self. If your shaft will not release when you untighten collet nut & you must pry the shaft out of the collet you already got a collet nut problem."

This is not always true Joe. The split collets I use are split from end to end. The 5/8" hex on the collet nut will lock this type of split collet in its tapered seat when used on both hard shafts & cables. Placing a 1/4" collar clamp on the cable or hard shaft directly behind the collet nut releases both shaft types when the collet nut is backed off.

Jim Allen

 

[Terry Keeley]

Low taper angles are "self-holding", I had to buy the special nut for my ER11 collet to release the cable.

 

[Brad Christy]

"Note to self. If your shaft will not release when you untighten collet nut & you must pry the shaft out of the collet you already got a collet nut problem."

This is not always true Joe. The split collets I use are split from end to end. The 5/8" hex on the collet nut will lock this type of split collet in its tapered seat when used on both hard shafts & cables. Placing a 1/4" collar clamp directly behind the collet nut releases both shaft types when the collet nut is backed off.

Jim Allen

Jim,

I think Joe was referring to the (unnecessary) third part that serves as the collet in most off-the-shelf collets. These tend to deform around the filaments of our flex shafts and then not like to release when loosened up, especially the brass ones.

This was another advantage to my making my own. I could eliminate the very much unnecessary part. A two pc collet is about as ***** proof as it gets. The only reason I can see for a collet "insert" is for changing sizes.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Terry Keeley]

416 Stainless is a breeze to cut, I highly recommend it. I could only find 1.25" locally, lol.

 

[Terry Keeley]

The Speedmaster collets are very good. I got a "random" couple thou runout and was able to get near zero moving the collet around a bit.

And this is with no pilot, I ordered them without figuring I would put them on hoping to get a better result. If I'd have known they were this good I would have probably just got them done.

Harry makes good chit.

 

[Terry Keeley]

 

[Mike Hughes]

Terry,
That seems weird how the speed master near the collet is further off than an inch away. You would think it got worse as you travel away? I'm confused. Did I miss something? Maybe just some dents in the shift are causing this?

 

[Terry Keeley]

Terry,
That seems weird how the speed master near the collet is further off than an inch away. You would think it got worse as you travel away? I'm confused. Did I miss something? Maybe just some dents in the shift are causing this?

The taper in the collet is the real indicator of how accurate the whole thing will be, that was about 0.002 (with no pilot!).

For the last test I moved the shaft around and was able to cancel out the runout in the taper with runout in the collet to get a near zero result.

With my ER unit the shaft runout is the same as the taper inside the holder no matter how you position the shaft since the ER collet and nut are DNA.

I have a couple flywheels that had the pilot holes screwed up from the Aeromarine collets and are out of round slightly, that transferred to the collet and shaft. The flywheel face has to be very good but any error in the pilot will also throw things off.

 

[RaceMechaniX]

Nice work Terry, looks like you found two good solutions. Hope to see a new video soon with no issues.

 

[Terry Keeley]

Nice work Terry, looks like you found two good solutions. Hope to see a new video soon with no issues.

Thanks again for the ER suggestion!

Might not take the thrust in the boat but I'm pretty confident it'll work on the stand, I'll know tomorrow.