Cable collet runout.

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Terry Keeley

Well-Known Member
Supporting Member
Joined
Jul 24, 2002
Messages
7,116
Getting a lot of vibs with my run-in stand, tracked it down to the 1/4" Aeromarine collet.

Pulled them off all my motors and found anywhere between 0.005" and 0.014" runout, some had bad threaded parts, some collets and/or nuts.

I remember going through this years ago with my 40 stuff, checking housings, chucking a few and making my own collets.

Anything good out there? Speedmaster maybe? Or do I havta make my own?


 
Didn't know Al had them, thanks.

Wonder what the pilot diameter is?

http://double-aceracingproducts.com/catalog/product_info.php?products_id=157

AA_CableCollet_A07.jpg
 
Getting a lot of vibs with my run-in stand, tracked it down to the 1/4" Aeromarine collet.

Pulled them off all my motors and found anywhere between 0.005" and 0.014" runout, some had bad threaded parts, some collets and/or nuts.

I remember going through this years ago with my 40 stuff, checking housings, chucking a few and making my own collets.

Anything good out there? Speedmaster maybe? Or do I havta make my own?




I have the same issue with Prather and Aeromarine collets. Not every collet is the same. Some are better than others. The Octura and Steve Much collets have less runout in general. At least based on my experience.

On a couple of collets, I have found the issue to be the face (the side that butts up the flywheel) not square. I have successfully "re-manufactured" the collets by taking a light cut to square it up.
 
Terry
Why you are checking the run out on the collet check the up and down on you bearings.I have seen .002 to .003 on the bearings.

Dave
 
I have the same issue with Prather and Aeromarine collets. Not every collet is the same. Some are better than others. The Octura and Steve Much collets have less runout in general. At least based on my experience.

On a couple of collets, I have found the issue to be the face (the side that butts up the flywheel) not square. I have successfully "re-manufactured" the collets by taking a light cut to square it up.

Yup, did that with some of my 40 sized collets, but these are beyond that I think.

Terry
Why you are checking the run out on the collet check the up and down on you bearings.I have seen .002 to .003 on the bearings.

Dave

I'm actually putting some pressure on the flywheel to take up the bearing play.

Speedmaster makes a super nice collet

They look the same as Al's and the Zippkit's Zen collets where the straight part goes into a "register" in the body and there's only one taper to worry about. Way better design that the Aeromarine units.

Have you checked them for runout?
 
Terry, I had similar issues with Aeromarine collets. I have measured much lower runout in Octura couplers.
On the electric side we have been using modified CNC DR11/DR16 collets. I will take some pics of the couplers later, but it is something you can crank out in your shop.
 
Terry, I had similar issues with Aeromarine collets. I have measured much lower runout in Octura couplers.
On the electric side we have been using modified CNC DR11/DR16 collets. I will take some pics of the couplers later, but it is something you can crank out in your shop.

Interesting. I didn't know ER collets were made that small, ER 11 would definately work:

https://www.maritool.com/Collets-ER-Collets-ER11-Collets/c21_56_60/index.html
I was looking at "double taper" collets since they were small too, but the size should be right on and flex cable isn't. ER collets have some "range".

http://www.tools-n-gizmos.com/specs/DT_Collet.html
 
Terry,

Just make your own. I've been making my own 2pc collets for years. As a toolmaker, I just couldn't find any OEM collets that ran true enough. With your attention to detail, this will be a breeze.

Start with the ID features of the nut, but turn out blanks first. Turn the OD above the points of the finished hex and face the shaft end. Turn out as many as you want. Then, bore out a soft collet matching the OD of the nut blank and do one operation at a time to all your blanks until you have the ID features done. Set them aside.

Start the same process with the collets, turning the OD and facing the shaft end of the collet. Then, bore out a soft collet matching that OD. Again, one operation at a time, turn your pilot diameter and step, drill and tap for the crank threads and bore the ID for the flex shaft. This should ensure almost perfect runout between the mounting face and the flexshaft. Set them aside.

Turn out a stub fixture, starting with the mounting end, matching a 5C collet of your choice. Mount into that collet, bore it for your pilot and drill and tap it for a threaded stud matching the crank threads. Do not remove from spindle until collets are finished. You can then, again, one operation at a time, turn out the OD features of the collet, matching the threads to the tapped threads of the nut. This should ensure near perfect runout between the ID and OD features.

Next, mount the fixture in a 5C indexing fixture. Mill the hex on both collet and nut, locking a nut onto each collet as you go. Tool pressure should only serve to tighten the nut onto the collet as you mill the flats. Once the hex is finished on each collet/net pair, remove the nuts and cut slits in the taper area of the collets.

Deburr and enjoy near zero runout. Don't forget to sweep up. 😁

You might also consider turning out a stub fixture, and, using your flywheel collet, turn the mounting face of your flywheel(s). Once you lock the flywheel onto the fixture stub, you can remove the nut and it should stay affixed. You'd be surprised at how far out this face can be.

This sounds like a lot of work, but it's really not. If your churn out a dozen or so units, you should be good for quite a while. IF you hang onto this tooling, collets and fixtures, you will be that much ahead if you ever need to make more.

I have found 17-4ss to be a very adequate material for these.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC
 
Collet 3.jpg
Terry,

This is The collet I make for my 21s and 45s. It has a 1/2" hex on the collet and a 7/16" hex on the nut,

Collet 1.jpgCollet 2.jpg

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC
 
If you seek the BEST? Buy Speedmaster Dive Collet & perform your same test. Them you will Buy More Speedmaster. I have a Box full of new & used Aeromarine collets than are junk.
 
Terry my mistake on the name I meant ER11 and ER16. Here are some pics. Measured runout is in the 1-2 thou range. mostly due to how precise the collet insert is. You can spend $20 on a full set or $50 on a single super precision one. They also work great with wire drives.

I tried the ER11 on a gas motor and the collet could hold the torque but not the thrust. So I would recommend the ER16 size for 67’s and larger.
3B255ADF-1A6E-43FF-8B12-0B826AE77203.jpeg53657041-8865-4777-80A1-0269DBF15ADB.jpeg2230127F-A865-43D0-89A0-0A7E1A90C6E5.jpeg13C8098A-CA2A-46DB-995C-6ECDB1F75417.jpegF529412D-4E55-436B-8D05-885F127C6335.jpeg
 
Just a short time ago The V5 CMB was taken to have a crank shaft balance issue. but i seen one that had a bouchie balanced crank in & contuined to break plug wires. after many motor people looked at the engine It was found to be the aeromarine collet the entire time causing the problem. Iam not telling you cant fix the aeromarine collet. But the Speedmaster dont need fixed. Nothing on my Boats but Speedmaster from now own..... I would not run a Aeromarine if you gave it to me. p.s. this problem is epic on a high reving hydro engine, Not as much on a mono motor, 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.
 
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Thanks much guys for the info, I'm gonna make my own with a "Teckniks" brand ER11 collet and nut:

https://www.techniksusa.com/wp-content/uploads/2019/01/TKS_cat_collets.pdf
This will just be for the SAW boat/test stand as I'll havta move the collet and nut around. Figure I need less than a thou or so runout for the stand with everything hard mounted like it is.

Nice piece Brad!

I'm gonna use 416 stainless for it's machinability. cut enough 304 and Ti to know better. I'll do the taper, O/D thread and then bore and single point the 8mm I/D thread for accuracy. Turn it around in my 5C collet, get it running dead nuts then face and turn the flywheel pilot. This from my "Consielleri", I'm not that good at all this yet, lol.

He also mentioned making a mandrel and turning the face of the flywheel, I checked and they ran very good (0.001" or so out near the perimeter) but dead true is obviously better for what I'm trying to do.

Good looking collet Ty, gonna try the ER11 in the SAW boat but if it doesn't hold I'll switch to another type, possibly the Speedmaster. There's no thrust loads on the run-in stand/dyno and I'm limited for space so this shud work.

I agree 100% Joe, Speedmaster makes top shelf stuff, I'll order some of their collets for these 67/80's and also my VAC 91's. I'm sure they'll be very good but for the dyno I need dead nuts accuracy.
 
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Terry,

About 416ss...

As a general rule, if it cuts like butter, it's probably butter.

17-4 PH machines about like A2 tool steel and is about as durable. I like to think of it as an all-around, "best of both worlds" stainless.

Food for thought.

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

About 416ss...

As a general rule, if it cuts like butter, it's probably butter.

17-4 PH machines about like A2 tool steel and is about as durable. I like to think of it as an all-around, "best of both worlds" stainless.

Food for thought.

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

Ya, yur right for sure but at 75 ksi it's as strong as common 304. Only half that of 17-4 tho:

https://www.alro.com/Resources/WebResources/AlroCom/MetalsGuideCatalog/PDFs/005-Stainless-Steel.pdf

I don't think that style does well with cable because it's for a specific shank size, cable is not a specific size and changes under load.

Brad


They're actually good for a range of 0.230" - 0.250" and apparently hold their TIR runout spec when collapsed:

https://www.maritool.com/Collets-ER...6_60/p14332/ER11-COLLET-1/4/product_info.html

Never knew these things came so small, thanksagain Tyler!

full
 
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