churchill bushing problem

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edstreet

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No longer confused....
I went to make my first churchill last night and noticed the bushings making this terrible wobbling and vibration, on closer inspection the hole is bigger than it should be. caliper shows the hole to be .284 and the other bushings I have to be .242. As it is now these bushings are unusable and will not provide any stability.

I called Berea and they tell me I need a special oddball sized mandral shaft. Does anyone know of compatible bushings for this kit that will work, other than replacing the taper and shaft?

Ed
 
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Firefyter-emt

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You could use a dead center and turn between center. Otherwise you are a slave to two mandrels.

Oh, you could also glue up some slimline tubes into some corian and turn your own bushings for them.
 

wdcav1952

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Ed,

Some of Berea's kits do require the "B" mandrel to fit the bushings. I tend to like using the B mandrel as it seems a bit stiffer than the smaller "A" mandrel. I bought the cigar kit B mandrel bushings from Beartoothwoods.com so I could make the cigar kit on the B mandrel. Mandrels are not that expensive, I have two of each size so that I can work on more than one kit at a time.

I think Woodcraft sells the bushings for the Churchill that will fit on the A mandrel.
 

Randy_

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Originally posted by edstreet
<br />I went to make my first churchill last night and noticed the bushings making this terrible wobbling and vibration, on closer inspection the hole is bigger than it should be. <b>caliper shows the hole to be .284 and the other bushings I have to be .242.</b> As it is now these bushings are unusable and will not provide any stability.

I called Berea and they tell me I need <b>a special oddball sized mandral shaft.</b> Does anyone know of compatible bushings for this kit that will work, <b>other than replacing the taper and shaft?</b>

Looks like you need to work on your measuring techniques a little. The Berea "B" mandrel has a diameter of 0.289"-0.291" so your bushings, if correctly measured, won't fit on a "B" mandrel. Similarly, the Berea "A" mandrel is 0.247" in diameter so the measurements of your other bushings look a little worrisome as well.

"B" is not a "special oddball" mandrel size. It is just the other Berea mandrel size. Quite a few of the Berea kits use that mandrel so it is useful to have if you intend to use a wide range of Berea kits.

If you are already using the Berea Precision mandrel system, the arbor will accept either size mandrel. You can purchase a "B" mandrel for 6 or 7 bucks. Unscrew the "A" mandrel from the arbor(the little flat on the mandrel is to accept a wrench) and screw in your "B" mandrel. I don't know if this will work with mandrel systems from other manufacturers. Neither CSUSA or PSI advertise replacement mandrels. It looks like you have to buy arbor and mandrel as a unit. Woodcraft sells replacement mandrels; but their threading is different from that of the Berea mandrels so they are "NOT" interchangeable. As was mentioned earlier, Woodcraft makes their own bushings and they are all designed to be used with "A" (7mm) mandrels.....even for the Berea kits they resell which normally require a "B" bushing kit.
 

Firefyter-emt

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Well hold on here... 1/4" is .245" just like Joe's replacement mandrels. If the mandrel in question is a PSI it very well may be slightly under. It's well known that PSI's mandrels tend to be "loose" when other bushings are used on them. Before I got smart and dumped the mandrel all togather, (and back to my PSI mandrel days) I had to use a thin strip of post-it note under the bushings to take up the slack of my Berea bushings.

I know that the mandrel I got from Joe is .245" and was measured with a set of Fowler calipers, not some cheap harbor freight ones.
 

edstreet

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No longer confused....
The caliper WAS zero when I started and yes it is a PSI, sad to say. I may have the 3rd digit off on both measurements but I do know the first 2 are correct.

I think I am going to try the no mandrel option, that seems the best move at this point. I have been looking to get away from the mandrel I currently have anyways.


Ed
 

Randy_

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Mandrel Diameters per manufacturer:

Berea......0.247" +0-0.002"

CSUSA......0.246" (no tol. mentioned)

PSI........0.243" (no tol. mentioned)

Woodcraft..unknown

From the above, you can see that bushings from Berea and CSUSA mught be a hair loose on PSI mandrels.
 

Randy_

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Originally posted by edstreet
<br />The caliper WAS zero when I started and yes it is a PSI, sad to say. I may have the 3rd digit off on both measurements but I do know the first 2 are correct.

You might get a magnifying and carefully examine the jaws of your caliper. There might be a small burr or a speck of dirt that is not allowing the jaws to fully close in the "zero" position.

To check the accuracy of your caliper, you could measure a sheet of a newspaper which should be 0.002" or a relatively new dollar bill which will be 0.004". If your caliper won't measure to 1/1000", you should probably give PSI a call and ask them to exchange it.
 

Firefyter-emt

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As you can see, with a PSI mandrel and Berea bushings you can be .005 off, that is way too much "slop" for pens. Now combine this with loose bushing to tube fitting and you can have some sloppy pens with new parts which are perfectly straight and true.

Ed, feel free to drop me an e-mail if you have any BCB questions, I think you will like it once you give it a shot. Worst case, you are not really out much money to give it a try and you can always use it just to apply the finish without CA chipping.
 

cdcarter

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You've got your answer ... it's a B mandrel. If you try and use "B" bushings on an "A" mandrel, you get exactly what you got.

I actually prefer a B, because it's more stable. Less risk of bending the mandrel or overtightening the nut and getting a barrel that's asymmetrical. In some cases, you can get "B" bushings for kits that you've probably been turning on an "A." I know that's the case with cigars.
 
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