Removing a 7mm transmission

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TonyL

TonyL

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Hi Folks:

I am pretty good with my HF transfer punch set. However, I can't seem to dislodge the transmission on a PSI Designer pen without taking the brass tube with it. I don't mind destroying the transmission, but I don't want the tube sliding out (especially if the tube and/or blank have been painted). Unlike the slims and trims, the Designer transmission is inserted deeper into the lower tube (leaving all but 13/16" exposed).

I made a nice pen this morning, certainly sales-worthy, but I noticed a few stray radial scratches. I need to sand more at the lower grits - so I thought I would throw it back on the lathe and refinish.

Any ideas on making the removal easier? I had the same is issue regardless of whether I used medium CA or epoxy to bind the tube to the blank (and yes, tubes are roughed-up).

Thank for reading and offering your advice/experience.

Best to all, and Happy Father's Day to all those dads out there..including ones with pets! :-)
 
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I hate trying to do that.

So if you bang on the trans from the nib the tube starts to move?

You could always try to buff out the scratches with your Barry gross buffer. Unless someone stole it. :-/
 
7 mm transmission

Very funny :-). Nope, I know that I needed to sand more. I didn't rush it, but I didn't examine it under my electron microscope :-) . It's a light blank, so you can't really see them, and there are only a few...but it bothers me.

I hope you are buffing a way in PA. I don't miss it.

Here's one of my world-infamous lousy photos.
 

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I never answered your question. Sorry. I can get the nib out (which i have to do first). When I bang on the transmission from the nib side, the tub slides out partially (sometimes).
 
It looks fine....but I know they are there and can be fixed. As we discussed, I want make my own. Thanks though!
 
the adhesion is not good if the brass tube begins to come out when you try to remove the nib. I would think the only fix would be to hold the transmission some way and sand it without placing too much pressure on the blank as to mess up the transmission. you could hold the transmission in a collet chuck type device.


good luck
 
It is really difficult to remove 7 mm transmissions. I have succeeded with about half that needed to be removed. The causes for needed to remove the transmission, a cracked blank (both wood and acrylic) that has to be replaced and residual scratches that were missed. I keep extra 7 mm tubes and transmissions so that if tube comes out and the transmission cannot be removed, then I replace both. I have small collection of tubes with a transmission in them. I even have two pair of the new PSI pen vise grips to hold the pen and I have trouble. My advice, do your best, be creative, and be prepared to replace the tube and transmission.
 
Thank you Don. I usually use the flat end against what I want to pop out. If that doesn't work, I turn it around. I am going to give it a shot now. Maybe the pen gods will smile upon me :-).
 
If you are only going to lightly sand the blank why not hold the transmission in a drill chuck in the headstock, lightly, and use a floating center in the tailstock to keep it aligned. I have done this to re-polish cartridge case brass pens without a problem. Be gentle and you will not have a problem.
 
When I first got started with turning, I read about a trick that I used several times to remove transmissions.

Drill a 1/4" hole in a scrap of wood, and then cut a saw kerf from the edge of the block into the hole.

Place the block of wood LOOSELY in a bench vise with the hole facing up and with the saw kerf parallel to the faces of the vice jaws. Put two 1/4" washers over the hole, and then insert the transmission through the washers into the hole with the pen nib pointed up. Lower the transmission/pen body until the end of the turned blank is no more than about 1/8" inch above the washers, and then tighten the vise.

Then, insert a flat-blade screw driver between the two washers, and twist. This will force the washers apart, pressing the upper washer against the body of the pen, while the transmission remains firmly but safely locked into the wood-block 'collet'. It may be necessary to repeat the process, loosening the vise and dropping the transmission further into the collet until the pen body is finally pushed off the end of the transmission.
 
I hate trying to work on 7mm transmissions. I usually just destroy them if I need to remove one. Are you sanding your tubes before you install them. You should always rough up a tube before you install it. This increases the glue area of the tube by a lot.. The only time I have had trouble with tubes not staying in place is when I have either not given enough time for the glue to dry or I have not roughed up the tube.. Hope this helps you.
 
7mm transmission removal

Wingdoctor said:
If you are only going to lightly sand the blank why not hold the transmission in a drill chuck in the headstock, lightly, and use a floating center in the tailstock to keep it aligned. I have done this to re-polish cartridge case brass pens without a problem. Be gentle and you will not have a problem.
Click to expand...

Thank you for the suggestion Bruce.
 
Thank you Les, Louie and Mike (yes Mike, I am roughing-up the tubes and allowing more than the recommended curing time). These are excellent ideas ( and photos). I am going to copy all to a pdf file and consult the next time it happens.

Best to all,

Tony
 
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