How to turn below the bushings

[mpex]

I'm finding that the actual bushings I'm using for slimline, roller ball and click pens are bigger than the kit components. I bought a digital caliper to make sure. I'm not sure how best to turn or sand the wood below the bushing size. Should I just use a smaller bushing that was meant for a different size pen kit, and then continuously measure with the calipers? Seems like a bit of a pain. I tried sanding down past, but that seems to cut into the rest of the blank too heavily and doesn't get right to the very end which is what needs to match the kit parts.
For reference: I'm a beginner using a mandrel.

Thanks for any suggestions!

Moishe

 

[NotURMailman]

If the issue is consistent with every kit you are buying, why not sand down the bushings?

 

[jmbaker79]

Would think this would be hard to do consistantly with a conventional mandrel and bushings, as far as getting to the edge. I'm sure your bushings are also smaller now than they were when you bought them from hitting them with a tool while cutting that last little bit by the edge. I turn between centers like lots of folks and measure with a caliper to over turn before applying a finish. You could trim down your bushings to the exact size you need or just turn between centers with no mandrel. Just a thought!

 

[Lenny]

Using a 60 degree dead center in the headstock and turning between centers would work if you wanted to try it. Even if you just use it for the final sizing (with calipers) and then applying a ca finish.... You might find you prefer it. You most likely will need a short tool rest as well to allow support close to the work.

 

[mpex]

You could trim down your bushings to the exact size you need or just turn between centers with no mandrel. Just a thought!

What would be the best way to trim down the bushings?

Using a 60 degree dead center in the headstock and turning between centers would work if you wanted to try it.

How does TBC help solve the problem? Don't you still use bushings when TBC?

 

[NotURMailman]

You could trim down your bushings to the exact size you need or just turn between centers with no mandrel. Just a thought!

What would be the best way to trim down the bushings?

Using a 60 degree dead center in the headstock and turning between centers would work if you wanted to try it.

How does TBC help solve the problem? Don't you still use bushings when TBC?

Depending on the amount of material you need to remove, I would sand them down.

Some poeple use bushings for between centers, some do not.

 

[Lenny]

I will use both regular bushings (when I don't have the others) and John's tbc bushings, to get close to finish size. I DON'T want to run the risk of hitting them with a chisel or sandpaper, so I like to switch to just holding the blank between centers (no bushings) for the final turning/sanding to size, which I check with digital calipers. You don't need a lot of pressure with the tailstock at this point, just enough to keep the blank spinning while using a delicate touch.

 

[azamiryou]

You could trim down your bushings to the exact size you need or just turn between centers with no mandrel. Just a thought!

What would be the best way to trim down the bushings?

Mount up a brass tube just like you're doing a pen, then you can trim the bushings just like trimming pen material. You can use sandpaper or your turning tools, depending how much you need to take off. This will dull your tools, so plan to re-sharpen them after. And the sandpaper will get full of black metal dust, so don't re-use the sandpaper to sand a nice clean blank or you'll get black dust all over it.

You may want to take extra off so that you can easily turn the ends to the correct size using calipers to check, and to account for variation in sizes of kit parts.

Using a 60 degree dead center in the headstock and turning between centers would work if you wanted to try it.

How does TBC help solve the problem? Don't you still use bushings when TBC?

Yes and no. Bushings aren't required for TBC, but they can be useful to provide more grip when going from square to round, and to give you an approximate target size. I think most people remove the bushings for final sizing, sanding, and finishing; this gets the bushings out of the way for sizing, prevents sanding or cutting the bushings and getting bushing dust in the wood grain, and prevents the finish from gluing the bushings to the pen barrels.

 

[mpex]

Mount up a brass tube just like you're doing a pen, then you can trim the bushings just like trimming pen material. You can use sandpaper or your turning tools, depending how much you need to take off. This will dull your tools, so plan to re-sharpen them after. And the sandpaper will get full of black metal dust, so don't re-use the sandpaper to sand a nice clean blank or you'll get black dust all over it.

You may want to take extra off so that you can easily turn the ends to the correct size using calipers to check, and to account for variation in sizes of kit parts.

I started this last night. Just using 100 grit sandpaper. I did it with the bushings from the click pen and slimline. I sanded it down about 0.2mm below the kit part sizes. I'm working on testing it now, but I think I'm going to take it down a bit more.

Using a 60 degree dead center in the headstock and turning between centers would work if you wanted to try it.

How does TBC help solve the problem? Don't you still use bushings when TBC?

Yes and no. Bushings aren't required for TBC, but they can be useful to provide more grip when going from square to round, and to give you an approximate target size. I think most people remove the bushings for final sizing, sanding, and finishing; this gets the bushings out of the way for sizing, prevents sanding or cutting the bushings and getting bushing dust in the wood grain, and prevents the finish from gluing the bushings to the pen barrels.

Looking forward to trying this! Sounds like the way to go. The only thing I'm concerned about with TBC at this point is getting 2 sections to match. For example if I'm turning down a slimline and want the upper and lower sections to match in shape.

 

[plantman]

Use a Fine metal file to bring you pen ends down to size. While your doing this, bring the bushings down to the size you want with the file. Jim S

 

[Lenny]

John has the triple-play set of bushings that work for all different kinds of 7mm kits.
I use them .... BUT .... there still are times when I will use a mandrel (In my case with a collet chuck) ... making modified slims is one of those times. It can be useful to have both blanks side by side so you can see your shape being formed.

 

[plantman]

John has the triple-play set of bushings that work for all different kinds of 7mm kits.
I use them .... BUT .... there still are times when I will use a mandrel (In my case with a collet chuck) ... making modified slims is one of those times. It can be useful to have both blanks side by side so you can see your shape being formed.

:wink::wink: Make yourself a cardboard or plactic template once you turn the first blank. Use this to guage the second blank. You could lable this template and be able to duplacate another pen in the future if need be. Jim S

 

[maxwell_smart007]

check that there is no buildup of CA on your bushings - if there is, it's rather brittle and you can break it off with a pair of pliers...

CA builds up rather easily, and can make you turn to the wrong size..