TBC - need bushings

[dansills]

Anyone able/willing to make the steel bushings with the 60 degree ends? Johnny cnc is sold out (need jr gent, baron/sedona & long clicker) and from reading his recent update on his website it could be a while before they are back in stock. Any suggestions or ideas????

 

[Andrew_K99]

Loose the bushings and get a few sets of calipers?

AK

 

[Canadian_Kid]

I am surprised that one of the bigger companies hasn't started to sell them yet. I am sure a cnc could pound them out pretty fast.

 

[dansills]

Got the calipers .. Much Better accuracy by combining the bushings as well as tbc IMHO. Plus, a whole lot less stopping and checking with calipers after every pass.

Thinking of making delrin or corian I guess if nobody can help with the steel - Anyone help me with the right bit to use to achieve e 60 degree indent? Never mind that - I could never make them accurately. HELP!!!

 

[azamiryou]

Make 'em yourself. They don't have to be metal - if you lack a metal lathe, cut them from delrin or even wood!

 

[Andrew_K99]

You could also use standard bushing and drill a 60° taper in the end with a center drill. You'd need a chuck and drill chuck to do this though.

 

[leehljp]

Aluminum will make a good bushing and is soft enough to turn on a wood lathe.

These center drill and countersink set will make your 60°.
Amazon.com: Dormer A221 Series Cobalt Steel Combined Drill and Countersink, Uncoated (Bright) Finish, Plain Style, 60 Degrees, #5 Size, 0.1875" Body Diameter: Industrial & Scientific

NOW for something that is not spoken of much here - in spite of what many people say - you do NOT have to have 60° dead centers or olive centers if you use standard commercial bushings to turn TBC.

If you use Johnnycnc's you do. But if you use the standard bushings, you don't have to do that. I started my TBC back in '08 by making my own non-60° dead drive from aluminum and using standard bushings. Johnny's are a much higher quality and I have some of his. On his, I do use the 60° dead and live centers.

 

[dansills]

Aluminum will make a good bushing and is soft enough to turn on a wood lathe.

These center drill and countersink set will make your 60°.
Amazon.com: Dormer A221 Series Cobalt Steel Combined Drill and Countersink, Uncoated (Bright) Finish, Plain Style, 60 Degrees, #5 Size, 0.1875" Body Diameter: Industrial & Scientific

NOW for something that is not spoken of much here - in spite of what many people say - you do NOT have to have 60° dead centers or olive centers if you use standard commercial bushings to turn TBC.

If you use Johnnycnc's you do. But if you use the standard bushings, you don't have to do that. I started my TBC back in '08 by making my own non-60° dead drive from aluminum and using standard bushings. Johnny's are a much higher quality and I have some of his. On his, I do use the 60° dead and live centers.

So you are saying just chuck the normal bushings between my dead and live centers and turn away? This be close to the same accuracy as the 60 degree ones?

 

[dansills]

You could also use standard bushing and drill a 60° taper in the end with a center drill. You'd need a chuck and drill chuck to do this though.

Have two drill chucks and a Beall so I may give this a try

 

[jcm71]

Aluminum will make a good bushing and is soft enough to turn on a wood lathe.

These center drill and countersink set will make your 60°.
Amazon.com: Dormer A221 Series Cobalt Steel Combined Drill and Countersink, Uncoated (Bright) Finish, Plain Style, 60 Degrees, #5 Size, 0.1875" Body Diameter: Industrial & Scientific

NOW for something that is not spoken of much here - in spite of what many people say - you do NOT have to have 60° dead centers or olive centers if you use standard commercial bushings to turn TBC.

If you use Johnnycnc's you do. But if you use the standard bushings, you don't have to do that. I started my TBC back in '08 by making my own non-60° dead drive from aluminum and using standard bushings. Johnny's are a much higher quality and I have some of his. On his, I do use the 60° dead and live centers.

So you are saying just chuck the normal bushings between my dead and live centers and turn away? This be close to the same accuracy as the 60 degree ones?

That's correct. I TBC with a Shopsmith and made my own dead center out of a bolt that fits nicely in my router collet. No problems on accuracy.

 

[sumterdad]

I used the regular bushings to tbc but it cut a grove in my dead center

 

[leehljp]

Aluminum will make a good bushing and is soft enough to turn on a wood lathe.

NOW for something that is not spoken of much here - in spite of what many people say - you do NOT have to have 60° dead centers or live centers if you use standard commercial bushings to turn TBC.

. . . But if you use the standard bushings, you don't have to do that. I started my TBC back in '08 by making my own non-60° dead drive from aluminum and using standard bushings.

So you are saying just chuck the normal bushings between my dead and live centers and turn away? This be close to the same accuracy as the 60 degree ones?

Accuracy - THAT is another subject! Johnny's ARE Accurate! Commercial are up for grabs on accuracy. Some are, some are not. Before getting Johnny's I always ordered two sets of bushings and checked them with calipers. With two sets, I usually could find 2 of the 4 that were very close to accurate at the least. Qualifying this - I lived in Japan until Dec of 2010 and as such it would have cost me more to send back off center bushings than buying two sets to begin with, so I did that. Some people might check and send back a bad set (or one) if they check and find it off center, but for me even now in the States, it is easier just to order two sets at the beginning.

The difference between Johnny's and commercials is that Johnnys will ALWAYS be right on and Johnny's will fit snug in the tube and not loose as commercial ones do. That looseness will cut down on accuracy also.

Back to the commercial ones as I mentioned - I know that they may not be as accurate as John's, but since I "know," I compensate by watching and measuring repeatedly. If I find inaccuracies of .003 or .004 or more in out of round or off center, I will usually discard that bushing. While I cannot find the articles now, I remember reading that skilled fingers can "feel" differences of something like .001 changes. So a pen off center or out of round will be able to be noticed by a person who knows what to look for (or feel).

IF you cannot get the bushings from John, measure what you have by using calipers and measure the hole to the outside of the bushing at several points around the bushing and then again on the other end. This will tell you how accurate your commercial bushing is relative to the hole being in the center of the bushing. But you need two bushings (or in some cases 4 bushings as in a Cigar pen). IN the case of Cigar, before I got my set from John, I purchased 3 sets of commercial bushings for it and found a good enough match to work on them. They still did not fit as tight as the one's that I eventually got from John.

When you can, get some from John, but if you can't don't let that stop you from turning.

 

[jd99]

I am surprised that one of the bigger companies hasn't started to sell them yet. I am sure a cnc could pound them out pretty fast.

I f some company started mass manufacture on TBC bushings we would end up with the same issue we have with the mandrel bushings.

Ther would be out of round the center wouldn't be concentric to the OD, etc.

Better to make your own, or have someone make them for you that you know will do a good job.

I would make a batch up but I don't have any free time. :frown: It's hard enough to get time to turn pens.

 

[Justturnin]

I turn between the regular bushings and get close to the finished size then I used to throw them up between centers (no bushings) to fix any out of round and apply finish.

Now, I have made my own Delrin finish bushings and I put them up there to clean them up and apply finish now.

 

[azamiryou]

IF you cannot get the bushings from John, measure what you have by using calipers and measure the hole to the outside of the bushing at several points around the bushing and then again on the other end. This will tell you how accurate your commercial bushing is relative to the hole being in the center of the bushing.

Note that what's important is the part that goes into the tube. If the wider part (that tells you when to stop turning) is out of round, it may be annoying but your pen barrel will still be round and centered.

I used the regular bushings to tbc but it cut a grove in my dead center.

This is one reason to drill the 60-degree cone in the standard bushings. accuracy is another - by drilling the cone, you may be able to improve the centering of an off-center bushing. This won't make it perfect, but it can make it better. It may even become useable in a pinch! Just be sure to mount it by the part that goes inside the tube, and minimize flex on your center drill (set the drill deep in the chuck, keep the tailstock quill short).

Another thing to do is if you have 7mm TBC bushings, you can slip those into your standard bushings. This won't improve the accuracy of the standard bushing, but it will get you a cone for the center to fit into.

 

[leehljp]

I turn between the regular bushings and get close to the finished size then I used to throw them up between centers (no bushings) to fix any out of round and apply finish.

This is the correct way to do it. Sometimes in a long and detailed explanations, the "understood" parts get left out. Thanks for bringing this up!

Now, I have made my own Delrin finish bushings and I put them up there to clean them up and apply finish now.

Some people use the delrin to finish and some don't. By the time I moved to TBC, I had a good 2 years of experience under my belt - of trying hard NOT to get much CA on the bushings and didn't need delrins. I was then able to keep from getting lots of CA on the centers. But this is a matter for individual preference and experience.

 

[leehljp]

IF you cannot get the bushings from John, measure what you have by using calipers and measure the hole to the outside of the bushing at several points around the bushing and then again on the other end. This will tell you how accurate your commercial bushing is relative to the hole being in the center of the bushing.

Note that what's important is the part that goes into the tube. If the wider part (that tells you when to stop turning) is out of round, it may be annoying but your pen barrel will still be round and centered.

IF the hole of the part that goes into the tube - is off center, then the blank is going to be off from the pen parts. I had one Sierra bushing that was a good .01 of center from the part that goes into the tube and the shoulder end also - therefore the blanks would not match up with the nib and clip end. Off centered holes will cause problems for matching up with the respective pen part. The blank may be (will be) round but it won't be round in the same relation to ( or match up with) the pen part that it is mated with.

What we are talking about is the technicalities of the differences between OFF CENTER versus OUT OF ROUND. OC and OOR both occur for different reasons and both cause mis-match of the blank with the pen parts.

I used the regular bushings to tbc but it cut a grove in my dead center.

This is one reason to drill the 60-degree cone in the standard bushings. accuracy is another - by drilling the cone, you may be able to improve the centering of an off-center bushing. This won't make it perfect, but it can make it better. It may even become useable in a pinch! Just be sure to mount it by the part that goes inside the tube, and minimize flex on your center drill (set the drill deep in the chuck, keep the tailstock quill short).

Another thing to do is if you have 7mm TBC bushings, you can slip those into your standard bushings. This won't improve the accuracy of the standard bushing, but it will get you a cone for the center to fit into.

I agree that the 60° cone will help and IS better. But the problem that I see is that most people get frustrated at the fact that they are being sent to buy more tools, after having bought a couple of mandrels, and are being told to abandon the mandrels in favor of cheaper TBC. :wink:

Below is a link to the non-60° mandrel that I made back in '08. it has the "ring scaring" from using without bushings, but it worked well. The same thing will happen on steel dead centers and can happen with the standard steel bushings. So yes, 60° chamfer would be better but it is not necessary to get started.

http://www.penturners.org/photos/images/940/1_Dead_drive_2.jpg

That blank of cocobolo above the dead center is the blank that drove me to try TBC. The CA kept lifting every time I separated the blank from the bushing. Finishing it without the bushings WORKED!

 

[dansills]

Lots I good stuff here. I guess I should have specified that I am simply tired of my turned blanks not matching up with my parts on one side. I have checked all the norms and decided to go to TBC to cure it. I have always used calipers for sizing even when using mandrel and bushings. The endless quest that I call a hobby is wearing on me.

I have decided to wait out for Johnny bushings and just use the standard ones to TBC for now. I will get them close and then remove to pure TBC to final dimension and finishing. Seems that is the general consensus. Thanks alot Hank for your insight

 

[InvisibleMan]

I love Johnny's bushings if the two ends of the blank are finished at two different diameters. Otherwise, I just TBC without any bushings at all. Just need one set of calipers locked where I need them, and off I go. The fewer variables, the better IMO.