# Anyone Have Experience With TBC Centers?



## TonyL (Feb 8, 2017)

Hey Folks:

I don't use a mandrel. I do use TBC bushings as well as the non-TBC bushings to turn between centers. I don't really have any trouble with the non-TBC (PSI or the like bushings), but I thought these centers _may _add some stability and possibly even truer turning. I wonder about the quality of these centers given the relatively low price. 

If you use them, I would like to know what you think.

Turning Between Centers Mandrel System MT#2: Arizona Silhouette=

Thanks!


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## Lenny (Feb 8, 2017)

Tony, the advantage I see is they will work with 7 mm pen kits. To turn 7mm kits between centers would otherwise require special tbc bushings. As you know, with 60 degree centers you can tbc using the regular bushings for everything larger than 7 mm. Of course, because they are machined to higher tolerances, the special tbc bushings are worth the extra cost.


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## Mr Vic (Feb 8, 2017)

My humble opinion: if you have standard bushings, reverse them in a Jacobs chuck on the headstock and then drill with a centering drill bit. This will give you the 60deg angle for your dead center and live center. Now they will be similar to your custom TBC bushings and can still be used on a mandrel when desired.

You could also get the same effect with and adjustable mandrel and a mandrel saver turning a single tube at a time.

That said if you didn't already have all the other stuff and were just starting out it's not a bad idea and you could still mount plastic cones on the shafts for finishing.


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## Lenny (Feb 8, 2017)

When I tbc I only use the bushings (whether regular or special tbc bushings) to get close to finish size. I then finish turning, sanding and finishing between 60 degree centers with no bushings. You can't do that with these.


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## dogcatcher (Feb 8, 2017)

I use a similar system to the AZ Silhouette system.  Mine consists of a collet chuck on the headstock with a short piece of a pen mandrel.  In the tailstock a drill chuck but it has ball bearings and turns like a live center, I also have a short piece of a pen mandrel in it.  I use the original bushings, nothing special. 

I also use a homemade version that is similar, I made some short mandrels, that start out as 3" long 3/8" round drill rod.  And about 3/4" long of that  is turned down so the bushings fit on them.


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## magpens (Feb 8, 2017)

I do it very simply by mounting a cone in the headstock chuck and a live center in tailstock.

No worries at all about bushing inaccuracies.


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## TonyL (Feb 8, 2017)

> Tony, the advantage I see is they will work with 7 mm pen kits. To turn 7mm
> kits between centers would otherwise require special tbc bushings. As you know,
> with 60 degree centers you can tbc using the regular bushings for everything
> larger than 7 mm. Of course, because they are machined to higher tolerances, the
> special tbc bushings are worth the extra cost.


 
Thank you Lenny. I have TBC bushings for 80% of the kits that I make - some from Constant, Nikitas, Berea, and my own family-related machinists. I even have them for slim and trim lines which I don't make anymore. 

I was just looking for a "tool/toy" to possibly improve the performance of the mandrel-ready bushings.

Thank you Lenny.


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## TonyL (Feb 8, 2017)

Mr Vic said:


> My humble opinion: if you have standard bushings, reverse them in a Jacobs chuck on the headstock and then drill with a centering drill bit. This will give you the 60deg angle for your dead center and live center. Now they will be similar to your custom TBC bushings and can still be used on a mandrel when desired.
> 
> You could also get the same effect with and adjustable mandrel and a mandrel saver turning a single tube at a time.
> 
> That said if you didn't already have all the other stuff and were just starting out it's not a bad idea and you could still mount plastic cones on the shafts for finishing.


 
Thank you Vic. I do have the right centering drill bit; but, i don't want to thin the walls any. I already find them light. I like the idea though. Thank you.

I was hoping more have actually used the units and had good things to say.


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## TonyL (Feb 8, 2017)

magpens said:


> I do it very simply by mounting a cone in the headstock chuck and a live center in tailstock.
> 
> No worries at all about bushing inaccuracies.


 
That's what I do it now. I also rotate the bushings a quarter-turn in opposite directions about 75% through my roughing. Before I kicked the mandrel 3 years ago, one of the experienced turners at WC recommended that I do that. I still do it even with my TBC bushings. I know why it is done, but have no idea if it does anything. About 98 at of 100 barrels turn true; the other 2 are barely noticeably off with no effect on the function or appearance of the pen.


Thanks folks. You saved me $30, Going to shop now to turn a few pens.

ttyl!


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## farmer (Feb 8, 2017)

*TBC*


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## Curly (Feb 8, 2017)

dogcatcher said:


> ......In the tailstock a drill chuck but it has ball bearings and turns like a live center, I also have a short piece of a pen mandrel in it......



I bought one of those chucks from Little Machine Shop. I found it had .003" runout if memory serves. When I called and asked if it was normal they said that was within limits. I set it aside and we went on to using 60 degree centres and regular bushings without modification and finishing without the bushings.


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## Charlie_W (Feb 8, 2017)

Tony, aside from what has already been mentioned, I just want to point out that if the stock bushings do not fit snugly on this mandrel stub, there is still room for 
error/ out of round. If bushings fit nicely, these centers could be helpful.
Good luck!


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## leehljp (Feb 8, 2017)

Just a warning to watch those bushings. it seems like they must be OK now, but back in 2006 - 2007 and 2008, a few bushings from different vendors were drilled off center. Since I was overseas, I would order two or three sets and get one good set. A few bushings were *visibly* drilled off center. While not as much of a problem for me but for a few, the bushings were sometimes too loose in the tube or on the mandrel.

At that point, I checked everything with calipers. As I noted, it doesn't seem to be  much of a problem now.

If a mandrel bushing was perfect, I used it between centers, but I sure grew to like JohnnyCNC's bushings.

Of course, I took the bushings off when I got down to near size.


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## mark james (Feb 8, 2017)

leehljp said:


> Just a warning to watch those bushings. it seems like they must be OK now, but back in 2006 - 2007 and 2008, a few bushings from different vendors were drilled off center. Since I was overseas, I would order two or three sets and get one good set. A few bushings were *visibly* drilled off center.
> 
> At that point, I checked everything with calipers. As I noted, it doesn't seem to be  much of a problem now.
> 
> ...



Yup, mighty nice, sigh...


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## Mikeyt (Feb 8, 2017)

I have the turn between center mandrel system I love it it. Have turned several items with them no issues at all and seems better then turning on a mandrel. The quality is great for the price I was surprised how good they are. Especially on 8mm and 7mm size tubes and I can turn between center with the bushings I have for the pen kits. 

Overall they work great 


Sent from my iPhone using Penturners.org mobile app


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## TattooedTurner (Feb 8, 2017)

Mr Vic said:


> You could also get the same effect with and adjustable mandrel and a mandrel saver turning a single tube at a time.



This is what I've been doing. I was considering getting this tbc setup but didn't realize it's effectively the same thing, thanks for saving me the money.


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## its_virgil (Feb 8, 2017)

Because I like (maybe a junkie) pen turning tools and because I teach and demo several times a year I like to have lots of options and new tools to show. 

I have this TBC mandrel system and have made about 10 pens so far. The tools is well made and works great. Better than other methods? Maybe not. But, I do like how it works and operates and I will continue to use it when I TBC. I have wasted $30 on tools that do not perform as advertised...several times...this is not one of them!

BTW, it will not solve problems with ill made or out of spec bushings. 

Now, to do the right thing...whatever that is.
Do a good turn daily!
Don








TonyL said:


> Hey Folks:
> 
> ...but I thought these centers _may _add some stability and possibly even truer turning. I wonder about the quality of these centers given the relatively low price.
> 
> ...


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## TonyL (Feb 8, 2017)

Charlie_W said:


> Tony, aside from what has already been mentioned, I just want to point out that if the stock bushings do not fit snugly on this mandrel stub, there is still room for
> error/ out of round. If bushings fit nicely, these centers could be helpful.
> Good luck!


 
Yes, and I don't like the idea of putting something that may add run-out. After, 20 to 30 barrels or so...I throw-out the mandrel bushings. 

Thanks. Again for $30...what am I going to get.

I am surprised that the LMS thinks that .003 is ok.


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## TonyL (Feb 8, 2017)

its_virgil said:


> Because I like (maybe a junkie) pen turning tools and because I teach and demo several times a year I like to have lots of options and new tools to show.
> 
> I have this TBC mandrel system and have made about 10 pens so far. The tools is well made and works great. Better than other methods? Maybe not. But, I do like how it works and operates and I will continue to use it when I TBC. I have wasted $30 on tools that do not perform as advertised...several times...this is not one of them!
> 
> ...


 
 So you bought it and like it...and I know the quality of your work is exceptional. Maybe when Barry comes to Atlanta in a few weeks, I will pick one up. To your point,  have given away some much higher-end stuff that I just didn't like..this maybe the bargain of the year. And if I don't like it, its yours 


Thanks Don.


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## TonyL (Feb 8, 2017)

leehljp said:


> Just a warning to watch those bushings. it seems like they must be OK now, but back in 2006 - 2007 and 2008, a few bushings from different vendors were drilled off center. Since I was overseas, I would order two or three sets and get one good set. A few bushings were *visibly* drilled off center. While not as much of a problem for me but for a few, the bushings were sometimes too loose in the tube or on the mandrel.
> 
> At that point, I checked everything with calipers. As I noted, it doesn't seem to be  much of a problem now.
> 
> ...


 

Thank you Hank, I have done that too and it worked at well. I still do it.


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