tbc or mandrel?

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hazmat74

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As the proud owner of a new-to-me lathe, i am sort of stuck. All along i have been planning to begin on a mandrel, mostly because it would be easiest to start with on my taig. But now i have a rikon 70-100 and the idea of learning by tbc intrigues me. I know they both have pros and cons, but i need to determine which direction to go in regard to what i purchase. I dont want to waste time and money where i dont have to.
 
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I have only the mandrel, no taper. On the taig, i was going to mount it in a collet. Now i have to rethink how to proceed. Once i get the rikon cleaned up, i may just do as you suggest. Going to baltimore this week but possibly the following?
 
I am leaning toward tbc. So many things to pick up with the different lathe. It is a serious change of direction after planning on rigging up the taig.

Extra question: where is a good place to pick up 2 mt centers? I am going to need live, dead and drill chuck.
 
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Mandrel all the way. I turn 3 pen body pieces at a time and as long as my lathe is running true they all come out just fine.
 
I turn all my sierras between centers, but still have to use a mandrel for the delrin finishing bushings. So I have one lathe set up with the dead center in the headstock and the other with the mandrel. Works for me.

All 7mm pens are turned on the mandrel (one of David's Better Mandrel Saver mandrels). I only have mandrel bushings for Jr gent and cigars. I'm just learning to turn them and will probably buy tbc bushings for them as well.
 
As you can probably tell, you've only just begun spending money. Be prepared to lay out another couple hundred pretty quick between tooling, bushings, finishing stuff, kits... :-/
 
Turning between TBC is my preferred method. Lazerlines is a good source for steel bushings for your TBC. A bit more expensive but they last a long time. TBC is also the way to go to apply CA finish, but without the bushings so there is no CA on the bushings to worry about.
____________________________
Everyday I'm vertical is a great day
 
No reason for a mandrel...as hundreds of threads and post will attest...friends don't let friends use mandrels!! Go see John Goodin...Johnny CNC
 
How do you turn 7mm without a mandrel. The bushings don't fit inside the tubes like they do on larger pens.

Sharon
Jim Burr said:
No reason for a mandrel...as hundreds of threads and post will attest...friends don't let friends use mandrels!! Go see John Goodin...Johnny CNC
Click to expand...
 
Either method does work just fine. I see no reason to switch to turning between centers if turning with a mandrel is working. I have turned both ways and both ways work well...at least for me. I have no reason to pay the price for the bushings when turning between centers offers no real improvement for me.I often turn between centers with no bushings at all. I finish my pens with CA and have no problem with gluing bushings to the mandrel or gluing bushings to the ends of the pen barrels. I have no need for special delrin bushings to use when applying CA to my pens. We do have members who take every opportunity to push turning between centers at every opportunity. Nothing wrong with turning between centers or championing the method but it is not the only way to turn a pen. And, it may not be for everyone. If using a mandrel ever fails for me I will probably become a between center penturner. But I don't foresee my trusty mandrel letting me down.:biggrin::biggrin:
Do a good turn daily!
Don
Dan Masshardt said:
We should just let two people write a point / counterpoint article on this subject. I've not even been around that long and it seems like we have this conversation constantly.

At the end of the day - either method works just fine.
Click to expand...
 
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Boxers or briefs?

Ford or Chevy?

Truth be known and not many have said this but here it is. A poor quality POS mandrel will cause you more grief than anything else. There are some high quality good mandrels that are worth their weight. TBC is the setup that I use and recommend to everyone but if you do go mandrel be sure to get a superb quality mandrel with an excellent setup.
 
sbwertz said:
How do you turn 7mm without a mandrel. The bushings don't fit inside the tubes like they do on larger pens.

Sharon
Click to expand...


Like this :)

400502_4969975049067_1281997688_n.jpg
 
Mostly i am trying to get costs under control. I know how this goes when getting set up and the less i confuse things for myself the better, so i am trying to pick one method and roll with it. I have a lot to learn about turning so in the meantime i can play until i decide which direction to go.
 
Where does one find David's better mandrel saver? I believe i am going the mandrel route to start.


sbwertz said:
I turn all my sierras between centers, but still have to use a mandrel for the delrin finishing bushings. So I have one lathe set up with the dead center in the headstock and the other with the mandrel. Works for me.

All 7mm pens are turned on the mandrel (one of David's Better Mandrel Saver mandrels). I only have mandrel bushings for Jr gent and cigars. I'm just learning to turn them and will probably buy tbc bushings for them as well.
Click to expand...
 
When I started out, I read through the library to learn as much as I could before I bought a bunch of tooling I'd never use. I originallay thought that TBC was a more advanced technique. But it's just different than turning with a mandrel. I've been turning now for almost 3 years, and never made a pen using a mandrel. In fact I don't own one. I've done many pens without using bushings, but I also own several sets from JohnnyCNC.

As others have pointed out, there is no right or wrong way. Just do which ever you feel is best for you.

Here's my list of pros & Cons. I'm sure that the list isn't complete.

Pro's:
Less chance for out of round blanks.
No Ca sticking to bushings. (I don't use bushings when I do finishing)
No mandrel to bend.
If you want to try a new kit, you don't have to buy the bushings. I only buy bushings for kits I plan to make on a regular basis.

Cons:
Only 1 barrel at a time.
Bushings cost more (but should last longer).
 
Ok here is another issue.

I have taken the liberty to do some good compares and the results speak for themselves. As previous mentioned items like 'cost' can also be explained in the below photo's.

Here we have TBC and mandrel bushings for the Gent Jr/Statesman Jr/Venus and related pens.
attachment.php





This is for the 7mm slimline, euro and related. I included a single 7mm slimline bushing and not the entire euro bushing set. The object in the bottom center is a euro mandrel, it is used to turn the end cap on a euro with a post stud. The TBC bushing set is the '7mm triple play' set by JohnnyCNC. The rings in the center are sizing washers also from JohnnyCNC.
attachment.php



As you can see the advantages of TBC is LENGTH inside the tube yields a longer, more stable and more accurate precision. Also the section outside is greater as well, this yields not only space between the dead/live center and provides extra tool rest support but also comes in very handy when hand sanding.

I have noted several times with a mandrel setup there is some wobble of the bushings because of the short length. If the mandrel shaft is not proper size there will be warping of the blanks.

Ed
 

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BSea said:
When I started out, I read through the library to learn as much as I could before I bought a bunch of tooling I'd never use. I originallay thought that TBC was a more advanced technique. But it's just different than turning with a mandrel. I've been turning now for almost 3 years, and never made a pen using a mandrel. In fact I don't own one. I've done many pens without using bushings, but I also own several sets from JohnnyCNC.

As others have pointed out, there is no right or wrong way. Just do which ever you feel is best for you.

Here's my list of pros & Cons. I'm sure that the list isn't complete.

Pro's:
Less chance for out of round blanks.
No Ca sticking to bushings. (I don't use bushings when I do finishing)
No mandrel to bend.
If you want to try a new kit, you don't have to buy the bushings. I only buy bushings for kits I plan to make on a regular basis.

Cons:
Only 1 barrel at a time.
Bushings cost more (but should last longer).
Click to expand...

I turned a new kit yesterday TBC without bushings (the first time I've tried that), and I was having a hard time getting the ends right with a round carbide tool. There's not enough room to properly turn the ends to size without nicking the centers.
 
Quoting Ed (Street):
As you can see the advantages of TBC is LENGTH inside the tube yields a longer, more stable and more accurate precision.

While this is true, the mandrel becomes an extension of the inexpensive bushings, giving you complete continuity from one end of the blank to the other.

IF your bushings are a snug fit to both the mandrel and the inside diameter of the brass tube, there is complete support throughout the spinning pen blank.

This conversation usually assumes crappy mandrel bushings and precision "Between centers" bushings. With this assumption, of course precision will win.

BUT, it is a flawed premise.
 
sbwertz said:
How do you turn 7mm without a mandrel. The bushings don't fit inside the tubes like they do on larger pens.

Sharon
Jim Burr said:
No reason for a mandrel...as hundreds of threads and post will attest...friends don't let friends use mandrels!! Go see John Goodin...Johnny CNC
Click to expand...
Click to expand...

Sure they do Sharon...John has them. That's all I use for slims...or any other pen for that matter.
 
I ordered a mandrel saver package from psi. That was the only executive buying decision i am making today. If i had my druthers(and a fatter bank account!) I would rig up for both and go hog wild. I mostly just want to get started. I have several things i will have to get over the next few weeks but need to go slowly lest my landlord be unhappy when i explain that rent went into toys. As for gluing things together, i have a taig that i can easily make delrin bushings on. Love that stuff and have used it quite a bit.

Also, pardon the lack of caps where normally required. Am on my phone and it is easier.

Eta: also, thanks for all the insight. Very much appreciated.
 
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The mandrel setup that I started with was a junk design. The shaft was to prone to bending and I did bend it.

Since then I have bought around 3-4 mandrels and this one below is probably one of the better mandrels I have owned.

attachment.php


This is the last mandrel that I bought and I was doing one tube at a time with it. Now it was more precise and better fit than the other setups I used as this one is adjustable.
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Same setup on the tail side of things.
attachment.php






ed4copies said:
Quoting Ed (Street):
As you can see the advantages of TBC is LENGTH inside the tube yields a longer, more stable and more accurate precision.

While this is true, the mandrel becomes an extension of the inexpensive bushings, giving you complete continuity from one end of the blank to the other.

IF your bushings are a snug fit to both the mandrel and the inside diameter of the brass tube, there is complete support throughout the spinning pen blank.

This conversation usually assumes crappy mandrel bushings and precision "Between centers" bushings. With this assumption, of course precision will win.

BUT, it is a flawed premise.
Click to expand...


Flawed indeed. Yes the shaft becomes part of the bushing and a good mandrel is a good thing. However you are still grossly limited to the bushing to mandrel contact area. I have yet to see anyone making precision mandrel bushings, is there anyone?

In the above setup a great bit of the adjustment weight is placed on the locking nut and not the shaft. Which makes the shaft less prone to warping. Also the shorter length further reduces warping.


panamag8or said:
I turned a new kit yesterday TBC without bushings (the first time I've tried that), and I was having a hard time getting the ends right with a round carbide tool. There's not enough room to properly turn the ends to size without nicking the centers.
Click to expand...

Hate to say it but wider is better. This is where your 1" wide chisels comes into play, flat nose scraper, skew chisel of some flavor or what not.
 

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I, too, bought the adjustable mandrel when I was getting started. I think I did my first pen- a Slimline - on it and decided it was just too much trouble to rig up all the pieces each time. I switched to TBC with bushings when I have them and without bushings when I dont have them. It works either way. A 60 degree dead center is cheaper than a mandrel setup, and turning is no different. I still turn too much or not enough.
 
edstreet said:
I have yet to see anyone making precision mandrel bushings, is there anyone?
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I think the bushings from lazerlines can be used with or without a mandrel. They are drilled through for a 7mm mandrel (I think). At least the bushings I have for my marksman eagle are drilled through, and I think when they 1st came out, they advertised that they could be used either way. I'm not sure though since I only TBC, and never gave it much thought for using them with a mandrel.
 
My first mandrel, and only one, was an inexpensive one with the mandrel saver. I eventually discovered that the rod in the headstock MT2 was off center, by a lot.
I would image that the better ones from Berea would not be that way.
My setup has a persistent .002" runout that I compensate for as much as possible. So, when I check the wall thickness of a blank turned between centers, it will never be spot on but when I am 2-3 thousands different, then I know the TBC bushings that I made are as good as I can make them. I spend a lot of time checking things to be sure they are running true and centered.
With TBC, I worry less about catches. You do need to keep better track of which ends of the blanks go together for grain match and it does take a bit more time.
 
airborne_r6 said:
ed4copies said:
...BUT, it is a flawed premise.
Click to expand...

The only flawed premise is assuming anything other than TBC or that voicing an opinion that runs contrary to the mainstream is acceptable on this site.
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The interesting thing here is that TBC or not has its own culture of "mainstream". There is alot of camps of TBC, and like any thing some people swear their way is the only way... TBC is alot like glueing your tubes, there is some people that will try to convince you their way is the ONLY way because its the BEST.

There is only 1 best.... its that one that works for you!
 
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Ok... A couple of quick pictures of my setup. This may not be the cheapest setup - but I'm really happy with it because of the options it gives me, its rock solid, and easily adjustable.

In the first picture, you can see the mandrel in a collet (not in the holder at the moment, a couple of 7mm bushings (probably pretty worn because they just space things for me - I use calipers for dimensions), and a mandrel saver which makes shorting the thing as easy as moving the tail stock.

In the other picture you can see the collet chuck, which at the moment is holding a "punch" from the HF set that I use for doing some closed end seam rippers on.

I will swap back to the other collet when it comes to pen time.
 

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