Some questions about how you d

[Bugmerc]

Hi guys, I am not super new at pen turning but I have some questions about how "you" do it.
First I have only turned a mandrel, I see the preferred method is between centers. So does that mean just mount the bushings between the centers, or do you even use bushings? If you do use the bushings, that would put the one up against my spur drive and actually wouldn't even reach the spurs, so I'm not sure I could drive it without changing my drive center.
If you don't use the bushings, how do you get to the correct size? Just measure as you go?

I have seen the "mandrel saver" or whatever it's called from PSI, that seems like a hybrid between mandrel and between centers. Not sure I see point if you choose between center turning.

Second is how do you store your bushings? I keep mine in the original tiny ziplock bags. Then I keep all my "pen stuff" in a rubbermaid tote. (I only do pens occasionally) I always fear if I don't seal the bag well, I might find, for example, 2 empty baggies and 4 or 6 bushings running free in the bin. What do I do then?

Thanks for you help!

Chris

 

[anectine]

To turn between centers you will need to change your drive center to a dead center. Look on e-bay in the metal working areas and look for a 60 degree dead center. These units are used often in the metal turning world. Make sure the taper on the drive matches your lathe.


To use the dead center you will also need a live center for the tail stock with a 60 degree cone. Actually almost any angle dead and live center will work, 60 degrees is the most common.

1. Put the dead center in the headstock, the live center in the tail stock.
2. Place the bushings into the blank
3. Now put the blank and bushing combo between the centers and tighten down enough that you can turn without stalling the blank.
4. You do not have to use the bushings, you can get a micrometer and mic your way to perfection. This works great as you turn more and more of the original bushing away by using them.
5. Now once your done turning, remove the bushings and remount just the blank between centers.
6. If you use CA as a finish, you can pile it on a mile high and not worry about those pesky bushings getting stuck to your pen.

As for the bushing storage, I think we all have our own system that works for us. Mine is a small piece of 1/8" plywood with the kit name burned into it and attached to the bushings with a short length of ball chain and clasp (think dog tags, or ceiling fan pull chain). These are all neatly tucked into a Plano tackle box.

 

[ed4copies]

Hi guys, I am not super new at pen turning but I have some questions about how "you" do it.
First I have only turned a mandrel, I see the preferred method is between centers. So does that mean just mount the bushings between the centers, or do you even use bushings? If you do use the bushings, that would put the one up against my spur drive and actually wouldn't even reach the spurs, so I'm not sure I could drive it without changing my drive center.
If you don't use the bushings, how do you get to the correct size? Just measure as you go?

I have seen the "mandrel saver" or whatever it's called from PSI, that seems like a hybrid between mandrel and between centers. Not sure I see point if you choose between center turning.

Second is how do you store your bushings? I keep mine in the original tiny ziplock bags. Then I keep all my "pen stuff" in a rubbermaid tote. (I only do pens occasionally) I always fear if I don't seal the bag well, I might find, for example, 2 empty baggies and 4 or 6 bushings running free in the bin. What do I do then?

Thanks for you help!

Chris

Hi Chris!!

Although it gets a lot of attention, I would speculate fewer than 20% of pen turners abandon the mandrel and go "between centers". Some swear by it---but it is far from the "preferred method" for all penturners.

There are several improvements over the 9"ish mandrel. I prefer an adjustable-length mandrel and turning only one blank at a time. This can be done with a "mandrel saver" or with the standard 60 degree live center in the tailstock.

I have tried turning between centers and concluded that there is more pressure exerted on the ends of the blank, making it more likely to crack, if you do NOT use bushings. IF you DO use bushings, there is no difference from using a mandrel---if the bushings are great, the pen will be great. Usually, turners that use "between centers" are using very well machined bushings. THAT is the real distinction, as far as I can tell.

FWIW,
Ed

 

[eliasbboy]

As far as bushing storage, I personally LOVE these containers from Harbor Freight.

They have 24 individual little boxes inside the main box. I use a permanent black marker and label each box with the lit name and model number in case something rubs off.




Here's the link. They run $5.

24 Container Storage Box

 

[eliasbboy]

Hi Chris!!

Although it gets a lot of attention, I would speculate fewer than 20% of pen turners abandon the mandrel and go "between centers". Some swear by it---but it is far from the "preferred method" for all penturners.

There are several improvements over the 9"ish mandrel. I prefer an adjustable-length mandrel and turning only one blank at a time. This can be done with a "mandrel saver" or with the standard 60 degree live center in the tailstock.

I have tried turning between centers and concluded that there is more pressure exerted on the blank, if you do NOT use bushings. IF you DO use bushings, there is no difference from using a mandrel---if the bushings are great, the pen will be great. Usually, turners that use "between centers" are using very well machined bushings. THAT is the real distinction, as far as I can tell.

FWIW,
Ed

I wish I read read this when I first tried TBC. My second go at it I tightened the tailstock too much and actually cracked the blank. A silly mistake but being new to TBC I wanted to make sure I wasn't going to get a face plate full of material flying off.

Oops.:frown:

Also, when I started out with a mandrel I just used the live center that came with my lathe. Until it was asked of me here, I never paid attention that it was NOT a 60 degree center, and was in fact wobbling a bit in the end of the mandrel. Just something else to look for if you're going to use a mandrel.

Good luck!

 

[Bugmerc]

OK, great! That's the info I was looking for. I didn't even think of a dead center!

Love the little boxes, and can't beat that price. I've been worried about the little baggies, these boxes will hold up much better.

Thanks again!

Chris

 

[tomas]

I use labeled pill containers. I take so many meds, there's an endless supply.

Tomas

 

[SteveG]

Chris, I do TBC all the time except on 7mm tube kits, and I do very few of those. I also use standard bushings. (The cheap, often poorly made ones that come from the seller of kits.) The key to my process, and many here do this, is the bushings will work and can be used to QUICKLY get the blank down close to finish size. It may be off a little, perhaps out-of-round, whatever, it is still oversized. That does not mater, because my next step is to set the bushings aside (Labeled Container), and complete the turning TBC, with no bushings, and frequent use of the calipers to bring that blank right in to the perfect size. Works great for me, and you notice there was no measuring done until I was close to final size, taking light cuts and needing only light pressure from the tailstock.
Steve

 

[Bugmerc]

OK Steve, that makes sense also. I may try that. So I am to assume that the bushings that you get from the kit maker are not always super accurate. I remember some issues early on and I blamed myself for not turning the parts very well. Now I can blame cheap bushings!

On a serious note, are there better made, after market bushings? Is it best to just go to the calipers and measure the kit parts directly and just turn to what you know is the correct final size?

Chris

 

[SteveG]

Chris, yuo are on the right track. The kit manufacturer's bushings are mass- produced, and known for being loose, off axis or non-concentric. They are made to fit on a mandrel rod, so are not tapered to fit the 60* centers, but will work on them. Some people will use a center drill to put the matching 60* seat where the bush meets the center, and this is some improvement, but not necessary. Very exceptional quality bushings are available from a member, johnnycnc at penturnersproducts.com. Be careful even if working with good bushes, as some kits will vary a bit in size, even from the same source. Time to go turn! Steve

 

[Dan Hintz]

The key to my process, and many here do this, is the bushings will work and can be used to QUICKLY get the blank down close to finish size. It may be off a little, perhaps out-of-round, whatever, it is still oversized. That does not mater, because my next step is to set the bushings aside (Labeled Container), and complete the turning TBC, with no bushings, and frequent use of the calipers to bring that blank right in to the perfect size. Works great for me, and you notice there was no measuring done until I was close to final size, taking light cuts and needing only light pressure from the tailstock.

That's my process.

Once I'm TBC, I use a parting tool (with calipers) to get the end down to the proper dimension, then I finish turn. Other than the parting tool, I use a roughing gouge for the entire process.

 

[its_virgil]

Preferred method? By the majority? If so, I must also disagree. Turning between centers is an excellent way to turn pens and is definitely the method of choice by many IAP members. Turning between centers gets a lot of favorable, and well deserved, chatter here. But, I don't think it is the preferred method used by a majority of those who turn pens. I have a couple of sets of between center bushings and use them when I turn those pens. But, I find turning on an adjustable mandrel, making one barrel at a time, to be just as accurate and no slower than turning both barrels at once.

I make this reply because the phrase "preferred method" seems to infer that it is the best way and/or used by a majority penturners. I am not trying to start an argument but just making some clarification on the subject.

Do a good turn daily!
Don

First I have only turned a mandrel, I see the preferred method is between centers.

 

[eranox]

OK Steve, that makes sense also. I may try that. So I am to assume that the bushings that you get from the kit maker are not always super accurate. I remember some issues early on and I blamed myself for not turning the parts very well. Now I can blame cheap bushings!

On a serious note, are there better made, after market bushings? Is it best to just go to the calipers and measure the kit parts directly and just turn to what you know is the correct final size?

Chris

The bushings aren't typically inaccurately sized--although they do get worn through use from sandpaper and the occasional errant chisel. The issue is that your pen's final diameter will vary some based on how much sanding you do and how thick you build your finish. So, the bushings can be used as a guide, but they aren't going to give you pinpoint accuracy.

Turning between centers alleviates a couple of problems. Firstly, mandrels can flex while turning, which leads to oblong turnings. This problem increases with the length of the mandrel, so an adjustable-length mandrel can help, a Mandrel Saver can help, and turning one pen barrel on the mandrel at a time can help. Still, the only way to eliminate mandrel flex completely is to eliminate the mandrel.

Secondly, turning between centers will allow the use of a caliper to measure the end diameters, which is a more accurate method of measurement than using bushings. If the pen barrel being turned is greater than 7mm, the bushings can be mounted with the barrel and then used as a rough guide, and then the bushings can be removed, and the barrel can be sanded to a precise size using the caliper. If the pen barrels use 7mm tubes, then the bushings cannot be mounted with the pen barrel.

I'm still fairly new to pen turning myself, and I turn most of my pens on a mandrel using a Mandrel Saver. If the pen is going to be exceptionally fancy, I'll use the mandrel and bushings to rough size, and then mount each barrel between centers and do the final sizing and finishing.

Regarding better bushings, one problem I've had is that the steel bushings generate black powder when abrasives contact them. This invariably gets onto my blanks and taints pens made from light-colored wood. A good tip that I read that I haven't had time to implement yet is to buy a thick white plastic cutting board from Walmart, and cut it up and make plastic bushings for your lathe. This saves you from having to buy bushings in the future, and prevents your pens from getting contaminated with black smudges.