mandrel-less pen help PLEASE

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RAdams

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Well, i went to make a pen this evening. This would have been the first pen i have made since going to my local IAP chapter meeting and learning tons of good helpful info. Anyway, the pen i turned this evening was "egged" or "OOR" or whatever you want to call a muffed up pen.

Well, reality set in, and i learned that it is time for me to get with the program.


SO... Where does a guy turn (pun intended) to get set up to make pens between centers?

I guess i need a new drive center? and of course bushings. Is there anything else needed for between centers pen making?


thanks in advance for the help!
 
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RAdams

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actually, i got lucky and was able to dig it up. I will be placing an order with Johnnycnc very soon!
 

jttheclockman

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Boy you read alot of people having out of round pens. Just wondering what is going on??? Have you figured out why yours was OOR??? Did you tighten the mandrel too tight??? Was the blank sitting in the bushings correctly??? Did you use the right bushings??? Is your lathe true??? Was your mandrel bent??? Is it an adjustable mandrel, and I ask because there are times you can shorten the mandrel and turn one blank at a time and the mandrel will not be bent then. Are you using a 60 degree live center??? If not then the old live center may have wore a hole off center in the end of the mandrel. So many things to check. Not that it is not a good idea to learn to turn mandreless but what went wrong.
 

leehljp

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Boy you read alot of people having out of round pens. Just wondering what is going on??? Have you figured out why yours was OOR??? Did you tighten the mandrel too tight??? Was the blank sitting in the bushings correctly??? Did you use the right bushings??? Is your lathe true??? Was your mandrel bent??? Is it an adjustable mandrel, and I ask because there are times you can shorten the mandrel and turn one blank at a time and the mandrel will not be bent then. Are you using a 60 degree live center??? If not then the old live center may have wore a hole off center in the end of the mandrel. So many things to check. Not that it is not a good idea to learn to turn mandreless but what went wrong.

John,

With all of the questions about what went wrong on the mandrel - are you trying to scare people to mandrel-less? :biggrin:

I agree with you that it sure is beneficial to know what is wrong in each case, and that experience is also a good teacher. But the sheer number of problems that can happen as compared to mandrel-less can be weighty when all you want to do is turn a pen.
 
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John M

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I was having a hell of a time with my mandrel. It is an adjustable one. Was out of round like crazy. I finally took it all apart, looked at it and put it back together, did not do anything, and now it is as straight as an arrow. I also shorten it when I can just to make it more sturdy. It is so noticeable when turning now that it is true.
 

artistwood

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i got some bushincs recently fron Johnnycnc to turn CTC and i ain't goin back! i was getting some pretty OOR pens. thought all matter of things were wrong with everything. turns out, even when i got it right, lathe working, mandrel perfect, just the right amount of tension, the dang things could go out of round. with the bushings, it was a lot better, but wasn't cured. i just recently (2 days ago) found out what the biggest problem was........ME! we talk of mandrels, bushings, tension, alignment and even when we get them all perfect, the one variable is us. i was holding the tools just solid enough to control the cut (i thought) but the blank was controling the roundness. it was pushing back the slightest amount and i was cutting a suface that resembled a shallow cam. my arms were acting like springs and allowing the tools to float somewhat when making the cuts. i couldn't tell it at the time and the end result was an OOR condition. i held the tool more firmly on the tool rest, (it helps since some of the numbness has gone from my left hand.......it may have migrated to my head) increased the speed, controled the tool and presto!.....round pen. even works better with the mandrel now but CTC is still my preferred method. i love it when a plan comes together. with all the experienced turners here, maybe someone can explain better than i can. i just keep going to the wood turning school of hard knocks....example, yesterday, i hit my finger on my shop vise and cut it, got a blood blister from an exploding blank (not my fault) got a drop of very quick curing superglue on my finger and burned it enough to blister (burned my toung when trying to remove said glue) but managed to turn 6 very round pens!!!! this hobby rocks...................bear
 
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leehljp

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So what happens when you turn OOR pens using a mandrel-less method?

I'm not saying it doesn't happen, just that the number of things that cause it are reduced by a factor of 3 or 4.

I did not go to mandrel-less because of trying to sidestep the OOR but I did because of the need to finish without bushings. Having said that, for many it is good and worthwhile experience to learn from the problems (such as OOR on a mandrel), and then learn how to correct that. Knowing one's lathe, the setup, ways to troubleshoot and eliminate problems is a great benefit. For the person like this whose lathe is highly tuned, I wouldn't recommend changing for the sake of changing.

However, not everyone is mechanically inclined and there are some fine creative artists out that can benefit from the reduced problems of simpler setups that mandrel-less provides.
 
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jttheclockman

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John,

With all of the questions about what went wrong on the mandrel - are you trying to scare people to mandrel-less? :biggrin:

I agree with you that it sure is beneficial to know what is wrong in each case, and that experience is also a good teacher. But the sheer number of problems that can happen as compared to mandrel-less can be weighty when all you want to do is turn a pen.


No basically I was trying to give this person and any other newbies an idea as to what to look for. There have been a few other points added since I posted and one of the big ones I forgot was US. We as turners can add a variable that is hard to detect if not aware of what we are doing wrong. There are many people that turn pens using mandrels so there is nothing wrong with it. I happen to do it both and they come out quite satisfactory at least to my eyes. Alot of times things are correctable. Good luck and happy turning.
 

RAdams

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Boy you read alot of people having out of round pens. Just wondering what is going on??? Have you figured out why yours was OOR??? Did you tighten the mandrel too tight??? Was the blank sitting in the bushings correctly??? Did you use the right bushings??? Is your lathe true??? Was your mandrel bent??? Is it an adjustable mandrel, and I ask because there are times you can shorten the mandrel and turn one blank at a time and the mandrel will not be bent then. Are you using a 60 degree live center??? If not then the old live center may have wore a hole off center in the end of the mandrel. So many things to check. Not that it is not a good idea to learn to turn mandreless but what went wrong.

No offense, but if i knew what was wrong, or what i was doing wrong, i would have simply corrected and went on. I wish i did know what was wrong, but really there seems to be too many variables for mistakes compared to CTC.

to answer your questions:

i have no idea why it is going OOR.

I may have tightened the mandrel nut (or the tailstock) too tight, again i have no clue.

the bushings tend to bounce around sometimes, so maybe my bushings are wallowed out, but they arent that old.

it was a Euro kit, so the blanks dont actually ride "on" the bushings.

Yes, they were the correct bushings for that kit.

I have a Jet Mini VS. so i am fairly certain it is true, or at least very very close. the drive center and live center line up perfectly when they are tightened down and such. is there another way to check the "true" of a lathe?

the mandrel may be bent.

yes, i have the adjustable mandrel (and my next step is to shorten it to one blank at a time.

no 60 degree center, just the stock live center that came with my lathe.

It may be my cuts. the blanks seem to flex back slightly when i am cutting. I use a spindle gouge or round scraper most of the time.

I have also went back and noticed that a bunch of my old pens are slightly oor too. I really think i need to go between centers with a digical calipration device.
 

jttheclockman

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No offense taken. Just thought I would throw a few things out there to help. Turning between centers may not be the cure all either but good luck with that. Don't forget the 60 degree live center when you buy and also the dead center if you are going to use Johnny's bushings. He will set you up.
 

bitshird

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So what happens when you turn OOR pens using a mandrel-less method?

Mr Wolf, I have several suggestions.

1 You throw your lathe in a scrap pile put all of your pen blanks in the fireplace and sell the remaining kits in the classifieds.

2 Or another option would be to get a new live center, Making sure it has the requisite 60 degree angle

3 Or align your tailstock and spindle


4 Failing option 2 or 3 see first option !! and take up fingerpainting
 

bitshird

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No offense, but if i knew what was wrong, or what i was doing wrong, i would have simply corrected and went on. I wish i did know what was wrong, but really there seems to be too many variables for mistakes compared to CTC.

to answer your questions:

i have no idea why it is going OOR.

I may have tightened the mandrel nut (or the tailstock) too tight, again i have no clue.

the bushings tend to bounce around sometimes, so maybe my bushings are wallowed out, but they arent that old.

it was a Euro kit, so the blanks dont actually ride "on" the bushings.

Yes, they were the correct bushings for that kit.

I have a Jet Mini VS. so i am fairly certain it is true, or at least very very close. the drive center and live center line up perfectly when they are tightened down and such. is there another way to check the "true" of a lathe?

the mandrel may be bent.

yes, i have the adjustable mandrel (and my next step is to shorten it to one blank at a time.

no 60 degree center, just the stock live center that came with my lathe.

It may be my cuts. the blanks seem to flex back slightly when i am cutting. I use a spindle gouge or round scraper most of the time.

I have also went back and noticed that a bunch of my old pens are slightly oor too. I really think i need to go between centers with a digical calipration device.

your problem is 90%guaranteed to be your live center if it is the original that was supplied with your lathe
 

RAdams

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thanks for all the help everyone. Lots to consider for sure. But really, if i am going to change live centers, and everyone seems to do so good with between centers, well i might as well make the switch.
 

bitshird

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If I were you, since it's going to be necessary either way, I would get the live center first and see if that doesn't take care of the problem. you may HAVE A HEADSTOCK / TAILSTOCK alignment problem, pretty unlikely on a jet but it could happen.,
 

leehljp

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One thing not mentioned so far - it is not uncommon to get bushing sets in which one bushing has the hole drilled off center. I use JohnnyCNC's bushings on my most common pens but I still have numerous bushings left over from the mandrel sets. These mandrel bushing sets work great on mandrel-less too - unless a bushing is drilled off center or too large. I have found that (for me) - 1 in 8 to 1 in 10 commercial bushings do have enough off-center drilled holes or hole size to affect OOR to some degree.

OOR problems common to mandrels AND mandrel-less/between centers:
• Head to tail stock alignment,
• Live center problems,
• MT problems (dirt, nicks etc.)
• Bushing holes drilled off center
• Considerably off square blanks


If ANY of the above 5 items are the problem, it doesn't matter if it is Mandrel-less/Between Centers OR with Mandrel set up - OOR can occur.

Problems that are unique to mandrels:
• Bent mandrels
• Nut too tight with blank fitting problems on mandrel
• Tail stock too tight
• Bushing holes too large
• Chisel pressure

One More Thing - AFIK, there is nothing unique to mandrel-less that causes OOR. A few people do have trouble with flaring the brass tubes when not using bushings during finishing. But this is not an OOR problem.

If you are aware of something that I missed on the above statement, please post it. I am not FOR one side or the other per se, I am for getting to the truth of the matter and what works best overall for different situations or people.

Mandrel-less alone eliminates 5 of the 10 problems listed. The other 5 problems are not problems of Mandrel-less use. When there is a combination of two problems, it can be frustrating to the "problem solving" challenged. This should not deter artists from making pens into art, which is why I advocate mandrel-less to many.
 
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rjwolfe3

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Mr Wolf, I have several suggestions.

1 You throw your lathe in a scrap pile put all of your pen blanks in the fireplace and sell the remaining kits in the classifieds.

2 Or another option would be to get a new live center, Making sure it has the requisite 60 degree angle

3 Or align your tailstock and spindle


4 Failing option 2 or 3 see first option !! and take up fingerpainting


Hah! My fingerpainting is worse then my penturning so that won't work. I am going to go with bushings being bad and will start ordering some from Johnny but man that will get expensive. I know the centers are good but not sure on alignment as this is a PSI lathe. I will keep plugging away and see what the future brings.
 

ldb2000

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So what happens when you turn OOR pens using a mandrel-less method?

Rob , I have several bad bushings , almost all with holes drilled off center and a couple of bushings that don't properly fit the tubes they are made for (one set is off by almost .004" too small) . Johnnie's bushings are a small price to pay for round pens .


Ron , don't throw out all your bushings and mandrels quite yet . Yes it is true that mandrels have allot of different problems and sometimes those problems add together to make for a terrible time trying to fix all the problems , however there are times that turning between centers won't work for your application , it's then that you will HAVE to deal with the mandrel problems . I say that you should figure out what is going wrong now so when you NEED to use the mandrel it will work correctly .

First , you need to get a 60 degree live center (you will need this with either method of turning) , and it might be a good idea to get a new mandrel rod in case yours is bent .

Second , keep the mandrel as short as you can and only turn one tube at a time .

Third , SHARPEN all your tools . A dull tool will make you press harder to take a cut and the harder you press the more the mandrel will bend .

Last is to check your bushings to see if they are good or not . A dial indicator with a magnetic base is cheap and will tell you if your bushings are drilled correctly and if your mandrel is good or bad .
 

jttheclockman

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Just one thing and I think it is a big thing is that if you are doing a two blank pen you can only do one at a time. Care must be taken to keep grain orientation proper especially if you have 4 different sized bushings. I still prefer the use of the mandrel if everything is working correct. I like to use no bushings when applying my CA finish. I have done a few pens using Johnny's bushings and will say this they are precision made items and a joy to use. But until I start having OOR issues with my mandrel I will continue to use it.
 
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