New lathe, first pen, slightly disappointed.

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Rusty914

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Mar 20, 2008
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58
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Madison, Alabama, USA.
Well, I've got all new gear at the house. New VS Jet Mini. New mandrel. New live center for the tailstock. New gouges & skews. I should be happy as a clam, but I'm not.

Something is wrong. I'm turning blanks off-center. There is a definate wobble at the end of the mandrel.

I've disassembled the mandrel (WoodCraft Pro #145997) and the shaft appears true. When I roll the shaft on a smooth surface, it does not appear bowed.

https://www.woodcraft.com/images/products/145998.jpg[img]

The finish on the point of the live center WoodCraft Morse Taper #2 141060) is wearing off.

[IMG]https://www.woodcraft.com/images/products/141060.jpg

As all of the equipment is new - I'm not sure what to suspect first. However, I'm fairly sure this is a problem.

Any thoughts on what to start examining?

thanks,
Rusty


(Yes, I know about turning between centers. No, I haven't tried it. Please... don't suggest that I invest in a bunch of special bushings so I can TBC. I may take that step someday, but I have a bunch of $$$ in this stuff now. Buying more stuff for this hobby isn't in the budget for a while.)
 
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Marc Phillips

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Jun 1, 2004
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A couple comments...

The live center does not look like it has a 60 degree point... and I am pretty sure the dimple in the end of that mandrel does... so no match there eh... Happened to me...

The other thing is this... and this is only my limited experience... but when I switched to turning between centers all of this wobble and offcenter and all that BS went away... the whole idea is to enjoy this, and there is no joy in Mudville when stuff wobbles...

I only invested a tiny bit of money for the bushings from Johnny... and never looked back. I also still use the regular bushings on cigars and other pens... only ones I bought from Johnny were the slimlines and the Euro bushings...

There's my 2 centavos.... good luck!
 

Robert Taylor

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Jan 6, 2008
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North Canton, Ohio, USA.
the center in your picture definately will not fit in a pen mandrel properly. it is designed for turning wood. i know you can say you are turning wood pens however the center is fitting in metal in your mandrel. a sixty degree machinist type live center will probably get you where you want to be as to accuracy. woodcraft has one with interchangeable tips, but you can find less expensive choices. littlemachineshop.com would be a good place to start. i made my first pen at woodcraft and was surprised that they don't seem to understand that there mandrels and centers do not fit properly. hope this helps, bob
 

tbroye

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Sep 3, 2007
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Sacramento, CA, USA.
I really have had any problem that I know of being off center. I have Delta Midi and the live center looks exactly like the picture. I have noticed the tip doesn't fit the end of the Mandrel that well, maybe I have been lucky all I get is a little noise and have to adjust the tension on the live center. Well off to HF with some Fathers Day money tomorrow.

Tom
 

gerryr

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Sep 22, 2005
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Billings, MT, USA.
You definitely need a live center with a 60 degree point, but I would check the alignment of the headstock and tailstock just to make sure that isn't causing the problem. Put a center in the headstock and a center in the tailstock and run the tailstock up until the two points are almost touching, maybe a couple of hairs apart. Look at it from every angle you can, rotate the headstock by hand. The points should line up.
 

thetalbott4

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Dec 3, 2005
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Roy, Utah, USA.
I would check the alignment of the headstock and tailstock just to make sure that isn't causing the problem. Put a center in the headstock and a center in the tailstock and run the tailstock up until the two points are almost touching, maybe a couple of hairs apart. Look at it from every angle you can, rotate the headstock by hand. The points should line up.

If you havent done this yet, it is essential. Even after a few months use, mine came out of alignment. I went through a bunch of mandrels and blaming my chucks (couldnt be the alignment cuz I already aligned it) until I finally decided to recheck the alignment and sure enough...it was only off by a hair but it was the cause.
 

JeffinWIS

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Sep 24, 2007
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Rural Green Bay, WI, USA.
While it is preferred to have the centers in alignment, being otherwise should not cause runout. That is definitely a "wood" center, you want at metal lathe type, 60* live center...that fits the center hole in your mandrel.
 

MobilMan

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Mar 30, 2008
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Safford, Arizona, USA.
Rusty, not disagreeing with everyone else. But try a few things before you go buying. Is you're work table perfectly flat & level end to end & side to side. If there is a twist of any sort it can put a slight twist to the ways of the lathe. When you bring the tail stock up to the head stock it may be true but the distance of the mandrel may be picking up the twist & throwing the points away from aligning. I have foung that the hole in the end of the mandrel isn't drilled deep enough to accept the very smallest point on that type of live center. I use the exact thing you show in the picture & run true. Drill it out 3/16-1/4 deeper. Just like this '>' will fit into this 'o' at some point if it isn't bottoming out. When you put the mandrel in the head stock, leave it loose, then stick the live center in the end of the mandrel and use it to finish pushing the mandrel in. It doesn't need to be tightened very much. Just turn the thumb screw on snug not tight. That will also keep you from a 'catch', it will let the blank spin free. One more thing then I'm outta here. Try changing speeds & see if the wobble [vibration] goes away.
 

Russianwolf

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Jul 13, 2007
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Martinsburg, WV, USA.
So with the mandrelk in place and the tailstock not touching, what does the tip of the mandrel do when the lathe is turned on? If it's staying at one point it should be fine, but if it's making a circle than their is a problem in the Headstock or mandrel.

Make sure the taper in the headstock is clean of debris. This can throw the mandrel off and cause problems too.
 

BruceA

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Jan 27, 2008
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Fayetteville, TN, USA.
Rusty,
I just bought the same Jet VS Mini lathe and it has the same live center you have pictured. That live center is meant to have wood directly attached, like you would turn a spindle. It's NOT meant to use with a pen mandrel. You need a 60 degree live center, like GerryR and arjudy above have recommended.

The very end of the point of the "wood" live center in the tailstock is taking all the pressure from the pen mandrel you're trying to use, and there's just not enough mating surface to make the live center turn consistently.

You're going to have the same problem if you haven't changed out the center that's in the headstock! That's got the same pointy tip that's meant for attaching directly to a wood piece. The Jet is NOT setup for using mandrels the way it's configured out of the box.

Another source to check is JohnnyCNC (check member listing for his website) for live and dead centers. I purchased a carbide tipped dead center, and one of his live centers earlier this month. Whether you are going to use the "between centers" method, or use a pen mandrel, you'll need to have both head and tailstock fitted with 60 degree tipped units.

Alignment would be the next thing to check, but you'll need to change out the centers as your first and necessary step.

Bruce in TN.
 

PenPal

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Canberra, A.C.T., Australia.
ALIGNMENT CHECK>

Fit a dead centre in the head and tail stock,bring them almost together insert a fine feeler guage between, bring up the tail centre gently , this is the only way I know to visibly check alignment as the deflection if out will be obvious and show which direction it is out. Remember to tighten the tail stock.
Peter
 

Petricore

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Jun 27, 2007
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Austin, TX
Unless you are turning alot of slimlines you don't need custom bushings... I've switched to turning between centers and only cost me like 8 bucks for a dead center, but I don't ever turn slim lines so it wasnt an issue for me, I just mount my normal pen kit bushings up :)
 

sbell111

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Jan 16, 2008
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Franklin, TN
I just picked up a Grizzly live center on Amazon for something like twelve bucks plus shipping. They had PSI ones for seventeen dollars with free shipping if the total of your 'super saver' items was over $25.
 

Rmartin

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Jan 14, 2007
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It's already been said the center you have pictured is for spindle turning, but I have to reply to the notion that turning between centers costs a lot of money. It's just not true. The bushings you have will work just fine, no need to buy any "special" bushings, except for 7mm bushings. Try turning a few cigars between centers. If you don't like it, no money spent.
 

Rusty914

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Mar 20, 2008
Messages
58
Location
Madison, Alabama, USA.
Thank you, everyone for the detailed responses.

I borrowed a live center from someone locally. Almost all of the wobble is gone! It's very, very close.

When I slid the tail of the lathe up towards the head, I noticed that the two don't meet perfectly. It is probably 1/32 of an inch off. (Down and to the left as you look towards the head.)

Is there a way I can adjust this, or am I close enough for our hobby?

thanks,
Rusty
 
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