mandrels...beating a dead horse

[dachemist]

Has anyone been able to purchase a straight mandrel recently? I've lost count of how many mandrels I've tried (commercial and "hand made" (by someone else)) and every mandrel I've bought has been bent (well, they didn't run true, I assumed because they were bent). I've had this problem with 2 different lathes, and 2 different collet chucks, along with a number of the MT portions of the adjustable mandrels.

I usually turn between centers but sometimes a mandrel is useful (i.e. <s>blatantly trying to steal</s> artistically licensing some of the ideas from Russ's videos).

I've tried to straighten my mandrels as described on Russ' website but it doesn't work for me.[B)] Am I an idiot?

I bought the stuff to make my own and tried once a week or so ago but that's a story for another post.

Thanks a bunch.

 

[wdcav1952]

Mike,

Roll the mandrel on a totally flat surface. If it rolls true, there is another problem. Bring the tailstock up to the headstock (preferably with a dead center in the headstock MT) and check to see if the headstock and tailstock line up. It sounds like something is not lined up correctly in your lathe.

 

[redfishsc]

Here is how [Penn State] solved my out of round problem.

For about 6 months I'd buy a mandrel, use it, cuss it, and toss it. I was using the Beall Collet chuck, supposedly the end-all be-all (beall = be-all?) of mandrel securing.

I did ABSOLUTELY EVERYTHING I COULD FIND ON THIS SITE AND EVERY OTHER SITE and NOTHING helped. Out of round pens, mandrel whip, you name it, I cussed it.


Along my penturning trek, I moved to another state and the new shop I was at had no drill press for me to <s>hog</s> use, so I had to order a jaw chuck to use for drilling with the lathe.


The Barracuda from Penn State appeared to turn HORRIDLY out of round. So I sent it back. They tested it and sent it back to me, said it was fine.


They included a great big washer to put on the headstock thread of my Delta Mini. Turns out the REAL CULPRIT was the thread on my Delta-- every one of my screw-on chucks/jaws were bottoming out on the threads instead of seating on them.

Using that cheap flat washer, barely 1/8" thick, keeps absolutely everything running true blue--- hundreds of pens and other turnings have proven that.

I had spent probably $150 on replacement stuff- mandrels, belt, headstock spindle (which came with the same threading problems as the old one, free of charge of course).

All I needed was a washer. AARGG!


Go to Lowes and buy a washer with a 1" hole and give that a shot. $1 could have saved me lots of busted blood vessels.

 

[nava1uni]

My lathe came with such a washer and I use and mandrel and it always runs true. I bought several extra to have on hand because I drop them and they roll under my tool cabinet and it is too heavy to move. Can't say enough about the washer.

 

[dachemist]

Thanks everyone.

I have checked the alignment and it looked ok.

I'll try the washer, that sounds like the kind of simple thing I would miss.[B)]

 

[Rifleman1776]

As has been suggested, they can't all be bad. After one or two, look to the lathe. Let us know what you find and how you corrected the problem.

 

[rherrell]

Here's what I use...

I made this one out of steel but I suppose you could use wood. Dial gauges are cheap, about $15 and some cheaper. Turn a piece to fit your banjo and put a hole in it!
Here it is disassembled...

And here's where I keep it, always ready to check ANYTHING for runout...

The mandrel in the photo is the FIRST and ONLY one I've ever bought.
Put it in the lathe, bring the dials pointer up until it touches and then turn the lathe by hand. I turn it so the high spot is TOWARDS me and then give it a little tap with a plastic mallet AWAY from me. It takes about 30 seconds to get it within .001 at the right hand end of the mandrel. I can get it closer but that is quite acceptable for pens.

 

[toolcrazy]

You also might consider:

http://www.woodturnerscatalog.com/store/New_Products___Taper_Mate___taper_mate?Args=

MT might be dirty. I'm ordering one today.

 

[redfishsc]

I hope you don't mind if I opine on that Taper Mate, but for the price, I'm pretty sure it's nothing that can't be done with a cheap pipe brush .


$4 gets the job done vs. the $18 for the tapermate. You can often find these brushes at hardware stores or at better aquarium shops.

 

[toolcrazy]

Originally posted by redfishsc

I hope you don't mind if I opine on that Taper Mate, but for the price, I'm pretty sure it's nothing that can't be done with a cheap pipe brush. $4 gets the job done vs. the $18 for the tapermate. You can often find these brushes at hardware stores or at better aquarium shops.

There is nothing wrong with options. THX

 

[PTJeff]

OMG!
Being a novice and not a machinist, I thought that all of the cr!p that I have been turning out was my lack of skill, then it was the lathe, POS (so I thought). Put a washer in, and now...OMG! everything is true and i'm just giddy. I really thought i was not going to get this worked out without a new and more expensive lathe. Thanks to all for this piece of information

 

[redfishsc]

Glad it helped.


While I'm not a physicist, I do believe quite strongly in Occam's Razor; the simplest explanation (or solution) is usually the right explanation (solution).