Thread: Mandrel saver ?

Sounds like a bad bearing , these things just use a standard sealed bearing ,not a thrust bearing ,but if its noisy under pressure that is not good at all . Are your ends squared up properly on your blank as if not it could push to one side and bind , I made my own in the end using a clutch throwout bearing from a mini I believe cheers ~ John

Hey Pariss the mandrel shaft isnt bottoming out in mandrel saver is it ? I use spare bushes as spacers to save having to adjust the shaft in and out for different length pen barrels.
Mine is a homemade one so may differ from yours.

Originally Posted by gawdelpus

Sounds like a bad bearing , these things just use a standard sealed bearing ,not a thrust bearing ,but if its noisy under pressure that is not good at all . Are your ends squared up properly on your blank as if not it could push to one side and bind , I made my own in the end using a clutch throwout bearing from a mini I believe cheers ~ John

Thanks John, yes, the ends are dead square. I only bought the thing out of curiosity, to see if it made any real difference, but think I will just sick with my 60deg cone dead centre, as it runs silent, and has never put a bow in the mandrel.

Got one and never had problems with it. Sounds like you got one made on a Friday arvo.

Originally Posted by cookie48

Got one and never had problems with it. Sounds like you got one made on a Friday arvo.

Yeah Cookie, I just pulled it of the tail stock and gave it a hard spin by hand, and you can hear the buggered bearing grinding away inside. Also, the head of the saver has several thou of wobble (play) in it, so I think your right. Hardly worth sending back to Gary GPW as the thing is only worth about $20. Anyway, I drop him an email just to let him know about it. Trust me to get a dodgy one eh

Originally Posted by Pariss

Yeah Cookie, I just pulled it of the tail stock and gave it a hard spin by hand, and you can hear the buggered bearing grinding away inside. Also, the head of the saver has several thou of wobble (play) in it, so I think your right. Hardly worth sending back to Gary GPW as the thing is only worth about $20. Anyway, I drop him an email just to let him know about it. Trust me to get a dodgy one eh

If its like mine then the shaft support in the centre is only held in place with an "O" ring can be pulled out ok. Worth taking it apart and taking the bearing to your local bearing shop to replace it cheers ~ John

The first one I got was a tad noisy from the start and didn't last long. I like the concept though and the one I have now is a good'un. I would definitely pay more for better quality / longer lasting if available.

Originally Posted by gawdelpus

If its like mine then the shaft support in the centre is only held in place with an "O" ring can be pulled out ok. Worth taking it apart and taking the bearing to your local bearing shop to replace it cheers ~ John

Will have to have a closer look at mine, didn't think it came apart but if so will replace with a better bearing, cheers, Des

Pariss,

I can not comment on the Mandrel Saver per se however there was a guy in the US who was having manufactured by his local machinery business his design version of a Mandrel Saver, at this time I was having trouble with my system (since cured) so I got in touch with the guy in the states who was a budding entrepeneur and could not follow my in depth discussion and also I felt I would not feed his need to improve his Mandrel Saver.

Starting at the beginning the system of nesting a Mandrel in a tiny point from a live centre which like everyone else I did, turning a full pen on a long Mandrel also meant bracing the Mandrel using fingers to reduce the vibration. Bingo I thought fingers are too important to risk in this way (seemed stupid) to me first I cut back to half a pen then 10 to fifteen years ago I eliminated the live centre nose into the Mandrel end.

Pushing this ad nausum over many years on this site and others with a view to sharing being met with so much ho hum for the last time this is my invention and the system I use on Taig Lathe, Pen Wizard, my own design faceting device, on my VL100, and on two other lathes.

Pic shows the VL100 with the Mandrel almost undressed only one bush showing
on the Mandrel sleeved into a Brass Sleeve inserted into the live centre 3/8 of an inch.after cutting off the threaded end of the mandrel. Other pics as well.
I use washers 1/4 inch to pack for undersized blanks. The tailstock pressure holds the blank. A lot of my ideas have been put into production but I feel the Mandrel Centre you speak of has need to be modified in some ways to even approach my method.
The consensus is the receiving method in the saver is sloppy, the bearings suspect two enemies of vibration free turning.

My apologies to resellers of the mandrel saver my comments based on their direct importer in the USA users fully substantiated under user reports.

Kind regards Peter.

Reading extensively the Commercial

Hey Peter, thanks for posting info + pics of your great setup. To be honest, I have had zero problems using the mandrel in the standard method. I use a Groz industrial model 60deg cone centre, which enters the spindle end dimple perfectly so there is no friction. I think the main problem people have with 'out of round' pens is that the round brass mandrel nut is over tightened, and that slightly bows the spindle. Also the dead center can easily be over pressured into the mandrel spindle causing it to bow and turn off center axis. I just finished half a doz Bullet pens using the standard mandrel method, and the serenity of a quietly turning lathe coupled with a background sounds of digital quality Roy Orbison and Dean Martin, and some great Jazz, beats mowing the lawn or taking the wife shopping on a Sunday that's for sure.

My other half, who is not a pen turner in any way, but deals with machinery in his job, says it is mechanical. If you are going to drive something without a positive drive then you require inertia. Therefore, with the mandrel saver you may have to operate the lathe at a higher speed.

Using the tail stock to apply higher axial load will reduce the life of the mandrel saver. As pointed out by John I think, this is only fitted with a ball bearing.

This is absolute double dutch to me but no doubt you clever blokes will understand what has been dictated to me. I have had no trouble with my mandrel saver so far.

Good luck,

Shirley

I bought one of the mandrel savers from the USA but its still in its box at this stage. I was a bit concerned that the pressure it put on the head bearings would damage the lathe. I will have to read up a bit more on it yet. At the moment, the rare moment I get to play in the shed, I am using an adjustable mandrel which allows its length to be shortened and takes some strain off it. It seems to work ok. But I am still seeking out a high quality stainless steel mandrel in 7mm and 8mm. That should stop any bending.
Greg

Originally Posted by plantagenon

I bought one of the mandrel savers from the USA but its still in its box at this stage. I was a bit concerned that the pressure it put on the head bearings would damage the lathe. I will have to read up a bit more on it yet. At the moment, the rare moment I get to play in the shed, I am using an adjustable mandrel which allows its length to be shortened and takes some strain off it. It seems to work ok. But I am still seeking out a high quality stainless steel mandrel in 7mm and 8mm. That should stop any bending.
Greg

Just be aware that a 7mm shaft is too big for slimline tubes even 1/4" dia size will not fit The standard shaft is a few thousandths smaller than 1/4 " dia, and all your standard bushes unless worn will also not fit I don't do many slims so I used 1/4" but had to ream the bushes to suit cheers ~ John

John is right, it isn't just 7mm and 8mm. I'm also not sure that using a stainless steel bar will overcome bending, depending on the grade of stainless it can also be soft.

Silver steel or drill rod, available from engineering places like Blackwoods is better and I have used that in both 1/4" AND 5/16", not cheap though.

I hardly ever use mandrels anymore as I they are just too imprecise. The majority of my turning is done with either no mandrel bushes, which basically limits you to turning 1 tube at the time, or closed end mandrels when I want to make a closed end.

Once you have used the no mandrel bushes, or between centre, turning you won't go back.
It does however require some investment in the bushes as you need 4 for every kit you use. I make mine from stainless 304 and haven't had to replace one yet.

I have used most of the variations and permutations of mandrels and hve never used one I was happy with, but maybe I'm just fussy.