Tighting mandrel

[rebfan04]

I am using a mandrel saver when i turn my blanks. I also hand tighten bushings with brass nut on end. I have a Delta lathe. Is it ok to tighten the tailstock on the mandrel? When i do this the sound that the lathe makes changes. If I was turning between centers I would tighten the tailstock correct. Just dont want to harm lathe.
Thanks

 

[jttheclockman]

You need a live center that matches the bushings or mandrel which is normally a 60degree. Tighten just enough to get the live center spinning and it keeps spinning when turning.

 

[Drstrangefart]

Yeah, I just run the tailstock in, connect firmly, tighten it until the belt chirps just a bit, then back it up to right at the point it goes quiet again. When I don't do that, the blank sometimes grabs the tool, and the blank stops turning for a second. I als hand tighten the brass nut as tight as fingertip. I COULD tighten it more, but manual labor left me with the ability to SEVERELY overtighten and not be completely aware of it.

 

[ctubbs]

I am completely missing something here. Are you using both the mandrel saver and the brass nut on the mandrel at the same time? I thought the idea of the saver was to do away with the nut and let the mandrel run free lengthwise.
I place a spacer next to the headstock, a bushing of the correct size, the blank, another bushing then the mandrel saver holds the whole thing tight enough to turn. The brass nut is somewhere in the tool cabinet. YMMV. Am I doing it wrong?
Charles

 

[ldb2000]

The object of the Mandrel saver is that you don't use the brass nut any more , the mandrel saver takes it's place and you tighten the blanks to the bushings with the tailstock . This puts the pressure of the tailstock on the blank not the mandrel and keeps the mandrel from bowing .

 

[PenPal]

With respect John and the Doctor of Strange this question involves the principle of loading the pressure on the spacers and the blanks using a hollow live centre where the point to point pressure is eliminated hence the name MANDREL SAVER. This method employs a hollow that allows the mandrel to pass through the live centre with a firm slide fit? I presume.

There is a video on the sellers site.

Rebfan you are obliged with your new system to maintain sufficient pressure through the hollow live centre to prevent the blanks free wheeling or simply put not turning and yes the lathe noise will change. Until such time as manufacturers catch up with the badly designed live centres and introduce thrust bearings in front of the headstock bearings and tailstock bearings extra unnecessary wear occurs. Untold years ago I started using a similr principle but nesting the mandrel about 3/8 of an inch in a brass sleeve fitted in the live centre, The pressure on my system my design is maintained by 1/4 inch washers used as spacers for small variations in length of blanks and I turn only half a pen with two piece pens. This works well for me normally find discussing my method seems boring for folks.

Have success I do.

Regards Peter.

 

[jttheclockman]

Ok I have no idea what a mandrel saver is so therefore disregard my comments. Sound to me like another gadget.

 

[ctubbs]

John, it is a live center with a hole where the point would normally be that allows the mandrel to slide through. The face of the live center then presses directly on the bushing giving the blank enough friction between the bushings and headstock to turn allowing the blank to be shaped. All this without putting any pressure on the mandrel thus eliminating mandrel bow due to being over tightened by the brass nut. It actually kinda works.
Charles

 

[Papo]

There has been a problem with a lot of mandrell savers from PSI that had bad bearings and were really noisy when turning.If your mandrell was bought from PSI they are replacing them free of charge.You can call them and they will send you a really quiet mandrell saver if in fact you bought it from them.
Good Luck
Be Bless