whats wrong with my mandrel?

[ss_11000]

hi all

i've made quite a few pens (around 20ish) :D since getting my lathe for xmas.

a couple of days later i went down to sydney and brought a mandrel along with other stuff. it worked really well;) up untill a couple of days ago. now, when i make pens etc, the mandrel will un screw it self from the morse taper. its really fustrating:mad: to have it stop spinning properly cos it means about 2 minutes more each time and its happening every minute or so (litterally)

why is this happening:confused: ? am i doing some thing wrong:confused: , although i haven't changed the way i was doing it b4 it started to do it?

stirlo:cool:

[Ashore]

it worked really well;) up untill a couple of days ago. now, when i make pens etc, the mandrel will un screw it self from the morse taper.

Stirlo I would say you have dropped or knocked the morse taper and you are not getting a full contact , a close inspection of the taper may show a bright spot or mark on the taper this would indicate a bruse
If you have or can get some bearing blue , by putting this on the taper push in as normal then remove and inspect you should have in excess of 90% contact, if not you need to remove the high spot / spots
Do this with the smoothest file you have and polish with very fine wet and dry

Rgds

[dai sensei]

If your morse taper is jammed into your headstock, and your tailstock is supporting the other end of your mandrel, how can it unscrew :confused: . Is your headstock or tailstock moving?

All else fails, you can use some Locktite.

Cheers

[Ashore]

All else fails, you can use some Locktite.


Do not use locktite the build up can give you an off centre plus it can make it almost impossible to remove, Morse tapers are designed for a metel to metal fit only

[DavidG]

Hi
Do you mean that:
1. The mandrel centre rod is screwing out the morse taper bit.
2. The morse taper bit is coming out of the head stock.
3. The knurled ring that holds the bits of wood in, is coming undone.
:confused:

[dai sensei]

Do not use locktite the build up can give you an off centre plus it can make it almost impossible to remove, Morse tapers are designed for a metel to metal fit only

Stirlo said the mandrel undid from the taper, not the taper out of the headstock. The locktite I was suggesting was for the thread, not the taper. Having said that, I cannot understand how it could undo, so maybe the problem is his taper turning in the headtsock, in which case I agree with you, don't use locktite.

Cheers

[bdar]

Hi Neil, I think we're on the right track with the mandrel unscrewing from the morse taper. I had one do the same and as you said a drop of loctite into the threads hole andscrewed the mandrel back in. Have had no problem since.

Darren

[Ashore]

Neil having reread it again I think you are correct and I was wrong:o

Rgds

Russell

[ss_11000]

Hi
Do you mean that:
1. The mandrel centre rod is screwing out the morse taper bit.
2. The morse taper bit is coming out of the head stock.
3. The knurled ring that holds the bits of wood in, is coming undone.
:confused:
hi davidg

i was talking about the rod unscrewing itself

[Hambone]

Hi ,
I would have thought that for the mandril to unscrew from the morse taper whislt the lathe is turning it would have to be a left hand and the tailsock center loose .Maybe I am reading the problem wrong.

Ron

[darley56]

What I don't undestand is that the mandrel is 2 parts 1) the morse tape 2) the rod if you dismantled the mandrel and reassemble you will see that you screw the rod clockwise into the morse tape,when you put the madrel on the lathe the lathe run anti clokwise is no way that the rod can be apart of the morse tape while truning a pen, especialy when you say that you trun few pens whit it and the last 4 you got this problem, do you ckeck your equipment before doing a pen?? I mean your drill press and vice ( may be you have centrered the blank but gosh I got the whole of centre :D , what I'm doing wrong? ) do you check your madrel before putting on the leathe? do you check the squareness of each side of the blank before mounting the barrels onto the mandrel? sit down and relax when doing pen all those questions come automaticaly, I think nothing is wrong with your mandrel, maybe you should take more care of your tools:cool: I got 5 mandrels and use them all when doing pens and nothing wrong with them. Now if you feel that the thread of the rod is not adequate to the morse tape just return to the seller for a change

[ss_11000]

hi all

darley- yes i check my mandrel before every use and i dont understand how its coming undone either( that is y i put it on here).

" do you check the squareness of each side of the blank before mounting the barrels onto the mandrel? " i didn;t no that really mattered all that much.

Hambone- its not left handed but i've noticed my tailstock pointy thingy (i've had a blonde moment ) has stopped spinning once or twice but i tightened it and it worked and the same prob still happened

other guys wats locktite ( sounds like a glue ) ( just gotta make sure) ( can u just use super glue etc.)

[bdar]

Hi Stirlo, Loctite is a form of super glue, CA, whatever you want to call it, there are many types. Someone else may be able to tell you the different types but use in industry for threads and fixing threads and the likes.

Cheers
Darren

[DavidG]

Hi
Jamb the morse taper into the tail stock (so it does not rotate easily). Get a pair of big pliers and tighten the rod into the morse taper bit. Good and tight.

When using the mandrel, keep just a little tailstock pressure on the mandrel to stop vibration and prevent it coming loose.

Dave..

[ss_11000]

thanks all for the advice and info.

i'll try it as soon as i can

[Hambone]

Hi,
I have been giving your problem a bit of thought.I am not a pen maker but I think your problem is that you are not using a pen mill ( check Carbatecs cataloge) .If you used this impliment it would square the end of the material back to the brass insert so that when you tightened the two up on the mandril they would not move .I think your problem is that the material you are turning is not square to the tube consiquently each time you take a cut it loosens up a little giving the impression that the mandril is comming out of the morse taper .Not often I am right so I am probably wrong again .Remember preperation is the main thing in anything you do .Less haste more speed.
Ron

[ss_11000]

hambone

most of the time my cuts are square and if not its very slight


"I think your problem is that the material you are turning is not square to the tube consiquently each time you take a cut it loosens up a little giving the impression that the mandril is comming out of the morse taper "

i take everything off the mandrel and its unscrewed from the mt. so i dont think its that. it was a good guess though

[ss_11000]

hey all

i fixed it!

i glued the metal tube thingy into the morse taper and it hasn't failed.

although I need to find a decent glue for acrylic . none of the ones i've tried have worked. all wood ones have worked pretty well.

thanx for all ya help!