MC900 centres not lining up

[jazza250]

Hi all,

Just bought a Carb MC900 to get started in wood turning.
Had turned a few logs into sawdust before making a start on some pens.
When i put the pen mandrel in the headstock, i noticed that it did not line up with the tail stock.
On closer inspection, it appears that the centres were out by 5-6 mm.
I can pull out the locking pin on the headstock, jiggle it around a bit, then lock it back in, but it is still out by 2-3 mm.

Is there a tolerence that these machines are made to?

Thought i would get some opinions before taking it back to the shop.

Thanks, Jared.

[Ashes]

I don't think you will find a spec on the tollerance of the centres. 2-3mm is a bit too much on that lathe.

Is it out by 2-3mm in the same spot. eg. is the tailstock always higher than the headstock or to the left for example. Just want to make sure that the drive spur and live centre are seated in the headstock and tail stock properly.

If it can't be easily adjusted, I'd be calling the shop. I have a MC900 that lines up much closer than that.

[rsser]

Is the diff consistent? (ie, swivel headstock, move tailstock, move centres in their sockets, and you get the same result with every combo?).

- you can have one or both centre pins bent
- you can have crud in one or both MTs (stick little finger in and feel)
- you can have grease or crud under the swivelling headstock or under the tailstock or both
- you may have slop in the tailstock: lightly cammed down, grip with both hands and try to swivel

Just options for elimination.

[Ashes]

Also check the bed of the lathe is flat. It is possible it has a dip/rise or even a twist in it. A straight rule can check that.

Just reading your first post again... have you put the tailstock right up against the head stock or have just lined it up with the mandrel?

When you have the mandrel between the headstock and the tail stock is there a visible wobble in the mandrel or does it run true. It is also possible that the mandrel is bent or out of allignment itself

[rsser]

Good calls Ashes.

[Edwards]

Hi all,

Just bought a Carb MC900 to get started in wood turning.
Had turned a few logs into sawdust before making a start on some pens.
When i put the pen mandrel in the headstock, i noticed that it did not line up with the tail stock.
On closer inspection, it appears that the centres were out by 5-6 mm.
I can pull out the locking pin on the headstock, jiggle it around a bit, then lock it back in, but it is still out by 2-3 mm.

Is there a tolerence that these machines are made to?

Thought i would get some opinions before taking it back to the shop.

Thanks, Jared.

Hey Jared.
There isn't a standard tolerance but if the centers are out by more than say .5mm, then it is unacceptable. An uneven floor will cause some light weight stands to deflect and even put a twist into the bed. Bolting a stand to the floor without correct levelling will also put your centers out.
I do not represent any machinery manufacturer or re seller.

Cheers
Edwards

[woodwork wally]

Hi Jarred
!. start with a drive dog in the headstock and bring the tailstock up with a live centre in and with the tail stock held firmly to your side of the bed try to align the headstock drive centre to it
.2.now move the tailstock down the bed keeping it firmly on the same side of the bed and put your mandrel in the head stock and see how far out it be Rotate the mandrel to check that it is not bent.:no:
3. if in this you still do not line up then start checking floor levels .
4. also check lathe bed for twist and bends using a long steel ruler along each bed and then by holding ruler on edge along one bed slowly move one end to the other bed ie. you are now checking diagonally rail to rail . If bed rails are straight and diagonals out then check floor for level . and pack up a foot to try to correct:2tsup:
6 Four was so big i decided to skip 5 . If all the above has not got you within 1/2 [read as 0.5] m.m.
then one 900 should return to sender.for a medical . It is not unknown for a bed to be U.T .S.:oo: and it is up to the supplier to ensure that they supply product capable of doing what is required and expected of it . the MC. series are dezigned as a spindle turning lathe first and foremost and pens are spindles .so if everything above has failed :?GO FOR THE JUGGULAR Cheers WW.Wally

[jazza250]

Thankyou for so many quick replies.

Yes it is always out in the same spot, live centre closer to me than drive spur.
Tried taking out the drive spur and live centre for a clean, and they appear to be properly seated.

I first noticed it with the pen mandrel, and had hoped that it was just the pen mandrel was bent.
But when placing headstock and tailstock up against each other is when you notice the mm difference.

The lathe is mounted on a fairly heavy wooden bench which appears to be flat.
Even if the bed was slightly twisted, would there be such an error when the headstock and tailstock is up against each other?

Will check out the bed later today, will let you know how i go.

Thanks, Jared

[hughie]

Jared,

Basically the range of MC's etc are made to a price level......design is reasonable, execution is often woeful.

Mine does not line up either, decided not to worry about it, as its not crucial. Unless your gonna go in for making "tremblers" or long finals etc like Robert Bosco I suspect you can live with it.

http://pagesperso-orange.fr/robert.bosco/trembleuren.htm

[jazza250]

Just returned the lathe to Carbatec and swapped over for another one that lines up. :)

Thanks for all replies.

Jared.

[woodwork wally]

Ripper mate Just as it should be . I'm glad they played ball for you Now ENJOY your newfound addiction without worrying about the machine Regards WW.Wally:aussie3::wave: