DML24 tailstock alignment

[M_Chavez]

Hi All,

I've got an old and battered DML24 that I've been using for an odd turning job and for making chessmen. I appreciate the lathe is entry-level at best, but so far it's done everything I wanted it to do.

I would now like to tick off penturning from my bucket list, and I need better performance from the old DML24. In particular, I'd like to try and get the tailstock aligned as well as possible to the headstock for drilling and threading.
From poking around the tailstock, it looks like I need to add a bit of material to the contact points to align with the headstock.
Are there any ways to add material on a permanent or a semi-permanent basis? Shims come to mind, but how do I hold them in place, unless I shim one of the tubes? Glue a shim to the tailstock with epoxy?

Thank you.

 

[Distinterior]

I have a similar lathe to you ( mine is a DML36 SH swivel head model) but it appears our tail stock's are the same.
I've had it for quite some time now and a couple of years back, I was having the same issue as yourself.

I wondered if my bars had a slight sag in them and ended up completely removing the lathe headstock, slackening the fixings that hold the bars at each end and rotating them about 180 degrees.
After reassembling everything, the tail stock realigned and has been fine ever since.....

 

[M_Chavez]

Thank you very much. I had a similar thought - whether the bars were slightly ground at the top by the tailstock moving in and out, which shaved off some of their height.
There's clearly some wear on the bottom of the tailstock, which I suspect is the main culprit.

I've put a straight edge to the rails and they seem to be straight - there's only a hair's width sag. I can rotating, but that won't be enough.

When we're talking about misalignment, right now, if I put good quality axi center tips right next to each other, the tailstock is about 1mm off at 9 o'clock. Raising the tailstock "foot" by 1mm aligns the centres well enough to pass the eyeball test - which will be good enough for me.

 

[Duncan A]

Assuming the DML's are similar to the old CL's, are the bedbar clamps the right way round? They have three contact points on them that ensure the bars are properly aligned.
More detail should be available from anyone with a manual.
Duncan

 

[M_Chavez]

Hmm... Wasn't aware of that.
"Thread the tailstock bolt through a square strap and up
through the hole in the headstock. Arrange for the two contact
points of the square strap to clamp on to the front bed tube, and
the single contact point to clamp on the back bed tube."

Mine are the other way round. For both the tailstock & the headstock.
Swapped the tailstock but still have the same alignment issue.

I guess, the logical way to approach this is to file down the tang on the headstock, and lower one of its sides by the said 1mm. This way the tailstock will become aligned.

 

[M_Chavez]

Ok. got the headstock off. Don't think I've had it off before. It has the same mounting arrangement as the tailstock - two feet on the back rails and one on the front. The single foot on the headstock is in perfect condition, while the single foot on the tailstock is worn. Suspect this is the main culprit.

I'll turn the rails 180 dgerees, assemble the lathe correctly, check the mis-alignment and will then kiss the headstock foot with a file. I think I can get this old dml running true.

 

[M_Chavez]

Ok, thanks both. I've cleaned & re-assembled the lathe, rotated the bars. Now it's aligned within about 0.5mm according to mk1 eyeball.
Who would have thought that assembling something according to the user manual will improve its performance!

I'll hold on with filing for now and see is this alignment sticks or not.

 

[ChaiLatte]

When you are to use the machine for pen turning, what will be in the tailstock?

I ask because in principle, you can create a feature in the tailstock exactly aligned with the headstock, no matter how maladjusted the tailstock is.

Hold a soft, blank Morse taper arbor in the tailstock, marked for clock position and note tailstock barrel extension. Put a drill bit in the headstock and drill a hole in the soft arbor. Ream the hole if required. That hole is exactly in line with the headstock.

You can then remove the blank arbor as you like and as long as you insert at the same clock position and use the tailstock at roughly the same extension, the hole will remain aligned with the headstock.

 

[M_Chavez]

Thank you for the advice.
Tailstock will hold taps, dies, reamers, drill bits, with the work held in a headstock chuck.

Currently I've got an old cheapo jacobs chuck that's got runout of its own, but I've just invested into a set of ER32 collets, a threaded collet chuck for the headstock and an MT1 chuck for the tailstock (because I'm tight and this way I can get excellent accuracy and only buy 1 set of collets).

Since it's MT1, I'm afraid I can't downsize any more.