Wabeco D4000 drilling issues

Due to trying to solve a drill alignment issue with my Wabeco, I tried my drill chucks in my Emco headstock taper, which required extra long arbors in order to seat. Thanks to the members, I now know that the chucks are OK to a thou. That still left me with a new German lathe which wobbles when it drills.

I have since spent a few hours trying to identify the actual issue with my new Wabeco D4000. Having just about established that my drill chucks are good, I started to realise that it might be a problem that I have dreaded to consider, a low pointing tailstock. When I did a dti test this week, the tailstock held pins or drills, seem to be between 3 and 7 thou low.

I put in two centres and a test bar and the tailstock shows perfectly level and after a bit of adjustment, aligned front to back as well. I clocked a 6mm x 60mm bar in an Albrecht chuck, totally spot on.

I've just put in a range of drills in the tailstock drill chucks and a parallel centre in the 3 jaw. Even when I rotate everything,chuck, drills and centre, under 30 x magnification, the tip of every drill is noticably low relative to the centre point. How is this possible if it passes all the test bar evaluations?

I have to admit that the lathe still has it's metal straps on the feet which you are supposed to remove and it is just sitting on a £100 carpenter's bench. Now every lathe, Proxxon PD360, PD400, Compact 5 and Cowells, that I've owned, turned very well and accurately without bolting down. I know that accurate levelling is necessary for high accuracy work, but all my other lathes could keep everything aligned to a thou, wherever they are kept. The bench is thick Beech and is roughly level.

Should I bolt it to a bench, level it reasonably and then see what happens, or should I go back to the seller, because of the misalignment.

Many thanks for all your help, Nick.

Before getting too into leveling etc, whip the tailstock off and make sure there is no muck under it.

Yeap, did that first time I noticed the drop and removed and checked the bore. As I say, everything is ok when clocking a test bar between centres, but the drill tips are always low.

Cheers, Nick.

Edited By Nick anon on 19/10/2016 21:50:11

It sounds like maybe the tailstock is the correct height, but the tailstock barrel axis is not parallel to the bed axis. Or the morse taper hole in the barrel is not parallel to the axis of the barrel and/or bed.

A quick check might be to extend the barrel of the tailstock well out, then do up the tailstock and barrel clamp.Mount the DTI base on the carriage and have the DTI pointer on the top of the tailstock barrel. When you move the carriage back and forth along the bed, the pointer should not move, or at least very little, half a thou or less.

A more true test would be to use a Morse taper test bar inserted into the tailstock taper and then run the DTI plunger along the top of the parallel section of the test bar.

In the absence of a Morse test bar you might make a rough substitute by holding a piece of ground bar from an old printer or silver steel in a known good drill chuck. Put it first into the headstock taper and rotate and clock it and get it running true, or take a fine truing cut over the length of it if you can. (No tailstock centre in place!)

The downward pointing barrel could be due to a burr or grit between the two halves of the tailstock where the back/front alignment is adjusted. Maybe disassmble and file/stone off any burrs and clean any dirt out.

It doesnt seem like a twisted bed would give that much tailstock droop but if you are getting into doing precision alignment it is good to have the bed verifed as straight by bolting it down and levelling it. Otherwise there is no guarantee you are starting with the literal level playing field.

It might pay to contact Wabeco for advice too.

As Hopper, but simply test as you have done, between centres but do it with the tailstock retracted, then extended? Clock on the extended tail stock? That would not be as apparent as a further overhang of a drill tip, of course. Using a test bar between centres means any error is being reduced as you move towards the headstock, not increased as when drilling.

This will tell you if the tailstock barrel OD is out of alignment with the lathe bed main axis. But it won't tell you if the tapered hole in the centre of the barrel is out of alignment with the OD of the barrel and therefore also out of alignment with the lathe bed axis.

It could be worthwhile having a look inside that tapered hole too and making sure there are no burrs or gunk kicking the male taper at an angle when inserted.

I would advise you to contact the seller or manufacturer to inform them of the problem before you try any remedial action. Making measurements will help you define the problem for them to address but making physical changes may void any warranty.

Would it be possible to mount a DTI on the main spindle chuck and rotate it round a test bar held in the tailstock. This should indicate the concentricity (or otherwise) close too and at a longer distance from the tailstock?

Mike

Thanks for all the good advice. I can confirm that I've already done a radial bore and radial test bar dti test, dti on carriage measuring test bar and quill parallelism and all seems fine. However when you put either a drill chuck and drill or even a fixed centre, the point of the tailstock held tool is low relative to the headstock.

I've cleaned the tailstock mating surfaces and quill bore, which were already very clean.

I'm unable to put a centre in the headstock without taking the chuck off, but since I've tried every drill or pointed tool in two positions, it shows that the error is a constant one coming from the tailstock end. However, to all appearances, the tailstock, the quill and the bore are all perfectly parallel with the ways.

I'm still confused, so I think I'll do another round of the main tests, write it all down and then email Wabeco to see what they say. Thanks again for all the suggestions.

Best regards, Nick.

.

I understand that you have checked for debris between the bed and the tailstock.

But the tailstock is made of 2 parts. There is the bit that mates with the bed and the top one which is adjustable from side to side. (not sure of their proper names)

Have to checked for debris / paint etc. between these two parts and that they are mated properly together. - I had a similar issue that caused me to pull my hair out for an hour or two until I sussed it.

Nick

Putting a test bar between centres pushes back on the tailstock barrel. Could this lack of pressure on the drills be showing as a droop at the point of a drill when there is no pressure on it. What happens if you tighten the tailstock barrel clamp, does the end of the drill move around?

Martin

I agree with every thing Nick has said about the Wabeco D4000 lathe including his previous reviews, I made the mistake of ordering a new D4000 that was deliverd to me in May 2016. What an heap of junk this machine is, so much so im replacing it with what I should of bought in the first place. Yes a Warco, having owned 2 myfords a Chinese 918 & the last 20 years I had an Emco Maximat v10p, I decided I wanted to stick with a European made lathe thinking it would be a quality machine @ around £4000 that I paid for the Wabeco including some accessories. How wrong I was, I cant even bring myself to selling the D4000 to some one else only for them to find out the hard way that this lathe is rubbish. Im standing the loss & simply replacing this machine, don't be fooled by so called German quality as I was.