Peter,

First … Wecome aboard !!

No, I don't have one of these, but I am interested to understand the problem.

Is there any way that you can check whether the error is in the position of the rotational stop, or in the dimensons of the parts? … I think that either could cause the mis-alignment.

MichaelG.

Peter,

Please correct me if I have mis-understood the construction, but;

given that the rotating head sits at an angle, I think that the 'thickness of its base' would move the axis of the socket up or down with respect to the tailstock taper.

Thus; the reason for my question was to understand whether the mis-alignment is constant [high or low], or if can be corrected by very slight rotation of the 'head'.

MichaelG.

Peter,

I don't have one of these but may I suggest, as a test, that you put a piece of round bar say 20mm in your chuck and machine a 16mm dia spigot on to it that matches the end of all the adaptors for the turret.
Now put the turret onto the 16mm dia you have turned (with the morse taper pointing at the tailstock,of course) and then carefully rotate the chuck, preferably by hand but slowly, and observe what is happening to the morse taper.
Does it run true? Is it a "parallel wobble or does the outboard end wobble more than the inboard end?.
This will help determine what is out of place on your turret
Bob D

What sort of lathe do you have ? I have a couple of tailstock turrets. A smaller one with the indexing on return and another that you manually index. The tool hole does not align dead nuts. It is a little off centre about 0.03mm 0.05mm TIR actual. Since the tailstock is actually 0.02mm above centreline , it is only about 0.01mm out, .It runs true to the axis of the quill, so have found the correct radial position that is the very best alignment. I just put a marker pen mark on the back of the unit that I sight by eye through the 2 oiler fittings on the tail stock.

Neil

Provided the detent is accurate enough to align all the holes with the same error perhaps you could rework the main MT arbor to fit a new one machined to fit but makes it an expensive kit. Really the finishing needs to be with it assembled but they probably thought their wonderfull CNC machines made bits that were all dead true 'cos it said so on the computer screen.

Hi Peter,

You will be best off returning the second unit back to ARC and get a refund. The first unit has been kept to one side. Once we have your second unit, we will send them off to our sub-contract engineering service provider for checking.

Clive: We have been selling this product for nearly 10 years from the same manufacturer. Over this period, we have had about six returns, mainly because of wrong hole size for the spigots – 5/8" instead of 16mm. The two units which were checked by Peter came out of a batch from which we have sold 35 units over fifteen months without any returns. If this information is difficult to believe, ARC is quite happy for Peter to check our stock-control records on his next visit. If he comes and speaks to me, I can show him. This still does not mean that there isn't a problem, but probability is low. I cannot explain why Peter has had a problem on his machine. For this reason, I will get the two units along with some units from the new batch checked. You are quite right in saying that it is ARCs responsibility to take up the problem with the maker. But, based on 10 years of sales with extremely low level of complaint for this product, ARC has to check the product before jumping to any conclusion.

Ketan at ARC.