Warco VMC adjustment.

[Mark P.Participant @markp]

Hello all I have just been checking the vertical head alignment on my VMC, the closest I can get is, left to right .02mm and front to back .04mm. Is this good? I realise that it is not a toolroom machine should I try to get closer to 0?
Mark P.

[Mark P.Participant @markp]

[Martin ConnellyParticipant @martinconnelly55370]

These numbers on there own do not tell enough to pass an opinion. If they are over a diameter of 10mm then they are probably unacceptable. If they are over a diameter of 300mm they are acceptable. So the question is what diameter are they measured across.

Martin

[Mark P.Participant @markp]

Yes Martin I should have said they were over a 10″ diameter. I used a piece of 1/2″ float glass as a reference surface.
Cheers Mark P.

[Russ BParticipant @russb]

If you turn your float glass or whatever you use about the spindle axis 180 degrees and then average the measurements that would account for any surface deviation in your reference surface – you could in theory use anything smooth – just use a marker pen in the spindle to mark the centre and the y axis to draw a line front to back and use these to aid accurate turning.

I dont recall what is or isn't acceptable by numbers, I always find fly cutting highlights what is unacceptable, if the lagging edge of the cutter leaves equally light ring marks cutting to the left, and to the right – that's spot on for me!

Front to back is a little trickier, but again if fly cutting cut down the center of the part, then when you unlock and move the Y to give a slight overlap (say 5mm) to cut the front and back the overlap should just lightly skim the initial center cut leaving rings but not really removing anything. I don't think you can adjust this anyway without rescraping the saddle, knee or column (or all 3!!) and determining which bit needs scraping and how much is a whole other game – although very rewarding (I thoroughly enjoy the meticulous metrology of it, each to their own!)

[Martin ConnellyParticipant @martinconnelly55370]

I have my tram set ever so slightly off zero left to right. What this does is allows the trailing edge of a fly cutter to burnish the surface when used in one direction. If used in the other direction I get the overlapping light marks described above by Russ. If this sounds like it should not happen you need to remember that the fly cutter tool may be deflected upwards when the leading edge is cutting but will have practically no deflection on the trailing edge.

The point is that getting tram to zero may not be worth the effort put into it if you are close enough for the results to be satisfactory. Your 0.04mm across 254mm is 0.0016mm across a 10mm end mill. and unless you are moving up and down 250mm in a single set up then your vertical features will be less than 0.04mm out top to bottom. Unless you are working in a totally controlled environment with a need for very tight tolerances I think what you have is fine.

Martin

[WindyParticipant @windy30762]

I have a Warco VMC and would like to check the R8 spindle for adjustment and lubrication.

The large cast iron spindle pulley was removed and found a lot of casting dust in the part the spline goes.

Do I have to take the quill assembly out to check spindle adjustment end float and lubrication are they sealed bearings as they sound dry.

[Roger VaneParticipant @rogervane67137]

Hi Windy

My guess is that if you want to just check end-float in the spindle you could do this by locking the quill and then finding some way of 'moving' the spindle so that you can check the actual end-float. You will need to remove the quill itself (complete with spindle) if you want to either repack or adjust the bearings.

When I fitted a raising block to my machine I removed the quill / spindle to reduce the weight of the turret assembly. The quill itself is easy to remove, and in an article that I wrote regarding the raising block I said….

" The first major item to be removed was the quill, complete with spindle. To do this simply remove the depth stop threaded rod and nuts. Within the depth stop is a capscrew that attaches the stop to the quill – remove this and the stop. To release the quill itself, wind it downwards using the downfeed lever until the quill disengages from the drive pinion, taking care to provide support as it is released. One word of warning here – control the return of the lever rather than just release it as the return spring is quite strong and will hurt if the lever hits you". Please note the warning – it is a strong spring and it does hurt if the lever hits you.

Hope this helps – good luck.

[Mark P.Participant @markp]

Thanks Martin, I think that I will leave it as it is and make something.
Mark P.

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