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HI folks. Does anyone out there know what the spindle clamping pressure should be on a Hitachi Seiki VM40? I have a problem which I'm sure is down to a drawbar issue, we have a Keltch gauge which measures the suspect spindle drawbar pressure at 2.5Kn. I seem to remember being told somewhere that it should hit minimum 4.2 Kn, but can't find any data. Anyone any ideas?
Thanks.

[RRL]

4.2 seems to be quite low. I would suspect that if this machine is a 40 taper the minimum should be about 5.9 (1326 lbf)! The max should be 7.8(1753 lbf).

The spec I quoted is for a Mori Seki SV40. I do have all the specs for Mori Seiki, but not for the Hitachi.

I hope this helps you out!

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Thank RRL.
That might indeed be useful. Are those figures you mentioned the actual specs for a Mori? We also have a couple of Mori NH4000 hori's, which may not be SV40's but are still BT40 (As is the Hitachi, by the way) so I would guss might be using a similar pressure.
Thanks

[RRL]

Yes, that was an actual Mori Seiki spec. I did find a little more info on the Hitahci VM40. The hand drawn print I was looking at stated 2000kg (4409 lbf)
which I believe is to high for a 40 taper. This is even high for a 50 taper.

[Rockyr49]

That's about right for a 50. 4000 to 5000 isn't unusual. Some these days are up to 8 or 9000. They vary greatly by manufacturer. Some of the older 40 taper Haas were less than 1000. LeBlond Makino on the other hand will run up to 2500 on their 40s. Mazak from 1500 to 2200. Bottom line is we don't like to see less than 1500 on a 40.

Rocky
www.spindlegrinding.com

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Cheers for the info gents. I'm waiting for Pollards UK (They bought out Hitachi UK when they went bust), all I have so far from them is ' I think it's about 4Kn'. So much for the supplier. They are having a look to see if they can find the correct spec. I'll post back when I get a reply.