R8 instead of MT3

[Nigel McBurney 1Participant @nigelmcburney1]

I did have a big turret mill with int30 spindle, good for holding clarkson and bristol ericson collet holders and the four tapped holes were great for bolting fly cutters direct to spindle face with minimum overhang.Abosolute pain in the backside with 3 mt adaptor, the adaptor had to be removed from the spindle taper to get at the extractor slot,to get over this I turned down a few taper shank drills to a parallei slot and held them in the collet chuck though only really suitable for light work, On the larger mills (50 inch table) 30 int is really too small,I should have looked for a machine with 40 int, there is not much 30 int tooling on the second hand market whereas there was/is lots of 40 int, so in the end I bought a Meddings 3 mt pillar drill 100 to 3500 rpm very good machine. to back up the mill for heavy drilling Regarding a choice of 3mmt and R8 one should look to the future,should you wish to upgrade to another machine I think a machine with R8 would command a better price. I have now downsized to an Elliott 00 omnimill (a gift from a neighbour) vert and horizontal spindle,this is the early version with 3 mt spindles ,on later machines the horizontal spindle was updated to 30 int, I suppose this gave a better drive for horizontal spindles and still allowed the use of 3 mt drills in the vertical spindle as there is a lot of daylight under the vertical spindle nose, A 3mt horizontal spindle nowadays (55years after the machine was made) makes thing difficult as availability of s/hand long arbours is virtually non existant,so if buying an older machine with horizontal MT spindle make sure it has a at least one arbour, with collars if so it will probably be for one inch cutters.And make sure the bearing collar which runs in the overarm support fits,.

[JonParticipant @jon]

If you had the choice when buying, without doubt R8.
If a machine was secondhand and MT3 that wouldnt rule it out for me either and never a problem removing takes 15 seconds, no lock up, nothing its used.

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