38mm spindle bore?

[ronald walker 1Participant @ronaldwalker1]

Hi folks,

I have noticed that the chinese lathes when capable rate their spindle bores at

38mm, doe's that mean the bore won't pass 11/2" bar, or is "38mm"just an approximate term? My lathe is a Sphere (Atlas clone) 10" swing, the bore will only pass 5/8". Iam eyeing up a Sieg 12" with 38mm bore and want to know if it will pass the bar. Thanks. Ronnie.

[ronald walker 1Participant @ronaldwalker1]

[Thor 🇳🇴Participant @thor]

Hi Ronald,

I don't have any 1 1/2 in. bar in my metric world so I can't test with such a bar. But I just measured the bore in my 290 lathe (a Weiss machine), it is 38.8mm so your bar should pass through.

Thor

Edited By Thor on 02/06/2014 17:27:10

[Gray62Participant @gray62]

My Warco GH1330 quotes the spindle bore at 38mm however, it measures at 38.4 which means it will accept a 1.5" bar. There is however a gotcha, as supplied, the bore is restricted in the centre portion of the spindle, the reason for this is that there is a long keyway in the spindle to locate some of the head gears and as such will not allow 38mm bar to pass fully through the spindle.

With care and a suitable jig, this bore can be opened out to accomodate the full bore throughout the spindle

[Nick_GParticipant @nick_g]

.

The spindle bore may be 38mm, but the bore of the chuck may be less and so limiting what size bar can pass.

Nick

[ronald walker 1Participant @ronaldwalker1]

A big thanks to all who answered.

God Bless.Ronnie.

[Ian S CParticipant @iansc]

The bore of the 8" chucks on my 1326BH lathe is 50 mm, spindle bore 38 mm + a wee bit, have not measured it, I think the bore of the 6" 4 jaw is 40 mm. Ian S C

[BazyleParticipant @bazyle]

Quite a few threads on forums mention having to bore out to meet the advertised size whether 38 or some other version. Looks like it should never be taken for granted and probably depends on whether they broke the drill on the last batch and are using the spare knowing the quality procedures are not that strict with all their customers.

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by ronald walker 1 on 02/06/2014 00:49:02:

My lathe is a Sphere (Atlas clone) 10" swing, the bore will only pass 5/8".

The Atlas 10F is specified as having a 25/32" bore. Mine will certainly pass 3/4" no problem. I wonder if the Sphere clone was different for some reason?

Russell.

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