Work Holding for simpletons

Nigel, you are correct it is just for an example, I have proper machine jacks, Wixroyd 15000.W0050 jacks and step blocks for when I do this sort of clamping. This was showing the minimum you could do to fix the issue and also the space behind the studs in the original photo was taken into account with the example shown. My preference would have been a good sturdy bar with holes for the studs going across the workpiece as has been mentioned above given the space available.

There is one of these jacks in this photo from 2017 and step blocks supporting the back of the strap clamps from the kit on the wall behind the mill.

Martin C

Yet again I must thank you all for the input. As bad as it looked I assure you it was solidly held and as Neil Wyatt said "light cuts, gentle feeds and an abundance of caution" are exactly what I used. I'm still alive enough to type this but haven't tried the big hole yet. I think I may invest in an angle plate and vise a bit more up to the job. That's really what my clamping kit needs for a better match up. The tee bolts I used in the pic were not part of the kit which is much meatier but the slots in my 4" vise are tiny. Christmas is coming so I'll see what that brings.

Meantime I have to say how surprisingly excellent blacksmiths drills are, at least on aluminium.

Tony Pratt if you ever get that DRO issue sorted please post your solution on here, with luck I'll still be around to see it.

Terry,

Had it come loose, you may well have destroyed the T-slots on one side or the other, before it came to a stop, or was launched in your direction. It is definitely worth asking before starting the job if you are not 100% sure that you can take (normal) robust cuts. Someone will almost certainly have needed to securely hold down something similar.

For a start it might save you scrapping an item or the tooling. It would not be the first I have scrapped a part because it moved while machining...

That;s your problem right there. Boring heads are not designed to be used in the tailstock and tailstocks are not designed to hold a boring head. You end up with waaaaaay too much tool overhang and the essential little bit of slop between tailstock barrel and body becomes amplified by the distance/leverage and will move about all over the place. The other problem with today's cheapo Chinese boring heads is the supplied carbide boring tools are useless until they have been correctly reground on a green grit grinding wheel.

If you can hold the job securely in your four jaw chuck, the best way to bore the hole after drilling is with a stout boring bar held in the toolpost and fed along by the carriage. For a 30mm-plus hole you should be able to use a boring bar with a nice solid half-inch diameter or so shank. It should stick out of the toolpost just a tad more than the depth to be bored.

For the drilling first, start with a centre drill then a pilot drill of maybe 5/16" or 3/8" diameter then your large drill, then bore. It may help with the "juddering" if you machine a flat on the job same diameter as the finished hole so your drills have a steady flat surface to get started on. But it shouldnt really be necessary.

You need to get yourself a good book on beginner level lathe work, such as The Amateur's Lathe by LH Sparey to get the basics down pat. Forums and YouTube are helpful but no substitute.

Edited By Hopper on 06/10/2020 02:02:46

Thank you Not Done It Yet, good advice, which is why I didn't proceed any further before coming here for advice, which of course I have accepted gladly.

And ditto to you Hopper, I will indeed now refrain frrom using the tailstock for boring.

I did buy Mr Hall's old book before the lathe arrived!