Removing large amounts of material?

[Paul Alciatore]

Hole saw in drill press (a big one) running at slow speed. CLAMP IT DOWN! Easy to quickly clear the chips by just raising the quill. Tooth brush dipped in some oil for applying cutting fluid while clearing the chips. Should go quickly. Then move to the lathe to finish.

[BCRider]

When you come right down to it, by the time you set up for trepanning you'd have it done by boring after the 1" drilling.......

If he (we) are only doing one part then I'd say you're right. But a 3.7 or so inch slug of 1" thick material is also a pretty nice item to have on the short ends shelf for a hobbyist..... Just sayin'. Sometimes the longer time to save turning good metal into swarf is worth the extra time.

[The Metal Butcher]

When you come right down to it, by the time you set up for trepanning you'd have it done by boring after the 1" drilling.

Yes... and no.

If he (we) are only doing one part then I'd say you're right. But a 3.7 or so inch slug of 1" thick material is also a pretty nice item to have on the short ends shelf for a hobbyist..... Just sayin'. Sometimes the longer time to save turning good metal into swarf is worth the extra time.

The first time is faster. Subsequent times, it is way faster to setup the tool. I've used my ~4" tool again for face grooving.

Now if he has 50 of these to do, he's better off sending them to me with some shiny tools in exchange.

P.S. Annular cutters work great if the material if you have the horsepower. I use a 3 3/8" a lot to make ~3" slugs.

[nc5a]

I've done several trepanning operations in both aluminum and steel 1" thick 7 to 9 inches in diameter with a 13 X 40 2 HP flat belt lathe. You can't hog into the work and your tool geometry need to be very good and needless to say (Sharp).
.

Tool almost through the work piece. Be very careful here as things can turn to **** real fast.


Trepanning operation done on this steel disc

[nc5a]

Trepanning an aluminum disk also 1" thick




Finished part

[Ian B]

You can buy tools made especially for face grooving: https://www.ebay.co.uk/itm/134111383...EAAOSwnC5ic6No

Overkill if you just have one to do, but at least you can see how they look.

Ian

[boslab]

I like trepaning myself, saves a chunk of metal, I tend to be a bit slower on speed than I see on video, it doesn’t affect anything, +1 on not breaking through, it won’t go well, just leave a bit, a mag dti on the bed can really help to know where you are, or dro if your lucky, note to self lock the cross slide and if you can’t lock the top slide ( if your using the carriage) keep it perpendicular so you can’t move the tool sideways
mark

[Black Forest]

You don't mention what other tools you might have available and how often you would have to do the exact same procedure. If a one off I would chain drill it the bore to size on the lathe. If more often then either a hole saw just under size or a trepanning tool and bore to finish size.

[elf]

If you have a mill, try this.

[Mcgyver]

I used a hole saw recently on cast iron, actually rather surprise how well it worked so I'd go that route. Also agree with the post that with speed and big cuts, it doesn't take that long to open it up with boring bar. You do however need a hefty boring bar so you can go at it aggressively

[strokersix]

Drill a small hole to thread your bandsaw blade thru and saw it out. Then finish in the lathe. This requires welding the bandsaw blade of course.

[oxford]

Gang drilling can have its uses but I really don’t see it being a whole lot, if any faster than drilling and boring on the lathe.

Maybe in the mill when using a boring head.

[wdtom]

I would say a hole saw, but drill 3 or 4 maybe 3/8 holes around the the inside of the saw cut to allow the chips to clear. Possibly you can find a taper shank with a thread that will fit the hole saw for a tight chatter fit. Or even make one.

[RB211]

Well, how about buying an Oxy Acetylene torch and cutting the center out? If you are doing a lot of these, this would be the cheapest/quickest method, then a simple lathe job to clean up.

[Dragons_fire]

any time I've needed to do that, I've used a rotary table on the mill and a smaller endmill it would get it cut out fairly fast, and then you can finish it up on the lathe if needed.