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holesaw on a lathe

Posted: Sun Apr 07, 2019 4:17 am
by liveaboard
Roughing out a large hole in a thick plate [20mm, 7/8"] on my small lathe.
I decided to try a holesaw; and was pleasantly surprised at how easily it went.
A bit of coolant from a spray bottle and it cut through pretty quick, with minimal binding or chatter.
holesaw on lathe.jpg
So I decided to try a bigger one on the next section; this is a 4" holesaw.
I bored a relief hole, I think that helps by giving the chips somewhere to go.
Again, the cut was quite civilized with minimal chatter.
big holesaw on lathe.jpg
After cutting the rough holes, I bored them both to press fit bearings for the center pivot my rolling jib hoist.
bearing holder plates 1.jpg
container hoist 2.jpg

Re: holesaw on a lathe

Posted: Sun Apr 07, 2019 8:44 am
by earlgo
Yes, I've done it too, although with not so big a hole saw. One just has to keep clearing the chips, or provide a chip ejection hole. The slug can be saved for a giant washer.
Nice job liveaboard.
--earlgo

Re: holesaw on a lathe

Posted: Sun Apr 07, 2019 2:04 pm
by GlennW
Wow, step drilling with hole saws. Who'd of thought! :D

Re: holesaw on a lathe

Posted: Sun Apr 07, 2019 3:00 pm
by Patio
Nice crane, that looks pretty handy!

Re: holesaw on a lathe

Posted: Sun Apr 07, 2019 3:55 pm
by pete
Patio wrote:
Sun Apr 07, 2019 3:00 pm
Nice crane, that looks pretty handy!
My thought as well. It looks to be more than well thought out and not a design I think I've seen before Liveaboard. Very nicely done.

I've never used hole saws as large as that on metal yet, but with the few I have that chip relief hole seems to be a lot more important than one would think. Drilling 2-3 around the perimeter seems to work even better. I've no proof, but my gut feeling is the saws cutting teeth seem to last a lot longer when there's less chips getting re-cut in the narrow saw kerf.

Re: holesaw on a lathe

Posted: Sun Apr 07, 2019 6:19 pm
by liveaboard
The chips jamb the blade for sure; vertical seems to work a lot better, I think because the chips come out easier. I was also withdrawing the blade often to help.
I drilled one 8mm hole on the larger cut, and the chips were worming on out.

The little crane; I wanted something very compact to fit inside the container without sacrificing much room, and I wanted it to reach out the door. So I came up with this.
The pivot bearings are leftovers / used, but the wheel bearings I bought new.
I should have made the wheels bigger.
The channel tracks on the walls were tricky, because they have to be parallel and straight. Got them pretty close.
The winch is an old thing I got at auction for $20, 10 years ago; customer to dismount it on site.
It turned out to be 30 feet up, in the center of a factory roof. I probably should have just left it there, getting it down was dangerous.
I test-lifted my 700lb drill press; lifts and swings ok, but the cross beam is hard to move with a load on the little wheels.
bearing block.jpg
tension block 7.jpg

Re: holesaw on a lathe

Posted: Sun Apr 07, 2019 7:39 pm
by Bill Shields
a non-industrial version of the core drill!..best of all worlds!

Re: holesaw on a lathe

Posted: Mon Apr 08, 2019 5:34 am
by RMinMN
If you plan to make several holes and the size isn't quite so large, this set of hole saws seems to work really well.

https://www.banggood.com/12pcs-15mm-50m ... ehouse=USA

I've only done a test cut with my drill press but it cut through 1/4" steel pretty nicely. Here's a Youtube review of them by Doubleboost.

https://www.youtube.com/watch?v=uNn8KGCgHXk&t=8s

Re: holesaw on a lathe

Posted: Mon Apr 08, 2019 5:18 pm
by johnfreese
The plates are larger than your chuck. How are you holding them on the lathe?
Running that size hole saw on the lathe was a wise choice. Most drill presses run way to fast for large hole saws.

Re: holesaw on a lathe

Posted: Mon Apr 08, 2019 6:29 pm
by jcfx
johnfreese wrote:
Mon Apr 08, 2019 5:18 pm
The plates are larger than your chuck. How are you holding them on the lathe?
Running that size hole saw on the lathe was a wise choice. Most drill presses run way to fast for large hole saws.
The first few pictures seem to show a tube welded to the plate.
Did I guess right ?

Re: holesaw on a lathe

Posted: Mon Apr 08, 2019 7:01 pm
by liveaboard
Yes, each plate has a short piece of heavy tube on the other side; the tubes are part of the build.
I actually bored right into the inner walls [with the lathe boring tool, not the holesaw] because the upper bearing is thicker than the plate.
In the past I've done the same thing, but then cut the tube section off.

Re: holesaw on a lathe

Posted: Fri Apr 12, 2019 2:15 pm
by akajun
Look up a tree panning tool. It’s actually easy to grind and they cut like butter. Ground one the other day to cut a 8” slug out of a 2” plate of mild steel.
Had to cut one side halfway through, then flip it over and cut through the other side till I just got through then pushed it out in my press then remounted in my lathe and bored to size.
No chip clearing or binding issues, just keep it lubricated during the cut and make sure you have relief on the tool