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small.planes
02-05-2010, 03:52 PM
Doing a little prototyping for work today, and needed to create a 70mm bore in a 1" thick piece of alloy.
Rather than just drill and bore, creating loads of swarf I thought Id trepan out the center slug. only problem was I dont have a trepanning tool...
So root about and find a Hole saw on a plain arbour. Mount in a boring tool holder, set square and on center, then use tailstock to push the whole lot so the twisting forces on the toolpost which you'd get if you used the powerfeed are not present.
Handily the female center for my changeable center set is just the right size.

http://i306.photobucket.com/albums/nn274/small_planes/05022010090.jpg

http://i306.photobucket.com/albums/nn274/small_planes/05022010091.jpg

The hole provided a very good place to pour coolent without it going everywhere.

http://i306.photobucket.com/albums/nn274/small_planes/05022010092.jpg

Done:

http://i306.photobucket.com/albums/nn274/small_planes/05022010093.jpg


Dave

small.planes
02-05-2010, 03:52 PM
And a more finished shot of the prototype, just before lunch...

http://i306.photobucket.com/albums/nn274/small_planes/05022010094.jpg

Dave

Timleech
02-05-2010, 05:26 PM
Whatever you do, don't hold a holesaw for a job like that in a keyless tailstock chuck.

Don't ask me how I know this.......

Tim

CountZero
02-05-2010, 05:31 PM
trouble getting it out again?:)

Black_Moons
02-05-2010, 06:34 PM
Nice job.. I hate the unflated smaller arbor for my hole saws...
Random tip: grind flats into the arbor so a wrench will fit it for removal (from the hole saw)

John Stevenson
02-05-2010, 07:09 PM
Thou needs one of these.

http://www.stevenson-engineers.co.uk/files/R8holesaw.jpg

The universal R8 hole saw [TM]
Two sizes 1/2" x 20 thread and 5/8" x 18 thread, with or without pilot drill.

.

tmc_31
02-05-2010, 10:29 PM
Small Planes,

That's pretty cool. I'll bet I'm using that little trick very soon. It looks like you are working in aluminum and I wonder how long the hole saw would last in something like mild steel or harder. I have using Champion RotoBrute hole saws for a while with my mag drill. They are carbide toothed hole saws that cut up to 2" thick steel. I was in Lowes the other day and noticed some similar hole saws by Ideal in the electrical section. They may have been a little cheaper.

All the best,

Tim

2ManyHobbies
02-05-2010, 11:22 PM
I love the coolant feed there. Massive quantities of coolant is probably something holesaws aren't that familiar with.

kendall
02-06-2010, 01:16 AM
Nice setup.

For an old semi-regular job I had to cut 4 and 3/8 steel disks out of 1.5 inch plate, materials were supplied and were 5x2 stock.
Best method I figured out was to set the material on a scrap of plywood on the drill press, set to to the lowest speed, set up the flood, and hook a bungie cord to the down feed. Turn it on and go do something else.

That's the job that -really- taught me that slower is better with a large hole saw. I 'knew' it before that, but really learned it on that job.

Ken.

small.planes
02-06-2010, 06:10 AM
Thou needs one of these.

http://www.stevenson-engineers.co.uk/files/R8holesaw.jpg

The universal R8 hole saw [TM]
Two sizes 1/2" x 20 thread and 5/8" x 18 thread, with or without pilot drill.

.
Nope, I dont have any liquorice R8 machines in my workshop.
Now if they were INT40 that would be a different matter ;)

The Arbour was actually made to use in ER collets on the mill, but boring the hole to exact size is so much easier on the lathe than with the boring head in the mill.

TMC31,
These are essentially hacksaws in a circle. Ive done quite a few holes in 10mm mild steel plate with this one and its holding up fine. They are not woodworking holesaws.

Dave

Timleech
02-06-2010, 06:26 AM
trouble getting it out again?:)

Yes, the combination of the saw vibration and the hex shank on a standard holesaw arbor works to tighten the chuck more.......and more.......and more..... to the point where it won't undo. I lost a perfectly good Rohm chuck doing that :(

Tim

J Harp
02-06-2010, 06:50 AM
Looks as if the hole saw was set off center (or centre?) a bit horizontally. Was that done intentionally to allow clearance and chip escape?

gda
02-06-2010, 07:26 AM
Yes, the combination of the saw vibration and the hex shank on a standard holesaw arbor works to tighten the chuck more.......and more.......and more..... to the point where it won't undo. I lost a perfectly good Rohm chuck doing that :(

Tim


I almost had that problem yesterday with a 1.5" drill and an Albrecht chuck in the lathe tailstock. Went to loosen it and it wanted to take my skin. I did not want to marr it up with water-pumps so I used a belt wrench and a couple of jars and it loosened up for me.

Your Old Dog
02-06-2010, 07:33 AM
Thanks for the post. I've avoided boring small holes larger every chance I get! I think I'll gear up to do it as Sir John suggested. I just don't have the patience to do a lot of boring just to see if something is going to work.

Kibby
02-06-2010, 08:13 AM
I've used these a lot. They hands down beat using a hole saw. They are expensive, but well worth it for the time they save.

http://www.hougen.com/cutters/cutters_index.html

BobWarfield
02-06-2010, 12:40 PM
I almost had that problem yesterday with a 1.5" drill and an Albrecht chuck in the lathe tailstock. Went to loosen it and it wanted to take my skin. I did not want to marr it up with water-pumps so I used a belt wrench and a couple of jars and it loosened up for me.

A lot of these keyless chucks are set up with for a spanner wrench. Before you take a pipe wrench to it, look for a small hole for the spanner. I didn't finally learn this until I saw it on a Glacern video and then went and saw most of my keyless chucks are set up this way.

DOH!

BW

Lew Hartswick
02-06-2010, 12:47 PM
Thou needs one of these.

The universal R8 hole saw [TM]
Two sizes 1/2" x 20 thread and 5/8" x 18 thread, with or without pilot drill.

. John that is just too slick. We have a bunch of extra end mill holders .
I think a modification is in order for at least one or two. :-)
...lew...

small.planes
02-06-2010, 03:54 PM
Looks as if the hole saw was set off center (or centre?) a bit horizontally. Was that done intentionally to allow clearance and chip escape?
Nope its not (intentionally) off center, but I have to admit I just eyeballed it to about the correct place base on a light cut I put in with a lathe tool. The slug was a reasonable amount (2 or 3 mm) smaller than the final hole, so I didnt worry over much.

Dave

jdunmyer
02-06-2010, 04:01 PM
I use hole saws all the time in my B'Port, running them quite slowly. The only trick is if you're working with thick material, say more than 1/8". In that case, you should either set it up so the hole saw intersects the edge of the stock, or drill a couple of 1/2" holes that intersect the saw's cut line. This allows the swarf to escape.

We actually cut flywheels for a small hit & miss engine out of 3/4" plate using a 6" hole saw.

Might have to make one of Sir John's arbors, those are neat.

abn
02-09-2010, 11:23 AM
I've been using hole saws in the lathe for some time now...I use the brazed carbide type mostly in aluminum and they cut very well. I'd like to try the single tooth type sometime for a performance comparison.

RKW
02-09-2010, 12:11 PM
I just got an email the other day from someplace that had the kits on sale ... I deleted it and moved on wish I had it now to post here. Anyone else get it?


I've used these a lot. They hands down beat using a hole saw. They are expensive, but well worth it for the time they save.

http://www.hougen.com/cutters/cutters_index.html

MuellerNick
02-09-2010, 01:02 PM
The job:
http://www.cncecke.de/bilder/uploadFiles/16348_106772539705_einstich3.jpg

and the tool:
http://www.cncecke.de/bilder/uploadFiles/16348_106772539705_kronenbohr2.jpg

Selfmade to my dimensions.


Nick

Toolguy
02-09-2010, 02:37 PM
Great looking tool Nick! Looks like it worked fine too.

MuellerNick
02-09-2010, 02:40 PM
Yes!
Nice curly chips! :)
Only problem is with deeper cuts that the chips can't come out and you have to remove them from time to time. Peck drilling ...


Nick