holesaw on a lathe

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pete
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Joined: Tue Feb 10, 2009 6:04 am

Re: holesaw on a lathe

Post by pete » Fri May 17, 2019 4:24 pm

Oddly the information about limiting the tool diameter with key less chucks seems to be not very well known by most of the people using them. Even the manufacturer's are pretty lax about pointing the problem out. I forgot to mention about using larger diameter taps in them as well. Those can create the exact same torque issues. I don't seem to have any problems up to roughly a 3/8ths tap. But tapping with them probably isn't the best idea anyway. Above 3/8ths in the mill I just use an ER collet.

A hole saw if it can do the job is likely the cheapest and most available method for most of us. Like most things related to machining it's not the only way to get the job done and hole saws have fixed diameter limits. Face cutting a groove or parting right through is called trepanning. Just for trivia purposes a gruesome detail is the name apparently comes from the early medical profession where they used a trepanning tool to bore large holes in peoples skulls. A trepanning tool can be made to do the same thing in a mill. It pretty much resembles an adjustable for diameter fly cutter with the cutting tools end pointing straight down. For tool post use in a lathe, http://www.penntoolco.com/trepanning-to ... olholders/ as one way over priced example. Everything I've picked about about trepanning mentions the tool grind is pretty critical to get them to work well. Plus the cutting tools radius has to be accounted for for both the O.D. & I.D. while grinding to get enough cutting tool relief. The one in my link clearly shows the radius used to help lift the chips up and out of the cut. Not getting those chips evacuated well enough can result in a quite spectacular crash if the tool binds up.
Last edited by pete on Fri May 17, 2019 4:59 pm, edited 1 time in total.

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BadDog
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Re: holesaw on a lathe

Post by BadDog » Fri May 17, 2019 4:59 pm

I've got some tap sockets made by Lisle that are really nice. The hard tap goes in and is held by o-ring, and driven by square socket at back. But the holder is substantially larger, and not hard/polished, so larger diameter provides more torque for the chuck jaws, and it grips very well in a ball bearing chuck because it's not hard or polished. Up to about 3/8 it works well enough in any non-keyless chuck (those loosen on reverse), but at about 3/8" I start using those holders. They also have standard socket/ratchet square drive on the back, so you can use them with a drill-driver, or ratchet can be a lifesaver if near obstructions. Tommy-bar square drives for sockets also work well in combination.
Russ
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RSG
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Location: Ontario, Canada

Re: holesaw on a lathe

Post by RSG » Sat May 18, 2019 7:28 am

BadDog wrote:
Fri May 17, 2019 4:59 pm
I've got some tap sockets made by Lisle that are really nice.
There's' something I never knew existed! Those are so cool! I have to get a set.
Vision is not seeing things as they are, but as they will be.

whateg0
Posts: 645
Joined: Sat Mar 28, 2009 3:54 pm
Location: Wichita, KS

Re: holesaw on a lathe

Post by whateg0 » Tue May 28, 2019 7:39 pm

Watched this video last night. A buddy of mine sent it to me and said there's another video of the guy making the tool.
https://youtu.be/VpUri-NGFyk

Dave

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BadDog
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Location: Phoenix, AZ

Re: holesaw on a lathe

Post by BadDog » Tue May 28, 2019 7:42 pm

RSG wrote:
Sat May 18, 2019 7:28 am
There's' something I never knew existed! Those are so cool! I have to get a set.
I had the same response a few years ago when I saw my friend using a set. Went right out and bought them, never regretted it.
Russ
Master Floor Sweeper

RSG
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Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Re: holesaw on a lathe

Post by RSG » Wed May 29, 2019 7:53 am

The things you learn here Russ ;)
Vision is not seeing things as they are, but as they will be.

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