Spinning the tool not the stock to cut tenons

For discussion of fitting and shaping stems, doing inlays, and any other stem-related topic.
Post Reply
LatakiaLover
Posts: 3120
Joined: Sun Sep 02, 2007 4:29 am
Location: Kansas City, USA
Contact:

Spinning the tool not the stock to cut tenons

Post by LatakiaLover »

In that S. Bang thread SEThile asked about how I cut tenons, since he knew I didn't have a lathe.

I said with a drill press. (DP's are pretty much a requirement in repair work to allow fast centering wherever you want, on any part you want.)

The trade-off is usually a lack of precision, because even small lathes are quite rigid while many surprisingly large DP's are not (small ones are usually hopeless), and cutting truly good tenons is somewhere between difficult and impossible on them. They normally end up grooved and inconsistent in diameter over their entire length.

It can be done, though. I had to design my setup, and find a good machinist to make some one-off components, but it was straightforward since the task is so well defined.

The cutter itself is one that Tim West used to sell (and hopes to again one day), and it's unmodified. The way it is attached to the machine isn't off-the-shelf, though. The mechanism to hold the stem stock (as well as molded & cast stems) is also not something that can be bought but must be made.

Why might you pipe maker dudes be interested in all this? Because it is FAST. A few minutes ago I grabbed a chunk of scrap stock that already had an air hole, chucked it up, centered it, and made a cut to illustrate the result. The total time for everything was under a minute. The cut itself took 8 seconds. Going deeper to make a full length tenon would have taken about 20 seconds.

Accuracy-wise, diameter consistency from end to end exceeds the ability of a high quality dial caliper to resolve. I'd guess it's within a couple of ten thousandths. No finish steps or final tuning is needed---the stems come off the machine ready to use as-is. I usually use both inner and outer chamfering cutters before removing the the stem, though, to give things a finished look.

Anyway, speed is again the reason I'm bringing this up. A high volume producer would probably recover the cost of a dedicated tenon cutting machine fairly quickly, depending on how long he takes with a lathe. Those of you who might have thought that, but decided against one for "quality of cut" reasons, this is for you: :D

Image
UFOs must be real. There's no other explanation for cats.
caskwith
Posts: 2196
Joined: Sat Dec 08, 2007 6:00 am

Re: Spinning the tool not the stock to cut tenons

Post by caskwith »

Could the same job be achieved with a boring head and suitable cutter do you think?
User avatar
BigCasino
Posts: 384
Joined: Sat Dec 29, 2012 10:36 am

Re: Spinning the tool not the stock to cut tenons

Post by BigCasino »

Chris, are you asking why one couldn't still spin the stock on the lathe, but still use the same type of cutter in their tail stock to cut the tenon? cause if so I was going to ask the same thing..LOL
LatakiaLover
Posts: 3120
Joined: Sun Sep 02, 2007 4:29 am
Location: Kansas City, USA
Contact:

Re: Spinning the tool not the stock to cut tenons

Post by LatakiaLover »

caskwith wrote:Could the same job be achieved with a boring head and suitable cutter do you think?
I looked those up and can't visualize how they work.

I always thought the hot set up for a pipe maker as opposed to repairman---since makers can standardize their tenon sizes---would be a 90-degree end mill with a tenon-diameter hole in the cutting end. One push = done.

The catch would be the tenon-diameter hole would have to get larger immediately beyond the hole entry, because the spinning contact between the freshly cut tenon and a normal hole's walls would cause galling (at the least) from heat expansion, and seize/snap off the tenon completely at the worst.

Such a set of cutters---three or four would be all you'd ever need---would completely take tenons out of the equation, production-wise. Chuck the stock, seat the cutter, set the depth, and zip... on to the next task. It would be the simplified lathe version of what I do. (No need for a floating center or size adjustability when manufacturing)
UFOs must be real. There's no other explanation for cats.
caskwith
Posts: 2196
Joined: Sat Dec 08, 2007 6:00 am

Re: Spinning the tool not the stock to cut tenons

Post by caskwith »

I have a milling cutter that cut's perfect 1/4" tenons, I just never use it lol.
caskwith
Posts: 2196
Joined: Sat Dec 08, 2007 6:00 am

Re: Spinning the tool not the stock to cut tenons

Post by caskwith »

A boring head works just like your tool, cuter head spins around and can be adjusted off centre by a set amount, used conventionally they cut holes, used in reverse they can cut posts (tenons), I use one for cutting feet on cuttys.
LatakiaLover
Posts: 3120
Joined: Sun Sep 02, 2007 4:29 am
Location: Kansas City, USA
Contact:

Re: Spinning the tool not the stock to cut tenons

Post by LatakiaLover »

caskwith wrote:I use one for cutting feet on cuttys.
And deny yourself the rapturous pleasure of doing it by hand? :lol:
UFOs must be real. There's no other explanation for cats.
caskwith
Posts: 2196
Joined: Sat Dec 08, 2007 6:00 am

Re: Spinning the tool not the stock to cut tenons

Post by caskwith »

LatakiaLover wrote:
caskwith wrote:I use one for cutting feet on cuttys.
And deny yourself the rapturous pleasure of doing it by hand? :lol:

Damn right, although there is still hand work to do blending it into the bowl, starting with a perfectly sized and round post makes the job much easier. Here is a pic. BTW I made the boring bar as well since I only had right hand and needed a left hand so that was turning, heat treated and ground for just this job.

Image
User avatar
W.Pastuch
Posts: 415
Joined: Tue May 25, 2010 10:16 am

Re: Spinning the tool not the stock to cut tenons

Post by W.Pastuch »

The oldschool French pipemakers use a machine that's called "machine a floquer", which is pretty much a horizontal milling machine. They use that setup for drilling stummels as well as drilling and cutting tenons on mouthpieces. The headstock on those machines has a a thread that accepts all kinds of cutters, some of them do exactly what George showed with the tenon cutter, which is the same thing Chris is talking about using a boring head.
When I visited a repairman in Paris (Au Caid) he showed me the coolest piece of pipemaking tooling ever: a precision tenon cutter with synthetic diamond cutting inserts and three micrometric screws for adjusting the dimensions of the tenon. Very nice, also very very expensive to make.

Personally, I don't mind just turning my tenons....
LatakiaLover
Posts: 3120
Joined: Sun Sep 02, 2007 4:29 am
Location: Kansas City, USA
Contact:

Re: Spinning the tool not the stock to cut tenons

Post by LatakiaLover »

keilwerth wrote: When I visited a repairman in Paris (Au Caid) he showed me the coolest piece of pipemaking tooling ever: a precision tenon cutter with synthetic diamond cutting inserts and three micrometric screws for adjusting the dimensions of the tenon. Very nice, also very very expensive to make.
And he's still alive? Why didn't, you know, accidentally push him in front of a train or something and have the cutter accidentally find its way into your luggage? (Tool sluts are known to be dangerous when in potential toolporn acquisition situations---"PTAS"---such as you describe.)
UFOs must be real. There's no other explanation for cats.
User avatar
Sasquatch
Posts: 5147
Joined: Tue Jan 13, 2009 1:46 am

Re: Spinning the tool not the stock to cut tenons

Post by Sasquatch »

There's a video of Blakemar briars being made, and he has all kinds of specialized tooling too.. very jealous of it.

https://www.youtube.com/watch?v=TuJN8HBOQoQ

Around 3:20 you see a tenon cutter extraordinaire.
ALL YOUR PIPE ARE BELONG TO US!
LatakiaLover
Posts: 3120
Joined: Sun Sep 02, 2007 4:29 am
Location: Kansas City, USA
Contact:

Re: Spinning the tool not the stock to cut tenons

Post by LatakiaLover »

Watching that video was painful. :lol: Much too casual and imprecise for me. Me likey Danish fit & finish, not just making tobacco access devices. Thanks for the look into a rapid production operation, though. :D
UFOs must be real. There's no other explanation for cats.
User avatar
Joe T
Posts: 72
Joined: Sun Mar 09, 2014 11:37 pm
Location: Washington

Re: Spinning the tool not the stock to cut tenons

Post by Joe T »

Sasquatch wrote:There's a video of Blakemar briars being made, and he has all kinds of specialized tooling too.. very jealous of it.

https://www.youtube.com/watch?v=TuJN8HBOQoQ

Around 3:20 you see a tenon cutter extraordinaire.
Wow... catching the pipe on fire as part of the staining process... that's exotic. :shock:
Joe Thieman
User avatar
W.Pastuch
Posts: 415
Joined: Tue May 25, 2010 10:16 am

Re: Spinning the tool not the stock to cut tenons

Post by W.Pastuch »

I would have to take more than just that cutter and airlines are somewhat partial to people carrying large amounts of tooling on board ;)

Oh man, not the Blakemar video again! I can't watch that, it gives me the chills... especially the guys sleeve right next to the spinning cutter, every time I wonder- wil it grab his hand or not. Waaay to dangerous....
User avatar
Sasquatch
Posts: 5147
Joined: Tue Jan 13, 2009 1:46 am

Re: Spinning the tool not the stock to cut tenons

Post by Sasquatch »

Yeah I know! I've seen it 20 times and it's still exciting! "When does he get wrapped around the spindle 27 times?"
ALL YOUR PIPE ARE BELONG TO US!
Post Reply