3/4 bent facing on shank

[timothy thorpe]

hi guys, thanks again for the help. another question regarding facing. how do you chuck the stummel so that the right angle is there to face the shank. i am able to do it of coarse, but it may take a few times to get the stem to fit flush. thanks!! tim

[KurtHuhn]

There's a couple different ways.

If drilling on a wood lathe:
- chuck block
- face shank with forstner bit
- leave block in chuck
- change to mortising bit
- drill mortis
This method will work every time. Then you can change the block angle to the airway and dril that.

If drilling on a metal lathe:
- chuck block
- face shank with left hand cutting bit (or with a forstner bit in tailstock)
- leave block in chuck
- put mortising bit in tailstock
- drill mortis
Should work every time.

If using a drill press:
- put block in vice
- face shank with forstner bit
- leave block in vice, do not move vice
- switch to mortising bit
- drill mortis
Should work as long as you don't allow the block to rotate in the vice even a little bit.

If drilling after shaping on a wood lathe:
Well, this gets hairy. Basically you're placing trust in some very dubious tools, but t works. Just be careful out there....
- chuck a pin gauge or drill rod stock that has a tight fit on your mortis in the headstock
- put the stummel on the pin gauge/rod stock all the way to the bottom of the mortis
- test spin at a low RPM to be sure that it won't slip off
- increase RPM so that you can get a clean cut, but no so high that you end up vibrating the crap out of the stummel, this can lead to shank failure
- using a sharp cutoff/parting tool, face the the shank
- stop just a hair before you get to the drill rod
- remove the stummel
- clean up the leftover wood by countersinking the mortis edge slightly with a countersink tool
This works every time for me, BUT, you have to be very precise with your cutoff tool. The best way is to simply practice - try the same cut on scrap briar or other woods. If your bowl top extends past the shank face in a line perpendicular to the mortis when inserted onto the rod stock, you will not be able to use this method. In that case, you can switch to narrow skew with a nearly flat angle and use it like a scraper spun as far left as is needed. Again, this requires loads of practive, and you may need to regrind your skew to the right angle to do it.

If using a metal lathe, the procedure will be similar, but you'll probably want to use a right hand cutting tool, since the cutoff tools for metal lathes seems to be narrow kerf - usually in the 1/16" to 1/8" range from what I've seen. But, heck if I know, I am not an expert on pipe making with a metal lathe. Perhaps Jeff, Jack, or someone else that uses one all the time could chime in.

Or, you could simply use Trever's tool.

[timothy thorpe]

There's a couple different ways.

If drilling on a wood lathe:
- chuck block
- face shank with forstner bit
- leave block in chuck
- change to mortising bit
- drill mortis
This method will work every time. Then you can change the block angle to the airway and dril that.

If drilling on a metal lathe:
- chuck block
- face shank with left hand cutting bit (or with a forstner bit in tailstock)
- leave block in chuck

hi kurt, thanks!!! thats the way i was doing it. what is a pin gadge?
- put mortising bit in tailstock
- drill mortis
Should work every time.

If using a drill press:
- put block in vice
- face shank with forstner bit
- leave block in vice, do not move vice
- switch to mortising bit
- drill mortis
Should work as long as you don't allow the block to rotate in the vice even a little bit.

If drilling after shaping on a wood lathe:
Well, this gets hairy. Basically you're placing trust in some very dubious tools, but t works. Just be careful out there....
- chuck a pin gauge or drill rod stock that has a tight fit on your mortis in the headstock
- put the stummel on the pin gauge/rod stock all the way to the bottom of the mortis
- test spin at a low RPM to be sure that it won't slip off
- increase RPM so that you can get a clean cut, but no so high that you end up vibrating the crap out of the stummel, this can lead to shank failure
- using a sharp cutoff/parting tool, face the the shank
- stop just a hair before you get to the drill rod
- remove the stummel
- clean up the leftover wood by countersinking the mortis edge slightly with a countersink tool
This works every time for me, BUT, you have to be very precise with your cutoff tool. The best way is to simply practice - try the same cut on scrap briar or other woods. If your bowl top extends past the shank face in a line perpendicular to the mortis when inserted onto the rod stock, you will not be able to use this method. In that case, you can switch to narrow skew with a nearly flat angle and use it like a scraper spun as far left as is needed. Again, this requires loads of practive, and you may need to regrind your skew to the right angle to do it.

If using a metal lathe, the procedure will be similar, but you'll probably want to use a right hand cutting tool, since the cutoff tools for metal lathes seems to be narrow kerf - usually in the 1/16" to 1/8" range from what I've seen. But, heck if I know, I am not an expert on pipe making with a metal lathe. Perhaps Jeff, Jack, or someone else that uses one all the time could chime in.

Or, you could simply use Trever's tool.

[JHowell]

With a metal lathe, drilling the block before shaping, you can simply face off the face of the mortise with a RH cutter before drilling the mortise. Turning the stummel on a mandrel inserted in the mortise (Kurt's last-listed option) is a great way to go, Todd Johnson posted that tip here a couple of years ago and it's a super method. Affords unparalleled flexibility in adding rings and flocs at any point in the pipe's construction. I wouldn't use a cutoff tool for this, though -- a LH tool ground at an angle or held in a LH toolholder mounted in a lantern-style toolpost can give you better access to the mortise face in the case of a bent pipe with a short shank -- the tool is fixed so that it extends to the right of the compound far enough so that the stummel doesn't whack it. Better finish, too, you wind up cutting with a keener edge with more positive rake. A cutoff tool has zero rake for side cutting. If you make your mandrel from a piece of 1/2" drill rod with a short taper to a 1"-2" stub for mounting the pipe you won't have the same problems with vibration -- the stiffer mandrel won't deflect as much. I use collets instead of a chuck for this, for greater precision and more clearance around the mandrel, but even with this I need at least 3" of mandrel extended to give access for the tool. Metal lathes in general are, I think, more massive and rigid than wood lathes and have less of a problem with the vibration of an unbalanced workpiece. Then you don't have to be so concerned about speed, but in any case you need a good friction fit on the mandrel.

Another option is to get an aircraft counterbore with a guide pin the same size as your mortise. The guide pin goes in the mortise and you can turn the counterbore by hand to face off the mortise. They're a little expensive, but work great. Search "aircraft counterbore" at www.mcmaster.com -- I have one with a 3/16" guide that I use for squaring bamboo.

For better advice on grinding toolbits than I can give in an hour of typing, look for a copy of South Bend's "How To Run a Lathe" (HTRAL). Copies are abundant on Ebay, and available online several places. Here, for instance:

http://www.wswells.com/data/htral/1913_ ... _htral.pdf

Jack

[JHowell]

Whoops, sorry, that link is to a 1913 edition of HTRAL, doesn't seem to have the section of grinding toolbits. I'll see about a link to a better PDF when it's not 2:30am and I don't need to get to sleep.

Jack

[timothy thorpe]

With a metal lathe, drilling the block before shaping, you can simply face off the face of the mortise with a RH cutter before drilling the mortise. Turning the stummel on a mandrel inserted in the mortise (Kurt's last-listed option) is a great way to go, Todd Johnson posted that tip here a couple of years ago and it's a super method. Affords unparalleled flexibility in adding rings and flocs at any point in the pipe's construction. I wouldn't use a cutoff tool for this, though -- a LH tool ground at an angle or held in a LH toolholder mounted in a lantern-style toolpost can give you better access to the mortise face in the case of a bent pipe with a short shank -- the tool is fixed so that it extends to the right of the compound far enough so that the stummel doesn't whack it. Better finish, too, you wind up cutting with a keener edge with more positive rake. A cutoff tool has zero rake for side cutting. If you make your mandrel from a piece of 1/2" drill rod with a short taper to a 1"-2" stub for mounting the pipe you won't have the same problems with vibration -- the stiffer mandrel won't deflect as much. I use collets instead of a chuck for this, for greater precision and more clearance around the mandrel, but even with this I need at least 3" of mandrel extended to give access for the tool. Metal lathes in general are, I think, more massive and rigid than wood lathes and have less of a problem with the vibration of an unbalanced workpiece. Then you don't have to be so concerned about speed, but in any case you need a good friction fit on the mandrel.

Another option is to get an aircraft counterbore with a guide pin the same size as your mortise. The guide pin goes in the mortise and you can turn the counterbore by hand to face off the mortise. They're a little expensive, but work great. Search "aircraft counterbore" at www.mcmaster.com -- I have one with a 3/16" guide that I use for squaring bamboo.

For better advice on grinding toolbits than I can give in an hour of typing, look for a copy of South Bend's "How To Run a Lathe" (HTRAL). Copies are abundant on Ebay, and available online several places. Here, for instance:

http://www.wswells.com/data/htral/1913_ ... _htral.pdf

Jack

wow! thanks so much. i will look for the counterbore this morning.

thanks, tim