Pegs making on a lathe with duplicator?

Quote: Originally posted by jdowning

Hi Yaron - a duplicator lathe for making pegs is basically simple in concept but the design details for conversion will depend upon the kind of lathe that you own. The starting point is essentially a metal turning lathe (rather than wood turning) that has a precision 'cross slide' as well as a precision longitudinal traverse. What do you have to work with? I make my pegs on a precision metal turning lathe but with shaped profile cutters - this being a much simpler/more economic set up than offered by a profile cutting lathe - particularly if you are not intending to go into peg mass production (Hundreds + of one style). Of course a computer controlled CN lathe would be ideal - but most of us do not have that option - although prices for this equipment are becoming more competitive in recent years for smaller machines.

I have attached a schematic sketch of how a basic duplicator lathe works - based upon a small sized metal working lathe. If your lathe is large it may not be suitable for conversion.

A steel template of the peg profile is mounted at the back of the lathe so that the outline can be traced with follower A attached to the rear of the lathe cross slide. Follower A is set up to be in alignment with the cutting tool B. The screw feed of the cross slide is disengaged so that the cross slide can be moved in and out by hand. The longitudinal traverse of the lathe table may be moved using the lead screw of the lathe (rotated by hand) or the lead screw may also be disengaged and the table simply moved back and forth by hand.
For best cutting efficiency the lathe needs to be run at the fastest speed

The concept is simple but the detail design would have to be worked out yourself according to the lathe dimensions. I do not have any step by step images to offer as I have never been motivated to construct a copying lathe even though I must have made several hundred pegs of various designs over the years.
If you only need to make a dozen or so pegs this would best be done freehand on a simple wood turning lathe. It is no more complicated than turning small spindles. Even if you have no prior experience of turning pegs by hand the technique is easily learned, allows full flexibility in peg design and it would still be much quicker than designing, fabricating, modifying and setting up a duplicator lathe.

Alternatively you might want to try using profiled cutting tools in an unmodified metal cutting lathe. I discuss this procedure on page 41 of this forum under the topic "More Making Pegs".

Good luck.

Quote: Originally posted by jdowning

I have attached a schematic sketch of how a basic duplicator lathe works - based upon a small sized metal working lathe. If your lathe is large it may not be suitable for conversion. A steel template of the peg profile is mounted at the back of the lathe so that the outline can be traced with follower A attached to the rear of the lathe cross slide. Follower A is set up to be in alignment with the cutting tool B. The screw feed of the cross slide is disengaged so that the cross slide can be moved in and out by hand. The longitudinal traverse of the lathe table may be moved using the lead screw of the lathe (rotated by hand) or the lead screw may also be disengaged and the table simply moved back and forth by hand. For best cutting efficiency the lathe needs to be run at the fastest speed The concept is simple but the detail design would have to be worked out yourself according to the lathe dimensions. I do not have any step by step images to offer as I have never been motivated to construct a copying lathe even though I must have made several hundred pegs of various designs over the years. If you only need to make a dozen or so pegs this would best be done freehand on a simple wood turning lathe. It is no more complicated than turning small spindles. Even if you have no prior experience of turning pegs by hand the technique is easily learned, allows full flexibility in peg design and it would still be much quicker than designing, fabricating, modifying and setting up a duplicator lathe. Alternatively you might want to try using profiled cutting tools in an unmodified metal cutting lathe. I discuss this procedure on page 41 of this forum under the topic "More Making Pegs". Good luck.

The fantastic gizmo someone should build is a peg-maker (or peg-shaper) that's based on the inexpensive Dremel tool line. The Dremel rotary tool with many attachments and bits, plus their little drill press, comes to about $150, and many people have them. This is nothing like a heavy-duty lathe, but it can be turned into all sorts of cutters/shapers/sanders/routers, and it's just right for weekend luthiers.

On the photo A is part of the basic tool set, B is the little drill press (and C is misc electronics ;-)

A peg reamer costs $35-$65, and an adjustable peg shaver $50-150. That's expensive, especially if you only need to work on a single set of pegs.

Many people already have the tool - it can act as a sander, plane, drill, cutter - and the little drill press is only about $35. It can hold the tool on its side as well.

If there was some way to make the Dremel do part of the job, maybe with a simple jig that would hold a peg at an angle to match the taper, one could turn the peg by hand and use the Dremel in its "drill press" to traverse and shave the peg, that might be a nice way to avoid buying more single-use tools.

Quote: Originally posted by fernandraynaud

The fantastic gizmo someone should build is a peg-maker (or peg-shaper) that's based on the inexpensive Dremel tool line. The Dremel rotary tool with many attachments and bits, plus their little drill press, comes to about $150, and many people have them. This is nothing like a heavy-duty lathe, but it can be turned into all sorts of cutters/shapers/sanders/routers, and it's just right for weekend luthiers. On the photo A is part of the basic tool set, B is the little drill press (and C is misc electronics ;-) A peg reamer costs $35-$65, and an adjustable peg shaver $50-150. That's expensive, especially if you only need to work on a single set of pegs. Many people already have the tool - it can act as a sander, plane, drill, cutter - and the little drill press is only about $35. It can hold the tool on its side as well. If there was some way to make the Dremel do part of the job, maybe with a simple jig that would hold a peg at an angle to match the taper, one could turn the peg by hand and use the Dremel in its "drill press" to traverse and shave the peg, that might be a nice way to avoid buying more single-use tools.

Yaron, you were asking about using a lathe. There are many tool-builders on this forum, so I was suggesting a happy little project for one of them and also reminding people about the Dremel .


Maybe someone will have a brainstorm while thinking about the lathe approach.

Quote: Originally posted by fernandraynaud

Yaron, you were asking about using a lathe. There are many tool-builders on this forum, so I was suggesting a happy little project for one of them and also reminding people about the Dremel . Maybe someone will have a brainstorm while thinking about the lathe approach.

I cannot possibly show you details, as such a thing has never been made. There's a rough idea, and maybe it could be made.

The general concept is that the little Dremel drill press can be set to a small angle relative to vertical. This angle determines the final taper of the peg. It can be copied from a model peg by placing model peg in fixture and a blunt bit placed in Dremel tool. As drill press UP_DOWN lever is actuated, angle can be adjusted for constant clearance from model peg, then drill press set-screw tightened. Then a work peg is placed in fixture. If the peg can be immobilized in a fixture in a vertical orientation, then the rotating bit in the Dremel with its face at angle theta from vertical will cut or grind into the work as the drill press lever is moved UP-DOWN, imparting the required taper. The peg must be rotated in the vertical axis for the cutting bit to work all around the circumference of the peg. The distance of the work peg fixture from the Dremel bit determines the ultimate diameter of the peg. Something like that.

Quote: Originally posted by fernandraynaud

I cannot possibly show you details, as such a thing has never been made. There's a rough idea, and maybe it could be made. The general concept is that the little Dremel drill press can be set to a small angle relative to vertical. This angle determines the final taper of the peg. It can be copied from a model peg by placing model peg in fixture and a blunt bit placed in Dremel tool. As drill press UP_DOWN lever is actuated, angle can be adjusted for constant clearance from model peg, then drill press set-screw tightened. Then a work peg is placed in fixture. If the peg can be immobilized in a fixture in a vertical orientation, then the rotating bit in the Dremel with its face at angle theta from vertical will cut or grind into the work as the drill press lever is moved UP-DOWN, imparting the required taper. The peg must be rotated in the vertical axis for the cutting bit to work all around the circumference of the peg. The distance of the work peg fixture from the Dremel bit determines the ultimate diameter of the peg. Something like that.