Thread: how to duplicate tapered legs

I have been turning for almost fifty years. The OP did not say how many he wanted to turn. he asked about duplicating turnings. this is how I duplicate turnings. As I stated in my first post my lathe has been specifically built for quick change overs. There is a template mounted on the rear of the lathe. For individual copying I can mount the original spindle where the template goes. otherwise a piece of 1/8" hardboard for a short run or plexi for longer runs. cut out on the band saw and clean up with a file in a few minutes. a change over between existing pieces can take from 10-30 minutes. If I have to make a new template it may take an our and a half. for something like butcher block table legs and about fifteen minutes to an hour a piece on the machine for each leg depending on pattern. for a straight taper the set up on any regular lathe might take me an hour. the holder for the router would be the only thing that might take time. an hour for the parts and wait til the next day to allow the glue to dry. I used a router for these because they would tend to whip cutting with a regular cutter. Climb cutting pushes the stock over just ever so slightly and leaves an over sized roughed in blank. Then the conventional cut brings it down to perfect size. if you conventional cut on the first pass the bit will pull the stock and you get undersized the first pass every time! LOL I don't know of another turner with a lever action tail-stock. I wouldn't try it with a typical screw setting tail-stock. My dad designed and built the first one before I was born. His business was custom turnings for over 60 years. Here is a video of how the template works. this is the first part of the run. I made it for the customer because they were concerned that I wasn't charging enough to make any money.

This is the first couple parts in a following order.

Anyone is welcome to stop by! just give me time to dust off a bit! lol

Well,
Alot has happened in this thread! I've had a PM from another forum member ( very experienced turner ) who has offered for me to come down and get a few pointers in person ( which i'll be doing later in the month ) I'll also be doing more practice as per what Ian has suggested.

Having said that, the longer term goal is to be able to make a heap of these, and do it quickly and easily - so ultimately I was looking for something along the lines of what Oreos is doing. Still, I am keen to learn how to do these things manually as well.

Having looked at the commercial duplicators out there, they all look pretty crappy ( save maybe the Vega one ) compared to what Oreos has built. Seems it's the kinda thing you have build yourself I guess.

Either way, I've gotten a heap of good info and tips from all of you, so many thanks - and by all means, let the Router Jig vs Experience debate continue!

Well I think what you do is bloody brilliant!

It is also what I might expect from a production line run by a professional. This is very far from the turnings I do as an amateur, where the development of freehand expertise is a central part of the reason a piece made is prized. It is why I cannot connect with those using computers to build furniture, and why I prefer to use hand tools. That is not a criticism of what you do, simply pointing out that the skills to build 4 legs for a table are something that an individual needs to develop through the actual use of chisels.

Regards from Perth

Derek

Echoing Derek WOW

Curious -- if you were asked to make 200 lace bobbins, how you go about it?
my younger sister is a lace maker and as I understand it, lace bobbins need to be a certain size, but don't all need to be identical

Oreos,
In conjunction with learning more conventional methods, I'm keen to build a jig similar to what you have. Although I'd like to be able to interchange a router with a more conventional blade.

In one of your videos, you are using a stationary cutter instead of a router, are you able to advise where you can get something like this? I was thinking maybe the blade head on a Sorby Turnmaster would be suitable if mounted appropriately -

One at a time lol. Can you give me a picture of a lace bobin?

They are just small spindle turing about 150mm long and average about 3mm thick at a guess with some beads and coves

Dave TTC
Turning Wood Into Art

the difficulty with most of the carbide insert cutters is that in most cases they are a scraper and not applied in shear. For that reason they are generally poor in a cross the grain cut. Those who really get Cutting the wood can if they are careful and present the tool properly get a shear cut with these tools. The cotter you have seen in most of the videos is a standard HSS tool ground with a lot of relief both on the side and on the top. It could not be used by hand! it would tend to self feed and catch with every attempt. there is no bevel to ride to control the chip. I do also use carbide insert cutters. these also have a lot of side relief and also a "chip breaker" relief. These will also lead to exciting catches if used by hand. They are commercially available for cutting aluminum. they come dead sharp on the cutting edge. Most of the inserts out there are ground for cutting ferrous metals and come with what is called a "hone" on the edge and instead of cutting they rub the wood off. The ones advertised for wood may come with side relief but the top is flat with a dead sharp edge. typical grinds for regular copy attachments are also ground with a flat top so that they scrape instead of shear to avoid grabbing and getting a catch. Which is why they notoriously provide a poor finish and require a lot of sanding compared to someone good with a gouge and skew. there is a lot of stuff going on at the cutting edge that many never really get an understanding of. They can be great turners because they find what makes it work but never understand why it works. regular duplicator chain drives are sloppy and dont have a fine enough control on the lateral movement of the cutter. For short items a better duplicator can be made when actuated by two levers and good swivel joints instead of one lever and a chain. the the cutter is ground to look like the front of a canoe and can cut equally well both to the left and to the right and the top relief gives a sharp cutting edge for good surface results.

OK, so you have applied more the kind of tools used on Metalwork lathes for your duplicator? i.e. this kind of thing, but then with the HSS bit ground in a custom way?


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tooling is customized to purpose most of the time. If you search oreos40 on youtube I have a few videos that might interest you. the short answer would be yes. tooling is adapted from many places. people use sharpened Allen keys for hollowing and Chinese balls. Some have used files for cutting and scraping. some use profiled scrapers for repetitive shapes. each person becomes comfortable with their own way of doing things. there are several different grinds for a spindle gouge each user uses the grind they use because they have come to be comfortable with it. some will laud superiority of one grind or another. one can learn how to cut with a tool without understanding why it works for them. when and if they come to know why it works it can be like waking up to a new day. most wood working classes teach how to make cuts with a tool, but few if any teach why it works best to do it that certain way as opposed to another. it is not looked at as a waste of time but not necessary if they can just learn to make a cut the prescribed way. I think cutting tool geometry is very important to understand. different material cuts differently. if I sharpen a tool for oak and get a nice of the tool finish there and switch to mahogany I get a fuzzy finish. if I grind for mahogany and switch to oak the cutter will lose its edge quickly.

3 mm wow thats thin. I will have to try it. I would like to see beads and coves on something that thin. what material? I am certain
it must be riven material to avoid cross grain.

Originally Posted by oreos40

3 mm wow thats thin. I will have to try it. I would like to see beads and coves on something that thin. what material? I am certain
it must be riven material to avoid cross grain.

3mm at the narrowest at a guess



Ive never made them. Just seen others

Dave TTC
Turning Wood Into Art