Thread: What do you think of the lathe copy things?

Hi Dingo,

I've never used a copy attachment my self and would only buy one if I had lots of VERY acurate stuff to do.

The best way I've found to get things the same (ish) is to draw out half of the shape on a thin piece of board (I use 4mm MDF because I've got loads but ply or even card would probably do the job) I then draw a line through each section of the spindle... so each side of a bead or cove, where fillets sit etc. I then put a small notch on the edge of the board on each line with a triangle file.

Once the piece is roughed round to aprox the max diameter of the piece hold up the board next to the spinning wood and put your sharp pencil in each notch, all the main details of your spindles are now marked out and will be within a mm or so on every spindle you mark.

You can now size each section between lines, so beads are marked and sized, coves are marked and ready to cut etc. Shape all the largest diameter stuff first and the coves last to keep the piece as sturdy as poss for as long as poss. Sand up then using a sharp chisel crisp off the fillets and anything else that has been softened by sanding... job done!

Hope this helps,

Richard

The duplicator is an acceptable way if you are in production and just have to crank out duplicates over and over again. I, however woul resolve to make mine individually. Make a master drawing full scale and fix it to a piece of plywood, cut out the shape and stand it in front of your work, then using calipers, parting tools and the like (I won't discribe how to use a lathe as I assume you already know how and Richard already discribed the process) and make duplicates (plan on one or two oops out of a dozen perhaps. but the finished result will be better. Unless you are commissioned to do the job by a fellow who doesn't care for the process.

I have a mockup of a ship's wheel to make in the near future, I plan to turn each as I go.

Depends of a few things.

I can see why you would want to go towards a copy attachment. You can burn up a lot of wood if your turning skills aren't good enough that you can easily repeat your actions in a consistent manner.

My experience with copy attachments as been that the cheap ones are usually worthless. They flex far too much and tend to chew up the work more than anything. And if you're trying to copy long thin spindles the added flex in the wood only compounds the problems associated with a flimsy copy attachment.

Couple things you may want to consider:

Simplify the turning so that reproducing the shape will be much easier. If you can get away with using only scrapers it'll be easier to reproduce the profile.

Or pack up the spindles and mail them to someone that will do it for you. You can send them to me if you want. You just have to pay for the shipping. I'm sure there's someone else here that's closer that'll step up to the plate. Within aus I don't thing the shipping will be all that much. Certainly much less than a copy attachment that you'll most likely never use again.

Or get some junk wood and practice. If you put in some determined time it shouldn't take too long to get good enough to do it yourself.

A Lathe copy devise...... you mean

Somone asked about this at one of his turning displays. his comment was they require a lot of sanding due to the way they cut.

Hi Ding

The biggest downside of the copy stuff is that you can only turn relatively simple profiles, (read boring). Also, it is impossible to get crisp turned profiles, and you are left with mammoth sanding, which further blurs any remaining detail.

Have a look at a cheap pine chair, compared to a good spindle turned piece, (should be able to find pics around here) to see the difference.

There is another way to solve your problem, without going this route----------- called practice .

On a more serious note, in the sort of job you are doing, one can get away with a surprising amount of variation in diameter of the features. Even variations in the shape of features has some tolerance, as the eye tends to gloss over if the pieces are not right side by side. Where you have to take great care is to ensure that the position of the feature is accurate, as this shows up to a much greater extent. To this end, it is best not to rely on measurement, but rather make up a pencil guage or scratch guage , and use that to mark out all the pieces, and then take great care to make sure they stay turned where marked.

Hope this helps,

I've not had one, but a friend got a Sears duplicator for a Sears lathe, and it was nicely made, but it would turn out the roughest pieces of junk I have ever seen. In this case, definitely NOT worth having. I am sure that there are good ones [for a price], but the one sold through Sears was not so great. Maybe one that uses a router in place of a tool bit would be better.

Here's an apparatus you can build to make duplicates with regular cuts, not just scraping. You make two copies of the pattern, cut out one of them, and set them up parallel to the spindle. Sighting along the top of the workpiece, cut until the workpiece and both patterns are in line.

http://www.delorie.com/wood/tips/parallax-jig.html

I haven't made one yet, but it sounds ideal, and it's been on my list for a while. It might be advantageous to darken or colour the no-cut portion of the background pattern for easier visibility.

Joe

Wasn't going to reply but can't help myself seeing as my name was mentioned.

Cheap copy attachments: Waste of time, money, space, energy, sandpaper and wood.

One word: useless. I am with TA.

There's a cheaper way of doing it. Make a story stick!

Turn the first piece you want to copy (or draw a plan), grab a batten the length of the work you want, mark off the positions of each important feature/change of dimensions on the batten and write the appropriate diameter at each mark. Then use a drill to drill pilot holes through the batten, slightly smaller than some nails which you drive through these holes to become scribes.

Turn your blank cylindrical to a rough size, then offer up the story stick so the nails scribe all your marks into the cylinder.

Using your calipers and referring to the measurements on the stick, turn each mark to final dimension with a narrow scraper. Then it's a case of playing "join the dots" between each mark, turning any fancy ogees, etc. Cardboard templates can help here if you don't trust yer own eyes.

Much more fun (and good practice) than using a copy attachment and you can honestly say you turned it all yourself... instead of pretending you did if all you'd really done was mount a blank on a machine.

Originally Posted by Wild Dingo

Worthwhile or a waste?

Don't know but Dean did a review on the Timbecon one that might be of interest.


Peter.

Copy attachments definitly have their place especialy in a commercial set up however the drawback with attachments for the home lathe is the don't have a powered cutter, so as mentioned above you get a rough cut, if you can live with bit of extra finnishing, you will find them very usefull.

Can't find it now, but I've seen an article (or web page) where a guy built a box to slide along his lathe ways. Mounted a router on top the same way other have done to do fluting etc.

The top was hinged, and the free end had a finger which could ride along a template. The router cutter seemed to do a much better job than the scrapers most simple copiers use.

Of course, the profile of the cutter limits what you can do. There was also an issue with the relationship between the size of the template and the workpiece size, due to the lever length between the hinge and the template follower.

Cheers,
Andrew

Guys,

It is not just the difference between proffessional and amateur kit we are talking about here. It is the whole concept of copy-turning, which by definition cannot even approach the detail and crispness of hand turning.

I will post some pics of 2 stools I have, both turned out of Pacific Maple, during my TAFE woodturning course. One was done by hand as a 1st year, the second in my final year, as part of the wood machining module. This was produced on a full size industrial copy lathe, with rotating cutterhead, auto feed, double divorce pipes and high lift doorhandles: the result is still cr-p!!!!!

Rant off, pics to follow tonight.

regards

This was produced on a full size industrial copy lathe, with rotating cutterhead, auto feed, double divorce pipes and high lift doorhandles: the result is still cr-p!!!!!

Was that the model with the chromed reverse double helix over and under dust extractor?

If so, no wonder, that was a real bad machine.