DIY copy attachment for lathe

[Mark Greenbaum]

I might have a job to make 30 duplicate spindle on my lathe. Has anyone made an attachment to copy spindles?

[Mark Greenbaum]

https://i.ytimg.com/vi/zF4IdMg5T3E/maxresdefault.jpg

[John K Jordan]

I might have a job to make 30 duplicate spindle on my lathe. Has anyone made an attachment to copy spindles?

Sorry, can't help with making a duplicator but I have opinions... :)

The inexpensive lathe duplicators I've seen in operation did in fact duplicate the shape but left the surface in horrible condition requiring a lot of cleanup. This was worse with certain woods.

When duplicating I prefer to make a "story stick" to transfer the important points, use calipers to set the diameters at those points, then turn with conventional tools. I always positioned a completed spindle behind the lathe for reference. The turning time is actually pretty quick depending on the skill with skew and gouge. The detail can easily be more "crisp". The surface can be excellent right off the gouge with only minimal/fine sanding required.

This method may result in some minor variations depending on the skill and care, but these are rarely a detriment. Spread out, such as spindles for stairs or even baby cribs, variations are rarely noticed. If noticed they may even say "custom" or "hand made" rather than "machine made" and add value.

JKJ

[Mark Greenbaum]

John K: Thanks for the reply. I know how to use story sticks, and I am OK with roughing, spindle and skews. But these will have to look like machine made because they'll sit really close to each other, and next to others that were already made (possibly machine made). I will have an existing piece to reference against, and I would do just the rough cutting this way.

[Reed Gray]

Well, I do turn some spindles. If I had 30 to do, I would make 35. I would use the story stick, and some calipers, or bent wire gauges, or even open end wrenches to get diameters, and then hand turn from that. Not sure I have seen a DIY duplicator, but I am sure one could be made. I did some pieces for a furniture repair guy and always had some extras because If I was making some thing, I probably would mess at least one of them up...

robo hippy

[Mark Greenbaum]

Yes, I will make 36, just in case.

[Marvin Hasenak]

Dale Maxim posted a sphere maker that doubled as a duplicator back in 2013. His was made of aluminum, but for this project, glued up hardwood such as maple will work, at least it did for my project. I made mine to use on both Taig and Sherline lathes to make furniture and stairway parts for doll houses. Another good design that is easy to make is the Ankar Duplicator, I scored one on eBay a few years ago, the original is not for a midi lathe, only the micro lathes like Taig and Sherline, but the design is easily copied and enlarged to work on any size lathe. I have used it to make well over a 1000 stair balusters, easy enough that I would use it while watching TV.

But for your project, I would use the Dale Maxim design, and I would buy a carbide cutter designed for a metal lathe to use. Or buy one from Captain Eddie and make the shaft shorter.

[Perry Hilbert Jr]

I know the complaint with duplicators is the rough surface left by the carbide scraper. Thinking out loud here, would mounting a fine bit in a router in place of the duplicator cutter, leave a nearly finished surface. The lathe could spin slowly while the router bit does the work.

[Mark Greenbaum]

Once I get the go ahead, I will worry about a design, or just try story sticks and calipers. These will be 23" long x 1.25" diameter, so not a real big challenge; but might have to consider some sort of small steady rest, too.

[Richard Coers]

Once I get the go ahead, I will worry about a design, or just try story sticks and calipers. These will be 23" long x 1.25" diameter, so not a real big challenge; but might have to consider some sort of small steady rest, too.
If the bid should happen to be red oak, double your estimate. Nothing tears out like a scraper on red oak. ESPECIALLY if you have to transition from square to a cove.

[Scott Winners]

I am getting the hang of my duplicator, but one step of that is leaving my pattern oversize so I can smooth the already mentioned rough surface using a planing cut with a skew or sand or whatever.

One problem with mine is the duplicator blade is a short piece of 1/4 x 1/4 bar stock in HSS with an edge ground at the end. I am treating it as a scraper and pulling a light burr on the round nose of the edge with a veritas doohickey, but edge life is very short. In practice I mount round stock, get close to my major and minor diameters with a parting tool, get to my diameters with the duplicator, rough out everything I can with big skew or big gouge, then bring in the duplicator to take off the last 1/8 or so. Then stop, leave the stock mounted, sharpen the duplicator bit, reinstall the bit, readjust the duplicator and then finish the surface on the mounted turning, and then finally mount the next roumd stock with a sharp duplicator edge already in adjustment.

What I am getting at it is learning to use the duplicator I have has pretty well convinced me it is a waste of time to use.

[Mark Greenbaum]

I know that. I turned a set of 4 x 5" diameter x 6'-0" long bed posts that were red oak. I got pretty good with my skew and sandpaper.

[Bruce Wrenn]

If these spindles are straight, consider using a router with a bowl cutting bit, mounted in a trough over bed of lathe. Search for making rolling pins for ideas of how to do this.

[Brice Rogers]

There is a fellow on Facebook under the name "The woodturners" who is in the UK and is a production turner. A simple spindle probably takes him 2 or 3 minutes to do. He uses a story board to transfer pencil marks. He is a master with the skew. For him, an order of 35 spindles might be a small order. You should check him out. He is an inspiration.

I think that the problem with most copy attachments is they are scrapers. As we know scraping typically results in tear out. I did see a CNC lathe (Italian made) with a Vee shaped cutter (when viewed from above) that would slice rather than scrape. But I've never figured out where to buy the cutter. Also because of its shape, it wouldn't work for doing a 90 degree shoulder.

[David Walser]

...I did see a CNC lathe (Italian made) with a Vee shaped cutter (when viewed from above) that would slice rather than scrape. But I've never figured out where to buy the cutter. Also because of its shape, it wouldn't work for doing a 90 degree shoulder.

You mentioned a CNC lathe, so I thought I'd mention Legacy Woodworking Machinery's line of CNC routers. In addition to the flat table common to most CNC routers, their machines include a lathe section. On their smallest machine, the 3'x5' Maverick, the rotary section is 50"x10", so you can turn some decent sized spindles. What makes Legacy's machine's different is their 'Conversational CAM' software, which allows you to use profile router bits. Want a 1/2" bead? Use a 1/4" round-over bit to cut both sides of the bead. Not only is this faster, it leaves a better surface than trying to produce the same shape with small incremental steps using an end mill.

No, I don't have a Legacy CNC (or any other brand of CNC). I don't have the room in my shop. But, gosh, I can dream, can't I?