A simple manual tracing attachment for any lathe.

[xalky]

A manual tracing attachment for any lathe. I've had this on my mind ever since a local blacksmith asked me if i could make knobs for him.

This is what it looks like all set up. You can see a handle that I just made for it in the lathe chuck. I make a pattern by tracing out the part I want to make, if i want to duplicate a part. Or i can design my own. I then cut it out onto some heavy sheet metal. I think I'm using 14 guage here. The heavier the sheet metal the better, it helps for to allow the stylus to glide a little better. I made some standoff blocks that clamp onto the back of the lathe bed. I had to make them tall enough to clear the digital readout protective cover and also to give me enough room to bolt a stylus follower mount. The stylus follower bolts onto the cross feed, where the follower rest would normally bolt up. I made the stylus out of a piece 3/8" drill rod, it's removable and it can also be rotated for better stylus orientation.

The compound is set in the same direction as the cross feed to allow for excellent part width fine tuning.



Here's a look at the standoff blocks that I made.



Here's a look at the stylus and mount.


A picture of how the compound is set so that you can adjust the diameter of the part independently from the pattern.



To use it I hog out the deepest parts of the pattern first by feeding in and running the carriage right and left. Once I'm close to the pattern I feed the cross feed into the pattern at one of the deepest points then I put some hand pressure on the cross feed wheel towards the pattern and move the carriage over till i hit the pattern. For the final pass , always working from the deepest part I move the carriage in the direction i'm working and as I'm doing that I turn back the crosfeed wheel just enough to get it to follow the pattern. Backlash actually helps a little here, because as you move the carriage right or left, if the pattern doesn't have a steep angle, the crossfeed will just follow the pattern, so long as the crossfeed handwheel is backed off to allow the crossfeed to follow the pattern freely. I got the hang of it within a few minutes.

Once its all turned down to the pattern, If you think the part should be a little smaller in diameter, just adjust your compound in. No need to move the pattern.

Then just file, sand, and polish for your final piece.

Every lathe is a little different, but the idea is there. I thought that this could also be used to turn a taper by clamping and indicating a piece of rigid straight edge to the blocks at your desired taper.

If anybody has any questions just ask away.

Marcel

 

[jam]

nice job please post a video

 

[xalky]

Don't hold your breath waiting for a video. I don't have a tripod or a decent video cam. There are no videos or even any write ups about such a thing, I know, I looked hard when I was looking for ideas.

This design works and it's simple to use and setup. The hardest part is making a template, but thats not too hard. I used a nibbler to rough out the shape and then fine tuned it and with a file and a die grinder. Once the template is made, it can be used over and over.

 

[valleyboy101]

I like it.
I made a duplicator for my wood lathe, but this is a nice idea for my metal lathe. I like the idea of using it to turn tapers.
Thanks
Michael

 

[pestilence]

I've been very jealous of Keith Fenner's hydraulic semi-auto tracer, but now I don't have to be!

 

[fretsman]

Very nice job, there, thanks for sharing your idea )

Dave

 

[Getaway]

Very Nice. You Just made my "wish list" tool making job longer. Thanks for sharing.

 

[xalky]

I've been very jealous of Keith Fenner's hydraulic semi-auto tracer, but now I don't have to be!

I've been keeping my eyes out for a hydraulic tracer, but most of them need lots of work because they've been laying around for years collecting dust, and they're not cheap even on craigs list. Then there's just the bulk of the whole setup...I don't have any room for that whole contraption when I'm not using it. Is this better than a hydralic tracer?.....absolutely not. It's better than "NO" tracer.:think1:

 

[righto88]

That is a pretty slick set up! Very nice.

 

[george wilson]

xalky: What mask of lathe is that?

I used to make all of the steel spinning chucks for the PGA trophies. I did the same thing as you,except my setup was more crude. I have T slots running in the in and out direction of the cross slide. I just made a finger,hardened it,and screwed it into a T slot with a t slot nut. To hold the template,I just welded 2 arms on each end,and clamped them to the lathe bed with powerful metal clamps.

These templates were quite large,being trophy size. I'd start from the high spots and hand feed in the down hill direction. When the roughing was done,and I was down to finishing cuts,I could switch to power feeds,still holding the finger to the template with my hand on the cross feed handle.

Years ago,LeBlonde offered a simple tracing attachment that relied on a heavy weight on a cable to pull the disconnected cross slide towards the metal. Seemed very primitive,but worked. I have not found that a heavy hand or weight was necessary. I preferred to use hand pressure turning the cross feed handle in case something got over loaded. I could easily back off if that happened.

I have a mechanical Lehigh tracing attachment,but it only moves 1 1/2". Not enough for a 8" diameter trophy urn shape.