View Full Version : Pimp my lathe, the thread dial

11-03-2005, 09:46 PM
Hi all,

I've gotten a lot of inspiration from this group, so I thought I'd share my first lathe-pimping project. A thread dial.

I'm still pretty new to the machine tool stuff, so don't be overly critical http://bbs.homeshopmachinist.net//wink.gif It was a good project since I got to use the lathe, mill, and rotary table.

The biggest accomplishment was cutting the gear. It took three tries, but in the end it was a success. The first attempt was to try to use a slitting saw; but it was too sloppy. The second attempt, the gear came loose from the arbor 2/3 of the way through. The third time was a charm. Here's a pic of the gear cutting setup.


I got the idea for the face layout from an old usenet posting. My leadscrew is 12 tpi, so I've got marks for fractions of 2 and 3.

Here's a picture of the finished product installed.


11-03-2005, 10:34 PM
The markings on the dial look really good. How'd you do that? I'd like to see a closer-up photo of it.


11-03-2005, 10:56 PM
Sweet job, very nice looking. One question, in your gear cutting setup shot, is that chuck spinning behind the rotary table? I take it you didn't hand crank it?

11-03-2005, 11:20 PM
Looks like a mighty fine project, and Well done! Is that machine a Griz G0516? I have one of those and was wondering if a thread dial was available. Now you have answered my question if one could be made. What size is your rotary table, and would you PLEASE post some drawings of your dial. Nice work.

[This message has been edited by lugnut (edited 11-03-2005).]

11-04-2005, 08:15 AM
Nice work!

11-04-2005, 09:37 AM

Here's a close up of the finished dial.

The face is etched with an etch-o-matic (www.etch-o-matic.com or I have a link or two to building your own). First I made a cad drawing, then printed it on a transparency, then exposed one of the UV stencils, and finally use the stencil to etch the part. Here's the cad drawing of the face.

The "rules" for using the different marks on the dial are (as sent to me by Dr. Robinson, the "inventor"):

TPI Example Dial
12x 12, 24, 36, 48, 60, 72, 84, 96 annywhere
6x 6, 18, 30, 42, 54, 66, 78, 90 any dot (single or double)
3x 3, 9, 15, 21, 27, etc. single dot
4x 4, 8, 16, 20, 28, 32, 40, 44, etc any line
2x 2, 10, 14, 22, 26, 34, etc. numbered line
1x 1, 5, 7, 11, 13, 17, 19, 23, etc. odd numbered line
½x 3½, 11½, etc. same line

Good catch. After I put the picture up I noticed that you could see the chuck spinning, and wondered if anyone would see it. Yes, I use the lathe for a powerfeed sometimes. I find some things like cutting 48 teeth tedious enough without hand cranking. http://bbs.homeshopmachinist.net//wink.gif That's probably the main reason I haven't moved the mill off the lathe yet, that poor-man's powerfeed has spoiled me a little.

You are right, it's a G0516. Littlemachineshop.com sells thread dials too, but they were out of stock when I wanted one. Plus when I saw Dr Robinson's post, I kind of wanted one that took advantage of the 12tpi lead.

It's a 6-inch rotary, another Grizzly special, the rotary, index plates, and tailstock for $250, I couldn't pass that up, even if it is crap, I will be able to learn from it.

The gear setup was probably the most challenging. I ended up cutting it with a normal 60-degree carbide insert cutter in a fly cutter. The fly holds the cutter at a 20-degree angle, so I had to factor that into the positioning. Here's the drawing I used to figure out the position.


[This message has been edited by d1ulookin4 (edited 11-04-2005).]

11-04-2005, 01:04 PM
Eric, very well done, I am going to check out that etching setup, the results look nice. Of course it doesn't matter if you have deluxe machines or not, its the man turning the dials that makes the difference. I notice in your profile that you are a software engineer, same here, how long have you been in the field?

11-04-2005, 01:36 PM
Here's two links to etching stuff. The first one is for an "exposure unit" for making the stencil. The second one is for the unit that actually etches the metal.



I made my own exposure unit with an aluminum box "dadoed" (woodworking term) out for a piece of glass. I just put it in front of a 300 watt halogen lamp for 45 sec to a minute and it works fine. I bought an actual etch-o-matic for pretty cheap off ebay, otherwise I would have made one.

The dial is larger than the etch-o-matic, so I stuck the stencil to the dial with double faced tape and etched it in pieces.

I've been doing software for about 12 years. My bachelor's degree is in electrical, but the software was easier for me.


11-04-2005, 07:48 PM

very cool. the dial came out excellent.

andy b.

11-04-2005, 08:02 PM
Very nice work, and thanks for the links!
Now I have another project to start. http://bbs.homeshopmachinist.net//smile.gif


11-04-2005, 09:09 PM
Nice work!I take it the top screw backs off and the unit tilts into the leadscrew right?Does that affect being able to see the dial or is it even a problem?

11-05-2005, 02:29 PM

The picture shows the dial engaged. The dial tilts backwards to disengage. It is at a slight angle to (hopefully) be easier to read. I polished the dial before I etched it, and reflection could be a problem. That is one point that might need a little refinement after some use. I also thought about andonizing it with a good contrasting color.

This is all a part of my learning process. I've only cut two threads with the lathe, and one of them got totally butchered. I thought with the dial, I'd be better prepared.
I'm also concerned that the lathe won't slow down enough for me to be able to actually learn to cut threads, but I will find that out. I expect that a hand crank is going to be next.

Thanks for all your positive feedback!


11-05-2005, 03:10 PM
I also have the G0516. I'm planning to slow mine down by using an extra motor mounted undernearh, driving the large motor pulley. The original motor will act as a jackshaft.
Nice threading dial. I intend to try to make one some day. Is your gear a 48 tooth gear?

Your Old Dog
11-05-2005, 03:45 PM
<font face="Verdana, Arial" size="2">This is all a part of my learning process. -Eric</font>

You learn a little quicker than I do ! Nice job!

jewelers use "black lacquer" stick with a match to color the recessed lettering in engraved cigarette lighters. Might work for you too.

charlie coghill
11-05-2005, 06:32 PM
Have you tried etching brass? I have a couple of projects that I made for the Grandkids and would like to etch them.

11-06-2005, 01:24 PM

Adding a second motor and using the original as a jackshaft is one of the best ideas I've heard yet. Thanks. I had been thinking about a DC conversion, but that seems a lot more complicated than I want to get into right now.

It is a 48 tooth, but a 24 would work also. The only thing a 48 will do that the 24 won't is allow for cutting 1/4 pitch threads, according to Dr Robinson. Physically, I think the 48 probably will fit a little better on the machine.

Your Old Dog,

The etching process leaves the etched inlay black. It's just that the contrast of that etching on a polished dial is hard to see at some angles. I was thinking of possibly andonizing the dial to a brighter color that wouldn't glare so much. Thanks for the tip.


I haven't etched brass, but it should be possible. It is a little difficult to sort out the requirements and materials, but from what I have figured out, you mainly need a different electrolyte for the different materials. There is a "general purpose" for basically all ferrous metals. I also got a bottle of the kind for aluminum. The web site is a little difficult to navigate, but on the "shopping cart" page, it shows one electrolyte for brass, copper, and bronze. That would probably give the best results.
I will email the link to the shopping cart page, if you want. I don't want to get in trouble for advertising. http://bbs.homeshopmachinist.net//wink.gif I also don't want people to think that I have anything to do with etch-o-matic. http://bbs.homeshopmachinist.net//wink.gif


charlie coghill
11-06-2005, 07:25 PM
Eric Please do send a link. I would like to etch these pieces.

charlie coghill
11-06-2005, 08:28 PM
Got it Eric, thanks very much.