Lathe carriage travel measuring

[John Conroy]

I've been thinking of installing a DRO one my,lathe like the one I put on my mill but I don't really want all the hardware and cables in the way. I don't think I need any better measure of travel on the cross slide as the feed dial has .001" graduations. The carriage however has .005" graduations and sometimes I want better resolution than that. I usually use a dial indicator with a magnetic base but that can be a pain to use. On the weekend I made up a bracket that clamps to the outer bed way over the inverted V and can hold either a dial indicator or a 6" digital scale that I have. Here are some pics of the project.

A small rare earthe magnet attaches the sliding scale to the carriage.

Another adapter for a 2" travel dial indicator, which I prefer if 2" is enough travel.

 

[Jwest7788]

Fantastic work as always @John Conroy

 

[PeterT]

I like it! I'm slowly getting around to 'aluminizing' my wood tail post DRO bracket mock-up. The sad part is, the 'woody' works perfectly fine so it has made me lazy.

- where did you source that DRO unit?

- when you mill that 90-deg notch in the clamp bracket, what's your method to setup? I made a lathe stop that had same notch feature. I put the part on a 45-deg angle in the vise so I could traverse with an end mill, more or less following layout lines. The part was short enough so I could clamp it ok, but a longer segment with a mid-span notch would be more of a bugger. Is there such a thing as a 90-deg pointed end mill that cuts this with the part laying parallel to table & V pointing up... kind of like how a dovetail cutter traverses its profile?

 

[John Conroy]

Peter, I got the scale at KMS, they were on sale for $29 and I bought 2. I think it is discontinued now, the SKU was IGA-35606. They do have a similar one IGA-35706 that has a separate scale and readout for $40

https://www.kmstools.com/igaging-digital-height-gauge-11098


I have a 90 degree end mill that I have used to cut grooves in aluminum but it does not like cutting deep cuts in steel.

I used my angle plate and small vise and mounted it at 45 degrees and used a 3/8" roughing end mill to hog out the V groove.

I used a digital angle gage to set the 45 degree angle.

I like your tailstock travel gage idea. I've been thinking of doing something like that.

 

[Johnwa]

I have a similar setup on my lathe. The only difference is I used a digital Caliper rather than a digital scale. Digital is nice as it's easy to zero it. Or change from metric to imperial.

 

[Matt_b_m]

@John Conroy. That's a great idea! I've been looking at DRO kits and I started to wince...then I factored exchange and decided to pause on the idea for a bit.
I think this would definitely get me started.

 

[John Conroy]

I used Peter's idea and made up a clamp type mount for the tail stock to mount either a dial indicator or digital scale there as well. It can be clamped anywhere along the length of the tail stock.

I also made up a plate to mount on the tailstock quill to measure travel with. I got to use my rotary table and boring head on this part.

I made a slit and drill and tapped a 6mm hole for the clamping screw.

 

[PeterT]

Looks real good. I cant find my plywood mockup pic handy to see which one I posted, but maybe it shows my overly complicated traveling plate that is attached to arbor similar to yours. It has a vertical pin slider arrangement instead of a DRO hard mount. I was concerned with the DRO flexing with any rotational play on the arbor. At least my tailstock has this, probably from some sort of keyway. I can see it move a tinge when a drill bit engages or whatever. I'm sure its probably not worth the diddling around, but thought I'd point it out. The plunger dial indicator wouldn't see this issue, but I wanted re-settable digital & more range.

The other thing I learned. The most advanced DRO in the world doesn't take into account the tailstock sliding back under heavier drilling pressure! (Light drilling no problem). I suspected something like this was going & explains some minor mis-measuring. You can only clamp the tailstock thing so tight with the lever & didn't want to gorilla the cam. I started using a way lube a while back. Everything slides beautiful now but maybe that has something to do with it?