ELS on Mini-Lathe?

[devils4ever]

Though it's probably fine, try screwing one of your fabricated parts into a commercial part. Reason being, if there's a scaling problem in the software, it won't appear because a wrongly-threaded nut will always fit a matching wrongly-threaded screw.

You are correct. I did cut a M8 with the old software and tried it on a commercial nut with success. I didn't have a M20 bolt or nut, so I made both, but they could be off. I did check with a metric thread gage though.

 

[ttabbal]

Good looking parts! I usually thread away from the chuck, so I just let it overshoot, back the tool out, and reverse to the start. With metric, I leave the half nuts engaged as I have an imperial leadscrew.

If you need or want interoperability, measure the outside thread with a thread mic or wires. Then use it as a gauge for the internal thread.

 

[devils4ever]

Good looking parts! I usually thread away from the chuck, so I just let it overshoot, back the tool out, and reverse to the start. With metric, I leave the half nuts engaged as I have an imperial leadscrew.

If you need or want interoperability, measure the outside thread with a thread mic or wires. Then use it as a gauge for the internal thread.

That's exactly what I did.

When I was first learning how to cut threads (not long ago), I cut away from the chuck figuring it was safer. I couldn't figure out why the thread I cut wouldn't engage the nut. Finally it dawned on me that I cut a left hand thread! I've seen Joe Pi's method of cutting threads on the lathe by cutting away from the chuck, but that method puts upwards pressure on the tool and tool holder and I'm not sure my little lathe would like it that much.

 

[GunsOfNavarone]

Good looking parts! I usually thread away from the chuck, so I just let it overshoot, back the tool out, and reverse to the start. With metric, I leave the half nuts engaged as I have an imperial leadscrew.

If you need or want interoperability, measure the outside thread with a thread mic or wires. Then use it as a gauge for the internal thread.

And now with the ability to have the lead screw move in the opposite direction as chuck, this is now something I can do now. Can run at a higher rpm with no stress of stopping in time!

 

[GunsOfNavarone]

That's exactly what I did.

When I was first learning how to cut threads (not long ago), I cut away from the chuck figuring it was safer. I couldn't figure out why the thread I cut wouldn't engage the nut. Finally it dawned on me that I cut a left hand thread! I've seen Joe Pi's method of cutting threads on the lathe by cutting away from the chuck, but that method puts upwards pressure on the tool and tool holder and I'm not sure my little lathe would like it that much.

I think it was Joe Pi that has a video where he is cutting threads (metric on an imperial L.S.) and he does disengage. However, when he reverses direction, he engages half but at the same point he started. Works well and it’s nice to be able to disengage before getting in too far. VFD has helped a bit with slowing quicker, but my resistor doesn’t allow for solid breaking like some do (Teco L510)

 

[devils4ever]

Here's a M20 X 2.5 thread cut in 1144 steel. I wanted to try this in harder material plus I needed this cut for another project.

The 2.5 mm pitch is equivalent to about 10 TPI which is pretty coarse and pushes the stepper motor to higher speeds. I really wanted to see if the ELS system could cut this coarse a thread in steel (harder) stock without missing a step. It worked great. Of course, I was only running the main spindle between 100 and 250 RPMs, but the leadscrew is turning faster than the main spindle since my leadscrew is 16 TPI.

I'm very happy with the finish. Near the end of the cut, I can only take 1-2 thou per pass. That's a limitation of the mini-lathe, not the ELS.

 

[GunsOfNavarone]

So....FINALLY got the last piece of the puzzle buttoned up. Changed the stepper to 1000 step/rev. Ran a couple thread tests, look great. I did turn the RPMS way up (1800) and I was able to error the stepper out, but that was at 8tpi. It was trying to move stepper faster than it's ability. I don't think I'll ever want/need to do ANY threading at 1800 rpm. I do want to play more with any limitations, but just glad all the little details are done. Nice smooth finish when power feeding. I feel like my power supply for steeper should be grounded. I mean the plug has a ground, but it attached to the bottom side of a butcher bock work table, but the CASE isn't ground that way. Not sure if that's a problem TBH.