Hello everyone!

Okay, so I've tried to read and attempted to use various fixes and such from this forum and others but I just cannot get this thing to run basic threads!

that said, I'm trying to use G76.
I've also tried the simple threads screen but it usually tells me my rpm is faster then feed?

When I run G 76 it seems to do all the prep proper, lines up and looks to cut thread BUT then when clearing itself to reset it cuts into the part!

I'm cutting towards chuck, in +X (spinning CCW).

This is the code I've been trying to run on some 1 inch stock I got laying here. (This is just where I ended up after a few days of buffering around so not sure what's right, but it's partial posting from the threading screen)

G0 G40 G18 G80 G50 G90
T07
G00 G53 X0.61 Z0.25
G00 X0.51
M3 G99 S87
G00 X0.510 Z0.25 F4.35
G76 X0.9405 Z-1.2 Q3 P0.05 H0.05 I29 R0.5 K0.25 L0 C0.5 B0.001 T0
G00 X1.25 Z0.25
M9
M30

This code crashes hard hahaha.

I had simpler code that would only cut a small line in the stock on its way to reset but I've saved over and don't have it anymore.

I posted a photo of what it was doing.

What the first cycle looked like when finished.

I also have an ESS smooth stepper. If that changes anything.

Okay,

So apparently there can be issues with the smooth steppers and threading. Which is likely my issue.

But, G32 and some code got threads working fine for me!

For anyone else looking I based my code off of here:

https://www.haascnc.com/service/codes-settings.type=gcode.machine=lathe.value=G32.html

Works well, and they laid out the explanation well.

Kyle

First of all, you need to get the LATEST ESS driver from Warp9. Anything before that does not work properly.

Second, trying to use info from the HAAS machines is not a good idea. HAAS do some things a bit differently. You need to read (study) the Mach3 doco and experiment a bit.

I found the Mach3 G76 code to be overly complex, as it tries to do everything. Well, fine, but . . .
I simplified it, cutting out tapered threads and a few other bits one never uses. I find it does the standard threads quite well.

For the record, I routinely use Mach3 for threading. Granted, sometimes I cut the thread not quite all the way and finish off with a tap or die, but there is a good reason for this. With a standard 60 degree V-tool you will get a 'thread', but it will not have a profile which complies with the Standards. You can use a matched threading insert - matched to the single size of thread you are cutting, but that works out expensive. A commercial tap or die does make the right final profile.

Cheers
Roger

First of all, you need to get the LATEST ESS driver from Warp9. Anything before that does not work properly.

Second, trying to use info from the HAAS machines is not a good idea. HAAS do some things a bit differently. You need to read (study) the Mach3 doco and experiment a bit.

I found the Mach3 G76 code to be overly complex, as it tries to do everything. Well, fine, but . . .
I simplified it, cutting out tapered threads and a few other bits one never uses. I find it does the standard threads quite well.

For the record, I routinely use Mach3 for threading. Granted, sometimes I cut the thread not quite all the way and finish off with a tap or die, but there is a good reason for this. With a standard 60 degree V-tool you will get a 'thread', but it will not have a profile which complies with the Standards. You can use a matched threading insert - matched to the single size of thread you are cutting, but that works out expensive. A commercial tap or die does make the right final profile.

Cheers
Roger

Thanks Roger!

Getting the latest ESS isn't in the budget haha. Good to know about HAAS as well, but I've run a few test runs with the code I wrote out basing off Thiers and my machine seems to like it and threads are fitting. Granted I did not use their code to a T, I blended a bit with a book I have and another video I  found on YouTube that simplified some stuff!

And yes, I realized quick that the regular A60 inserts won't do certain threads and that you need to buy various types that fit certain pitch angles. Which I'm good with, I have holders already so getting the inserts isn't a sweat.

I will keep it in mind about finishing with a regular tap/die though, but those get expensive too once you start buying for threads over an inch! Haha.

Most of what I will thread is basic straight threads so not really needing G76. Would be nice, but not needed.

I've got various sets of code already written and will modify the G32 sets as needed 

Take care!

Kyle

Hi Kyle

No, I did not suggest buying a new ESS. What I am suggesting is getting the latest DRIVER, from the Warp9 web site. It is free.

The problem with Mach3 by itself is that it averages over several revolution to get the spin, and that is totally useless for threading. The latest ESS DRIVER does assume an encoder on the spindle motor (which may cost), but with that the ESS itself can do wonderful threading. The ESs uses the spindle encoder pulses to measure the spin rate, because the spin WILL change when the tool hits the metal. The spin will slow down. Now, it is extremely unlikely that the spindle motor power supply can compensate fast enough, so the ESS does not try for that. Instead the ESS adjusts the immediate Z axis feed rate to match the current spin. If the spindle slows a bit the ESS slows the Z axis to match.

There are complications of course to do with encoder noise, but with a 512 edge encoder you can average the spindle pulse rate over (say) 32 edges and correct the Z feed rate 16 times in one spindle revolution. (16x32=512) This works.

The cost of large taps and dies - yeah, problem. I am more likely to be threading M2 up to M8 (or even M11), but I understand.

Cheers
Roger

Hi Kyle

No, I did not suggest buying a new ESS. What I am suggesting is getting the latest DRIVER, from the Warp9 web site. It is free.

The cost of large taps and dies - yeah, problem. I am more likely to be threading M2 up to M8 (or even M11), but I understand.

Cheers
Roger

Ahh, yeah I could probably go and get the driver. haha!

As for my lathe, I do have a cherry hall that measures 1 revolution each pulse that mach3 receives. My lathe is a gear head lathe that custom modded to run CNC haha, so I got no control over spindle unless I manually change gears. Good and bad maybe, but when tool hits in it rarely bogs it down any!

Ill be doing just some bigger farm parts so some stuff is larger threads and I can just custom threads and weld parts in sometimes lol.

Appreciate all the info, it's all good to know as I plan to also build myself a mill at some point.

Cheers,

Kyle

Oh - Gear Head? That is very different! In fact, that is what the latest ESS driver tries to emulate.

Now you have to allow for slop (or backlash) in the Z drive. Easily solved: on retrace just go a few mm beyond the start of the thread before starting the next cycle. Or have I misunderstood the photo?

If so, try C=3.0 maybe?

Cheers
Roger