Electronic leadscrew on a big boy lathe

[rons]

A dream. I would build a flip cover for the LCD.

 

[Garwood]

Is this GUI a product, a 'freeware' project, or something he wrote himself? Curious, that's all...

It's just an Arduino microcontroller that takes orders from a Raspberry Pi computer driving a nice quality 7" touchscreen. There's no magic, it's about $100 in cheap hardware stuffed inside a hunk of anodized aluminum. It's about the same size as a Kindle so it would basically mount to the machine near the threading chart.

This is really not complex to make it work. It's a damn microcontroller running dirt simple code.

 

[Garwood]

not sure how feasible this is, but incorporating an adjustable proximity sensor (think bed mounted stop) and some way of doing a quick retract of the threading tool would allow you to program a stop feed + stop spindle -> retract -> rapid carriage reverse to start (2nd proximity stop) -> reverse retract (whatever word that would be).

The retract/ re-engage threading tool could be based along the lines of those quick retract threading tool holders + a small stepper motor.

Just spitballing, no idea how I would do that, but it would allow easy threading to a shoulder and ease the hassle of keeping the half nuts engaged for metric threading.

I don't want anything operating the cross slide except me. I can turn the handle. It's a manual lathe. I just want the tool to feed at the proper pitch. I like the prox switch idea. A prox switch on a magnet would be a worker or attach prox sensors to the carriage somewhere and add adjustable collars to a rod.

 

[thermite]

It's just an Arduino microcontroller that takes orders from a Raspberry Pi computer driving a nice quality 7" touchscreen. There's no magic, it's about $100 in cheap hardware stuffed inside a hunk of anodized aluminum. It's about the same size as a Kindle so it would basically mount to the machine near the threading chart.

This is really not complex to make it work. It's a damn microcontroller running dirt simple code.

Yaz. It is simple. Also indifferent. No "conscience".

'"Los que se llamen 'computadores', se trabajen con putas!"

Those who call themselves computer workers work with whores.

Feedback control "executive" matters.

See heavy jet wheel brakes where an Airbus 380 worth of lives can be at risk..

ADA still lives!


AN/FSQ-7's Air Battle Computer (Whirlwind II) JOVIAL never quite died, either!

Warbird and missiles thing...

 

[Strostkovy]

If I were to do it I would add an encoder to the spindle. A very basic program with an Arduino or similar to count the pulses, divide by the desired number, and output fewer pulses.

The only control I would put on is a power switch, rotary encoder for selecting thread pitch, a small 7 segment readout and a button to lock it. Probably X.XXmm resolution, and then push the encoder in to get 0.00Xmm resolution.

I recommend connecting the servo overload to e-stop on the lathe and adding an interlock switch to the gearbox so you can't engage both at once.

There is no reason to involve any sort of operating system here.

The encoder approach will also maintain synchronicity as you manually turn the chuck for lining up threads or something, and is largely jitter free.

 

[CalG]

A Compumotor S7 drive is readily numerically slaved to any pulse input.

There are several operator panels that could be populated with a selection of thread pitch results.

 

[3t3d]

A Compumotor S7 drive is readily numerically slaved to any pulse input.

.

In that simple case you would Have to run the lathe in reverse t retract the carriage.

 

[CalG]

In that simple case you would Have to run the lathe in reverse t retract the carriage.

Yes, a press of the button.

Programming the interface initially would take time.

 

[DDoug]

In that simple case you would Have to run the lathe in reverse t retract the carriage.

Why ?
Doo you always doo that with the normal geared system ?

 

[thermite]

Why ?
Doo you always doo that with the normal geared system ?

In a word? Yes.

Single-point threading on large lathes has been done away from the headstock more often than not, last 100 odd years.

Ever since they GOT "reverse". And speeds above that of African Land Snails.

At even their ponderous RPM, they just don't stop - nor anything ELSE - as smartly as small lathes with light work.

Too much at-risk trying to finesse around that.
So we did not.

 

[DDoug]

In a word? Yes.

Single-point threading on large lathes has been done away from the headstock more often than not, last 100 odd years.

Ever since they GOT "reverse". And speeds above that of African Land Snails.

At even their ponderous RPM, they just don't stop - nor anything ELSE - as smartly as small lathes with light work.

Too much at-risk trying to finesse around that.
So we did not.

Gee, I dunno, when threading on the American I ran, and several other nice pieces of American Iron, I simply kept the spindle running, dropped the half nuts, spun back the cross slide, and cranked the cross slide back to the start.
Re-enter the cross slide to the stop, add a few thou on the compound, and wait for the thread dial to come around.

How would changing to electronic leadscrew be any different ?

Threading towards or away from the chuck doesn't change how you use the leadscrew & dial.

The spindle is running, and the leadscrew is synchronized, don't change it.

 

[thermite]

Gee, I dunno, when threading on the American I ran, and several other nice pieces of American Iron, I simply kept the spindle running, dropped the half nuts, spun back the cross slide, and cranked the cross slide back to the start.

Nothing to do with whether the LS is geared or electrified, no.

If you don't have to go tight to a hard shoulder, similar "feature", or thread a blind-bottom bore? That's OK.

If you DO have a blind bore or hard feature? You thread AWAY from it.

BFD.

Missed that at training?

Pittsburgh's IA schools were still teaching it to kids. But I'm OLDER that your generation. And - vintage of 1945 - BY about a full generation, IIRC?

"Present Day".. Joe "Py" is not the ONLY one with a video on it for those playing catch-up.

There are several folk "re-discovering" what EVERY pro turner used to know.

Go figure how TF it ever got forgotten about, it's that easy and that convenient a way to avoid ruination, or even simply lower stress levels?

And the nastier the lathe? The more important it is.

Most old-timers have run more and nastier lathes and mills than youngsters would believe could even be TRICKED into making usable parts.

It was what we had, and most times it was ALL we had.
Couldn't do the job with what they gave you?

Didn't long keep the job. "Union" or not.

 

[DDoug]

Nothign to do wothwhehter theLS is geared or electified.

If you don't have to go tight to a hard shoulder, similar"feature", or thread a blind-bottom bore? That's OK.

If you DO have a blind bore or hard feature? You thread AWAY from it.

BFD.

Missed that at training? Pittsburgh's IA schools were still teaching it to kids. But I'm OLDER that your generation.

Joe "Py" is not the ONLY one with a video on it for those playing catch-up. There are several folk "re-discovering" what EVERY pro turner used to know.

Go figure how TF it ever got forgotten about, it's that easy?

Yes, exactly, but my question to someone else (3t3d) was why reverse the spindle ?
That's done when you don't have a thread dial (I have done this) and leaving the half nuts engaged
at all time.

Threading to/from the chuck is NOT the answer.

 

[thermite]

Threading to/from the chuck is NOT the answer.

Neither is a pair of US Navy A6, full ordnance racks laid on what HAD been a Viet village that I considered overly rude. "the answer".
But I only ever did THAT the one time.

Threading away from the chuck has served me MANY times since 1960. And counting. Over 61 years, is that?

So you can have any answer you care to choose.

No foul.

I'll stick with what works for me.

Thread inch on 10EE. Thread Metric on Cazeneuve.

Caze can DO "inch". Until "CNC" it may have been the best all-manual I/M single point threader anybody ever shipped.

Cazeneuve HBX360 Lathe

Same as first photo Tony shows, mine is "first generation" with both the "B" special apron extended threading range, and the "C" capstan tailstock with hollow "though bore".

But all the feed dials are Metric. Why beg confusion in the details working an "inch" thread if one can do "inch" on a 10EE with "inch" dials, too.

And.. thread "away from" a feature if it is wiser.
Else not.

"Choices" are just an integral part of "life's bitch travesty" ain't they? Ain't never figured out what a "rich tapestry" tastes like. Don't have a Swiss-French bakery handy no more.

I was doin' fine.. until I put that second bumfodder roll-holder in the loo as "fall back".

Ever see an ambidextrous person try to make a decision as to .. never mind.. at least I usually escape before I fall asleep on the damned stool out of indecision..

 

[DDoug]

In that simple case you would Have to run the lathe in reverse t retract the carriage.

Why ?
Doo you always doo that with the normal geared system ?

Answer pulleaze ?.....

 

[thermite]

Answer pulleaze ?.....

Because his simple rig coupled the Parker Compumotor hard, direct and.... one doesn't dare to release the 'arf nuts 'til DONE-DONE..

Running a basic tranposing conversion Inch to Metric OR Metric to inch, ALSO means having to keep the 'arf nuts engaged.

That is part of why you do not want to thread tight to a feature - safer to thread "away from".

Only WHEN you have put all the resolvers and "brains" into an electronic LS? THEN you have the ability to "pick up". Not before.

There is a good example of that in the Cazeneuve "factory" video wherein they are demo-ing their "teach in" Siemens-controlled hybrid manual/CNC "Optica" lathe. They now and then insert the odd "flashback" to its "daddy", the HBX-360-BC I have, to compare to how the new way is faster and easier than the old way.

BOTH can "repair" threads, BTW. "pick up" is built into that daft "special apron", mechanically.

FAR easier for the Siemens, 'coz the NEWER lathe uses a servo spindle, not the vario-drive belted one of the older lathes.

But the Siemens CNC hybrid, used on a couple of OTHER "teach in" as well, is "rocket science" .... compared to "just" an Arduino leadscrew gone electronificated.

And priced accordingly, if not also overpriced, one can take as a GIVEN.

I did say "Siemens"?

CAVEAT: There are SEVERAL hybrid lathes of this sort. Have been for "a while already". Cazeneuve is not the only.

I have no Idea where Cazeneuve sits as to good, bad, or indifferent in the present market, either.

Price was right for what I got, so it will do me well-enough.

 

[CarbideBob]

Why ?
Doo you always doo that with the normal geared system ?

In a normal gear system you have a dial that you reengage the nut to.
This locks you into the same tooth and if your engage timing off a small amount the slide stills pulls forward or waits a tad to put you on the same path.
It automatically compensates and does the chase or lag needed.

In an electronic geared system you need to sync the drive back to the same spindle index/ slide position for pass number two.
Due to a bunch of issues this is not easy.
My first Galil controlled threading machine was a VMC. Rigid tap easy. The spindle stopped, turn on the axis gearing, start and reverse spindle. Tap moves in and out.
This the same as the above reverse the spindle but a note here is any lash in the drive/screw system a problem on that backwards move.
Then came my first lathe needing the gearing unlocked, return the slide and lock it back in just right for pass 2....
On paper or in a perfect world with no signal delays, processing loop times and update rates it seems so easy and for sure if you want to thread at 50rpm or less like a thread grinder that is much easier.
Bob

 

[Joe Gwinn]

I did an analysis of such issues for the AtomicELS and Electronic Leadscrew groups.

Here are the links to the relevant postings:

https://groups.io/g/E-Leadscrew/message/8802 (Trajectory Planning by Position - Expanded (20210830))

https://groups.io/g/E-Leadscrew/message/8803 (Position Trajectory-Plan Implementation (20210830))

 

[DDoug]

In a normal gear system you have a dial that you reengage the nut to.
This locks you into the same tooth and if your engage timing off a small amount the slide stills pulls forward or waits a tad to put you on the same path.
It automatically compensates and does the chase or lag needed.

In an electronic geared system you need to sync the drive back to the same spindle index/ slide position for pass number two.
Due to a bunch of issues this is not easy.
My first Galil controlled threading machine was a VMC. Rigid tap easy. The spindle stopped, turn on the axis gearing, start and reverse spindle. Tap moves in and out.
This the same as the above reverse the spindle but a note here is any lash in the drive/screw system a problem on that backwards move.
Then came my first lathe needing the gearing unlocked, return the slide and lock it back in just right for pass 2....
On paper or in a perfect world with no signal delays, processing loop times and update rates it seems so easy and for sure if you want to thread at 50rpm or less like a thread grinder that is much easier.
Bob

Correct if I'm wrong, but the OP's lathe currently has a properly functioning leadscrew, and thread dial ?

Why would the thread dial need removed for said conversion ?

 

[CalG]

Correct if I'm wrong, but the OP's lathe currently has a properly functioning leadscrew, and thread dial ?

Why would the thread dial need removed for said conversion ?

It doesn't need to be removed.