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John Stevenson
12-20-2008, 08:24 AM
Anyone got any sketches, drawings , instructions etc on how the high speed threading works on the HLV ?

.

aboard_epsilon
12-20-2008, 09:40 AM
I don't know what you mean John

The high speed threading is on the HCT machines isn't it ?

If that's what you mean ..have uploaded manual here ..scroll down to aboard_epsilon's upload

http://groups.yahoo.com/group/Hardinge-Lathe/files/

The bit about using the threading attachment is in the later part of the manual.

all the best.markj

Carld
12-20-2008, 11:12 AM
Why can't you high speed thread on any lathe if your daring enough to thread at say, 300 rpm.

dalee100
12-20-2008, 11:28 AM
Hi,

You certainly can run as fast as the tool will stand. The problem is stopping. The reality is, you can only go as fast as how quick you can stop the process. I hope I'm making clear the idea.

dalee

Spin Doctor
12-20-2008, 11:44 AM
The key to the system is the one way dog clutch set-up in the lead screw drive. I've got an idea how to build something that should work, at least I mand some guys I worked with who are some very sharp Tool Makers and Machine Repairmen can't find any holes in the idea. Coupled with the stop rod it allows you to thread right up to a shoulder at 1000rpm if the tooling will handle it. One nice feature would be if the the taper attachment could be set-up as a tracer with a cam to back the tool out so as to avoid a groove at the end of the thread. Plus if you are feed ing in with the compound the end of the thead is always getting closer to the shoulder. Actually when I had access to HLV-Hs I always fed the tool straight in when doing this. The other nice feature for threading on them is the Quick Retract on the compound

This is the Lead Screw Reversing Drive. I won't claim to of come up with something original here but if this is between the gearing set for the thread being cut and the leadscrew I think it would work

http://img.photobucket.com/albums/v19/markandannie/Leadscrew%20Reversing%20Drive/LeadScrewReversingSystem5.jpg

The Hardinge parts layout is on page 47

Ian B
12-20-2008, 11:55 AM
John,

Is this the same as the Ainjest high speed threading attachments? They give a settable end stop that drops the leadscrew nut out of engagement, and then some gearing that only allows correct leadscrew reengagement.

Probably why an Ainjest on an imperial machine can only cut certain imperial threads, and no metric threads.

Ian

GadgetBuilder
12-20-2008, 11:57 AM
I believe the HLV uses a dog clutch similar to the setup Cleeve describes in "Screwcutting in the Lathe". The HLV has some refinements such as power feed for the leadscrew to move the carriage back.

Cleeve covers the concept well and has pictures of a dog clutch setup he made for his Myford. The basic idea is the half nuts remain engaged and the leadscrew gearing disconnects from the spindle via the dog clutch trigger mechanism. The tool is retracted, the carriage wound back (by reversing the leadscrew), the next cut put on, and the dog clutch engaged. The dog clutch always picks up with the same relationship between spindle and leadscrew so the tool automatically picks up the thread, similar to stopping the lathe and reversing between passes. No threading dial needed and it works for metric or imperial threads.

John

lazlo
12-20-2008, 12:02 PM
Is this the same as the Ainjest high speed threading attachments? They give a settable end stop that drops the leadscrew nut out of engagement, and then some gearing that only allows correct leadscrew reengagement.

That's essentially how the Hardinge high-speed threading works. There's a stop rod for the dog clutch, and it has adjustable stops that are triggered by the apron. So you can literally go flying up to a shoulder, and the apron hits the leadscrew dog clutch stop, and pops the dog clutch. The apron stops on a dime.

Then you reverse the leadscrew, and the carriage winds back 'till it hits the opposite dog clutch stop.

John: if you look at Martin Cleeve's Screwcutting in the Lathe -- he talks a lot about the Hardinge dog clutch. The version he made for his his Myford is modeled after the Hardinge dog clutch mechanism. The problem is that for any lathe with a quick change gear box, you would have to make a Rube Goldberg mechanism to get the stop trigger up and over the gearbox, because you have to clutch the leadscrew on the drive side, to keep it synchronized with the lathe's spindle.

GadgetBuilder
12-20-2008, 12:23 PM
Lazlo:

Thanks for noting that Cleeve copied the HLV, I thought I recalled that but wasn't certain. Cleeve is one of my favorite writers, very pragmatic - everything I've copied from him works well.

I'd like to have a dog clutch on my lathe but haven't figured out how to do it nicely. In lieu of that I added a simple auto-stop to the carriage of my 7x12 which, combined with a retracting toolholder, makes threading much faster and less exciting :D As with a dog clutch, I now thread to a shoulder at speed... previously I used a hand crank. See: http://www.gadgetbuilder.com/ThreadingTools.html#AutoStop

Not as good as a dog clutch, I still need the threading dial and it doesn't work for metric threads. But it is still a big help.

John

Edit: I eventually built a dog clutch too: http://www.gadgetbuilder.com/Dog_Clutch.html

Spin Doctor
12-20-2008, 12:35 PM
One thing most people do not understand about cutting threads on the Hardinge (and I am not pointing any fingers here) is that once the leadscrew and halfnut are engaged you do not open the half nut until the job is done. All of the dropping out of the leadscrew takes place inside of the gearing. It doesn't matter what the lead of the thread is, inch, metric, DP or Module. As the dog clutches are one way they only have one point of engagement. They can not get out of time or phase as long as none of the settings on the QCGB or thread range dial are changed. Another point. The Feed Motor on the Apron does not drive the leadscrew. It drives the gearing in the apron that is connected to the longitudinal and crossfeed hand wheels. The longitudinal and crossfeed are engaged by means of clutch assemblies.

lazlo
12-20-2008, 12:44 PM
Sorry for the partial duplicate of the Martin Cleeve reference John -- I think we were typing at the same time :)


I added a simple auto-stop to the carriage of my 7x12 which, combined with a retracting toolholder, makes threading much faster and less exciting :D As with a dog clutch, I now thread to a shoulder at speed... previously I used a hand crank. See: http://www.gadgetbuilder.com/ThreadingTools.html#AutoStop

That's pretty neat! There's a high-speed threading attachment like that that you could buy for the Colchesters. Like your's, it mounted on the right side of the apron. It's an extra set of half nuts, and it releases when it hits a apron stop, much like the Hardinge stop rod.

Spin Doctor
12-20-2008, 01:13 PM
One aspect of threading at high speed on the HLVs. It is noisy as all heck, The gear train has got an awful lot of meshing going on with not a lot of lubrication

lazlo
12-20-2008, 01:17 PM
Spin, when you thread into the dog clutch on the Hardinge, does it stop and reverse, or just stop (and then you reverse manually)?

I never did understand how the Hardinge dog clutch is able to engage and disengage at high speeds.
If you look at the pictures that were posted on PM, the Hardinge dog clutch is just a square tooth -- it's not even tapered...

John Stevenson
12-20-2008, 02:08 PM
Thanks guys, some food for though and a couple of points.

First the Ainjest was developed purely as an add on to a Colchester lathe without having to modify the lathe.
It is a stop gap measure that if the lathe had been designed with a dog clutch, wouldn't have been needed.

I have the Cleeve book and it's very good, it can get quite heavy at times with the maths but I can't see any other way to address a subject that is based on mathematical formulae.

The reversing dog clutch in the book is credited to being off a Hendy - Norton design, cira 1914 but in another section of speeds he does mention the Hardinge, hence the question.

One very valid point Cleeve does bring up on the reversing dog clutch [ his design on the Myford wasn't reversing ] is the time taken to wind back.
An example he uses of a 10 - 1/2" long thread at 18 tpi cut at 200 rpm would take a minute to cut, 10 passes to complete the thread would mean ten minutes but also ten minutes on non cutting return time.
Over 250 pieces that would cost a working week of 40 hours.

.

lazlo
12-20-2008, 02:18 PM
John, you mentioned awhile ago that there was a new Sieg lathe coming out that had "high speed threading."

Do you know what they're adding to the lathe to facilitate high-speed threading?

S_J_H
12-20-2008, 02:29 PM
While not high speed, it is a pretty fast method.
Some of you may find the threading setup on my very old Artisan lathe interesting. It uses an 8 tooth dog clutch on the leadscrew. There is no halfnut or threading indicator and it can cut threads at a pretty quick pace.
http://i109.photobucket.com/albums/n48/S_J_H/vintage%20Artisan%20lathe/Artisanlathe023.jpg
http://i109.photobucket.com/albums/n48/S_J_H/vintage%20Artisan%20lathe/Artisanlathe024.jpg
http://i109.photobucket.com/albums/n48/S_J_H/vintage%20Artisan%20lathe/THREADINGTEXT.jpg
http://i109.photobucket.com/albums/n48/S_J_H/vintage%20Artisan%20lathe/ArtisanThreadinginstructions.jpg

Steve

lazlo
12-20-2008, 02:35 PM
Ah, that's interesting -- because the Artisan dog clutch is on the "wrong" side of the gearbox, it only synchronizes with threads divisible by 16.

That's why Martin moves the leadscrew stop up and over the gearbox, so you're synchronized with the spindle itself, which doesn't have an any limitations related to the relative position of the gearbox output, and therefore works on imperial or metric threads.

lazlo
12-20-2008, 03:16 PM
The reversing dog clutch in the book is credited to being off a Hendy - Norton design, cira 1914 but in another section of speeds he does mention the Hardinge, hence the question.

John, I just doubled-checked my copy, and while Martin shows the patent diagram for the Hendey auto-reversing dog clutch on page 86, which uses a pair of opposing crown gears, the version he built, which is on page 91, is very similar to the Hardinge design.

This is the Hendey design. The dog clutch selects which of the two crown gears drive the leadscrew. Completely different design than what Martin built:

http://www.lathes.co.uk/hendey/img41.gif

aboard_epsilon
12-20-2008, 03:32 PM
that looks familiar

http://img.photobucket.com/albums/v190/aboard_epsilon/fritz/pres2.jpg

all the best.markj

Melvin
12-20-2008, 04:10 PM
When I was an apprentice,our Harding Chucker lathes had a series of thread ed ring masters that fit on the end of the spindle. Then there was an overarm that a similar threaded segment on it. The over arm was lowered,and it locked in place,the threading tool was in the overarm,when the two threaded masters engaged the overarm traveled until it hit a stop,raised up,and returned. You couldn't thread more than an inch or so of length but I have threaded 8 pitch acme in brass at 2000 rpm with this setup.
Melvin

alsinaj
12-20-2008, 04:16 PM
I have a Hendey equipped with the dog clutch described in this thread.
I have never had the guts to do high-speed threading to a shoulder.
What worries me is, how precise and repeatable is the clutch release mechanism? Another thing: what is the procedure for setting up the clutch release point?

Anyone out there with experience of this?

lazlo
12-20-2008, 05:00 PM
that looks familiar

Mark, is that an anti-backlash adjuster? That looks like the slide for a mill head?

The Cincinnati adjustable anti-backlash mechanism used a double crown gear arrangement much like the Hendey auto reversing dog clutch. Work of art, IMHO :)

aboard_epsilon
12-20-2008, 05:16 PM
Mark, is that an anti-backlash adjuster? That looks like the slide for a mill head?

The Cincinnati adjustable anti-backlash mechanism used a double crown gear arrangement much like the Hendey auto reversing dog clutch. Work of art, IMHO :)

its the reversing mechanism for feed on the table of a Fritz Werner universal milling machine ..

it's upside down in the photo.

it turns the other way up and engages with this gear here

http://img.photobucket.com/albums/v190/aboard_epsilon/fritz/fritz1c.jpg

the machine has extended hand wheel for driving dividing head ..for spiral milling etc .

http://img.photobucket.com/albums/v190/aboard_epsilon/fritz/fritzfront.jpg

all the best.markj

Mark McGrath
12-20-2008, 07:02 PM
The Elliott and Butler 460 and 550 lathes also have single point clutches for threading.Withdraw the tool at the end of the pass and pull the clutch from forward to reverse (or vice versa ) and the spindle runs on the same direction but the saddle reverses back to the start of the thread where you put on another cut and reverse the dog clutch.
I have a pdfmanual for these machines but not sure how clear it is on the parts if you want a copy.Send email addy.
The best set up of the lot was the Ward 7 and some of the Herberts.Pull one lever and it retracts the tool,bang the spindle clutch straight into reverse (without stopping) and power back to the start,add cut and shove lever back in.
Mark.

J Tiers
12-20-2008, 08:36 PM
A quick feed stop still only solves half the problem......

You still need to pull out the tool repeatedly at same place, or use a runout groove. The latter cannot always be used, so............??

That Hardinge threading deal requires the groove, no?

lazlo
12-20-2008, 10:06 PM
Jerry the Hardinge has the famous quick-retracting toolpost. George Thomas made a great replica that's described in detail in the Model Engineer's Workshop.

The lever on the top-slide pops the toolpost backwards:

http://www.lathes.co.uk/hardinge/img1.gif

lazlo
12-20-2008, 10:18 PM
its the reversing mechanism for feed on the table of a Fritz Werner universal milling machine ..

it's upside down in the photo.

Wow, that's gorgeous Mark! That's a true labor of love restoring it -- I'm guessing that pile of other pieces is your To-Do list? :)

Great job on the Deckel-Green paint!

aboard_epsilon
12-20-2008, 10:36 PM
it's all finished ...well it was finished a year ago ..just needs asembling.........other jobs have held it up .

all the best.markj

SVS
12-21-2008, 05:51 AM
I have a Hendey equipped with the dog clutch described in this thread.
I have never had the guts to do high-speed threading to a shoulder.
What worries me is, how precise and repeatable is the clutch release mechanism? Another thing: what is the procedure for setting up the clutch release point?

Anyone out there with experience of this?

The Hendey dog clutch release/reverse is super quick done manually. I've suspected some mushiness with the auto stop so seldom bother to set the stop collar, but I don't get many good excuses to cut threads either.

Should repeat quite accurately, but getting the stop set so it repeats at the correct spot takes some messing. Collar is on the feed clutch control shaft. When it bumps the apron feed should go to neutral. I think. Theres a limit to how fast a Hendey should run when reversing feed on the fly. Just starts to bang too loud for comfort.

If you're lucky you may have the quick retract feature on the cross slide. It's unobtrusive-I owned a 51' 14x30 18spd. for a year before I figured out what the little square head shaft on the left side of the cross slide was for. I don't know when Hendey introduced this feature or what lathes might or might not have it.

Scott

Peter S
12-21-2008, 06:58 AM
Holbrook might be another lathe to look at for ideas. I think they had high speed threading. The ones I have seen had a quick-retract on the cross slide, but I don't know how the rest of it worked.

motorworks
12-21-2008, 10:51 AM
The Lion lathe I have (20 x 40 model)
has a nice feature that come in handy
for threading.
When doing RH threads or threads going toward the head stock
at 150 RPM's, I leave the half nut engaged and when I reverse
the spindle to back out the carriage the spindle runs at 250 RPM's
i.e. It backs out at almost twice the speed.(no gear changes needed)
Makes threading that much quicker!

eddie

John Stevenson
12-21-2008, 10:55 AM
Yup, My small TOS 14 x 40 does the same, makes it real handy to speed the job up.

.

lazlo
12-21-2008, 11:58 AM
Holbrook might be another lathe to look at for ideas. I think they had high speed threading.

I think the Holbrook setup was like the Monarch 10EE electronic leadscrew reverse: there were microswitches on stop-rods, and the carriage hitting the microswitch would trigger a programmed reverse.

Just as cool as the Hardinge single-tooth dog clutch, but more modern, and probably a lot quieter :)

By the way, one of the British members on PM recently turned me on to the Holbrook Minor -- that's now on my "Ultimate Lathes" short list, along with the HLV-H. Seems like they're rare as Hen's Teeth in the 'States though...

John Stevenson
12-21-2008, 12:14 PM
By the way, one of the British members on PM recently turned me on to the Holbrook Minor -- that's now on my "Ultimate Lathes" short list, along with the HLV-H. Seems like they're rare as Hen's Teeth in the 'States though...

I used to have a T13, bought it off the local scrappie for 50 but unknown to me at the time most of the guts for the screwcutting box was thrown in the bottom and the cover put back on.
I did manage to sort a fine ratio out and lacking any selectors tack welded the gears to the shafts.
Sound terrible but without it was little more than scrap.

One of the rewind people bought it just to skim comms up on, in fact they have only recently scrapped it when they bought a bigger lathe. This one was all electric speed change, 4 direct speed obtained by switching the motor from 8 to 6 to 4 then to 2 pole, 4 backgears by a mechanical gearbox in the base.

There is a Holbrook minor abandoned in a local building about 1/2 a mile from where I am with all the wiring hanging out in bunches.
The guy has tons of gear and won't part with anything.

.

lazlo
12-21-2008, 12:30 PM
This one was all electric speed change, 4 direct speed obtained by switching the motor from 8 to 6 to 4 then to 2 pole, 4 backgears by a mechanical gearbox in the base.

I believe the Holbrook Magna/Major/Minor were all like that: a 2-speed motor driving a gearbox that was mechanically isolated from the head and driving the spindle via a Poly-V belt.


There is a Holbrook minor abandoned in a local building about 1/2 a mile from where I am with all the wiring hanging out in bunches.

Man, you know how to make a guy feel bad John! :) That'd be a fun rebuild: just modernize the electrics like Macona did with his 10EE, and you have the "ultimate" toolroom lathe.

John Stevenson
12-21-2008, 12:44 PM
Man, you know how to make a guy feel bad John! :) That'd be a fun rebuild: just modernize the electrics like Macona did with his 10EE, and you have the "ultimate" toolroom lathe.

He's quite a nice guy though, I have know him for years, he's got to be in his 80's now but very fit, collects everything and money doesn't mean a lot to him.
He's got about 8 Myford lathes, all pristine, a late variable speed Boxford, some Colchesters and loads more. He just doesn't part with anything.

I could go down on Monday and ask to borrow say the tailstock off his Boxford as I wanted to copy it to fit my lathe for a week.
He'd lend it to me no problem but after a week he'd call round and ask if I'd finished with it. if I said no I need another week then he'd do the same the following week if I hadn't taken it back earlier.
That's just the way he is.
I have borrowed many manuals off him over the years and he's also borrowed stuff off me.

Biggest worry is he has no kids and his wife is already ga-ga and he has to take care of her. Scrap man will finish up with most of it.
I don't really need anything as I don't have room and I already have a CVA lathe and a Russian 1020 which is probably just as well made.

Rustynutz
08-05-2009, 02:59 PM
My Colchester master has a shear pin at the business end of the lead screw and I was thinking of making a lever that would disengage that pin, with a small removable dog fitted on the saddle to allow for re-engagement this dog could be attached by clutch to the x screw so as you back off the thread its automatically ready to engage again, also the dog could have switches on it so you can only go in one direction (have to think that one through)
any thoughts or comments on this idea???