Acme Rod

[woody1Participant @woody1]

Hi all,

Need a length of acme rod for my ML1 cross slide which is bent any suggestions on a source I can only find american companies?

Bit of a disaster really it came like it also with buggered handle threads. Straightened it as much as i could but its not good enough. I modded with the addition of bearings to make movement more smooth however when the handle is from about 12 to 3 o'clock the bend causes the outer handle to rub inside the bearing housing.

Thanks,

David.

[woody1Participant @woody1]

Bent Cross slide Lead Screw

[BazyleParticipant @bazyle]

Probably best bet is to find someone (on a CNC forum) who is upgrading newish machine to ballscrews.

[BERT ASHTONParticipant @bertashton57372]

I remember many many years ago my first lathe was a ML1 and I had a similar problem.

So I swapped the acme cross slide screw for a length of withworth studding, I am not sure

if I used BSW or BSF, I then made a new micro dial to suit the screw pitch.

This lash up lasted me for years until I could afford a Super 7.

Bert Ashton.

[John HaineParticipant @johnhaine32865]

Try Zapp Automation or Marchant Dyce, though stainless studding isn't a bad substitute for the short term.

[woody1Participant @woody1]

Cheers for info,

Think I'm going to have a crack at grinding an acme thread tool and machining a short test piece. I can grind the bit I have an acme thread gauge. However I'm not sure of the thread specs of the cross slide lead screw. Would any one know? its an ML1 as mentioned. I know the lead screw is 8 TPI not thats of any help.

Thanks,

David.

[bodgeParticipant @bodge]

Done the same thing as Burt, used a bit of studding, metric 10mm was all that was handy at the time. made the nut in two pieces, the flat bit , and the threaded bush with a reduced bit on one end, which is tight push fit in the centre hole of the flat bit . So when i need to replace it , just knock the old nut out, then just push a new one in, & a new bit of studding

To get a good fitting nut i put four nuts on a gash bit of studding [ not tight , left them a bit loose ] then weld them up, J.S.-style, [ takes care of any lash ] then turn to suit

On an ml 1 though are you sure its acme & not a square thread, myford also had a spell using 12 tpi screws with 80 division dials,

bodge.

[John Stevenson 1Participant @johnstevenson1]

Posted by woody1 on 22/09/2015 16:15:01:

Hi all,

Need a length of acme rod for my ML1 cross slide which is bent any suggestions on a source I can only find american companies?

David.

Nope no suggestions as you haven't told us anything that can help only Acme which it may not be.

What size, what TPI, is it acme, how many divisions on the dial.

Sorry if this sounds harsh but an ML1 will have passed through many hands and the likelihood of it having been butchered is very high.

This is a unique opportunity to now do something about it and finish up with something far, more usable that when it was made.

Bodge mentions 12 tpi screws which were made and fitted, unfortunately 12 into 100 means you need a dial with 83.33333333333333333333 divisions

8 tpi will give you 125 divisions on a tiny dial and you then have to do the remainder 25 maths in your head.

10 Tpi will give the best option and a S/H one off an old ML7 could probably be adapted to fit.

[KWILParticipant @kwil]

ABBSAC of Worcester is a good start.

[duncan webster 1Participant @duncanwebster1]

see previous thread at http://www.model-engineer.co.uk/forums/postings.asp?th=65338

[woody1Participant @woody1]

Thanks,

 

Comparing with a vice and wheel jack lead screw, i’m sure you are correct. Not sure of an easy fix other than sourcing a replacement. Image attache (old) if you look jet behind the bearing you can see some porosity where i had to turn (with difficulty) the mashed and bent handle threads before fitting, welding and threading. 

 

The machine is o.k. Gone from a chattering wreck to easily capable of taking 1/16 + cuts on free machining steel. Want to sell to buy something larger but A: I don’t want to sell some one a lemon and B: the more belles and whistles I have (which are extensive) the more value.

 

Cheers guys.

 

 

 

Edited By woody1 on 22/09/2015 19:45:09

[woody1Participant @woody1]

Cheers for the recommendations my mac book is a pain. Ill look into it.

David.

[bodgeParticipant @bodge]

Unfortunately 12 into 100 means you need a dial with 83.3 recurring, but myford at the time didnt think that was too much to worry about, so like it or not 80 div, dials, [ though the dials werent to bad, resetable, and not made of marzak ] Also fitted to their so called 4 inch precision lathes.So any old bit of 3/8 ish studding will do !… 10×1.5mm gives about 60 thou p/rev or .005 indicated on dial is .004 movement of tool, So the general method is get it some where close, check for size with a mic, then take last couple cuts using dti,

A bit of a guess but would think the screw dimensions most likely 3/8 dia x 10 or 12 tpi more likely square , but could be acme. as J.S writes need a bit more info…

bodge.

Ah, just seen the pics & text,…..think you are now entering the realm of the law of diminishing returns, so try find parts at right money!!

Edited By bodge on 22/09/2015 21:05:06

[Peter G. ShawParticipant @peterg-shaw75338]

Why not have a go at making one? My lathe has, as standard, a non-T-slot cross-slide. I also have a T-slotted cross-slide which was supplied as a special , but to use it requires transferring the existing handle & leadscrew from one bit of gubbins to the other, something of a pain and which doesn't really encourage me to use the T-slotted device especially as adjustment for smooth handle rotation can be a bit problematic requiring gentle adjustment withing the clearance of the three fixing screws.

My lathe (Warco 220) is metric throughout so I assume the leadscrew is metric. I've ground up a tool from an old file and made a gauge from a piece of 1mm steel, and experimented with it. First time was a disaster as the tool broke, and before I realised, nicely gouged the test thread I was making. Tried again, with complete success, so I'm now about to set about making the complete item.

Dimensioning was easy – measured the OD of the existing, and the pitch, and looked up everything on the internet and other places. Tip width was a problem – eventually I set the micrometer to the required value and did it by comparison of the tip against the gap.

I'm not sure what steel I should be using, but given the amount of use it will get, I suspect good old EN1A will be ok, and that's what I'm using. It runs in a brass nut incidentally.

Regards,

'av-a-go Joe' AKA,

Peter G. Shaw

[woody1Participant @woody1]

''Sorry if this sounds harsh but an ML1 will have passed through many hands and the likelihood of it having been butchered is very high.''

 

''This is a unique opportunity to do something about it and finish up with something far, more useable that when it was made''

 

I have butchered it in a good way (it has one previous owner). Only machine I could afford at the time, which my mentor was supposed to come and look at with me, however he developed medical problems and died shortly after so Im stuffed in all holes.

 

Edited By woody1 on 22/09/2015 21:04:43

[davebParticipant @daveb17630]

I bought a 3' length of 1" x 5TPI Acme threaded rod from the USA, cost £12 for the rod, £24 for carriage and arrived within 10 days. This was less than half the best price I could find in GB.

[OuBallieParticipant @ouballie]

daveb,

Details of supplier please.

Using iPad 1 after iOS9 screwed up iPad 3, so well done Apple you are now rivalling Microsoft.

I thought I'd learned to wait for .0.2 release before updating.

Geoff – Stupidity overcomes all reason

[John PParticipant @johnp77052]

Hi there

I feel for Woody's predicament and the frustration of trying to find
a replacement leadscrew ,in these metric times there is not much
interest in these old imperial sizes .
Whilst suppliers may well list the size you need there is no guarantee
that it will be in stock or made any time soon.
The only option to make it yourself,i have screwcut several leadscrews
of different sizes from about 7/16 up to about 7/8 inch in 10 and 8 tpi.
The experience can be time consuming , tiring and at times end in a
complete disaster.Some years ago such an event took place which
ended up in me devising a different way of doing this job.
The screws that i cut now are set up in the lathe the job is started
and the machine gets on with it ,there is no operator intervention
needed during the process.
Here is a photo of three screws 5/8 ,1/2 ,3/8 inch 10 tpi RH, the
1/2 inch has thread length of 20 inches and the 3/8 just over
13 inches.The screws are cut to full depth in a single pass in
either free cutting EN1A or EN8M .
An article was written and submited to MEW just over 4 years ago
and by some coincidence an updated version 3 of this was sent to
Neil only a few days ago.
Whilst in the short term this provides no solution to Woody' problem
it may well be of some help to those who wish to make these items.

John

[davebParticipant @daveb17630]

Geoff, I sent you a PM. Dave

[mark costello 1Participant @markcostello1]

If anyone needs a part sourced from "the Colonies", I would be glad to help.

[Author]

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