Archdale vertical milling machine leadscrew.

[Chipmaster]

The thread on the left hand end of the X axis lead screw on my milling machine which adjusts end float in the ball thrust bearing gave up the struggle just over a week ago so I could only use the x axis in one direction.

Picture with the left end of the table / bearing housing removed.

Archdale lead screw prob 1 by Andy, on Flickr

Stripped 5/8” x 20 tpi Whitworth form thread.

Archdale lead screw prob 3 by Andy, on Flickr

Archdale lead screw prob 5 by Andy, on Flickr

The table from above.
P1050567 by Andy, on Flickr

Archdale lead screw prob 14 by Andy, on Flickr

Clipboard01 by Andy, on Flickr

The lead screw was easy to remove and has no obvious wear.

Archdale lead screw prob 2 by Andy, on Flickr

I decided I would machine off the damaged thread and re-thread it 9/16bsf – the next size down also saving as much of the diameter of the end of the lead screw as possible.

Clipboard01 by Andy, on Flickr

The keyways that used to secure the locking collar with internal tabs have almost gone so I have to consider how to lock the new adjusting collar. The original collars stayed within the bearing housing or boss which is probably safer. The keyway would prevent the collar coming undone under a heavy load when the table is moving to the right. I think I’ll settle for a simple locknut when I put it back together.

Lead screw with a 9/16bsf collar screwed on to check the thread cut by the lathe is ok.

Archdale lead screw prob 17 by Andy, on Flickr

I thought my Archdale milling machine was probably on its swan song when I bought it about 25 years ago. However, it has kept going and served me pretty well, not bad for £120. The locking collars on the end of the lead screw have come undone occasionally since I started using the machine but I was able to tighten them up again until a week ago. I could buy another milling machine but I have a good range of 40 INT tooling for it and I don’t want the upheaval so I hope this fix will last a few more years.

P1050566 by Andy, on Flickr

P1050568 by Andy, on Flickr
P1050572 by Andy, on Flickr
P1050573 by Andy, on Flickr

The machine came without any history, there are no model or serial numbers on it. I suspect it is about 70 years old because I have seen a couple of identical Archdale milling machine for sale on eBay, one of them had a plaque stating ‘War Finish’ on the front. Do any other MEM members have the same machine?

Archdale VM2461 Miller on Ebay July 13 [3] (2) by Andy, on Flickr

tbc
Andy

[john mills]

that thread does not look that bad good cleanup and screw cut a new nut that fits .the old nut was the main damage .If you have made the nut and the thread to a neat fit it should serve ok.if only the top of the tread is damaged  the thread could just be screw cut a little deeper  and a new nut screw cut to fit.

[Chipmaster]

Thanks John,
perhaps the pictures are deceptive, the thread on the lead screw was tapered down to the end and beyond salvation. I couldn't identify the thread, it was 5/8 x 20tpi but appeared to be 55 degrees not 60 as per 5/8 British Cycle.
I do understand your suggestion of picking up and cutting the worn male thread a bit deeper. However, I wanted a clean start forming a reliable standard thread. I already had the tap and die for 9/16 bsf to hand in case screwcutting with my lathe needed a bit of help - I don't get much practice at that.
Cheers
Andy

[steamer]

I love the bronze plaque stating it's a "War finish"....LOL...apparently they could spare the bronze for the plaque but not the nice paint..

Nice job....it's good to see the old girl get a new lease on life!.

Dave

[tghs]

most likely time and man power was not spent on the cosmetic finish,, as long as it worked it was out the door.. didn't have apprentices around to do the finish work..

[awake]

Interesting mill - looks like a relatively small table, but a full knee for generous Z travel - ? And at least one axis of power feed supplied by the main motor through the coupler.

With a 40 taper and fixed head, this ought to be a very capable little mill!

[john mills]

if cutting the new tread which a die you did need to be able to get a good start.
looks like you have a colchester chipmaster lathe we used on of those at apprentice training school with that same
collet chuck ,thats over fifty years ago.these old machines were well built solid machines .nothing fancy but good working machines i often think it would be good if the chinese copied some of these in stead of the light bridgport type.
For screw cutting you need to try  and practice you don't have to go quick.just try cutting a thread .

[Chipmaster]

The old Archdale milling machine has a new lease of life, and backlash is imperceptible now the leadscrew endfloat can be taken up, I'm very pleased with the result and wish I had dealt with this years ago.

IMG_0453 by Andy, on Flickr

Here's a short video of the table moving under power.
<a href="https://www.youtube.com/watch?v=_FpPP3ZUjBo" target="_blank">http://www.youtube.com/watch?v=_FpPP3ZUjBo</a>

Archdale sorted out by Andy, on Flickr

Hi Andy,
Yes it's a good size for model engineering. The table excluding the tray on the left side measures 25" x 10" with a clearance of 14" between the table and spindle nose.

John,
the lathe is a Chipmaster built 1969.
I did indeed practice my thread cutting before working on the leadscrew. I went as slow as the lathe would go (35 rpm) so I could withdraw the threading tool as it approached the shoulder.

Cheers
Andy

[john mills]

yes i had not notice the change i had used a c for chip master.

[awake]

Very nice. Where do you control the speed of the table movement, and what starts and stops it? I was thinking the little lever on the front would be the control, but it seems to be in the same position both in moving and non-moving pictures.

[Chipmaster]

Hi Andy,
Thanks for showing an interest in the Archdale, perhaps I haven't appreciated the machine as much as I should.

There are three levers and one knob on the right hand side of the machine, the two upper levers select the spindle speed. The lower lever selects four traverse speeds and the plunger with a black knob on the end is pushed in or pulled out to select the direction of the traverse. It also has a mid way neutral position.

IMG_0456 by Andy, on Flickr

This plate shows the spindle speeds available. The machine can be a bit messy at the higher speeds as it leaks oil down on to the spindle nose then flings it around when started up.

IMG_0457 by Andy, on Flickr

My YouTube video taken this morning shows the lever on the front of the table that engages the traverse and how the feed is disengaged by an adjustable stop which operates in either direction. I ought to make a pair of proper stops for the machine.
At the end of the video you'll see the oil pump sight glass on top of the machine which is fascinating.

<a href="https://www.youtube.com/watch?v=m0CvRtx-YBA" target="_blank">http://www.youtube.com/watch?v=m0CvRtx-YBA</a>

Andy

[Alyn Foundry]

Hi Andy.

A great job! You can come over and fix my Knight now?

You may have heard me speak of a guy called Alex, he mentored me in engineering many years ago. He ran a small precision engineering business. Well....

His choice of milling machine was in second place, his Archdale. Noted for its very generous " Z " axis but his favourite was the Dufour. He reckoned there wasn't a better machine for heavy production out there at the time.

Oh, and they're both still working hard today, Alex passed on but are still being driven by Tim, his son.

Cheers Graham.

[Chipmaster]

Hi Graham, of course I’d love to help but unfortunately I haven’t got waders and there’s the other problem of too many castings to be attended to.

Andy

[awake]

Very cool. Thanks for the additional info! Is the traverse drive partially disassembled in the picture?

[Chipmaster]

The leather boot that is supposed to cover and protect a universal joint has deteriorated so I’ve detached one end of it as I look at what I can do about it. A shield would probably suffice because the swarf I make doesn’t travel that far.
Andy