Restoring a Boxford AUD ll

[Finn HammerParticipant @finnhammer30770]

[Finn HammerParticipant @finnhammer30770]

All,

My name is Finn Hammer, I am a toolmaker by trade, finished my apprenticeship in 1972, but the last 32 years I have made my way as a Chiropodist. As a side business, I construct Tesla Coils.

I recently bought a Boxford AUD ll lathe, and I thought my considerations during the rebuild would fit well into this forum.

The lathe had been dismantled by the previous owner, and this should prove beneficial to me, since I could handle it on my own.

Here you see it on the trailer, just arrived.

There are a couple of goofs on the bed of a boxford, the first is the pit for swarf and coolant right under the parking space of the tailstock, at the far end of the bed.

I sealed it off with a aluminium plate

And that should take care of an otherwise annoying cleaning task.

The other goof concerns the tightening and loosening of the clamping bolt at the front of the spindlestock. Even with a special spanner this is an inconvenient task. However, by drilling a hole in the bed casting, and exchanging the hexagon bolt with an allen bolt, the key can be inserted from below. Much easier!

I sent the stand to sand blasting and priming, and this saved me a lot of time and effort, and produced a wonderfull finish.

You can see that I added a VFD to the machine, a 4kW unit, which can stop the motor in ¼ of a secont without going into overvolt tripping. This VFD has an annoyingly loud fan, which got replaced.

[Finn HammerParticipant @finnhammer30770]

The stock contactor was always noisy, hummm, buzzzz, you get the picture, so out it went, and here is the wiring diagram for the standard 4 pole contactor I replaced it with.

I am sensitive to sound. here is the wiring diagram of the new contactor:

The box with stop, fwd. and rev. buttons contains some relay logic, to keep the VFD turned on by a press on a button, and also disable the opposite button.

It also contains the option of adding an external stop switch, which can come in handy, when threading into a bottom hole.

The wiring diagram is here:

There is one decision coming up rapidly now, choise of spindle nose.

If I keep the stock 1-1/2"x 8 TPI nose, I will have to machine 3 backplates for the tooling I intend to purchase: a 160mm scroll chusk, a 200mm 4jaw independent chuck and a faceplate. (the latter will be waterjet cut and mounted on a ready made adapter plate for the spindle nose of my choise, the ISO 902-3/DIN 55027. I bought the standard PDF.

My main concern here is the extra added overhang that will inevitable be the result of this setup.

If I turn the adaptor according to the standard, this will be the outcome, and I even have to trim the labyrinth faceplate to make way for the 3 nuts:

I don't feel too comfortable with adding almost 25mm of extra overhang, so I propose to slim the adapter slightly:

The flange is 20mm thick, which seems reasonable on a spindle with a 40mm bore, but the Boxford is tiny in that conparison, so I will trim 8 mm off the flange, to make it 12mm thich

The bayonet plate is 6mm, I will make it 5mm instead.

Lastly, by trimming the nuts down to 8mm length instead of the original 12, I will reduce the extra added overhang by 13mm.

I am not at all sure this will matter, seems like I am rapidly entering the territory af the diminishing returns, I will see what you guys have to say about this.

[Gerard O’TooleParticipant @gerardotoole60348]

Hello Finn,

I am watching with interest, having recently bought a Model A Boxford.

It all looks very good.

[BazyleParticipant @bazyle]

Did you notice that in the 'lathe improvements' thread Niels was initially thinking of modifications to a Boxford spindle?

[old martParticipant @oldmart]

There may be more than one drawback to changing the standard backplate for your ISO/DIN adaptor. When you produce the 1 1/2" register and thread in the adaptor and fit it to the spindle, the front will require machining to get it to run true. All backplates fitted to threaded spindles are machined in situ. The only advantage of your adaptor that I can see is being able during assembly, to provide a positive locking to the thread to ensure the lathe is safe to use in reverse. The locking could be permanent as long as it did not interfere with removal of the spindle from the headstock.

160MM chucks are much bigger than 5" / 125mm chucks, in weight as well as length. There will be a sacrifice in overall length between centres as well as a small stiffness loss.

[not done it yetParticipant @notdoneityet]

Boxford? Screwed-on chuck? You are going to arrest the spindle from high speed, to rest, in a 1/4 second? I do hope you have nothing screwed to the spindle, or it may well unscrew in about the same time, or less. Wear your toe-tectors and don’t stand in line with the workpiece/chuck is my advice if you try that trick too often!

Seriously – don’t do it. It is dangerous.

[Niels AbildgaardParticipant @nielsabildgaard33719]

Posted by not done it yet on 28/11/2020 00:33:32:

Boxford? Screwed-on chuck? You are going to arrest the spindle from high speed, to rest, in a 1/4 second? I do hope you have nothing screwed to the spindle, or it may well unscrew in about the same time, or less. Wear your toe-tectors and don’t stand in line with the workpiece/chuck is my advice if you try that trick too often!

Seriously – don’t do it. It is dangerous.

Hear,hear

My chinese sewing machine motor on a 180 lathe unscrewed a 100mm chuck and I will never even think of screwed on lathe workholding tools.

Next time an impoverished and starved Boxford follows me home I will make it a new spindle and be my fifth .

[Finn HammerParticipant @finnhammer30770]

All:

I thank you for your safety considerations regarding the possible unscrewing of the chuck while reversing the spindle, or by simply bringing it to an abrupt stop.

And please excuse me for not stating the obvious: That the DIN 55027 adapter will of course be secured to the spindle with locktite.

Old Mart:

You say that the 160mm scroll chuck is much bigger in length.

Hardly, I would say: The standard P&B 130mm chuck measures 76mm from backplate seating face to the front face of the chuck, whereas the total length of the Zentra chuck I am going to buy is only 68 mm. This places the front face of both options on the same line, therefore no recuction in stiffness .

Niels:

I have seen your spindle creations, and they are definately a step in the right direction, however:

There seems to be no feedback to the leadscrew, thus no automatic feed, and no threading ability.

What standard do you adhere to for the spindle nose?

And finally, although the back gear is inherently noisy, I think I might need it for heavy duty coil winding.

Cheers, Finn Hammer

[Finn HammerParticipant @finnhammer30770]

The Boxford is now closer to being operationable, spindle is in, and pre-preloaded, a test run will show if it shows a proper temperature rise when running.

The belt that I have is a disaster, however:

This belt keeps getting longer by the minute, and I wonder what you guys do, it is a hard job to join it inside the motor cage of the support, and I have to take links out all the time. No option to tighten it either.
What do you guys do????

I have just talked to a distributor who sells these belts,:

https://www.fecconsulting.dk/kileremme/accu-link-kileremme/megadyne-accu-link-kilerem-profil-a.html

And I have no doubt that it will function exedingly well, but the smallest amount I can get is 7.6 meters, enough for 5 lathes. Anyone in for a group buy, one belt at 1.5 meter would cost 35€ ex. shipping.

Cheers, Finn Hammer

Edited By Finn Hammer on 05/01/2021 15:08:04

Edited By Finn Hammer on 05/01/2021 15:09:37

[AJAXParticipant @ajax]

You can buy those link belts on eBay – no need to purchase 7.6m

They cost about £18 per metre.

I bought some for my Denford lathe and they work just fine.

[Alan CharlestonParticipant @alancharleston78882]

Hi Finn,

I bought a new T Link drive belt when I restored my AUD from here:

http://www.lathes.co.uk/page4.html

Tony quotes 60 pounds for a 1.4 meter length which is required for a Boxford. This seems a lot more expensive than the 18 pounds/meter from eBay but on the other hand, mine hasn't stretched since I put it in a couple of years ago.

Regards,

Alan

[Finn HammerParticipant @finnhammer30770]

So far so good, the new spindle nose is now a reality in hardware, turned out from 34CrNiMo6, a tough variety of the steels.
Next step is a trip to the hardening shop, and next again to the grinding shop.

I will not do any of those 2 operations, they require specialist treatment for the best result.

Soon, I can put the new chucks up and start to turn out parts.

Cheers, Finn hammer

[Brian HParticipant @brianh50089]

Quote " No option to tighten it either." I had a similar problem with belt wear and someone reminded me that there is adjustment on the countershaft brackets because they are slotted.

I had forgotten about this because the belts have not needed adjustments for years.

Excellent job on the restoration, it looks really good.

Brian

[Ady1Participant @ady1]

lovely

[Finn HammerParticipant @finnhammer30770]

All,

I had a word with the tool grinding shop, the manager refused to give a quote, because as he said, maby the guy is able to finish the job in 3 hours, maby it will take him 8, and if I give you a quote on the low side, I am going to pay the difference myself. Very unprofessional, since it means that the price would vary between 3000DKr and 8000DKr (300-800pounds sterling).

That's potentially 3 times what I payed for the lathe in the first place.

Since the steel I made the nose off is already much harder than the steel the scroll chucks are made of, I decided to cansel the hardening and grinding, and instead rely on a turned finish.

Not bad at all, the nose is now turned in situ, and thus there is no runout at all.

What you will see here is a Boxford that thinks it is a Weiler, which is very far from reality, so I guess it is a very sad thing indeed, but I am happy, so who cares.

Image with the old Pratt and Burnered 130mm chuck:

Not a pretty sight

here is the new DIN55027 short taper nose

and here is the new Zentra 160mm chuck in place

I like this, because it gives me the opportunity to quickly change from 3 jaw to 4 jaw to faceplate, as I originally intended.

Cheers, Finn Hammer

[Howard LewisParticipant @howardlewis46836]

Good work!

Ready for lift off, and years of pleasure

Howard

[Eddie GilesParticipant @eddiegiles29991]

I have just bought a aud training lathe. Not sure I’ve done the right thing. There is back lash in the tool post x and y axis . Where can I get spare parts for this? Your opinion of this lath please.

[Thor 🇳🇴Participant @thor]

Posted by Eddie Giles on 26/12/2021 15:02:49:

I have just bought a aud training lathe. Not sure I’ve done the right thing. There is back lash in the tool post x and y axis . Where can I get spare parts for this? Your opinion of this lath please.

A bit of back lash in the feed-screws is normal. Not sure if they stock what you need but here are a few links:

***Link***

***Link***

***Link***

 

Thor

Edited By Thor 🇳🇴 on 26/12/2021 17:37:25

[BazyleParticipant @bazyle]

"AUD training lathe" ? Check out Lathes.co.uk to see which one you have (who also do some spares). Backlash isn't really a problem as you can compensate. There are lots of spares popping up on ebay but don't rush in until you have done a bit of playing around to get to know it and lathework better. There are also other sources if you google images for 'Boxford Lathe Spares' you will see parts lists and several companies dealing in parts.

[GavlarParticipant @gavlar]

Posted by Eddie Giles on 26/12/2021 15:02:49:

I have just bought a aud training lathe. Not sure I’ve done the right thing. There is back lash in the tool post x and y axis . Where can I get spare parts for this? Your opinion of this lath please.

TUD – (Training) No lead screw, no powerfeed in either direction

CUD – Has a lead screw, power feed in one direction, no gearbox, screwcutting by way of changegears.

BUD – As CUD but power feed in both directions.

AUD – As BUD but with a gearbox.

Boxford themselves are not very good for spares, they have a very limited and ever diminishing supply. Their prices on their spares site are high, out of date, plus vat and plus post. Seller 'RELTUB34' on ebay makes cross slide and compound slide nuts in both imperial and metric. He will make to order if what you want is not currently listed.

I have in the past put a cut in a cross slide nut and squeezed it together to eliminate backlast as a stop gap measure.

 

Edited By Gavlar on 26/12/2021 18:52:10

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