How to remove a chuck from a Boxford model A

[Ian S CParticipant @iansc]

Went back to the local Men's Shed today to do a bit more toward getting the Boxford A up and running. Problem; the 4 jaw chuck is stuck in place, it;s got to come off. The chuck it's self is damaged, 3 out of the 4 square key holes have a side out of them.

I'v got a copy of a hand book off the web, and their suggestion is to lock the back gear, put the key in the chuck, and give the key a bump with your hand. I prefer to put a bar across the jaws and tighten the jaws on it, and I tried that to no avail, what next?

Another wee problem, how do I slacken off the belt, it's go something to do with the lever just to the right of the thread cutting gear box, I think the set up is a bit of a lash up, the hand book shows the jack shaft tilting via a lever from the top of the head stock, but it does not show the above mentioned lever by the gear box.

Here's a photo of the machine.

Ian S C

Edited By Ian S C on 01/05/2018 11:21:23

[Ian S CParticipant @iansc]

[HopperParticipant @hopper]

Be careful using the backgear to lock the spindle if the chuck is firmly stuck. Busted teeth have been done that way before!

The time honoured method instead is to use a bit of impact by the placing of a block of wood between chuck jaw and bed, with top of wood at about centre height. Using the countershaft pulley etc to spin the spindle by hand in the reverse direction, give it a good quarter to half turn to build momentum before one of the chuck jaws smacks into the wood block. This should free the chuck in most cases.

If not, you can try the same process but under power in the lowest backgear, if your motor has a reverse switch. Keep fingers clear etc etc of course. I've never had one stuck so tight I had to go this far but it is recommended on lathes.co.uk so perhaps not as barbaric as it sounds.

[Dave HalfordParticipant @davehalford22513]

Posted by Ian S C on 01/05/2018 11:13:31:

I'v got a copy of a hand book off the web, and their suggestion is to lock the back gear, put the key in the chuck, and give the key a bump with your hand. I prefer to put a bar across the jaws and tighten the jaws on it, and I tried that to no avail, what next?

Ian S C

Edited By Ian S C on 01/05/2018 11:21:23

Hi Ian,

What normally comes next is the substitution of 'hand' for hammer which is how the key holes get cracked.

Generally, how gummed up is the rest of the lathe? Old oil sets like glue over time so if it's been undisturbed for tens years or more there may be old oil acting like thread lock. heat will loosen it, you only need 50C then it should come off normally.

[BazyleParticipant @bazyle]

To slacken the belt you move the handle beside the two Norton gearbox handles. It goes through the base to a cam that moves the motor plate.

If you take out the backgear layshaft you can 'get at' more of the bull wheel to grip more of the teeth to distribute the load. I sometimes keep the belt tight, grab the belt both sides of it with one hand and squeeze which grips the pulley to hold the bull wheel by its two pins not the teeth. Does that make sense? This is actually easier than an underdrive version.

[RichardSParticipant @richards31161]

Ian

My guess is that if 3 out of 4 jaw screws are broken then you are down to unbolting the chuck. From there then WD40/paraffin/3-in-one on the end of the thread might loosen the backplate. Alternatively remove headstock from lathe and stand nose down in a tray of diesel. Last ditch, machine the backplate off.

To remove the headstock.
Remove the right hand layshaft bearing holder, this allows you to get the belt off the layshaft.
Remove the changegear cover.
Remove the banjo.
Release the two headstock clamp bolts that are under the headstock between the ways. The front one will need a _short_ (4″ long) spanner.

If the belt is currently tight then the belt tensioner is incorrectly setup.
You will probably need to take the belt off the layshaft to fix. The mechanism is basically a pin in a spiral groove and the tensioner quick release lever should be pointing straight down when tight. The quick release lever passes through a threaded bush in the front of the bed support that sets the tension.

More info about the belt tension mechanism can be found in the boxford parts list pdf in the file section of the Boxford Lathe group on Yahoo groups.

Hope that helps.

[Speedy Builder5Participant @speedybuilder5]

I have a Boxford AUD, slightly different, but DON'T lock the BACKGEAR, unless you have some spare parts. From what you say, the 4 jaw chuck has seen some brutal service. a little more won't hurt – possibly look for another one?

OK, this is what I would do – Put a bit of 1" square x 4" long into the chuck, drill a centre into it. Move the tailstock up to the end of the bar and lock into place.

Put some protective wood onto the bed ways.

Ensure the leadscrew tumbler gears are in neutral.

Make sure the motor / drive belt are engaged (not powered up).

Put a 1" spanner onto the square bar and give it a really good hit with a club hammer (4 lb ish) or copper / lead mallet.

There should be enough mass in the spindle / drive belt / motor to allow the chuck to be "shocked" off.

The headstock bearings are solid enough to absorb this shock.

BobH

[BazyleParticipant @bazyle]

You can repair the sockets by welding in a piece of metal but it then sticks out. Ok for a home set-up but not safe for a public use machine. You can instead build up some wall with weld and recut the socket with a simple home made spark eroder.

As you are new to Boxfords note the screw in the middle of the threading clutch on the apron is reverse direction thread and check the brass shoe inside the headstock that disengages the bull wheel from the front handle as it is almost certainly work to nothing by now. Finally when taking the apron apart be aware one of the grub screws is hiding another one way down the hole.

[Jon GibbsParticipant @jongibbs59756]

As a last resort you could always unbolt the chuck and turn off the backplate.

Most 4-jaws have front mounted screws and a new backplate can easily be knocked up or even bought cheaply.

It'd be a lot cheaper than a bu$$ered bull wheel.

Jon

[Howard LewisParticipant @howardlewis46836]

+1 for NOT engaging back gear and hitting the Chuck key.

Clamp a piece of timber or steel bar across the jaws, ensure that the belt is tight. You need as much inertia attached to the spindle as possible. .

Hit outer end, HARD with a heavy ( 2lb – 1Kg minimum) hammer. If at first you don't succeed, repeat. Eventually, the chuck should unstick.

Howard

[ShugsParticipant @shugs]

Go with Speedy Builder5's suggestion. Had the same problem also with a AUD and it worked for me, school lathes long story. Was a 3 jaw chuck so used piece of hex bar.

I got the method from "DoubleBoost" of You Tube fame.

Shugs

[David George 1Participant @davidgeorge1]

All my chucks have a keyway for a C spanner and if it dosnt come off easily I just give the spanner a tap with a mallet to remove.

David

[Ian S CParticipant @iansc]

Thank's guys, I'll head off in the morning tomorrow and try a few ideas, I better put my big screw driver in the tool box in case I have to take the chuck off so that I can turn the back plate off, I can soon make a new back plate.

Ian S C

[Ian S CParticipant @iansc]

Here's the data plate, sn., 2355 A 367, has some got a clue to the age of the machine?

Ian S C

[Jon GibbsParticipant @jongibbs59756]

I'd guess it was made in 1950… **LINK**

Jon

[Niels AbildgaardParticipant @nielsabildgaard33719]

The  problem is to lock the spindle without using/damaging the backgear.

An australian  tool

 

**LINK**

 

Edited By Niels Abildgaard on 02/05/2018 20:45:54

[Ian S CParticipant @iansc]

Niels, that looks like a good idea, we spent the morning today squeezing the belt with my left hand, while I hit a bar gripped in the chuck with a club hammer in the right hand.

I think I'v found the problem I was having trying to slacken the belt, it's too small. It will get cut off, and replaced with A section link belt, that will save having to strip the head stock to replace belts now and in the future.

Ian S C

[BazyleParticipant @bazyle]

Be aware that the larger sizes of link belt don't fit on the largest pulley in the headstock.

There is quite a lot of leeway in the belt length provided you can move it between pulleys when the motor is touching the headstock. The sliding motor system is actually rather good compared to some other methods.

[Niels AbildgaardParticipant @nielsabildgaard33719]

My Boxford (not UD) did run with A size Powertwist belt direct from motor to max diameter pulley for years.

**LINK**

[Ian S CParticipant @iansc]

I use Power Twist belts on my Large Taiwanese lathe(B section), that's why I feel that's the way to go.

Ian S C

[Swarf, Mostly!Participant @swarfmostly]

Ian,

I hope that your efforts will be successful.

When you get there, please be sure to come back and share the conclusion – please don't leave the thread hanging!

Best regards,

Swarf, Mostly!

[BazyleParticipant @bazyle]

I think we have got to the point of wanting a live video stream of the action!
I expect the power twist belt may be thinner than my old metal stud Brammer belt.

[Ian S CParticipant @iansc]

Don't worry I wont keep you hanging, but sorry I have no video capability. One problem is I can only get to the lathe on Tuesday and Thursday mornings, but no one is in a rush.

If the worst comes, I can turn the back plate off the spindle nose, a new back plate is easy enough to make, can do most of that at home, leaving facing, and final dia of the spiggot to do on the lathe it's self.

Ian S C

 

Edited By Ian S C on 05/05/2018 12:23:16

[JohnFParticipant @johnf59703]

HI Ian, I had a thought today but saw Niels post showing the clamp — good idea, asa matter of interest I was thinking in terms of an expanding mandrel inserted into the spindle with a hex or square on the ned for a spanner but maybe the clamp style is easier to make and probably more effective ?

Good luck John

PS was close to you a few years back at a family wedding near Lake Coleridge

[Ian S CParticipant @iansc]

JohnF, I think the external clamp would have greater gripping power than an internal mandrel. I was speaking to a friend today at Church, he is the owner of a local engineering firm, and specializes in engineering machinery, he's going to come and have a look at our lathe, he also hinted that we might need something bigger(when he took over the firm from his father he got rid of a lot of machines, a number of capstan lathes etc.).

If they need a lathe urgently I can take my Super Adept along, at least it works.

Ian S C

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