Boxford Cross Slide

Still trying to refurbish the Boxford AUD.

The Cross slide has several thou of movement, mainly in the middle of the travel.

The entire slide including the leadscrew can be pulled backwards and forwards and it seems to be play between the leadscrew thrust bearing and the saddle itself.

Is there any way to tighten this up?

Someone suggested that I adjusted the cross slide dial, but it seems immovable longitudinally on its shaft, though it can rotate to reset a zero.

On a second issue, the Cross slide dial has 250 divisions, corresponding I thought to 125 thou of movement per revolution, 250 thou change in diameter.

Putting a DTI seems to indicate only 100 thou, plus or minus the movement mentioned above.

Is it likely that the leadscrew had been changed or am I misunderstanding the nature of the beast?

Lastly, it has been fitted with a one HP single phase motor. The revs drop perceptibly under any load. Indeed I can all but stall it by applying 'squeeze' finger pressure to the main lead screw where it leaves the gear box and did stall it parting off a 20 mm delrin bar using a 1/16th parting tool. Using it on steel only removes dust rather than swarf or chips with any tool.

Is this normal? Everything seems to turn freely and with the belts removed light pressure turns the chuck. After 30 mins at the highest speed the intermediate pulley shaft is warm, but the headstock is still cool to the touch.

Any help gratefully accepted Robin

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I do not know the AUD however I would strip and look closely at the "pinning" or "grubscrewing" of the screw assembly to the crosslide . sounds like slop there.

Alternatively 2.5mm = .10" You have a metric screw!

Only on a Myford ;-)

Are you sure that you are stalling the motor and it is not just belt slip? Particularly the belt from intermediate pulley to the spindle. In a high gear with the belts fitted can you easily manually rotate the chuck and see the motor turn.

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Richard Edwards

On 15 Feb, 14:20, Richard Edwards wrote:

from tonys site

Notes on Conversion to Single-phase Electrics Whilst the rear-drive machines have a reasonable amount of space behind the lathe to fit a replacement motor (although capacitor boxes may have to be relocated) the under-drive lathes are a little tight on room and, although the conversion is perfectly straightforward, there are one or two simple points worth bearing in mind: the original motor, if 3-phase, will almost certainly be 0.5 hp if originally supplied to the education and training market, or 0.75 (and occasionally 1 hp) from the industrial sector. Replacing it with a modern 0.5 hp 1-phase motor will mean, inevitably, that the lathe will no longer be able to start on top speed and, even if it does, will have insufficient power to be useable. The experience of many users suggests that a minimum of 1 hp is necessary for a successful installation, whilst others consider that an even better solution is to use a 1.5 h.p. motor. In the latter case, problems may be encountered getting it into the limited space available, especially if it's a modern type with a large plastic box shielding the capacitor and terminals. First, install the motor as far back on its mounting platform as possible (you will need to drill new holes in the plate) having first checked that there is still enough room for the belt- tensioning rod to function properly. Second, to enable the motor to clear the floor, lift its mounting platform as high as possible on the over-centre adjuster and use a shorter "link" belt for the drive - it might even be necessary to adjust the length of the tensioning rod to accomplish this. Another trick is to remove the plastic box from the motor and remount the capacitor remotely, preferably in a place where replacement is easy when it fails (as it will). Do not forget to engineer a suitably safe cover for the terminals and clip any new wires securely to the stand. As a last resort, because the base of the motor compartment is open, the lathe stand can be mounted on raiser blocks at each corner and the motor allowed to hang down into the space created.

having read all that ... I've converted a three phase one to single phase 3/4 hp ....and it ran fine ...this was a big motor ,,,,dont know how you stuffed a 1hp single phase in there .

you should be running in back gear to get the grunt and torque out of it.

high speed light cuts.......... out of back gear .

all the best.markj

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This indicates a metric micrometer dial, check the actual movements of the compound slide and main leadscrew to check whether it is a 'metric' machine. The main leadscrew is either 8tpi or 3mm pitch, the compound is 0.1" or (presumably I'm not certain) 2.5mm

It is an Imperial leadscrew, depending on the answer to the above either the leadscrew (& nut) has been changed or the dial and possibly other parts of the slide have been changed.

I have a Smart & Brown which is similarly a Southbend clone and the micrometer dials were either screwed to the leadscrew and prevented from turning by a grubscrew with a brass pad onto the thread or on some other (later?) models a sliding fit on the leadscrew with a grubscrew and pad. In the former case the threading allowed for adjustment of the end float in the latter the adjustment is by shim washers between the micrometer dial and the handle. In both cases the handle is pinned to the leadscrew with a taper pin.

HTH Richard

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Cross slides on metric machines (of all manufacturers I know of) indicate diametral change whereas Imperial machines show slide movement.


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As always these days I am pushed for time but a couple of comments on your questions. The cross slide leadscrew on an AUD normally has a couple of ball thrust races that provide location. If you have found the Yahoo Boxford users group:

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Try a search within messages on "thrust washers for cross slide" and it will point to a number of possible causes and fixes. Depending on the age of your machine it may have a design that is closer to the Southbend original and there is a good information on repair here:

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Can't help with the dial graduation except to say that there were a number of dials available including a "direct reading" version.

On your motor issue you don't say what motor you have; my own AUD was single phase from new and has a Crompton Parkinson 0.75hp 1425 rpm motor fitted and I can assure you that it provides plenty of grunt and you will certainly not stall it as you describe whilst keeping your fingers. Mine parts off 2" steel with ease and would do so all day. My only experience here is with a cheap (MM) motor that I bought for my old 918 lathe, while small and marked at 1hp it wouldn't pull the skin off a rice pudding. In my opinion, the only 1hp thing about it was the marking, I replaced it with a very old .5hp Hoover motor and had no further problems with that machine. Have you another single phase motor you can try? Unless you are doing something unusual a good quality .75hp motor will be fine although a 3 phase and VFD would be my choice if I were to remotor mine. Sorry but I'm no electrician so can't give any clues as to what might be wrong with your motor. The warm intermediate shaft is fairly usual. If it is the older plain bearing type it needs lubricating daily down the centre of the shaft, if the newer ball bearing type it is "lubricated for life".



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