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Boxford electrical problem

Boxford lathe kept cutting out.

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Nicholas Farr22/02/2021 22:33:19
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2683 forum posts
1248 photos

Hi Graham, you might find a ratings plate on your motor by using a mirror underneath it.

Regards Nick.

Tony Ray22/02/2021 23:46:21
177 forum posts
43 photos

As someone else has said you need to try running it with the belt on the smallest pulley at the bottom and the largest at the top, this is the lowest speed for the spindle and presents the lowest load to the motor. In the winter the grease is colder and the spindle will be present a greater load. Single phase motors can suffer from poor starting torque depending on which of the 5 types described earlier some are better than others. The highest load is presented to the motor as it attempts to get the Spindle moving and is reduced as it gets up to speed, it’s like starting to push a shopping trolley once you get it moving the effort required to keep it going is reduced. So it could be that at the highest load in the cold with an underpowered motor it’s ntbgetting up to speed and it’s over currenting the contractor..

not done it yet23/02/2021 06:58:22
5790 forum posts
20 photos

Thanks for the support, Ray. Yet another case of KISS, for diagnosing a problem.

My mill had the same, or similar sypmtoms, until warm.  Failed to reach full speed, dropped back to the starting windings - accelerated again -and just oscillated between the two states.

Edited By not done it yet on 23/02/2021 07:01:00

Brian Morehen23/02/2021 07:54:15
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146 forum posts
11 photos

A common fault two much grease pumped in which has now jammed the centrifugal switch have seen this problem many times , I think you have now got to strip and clean your motor looks like you my have over greased your motor

Regards Bee.m

noel shelley23/02/2021 11:58:31
486 forum posts
14 photos

Hi Graham, SO with the belts off it runs OK ? Let it run for 5 mins. If it has kept running and the motor is not hot or even warm you can assume the centrifugal switch is operating. If this test fails then one has take it that the motor is at fault. Any capacitors can be checked with a good meter, and if much under spec be replaced. They may be +or- 20%. If replacing note the voltage rating, do NOT go lower ! The centrifugal switch is inside the motor which will have to be dismantled to work on it. Though a simple device of springs and weights it can be fragile so handle with care, cleaning is all it may need, use NO oil or grease.. With the belts off, is the counter shaft above the motor free, turns with little or no resistance ? Are the headstock bearings free, turn with little or no reistance ? If the answer to these questions is no then clean and relubricate with the recommended lube.

The middle unit on your control panel should be the contactor/on off control. Your panel has an isolator on the right and reversing switch on the left. The reversing switch should only be used to dictate the direction of rotation, NOT to start or stop the motor, running the motor is done using the green or red push buttons. The contactor should function as the current limiting device, being set to the the motor rating as shown on the data plate, which in your case is not visible. As has been said using a mirror may reveal the info.It is possible that the overload device is dropping out due to age or being disturbed in moving. Re setting is usually by a graduated wheel that may be marked in amps or by reference to a scale on the inside of the case. Depending on the motor a figure of 4 to 5'5 amps would be about right. 10 secs for the contactor to drop out sounds like high current draw. But why ? How is the lathe connected to the supply ? 13A plug.

Will the motor run in both directions with the belt off ?

Good luck Noel.

Graham Halstead23/02/2021 22:24:21
15 forum posts
9 photos

Many thanks to you all. Very helpful advice and things to check. I hadn’t even thought of most of the things that have been suggested. I won’t be able to try the ideas for a few days probably the weekend . I will report back on my findings. Can’t wait to get to use the lathe . I have a car project waiting for some bits to get turned. I’m still going through the lovely chaps old tools and trying to work out what is what. I have a milling slide but looks like the screw has been bent at some stage so it does not really work too well. I was hoping to be able to do some simple turn mill ops. I guess if I had my old skills back when I was an apprentice long ago I could have made a new screw. I push a mouse around for a living these days so lost so much of what I learnt back then.

I had run out of where to go to find help and then I remembered this website when I was searching for machining tips some time ago. So glad I joined and was able to tap into a huge knowledge base.

Will update you all soon

many thanks

Tony Ray23/02/2021 23:30:06
177 forum posts
43 photos

You can get those skills back, YouTube is a great resource. Hopefully the thread in your vertical slide is the same flavour as your lathe ie imperial or metric that will make life easier. In the meantime you can Chuck one end of the screw in the lathe to assess where the screw is bent and attempt to straighten it. It doesn’t sound like you could make it worse.

Graham Halstead28/02/2021 08:16:23
15 forum posts
9 photos

Thanks all. So managed sometime on the lathe. So I can run in lower gearing without cutting out. Ran for a while yesterday and then was able to run highest pulley speed. Cold weather I expect being the issue on motor load. Seemed ok once everything had warmed up. I did however encounter the next problem. Just taking a cut and the Chuck slowed and actually stopped. Slipping headstock drive belt arrggg!. Took the cover off and sure enough belt looks pretty old and oil contaminated as I see they do after some years from my internet searching. Decided to order a new T belt. Hopefully fairly easy fit. Any advice on that? Will try and get motor spec today with a mirror. I may overhaul bearings and get new v belts while I am at it just to make it more robust as it rattles along so I think it’s all pretty worn. Bearing replacement looks straightforward?

It may sound stupid but in fwd the Chuck turns right direction but lead screw for the main bed , drives the bed left to right which just seems wrong to me. Couldn’t see a means of switching lead screw direction in dependant of Chuck rotation direction.
many thanks to you all and you have all helped in solving my problem . It’s a pain at the moment when I just need to crack on with some bits but I think it’s needs a bit of downtime and sorting the issues to get it to a reliable state.

will take a look at the milling screw , as you say I could try and straighten, seems a decent vertical mill slide and not a Chinese copy . Might even be a boxford original, I looked and nearly fell over when I saw what they fetch on eBay.

many thanks

not done it yet28/02/2021 08:26:36
5790 forum posts
20 photos

There will be a pair of ‘tumbler’ gears just below the spindle, to change the lead screw direction. There may even be a neutral position so the lathe can be run without power feed to the bed.

Tony Ray28/02/2021 09:25:54
177 forum posts
43 photos

Here

**LINK**

the two gear of the same tooth control enable direction of feed to be reversed. Only one is engaged at a time.

I think you would benefit from a copy of How to run a lathe originally a Southend publication Boxford did their own. I have a copy at A4 in a loose ring binder that I don’t need it’s yours fo the price of the postage if you would like it.

Regarding the belt change make sure you remove all trace of grease/oil from the pulleys. I can’t remember how much of the top pulley can be seen to do this. That aside you can cut the old one and us it to pull your new one over the top. Go a little tight on the tension as is will ease off as it stretches. You do want one of the belts to slip in a jam situation as that could save eg the tumbler from stripping. If your tumblersare steel I’d recommend changing them to tufnol or similar as it brings an improvement in noise levels but this is’t essential right now. Regarding bearings not sure which you are referring to. By all means change any in the drive train but I wouldn’t’ touch the headstock yet unless you know you have an issue, getting the preload right is tricky. I can’t recall if the Plummer blocks are plain or raced, if plainI’d hope that you can get some direct online replacement sleeves.

Tony Ray28/02/2021 09:33:35
177 forum posts
43 photos

Meant it say well done you are making progress and getting to know the machine along the way. Next thing you’ll be asking about is tool bits and grinding. If you don’t have an off hand grinder you’ll need one imho. Using HSS is overall cheapest and you will learn how to grind what you need.

Tony

Graham Halstead28/02/2021 10:34:05
15 forum posts
9 photos

Hi thanks for the info on the tumbler gears. Seems so obvious now and I feel like a right idiot. The lever on the side I thought was to do with speeds as it’s by the speed range label and shows the lever. I’ve twigged it’s the lever on the top of the machine on the label. Yes I do need a book! Many thanks for the offer Tony. I’ve just emailed the chaps widow to see if he had the paperwork on the machine , I’m sure he had it somewhere. If she finds something great, if not I will let you know Tony and pay to get your copy. I will do some more research as it’s definitely needed. Thanks for the link also. Appreciate the offer.
bearings I refereed to replacing were the pulley shaft ones not the headstock, so should be straightforward pushing out of the plumber blocks. Doubt they have been replaced since it was new.

used to grind my own tools back in the day, so will have to brush up on those angles. I do have a bench grinder so that will help. It’s got the original tool clap on the top and not a quick change height adjustable tool post. Would be much easier with a height adjust quick change, anyone recommend a conversion or kit that fits direct to Boxford? Just watched Enots engineering on YouTube and rebuild of boxford . Would be great to be able to do that level of strip and rebuild. I have a hill climb car to build so maybe save that one for retirement!

Speedy Builder528/02/2021 11:01:06
2257 forum posts
170 photos

Graham, search this site "Link Belts" - DO NOT BUY CHEAP is my advice - you get what you pay for.

Bob AUD

Graham Halstead28/02/2021 11:14:16
15 forum posts
9 photos

https://store.lathes.co.uk/belts/nu-t-link-v-belt

went for this hope it’s the right one!

thanks

Clive Brown 128/02/2021 11:15:33
630 forum posts
26 photos

The Boxford / South Bend book is on-line, in rather poor quality Here

Oldiron28/02/2021 11:48:54
763 forum posts
23 photos

Graham Check your inbox at top of page.

regards

Tony Ray01/03/2021 00:39:38
177 forum posts
43 photos

Hi Graham,

Regarding height adjustable tool posts you have have 3 options which I will describe by the original makers names:

Dickson

The correct size is S1 ( there is a shorter S1x I don’t think this is what you need but as I have a Boxford branded one that came off my AUD I’ll check tomorrow). Genuine tool holders are great, imported ones are variable from ok to rubbish.

Bison also make a version and most parts are interchangeable particularly the tools holders.

Multifix

if I were starting from scratch this is the onE I would choose. Like the Dickson genuine items are pricey. PeeWee tools in Germany are reported to sell a high quality copy. There are a series of measurements that have to be taken to determine what size is required. PeeWee

Aloris

This is popular in the US. You will find hard to get genuine used parts in the UK but again Far Eastern versions are available. I can’t comment on them as I have never used one.eg Arc

This is quite an investment but as long as you already have decent chucks is probably the first thing I would add.

not done it yet01/03/2021 08:08:09
5790 forum posts
20 photos

Do remember that a QCTP is not a panacea for every lathe user..

They have only two distinct advantages. 1). Quick and easy tool changes and 2). Easy and quick tool height setting for tool cutter height adjustment.

There are down-sides which can particularly adversely affect new starters and/or those that do not understand there are cons as well as pros.

The tool overhang is the main con. The original lantern type tool-holders allowed the cutting point to be retained as close to the saddle centre-line as possible. A compact 4 way tool post (probably fitted with two cutters) is quite good in this respect. QCTPs typically hang the tool out much further, so the smallest which will fit the lathe is probably best (but limits the cutter size that can be used).

Cost, unless one can make extra tool holders, is yet another factor. Not all tool holders (particularly from different suppliers) are perfectly matched to the post. Some holders are not easy to duplicate.

Every possibility for tool deflection is exaggerated - making a well-worn lathe less easy to be used successfully by a newbie, particularly with less than optimum cutters and/or materials which may be more difficult to machine. Gib adjustments are more important - and these may not be optimal if the machine is worn (unevenly). Parting off may be found to be more difficult - leading to the belief that parting off is universally a difficult process.

There is variable quality form some suppliers (buying cheap is more likely to be folly on the part of the unsuspecting purchaser).

A couple of 4-way tool posts might well provide a better option, as a starter, for a beginner.

YMMV, of course, but do just consider both the pros and cons for your particular situation at this present time is all I am saying.

Howard Lewis01/03/2021 14:41:49
4683 forum posts
10 photos

Not a Boxford owner, but have used / made fourway posts on Myford ML7, Raglan and a Chinese 12 x 24 lathe.

The Raglan, in standard trim, offers the choice of 4 way, (but not Top Slide ), or a single toolpost with a Top Slide.

I made a fourway to fit onto the Top,Slide. Because of height considerations, it was a little skinnier than I would have preferred, but it did the job.

For the Myford I made a a rear toolpost to carry a parting tool.

For the BL12-24 I made the rear toolpost an indexable four way, to match the front post. The two posts enable 6 tools to be carried at any one time. The rear 4 way quite often has to come off for use with a collet chuck, to work close up to the chuck.. It only comes off at other times to be an exhibit on the Club stand at a Show

(What is a Show??????????? )

Some time ago, there was an article extolling QCTP, but it said that the time to change holders was little different from rotating a 4 way with tools already set to height.

Many times, I considered changing to a QCTP but desist, due to lack of storage space for all the holders required,

(at least 9 ) and the total cost thereof. Both make me stick with the 4 ways.

Howard

 

 

Edited By Howard Lewis on 01/03/2021 14:44:06

Graham Halstead02/03/2021 22:27:46
15 forum posts
9 photos

Many thanks all about QCTP and your advice. Very grateful for the wisdom and experience. I’m not doing huge amounts of machining but I would get fed up setting up tool height all the time I wanted to swap a tool in and out. I’m probably at the light engineering end of the spectrum so not into a lot of steels and heavy cuts so it would work. It is an investment as they aren’t cheap. I hate buying kit that fails or is just poorly made. It’s not something I need to decide on right now, drive belt arrived so have a couple of days holiday , so going to try to get the old gal up and running and in a more fit state to then use in anger. Really happy the electrical issue turned out to not be a huge problem. Thanks to you all again.

where do you guys buy most of your materials from? I would be looking mostly at the aluminium alloys and maybe some small stainless for top hat bushes etc.

metals 4u and places like that don’t seem too costly.

starting to bring back the days of my youth and apprenticeship memories. I remember well when apprentices used to present their hard worked on parts only to have it thrown down the shop if the instructor found one burr on it. Certainly taught you to deburr ! Loved it all tho and so glad I did it and the days when apprenticeships were proper ones. If only I could remember half of it now.

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