Member postings for Ajohnw

I'm pretty sure the Model Engineer one moved the work. Usually made of mild steel so they can jam up and need lots of grease - just in case some one is tempted. Might be better to use cast iron.

John

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You can get the general idea of how it's done here by offsetting the work. A relieving attachment does the same thing automatically and indexes round to each point required on the tool. Sometimes 1 point on one rev and another on the next.

**LINK**

There is also a better way of putting a gear cutter form on them than shown here. It uses the top of 2 round button set a certain distance apart and at an angle.

There was model engineer design for an attachment and also details of the form tool for gears. You might find details of both on the web.

John

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I'm much the same on my Boxford but not so long only around 15 years, so long I am not sure. I don't usually machine for hours on end, just bits and pieces. It took several months to get the slides right, several adjustments. They are still a little tight really but better than having them loose. Bearings adjusted I don't know how many times for the 1st year as they settled down.

Then I decided to strip the entire lathe head. I soon found out why the bearings were tricky. I heard a rumour that Boxford have been known to make the fit on the spindle too tight - very true. I cleaned up all of the old grease and took a few um off the end of the spindle with a lap on a Peatol lathe. That fixed the fit. I then had the bright idea of greasing the spindle to ease fitting - a really bad idea as the grease messes up adjustment and wont go away. I also decided to grease the outer side of the spindle where the back gear runs. Seemed like a good idea as ME10's are a pain to pump oil in to lubricated it. Trouble is that the heat conduction from the spindle is now so good that the bearings no longer warm up and tighten a touch - not sure if that is good or bad yet but I wouldn't mind betting I will have to strip it again, clean up and use oil as before.

One irritation. The lathe has a slight wobble on a large pulley on the counter shaft. Vibrations from this shows a slight few if that um pattern in the finish when I try hard. First attempt to fix - replaced the bearings - no change so then checked that the pulley is square to the shaft - it seems to be. So it seems the casting carrying the bearings is warped. I then tried a lighter pulley - seemed to improve things but while using the lathe the lot came loose - not sure why. I'm currently tidying up to have another go at re assembling that set up. Next step will have to be a reduced diameter on one end of the counter shaft to carry some sort of self aligning bearing set up that I can move about. I reckon the error is ove 1/16in.

Taper last time I measured it with 6in of 1in ms bar sticking out of the chuck without a centre was under 0.001in. Might be less if I had run the tool along several more times. I don't stress the bed to correct error as the stand it's on isn't rigid enough - an old kitchen cupboard and a window sill. I did the same as I have done with other lathes like this one. Bolt through the tray fixed rigidly with a nut. Another nut to support the lathe each leg carefully adjusted to support it evenly. Then a nut on top to hold it down but I leave these finger tight..

john

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When buying a lathe especially a used one it's best to go for those which come with the basic attachments - 3, 4 jaw, face plate and the steadies preferably both but especially the fixed one. A good solid maybe rather old drill chuck is a good idea too.

I'm going to need to produce some very round precise work eventually for a Pultra spindle. One thought has been mostly doing it between centres so I looked around for signs of a between centre test bar. All seem to have morse tapers on the end - not what I want. I came across suggestions for making one. With more detail it sounds feasible. Might be of use to people.

Hold one end of a piece of sliver steel as closely on centre as possible. I'm thinking well sub 1/10 thou, no movement at all on the dti. Same the other end in the fixed steady. Face off, recess and centre drill not using too small a size as it needs to produce a round hole even if the tail stock is marginally off centre - a very small one might bend. I'd also turn the end down for a short distance and chamfer the ends, Reverse and do the same to the other end. The 60 degree part of the centre hole shouldn't be very wide - say 1.5mm or less.

This should finish up with a shorter version of what is used to set up lathes - one problem is that I understand that they may use DTI's with sort of bar like attachment on the end so that the bed error can be dealt with separately. Errors in the bar should be well short of the usual +/-0.0005in error typically quoted for between centre work where large numbers of parts are being made.

One other thing I have found concerning round parallel parts just held in the chuck is the need to make repeated cuts at the same setting due to the work bending and slight play in the bearings. Too much play in the bearings can even cause problems when this done. The drive belt might be positioning the spindle.

There are other fixes to achieve perfection that take the lathe completely out of it. The travelling steady or the type of cutter boxes used on capstan lathes. This is using the same principle as centreless grinding uses - circles and 3 points. Things have to come out round. I expect a comment on that but don't believe the 50p piece argument as massive numbers of things are made this way and come out round to very fine limits.

John

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On the Acute I would like to see examples of it sharpening various tools - lathe, mill etc. I manage by hand as far as lathe tool bits go.

Noticing an earlier comment about touchy with wheels that is an area that concerns me. While it's possible to buy all sorts of wheels and many have a max speed rating I see little signs of optimum speeds against the materials being ground. Maybe there is something some where but I haven't found it in a usable fashion. Take diamond wheels for instance - % diamonds and usually the size and thickness of part that actually has them are often quoted. I did ask one supplier of a small watch maker sized wheel and had the reply 2,800rpm. Frankly I don't believe that given it's size and the fact that watch makers grind on the lathe. This was a specialist diamond tool supplier too or reckoned they were. The other aspect is that surface speed should be the main factor not rpm.

Some one mentioned grinding on the lathe. I have come across several old lathes that had probably spent many years lying around in the corner of some factory eventually going to scrap. They often have white wheels in their cupboards so at one time I feel grinding tools on the lathe was fairly common. The wheels were generally white and some what coarser than a typical tool grinder sharpening grit wheel but would still give a decent finish. Some were too fragile for actually shaping tools. I'd guess people just covered the lathe.

John

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Tubes crush when bent so concrete should help but unfortunately shrinks when it dries and doesn't take kindly to being bent much either - that's why rebars are fitted in structures but that would make filling difficult in this case.

You will find that stiffness goes up markedly with diameter for the same wall thickness. If I remember correctly the width preventing the deflection goes up at a cubic rate were as the other one doesn't so diameter has the biggest effect in this case.

I'm pretty sure you could find simple sums in Machinery's if you want to work it out - almost bound to be in imperial though. They do work correctly.

John

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Transformers are often rated for an insanely high temperature rise at full load. Worth looking at the specs if some one intends to do that. There are sometimes industrial rated ones about - much lower temperature rise but they will be a lot larger. The regulation with load is also worth looking at - that is determined by the winding resistance to a certain extent so poor regulation will often mean a high temperature rise. The 2 tend to go together,

Personally if for something serious I tend to buy transformers of RS Components or Farnel as specs will be available or Ebay at times if they give a brand and specs can be found or there is sufficient info in the listing.

Given Nicks apparent problem I might use 2 well under rated when in parallel too even though it's frowned upon. Sounds like the regulation will be crap anyway and that will help them share.

It's sometimes possible to wind a few extra turn on a normal transformer using insulated wire to get a bit more volts but the coupling is likely to be poor. RS Components did do 100VA transformer kits. They may still do. I have built a couple in the past using these. They specify the turns per volt and it isn't too difficult to lay a neat winding by hand. Only thing is they may gave uprated them now so some bigger number but the specs should give a clue to how hot they will get and that can be more or less be guestimated pro rata with load.

John

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Mt DW Mk1 has a 4 step pulley. I have a feeing that is what the drawings show as well. I would have to ask my "filling assistant" where the #### they have been put to check.

It also has the "back gear" but I feel that the need for that may be a little back dated now. There would be a need to get into similar arguments some watchmakers have about the relative actual sharpness that can be achieved on gravers made of different materials. Even worse if old tool steels from various sources that were made in witches cauldrons are considered. These days steels have standards. Different brands once ruled and no one really knows what methods were used to produce them.

John

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Maybe these posts have bought the web site up again. No problem here.

John

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I use an ER16 2 morse collet holder with mine - mostly to give good visual clearance for smaller things and cutters. I also use a set of ArcEuro morse taper collets for bigger cutters. It's fun buying some all thread to suite the collets and then drilling and taping a short length to suit the DW draw bar and loctiting it in.

My boring head fits on the myford spindle nose. I also have some carbide tipped screw fitting face cutters that will have an adapter made for them at some point. I tend to do things like that when I need them.

Adding a bit more - my dore dividing head also has a myford spindle nose so as I use a boxford I have a 3morse to myford adapter for that.

John

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Edited By John W1 on 05/06/2015 15:27:02

Edited By John W1 on 05/06/2015 15:28:32

To my eyes the meat in the castings around the various shafts looks thinner than it should be compared with the original Alan. My MK1 has 3/8 in minimum.

On the other hand it's easy to forget that people can produce cast iron castings at home if they wish. Not really a good idea unless they can be stress relieved. It's often best to fabricate. It might have a base off a heavy duty drill machine. All sorts of things are possible. I've not had the table off mine.

It's fairly normal to find variations. My table has 2 slots at the edge and no centre slot. Sounds odd but a Dore dividing head fits nicely and a decent sized milling vice can be fitted across the table if needed. I often use a small rather well known Record drill vice for small work. That just fits the usual way in one of the front slots. There is also a plate that can be fastened in the outer slots. It was fitted with one of those small tiltable milling vices but these are too flimsy in my view.

John

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Edited By John W1 on 05/06/2015 14:36:44

Edited By John W1 on 05/06/2015 14:37:31

The problem may be the HSS. Try to buy some that mentions cobalt. M35 or M42. From memory M35 which is ok is around 5% cobalt. This will cost more than plain HSS but it is worth it. I'm pretty sure that some one on ebay lists some M35 toolbits, harry something or the other. Failing that Cromwell tools have all sorts.

When you grind HSS tools have some water handy and don't allow the tool to get hot enough to colour. That even applies to the above.

Cutting speed too as has been mentioned but if I were you I would experiment with slower ones. Most quoted figures in that area are based on production rates against tool wear. There can be all sorts of reasons for running more slowly.

John

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I don't think I would use my cutting oil Neil. It tends to collapse bottles it's left in and go down all on it's own. I just smear some on work at times. I cured the disappearing oil by putting in a sealed jam jar with a test tube strapped to the side. I just take a few gollops out of the bottle and drip it into the test tube. The test tube also serves to hold the brush I use.

The cutting oil came mail order from Morris Lubricants. 5lt which should last me for ever. Good but not as good as the thicker stuff that used to be used on auto's where splash got on peoples overalls and gave the testicle cancer and dermatitis elsewhere - there is a message there about using oils intended for other purposes. The stink of some automotive stuff is enough to put me off anyway..

I'm afraid I usually run the change wheels to the gearbox dry. I have been meaning to take the cover of the gearbox and use moly grease on the gears for about 13 odd years since I bough the lathe. I have put a touch of cycle oil on them at times - all wrong and have wondered about using chain lubricants maybe waxy types on the change wheels. Boxfords have a separate feed drive so the lead screw doesn't receive much attention or need it really as I don't screw cut all that often. I just make sure it's clean. Rags usually have some oil or the other on them.

John

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I fail to understand why people use engine oil for general lubrication of a lathe when they can buy iso 32 hydraulic oil instead. Personally though I find the best thing for slide ways is slide way oil. Little is needed and it hangs around for some time and doesn't absorbing moisture from the air or gum up like most automotive oils do. In fact I wish I could get the next grade up in small quantaties which is suitable for vertical surfaces. Automotive oils are designed to run hot for long periods. They also have all sorts of additives in them. It's also well know in some circles that if these oils are changed at say twice the recommended interval things might never wear out. They aren't as great as some might think. They did get well ahead of engine etc technology for a while but those days have gone.

Real gearhead lathes generally use hardened and ground gears. It's easy to see when a lathe has these or even by ear. I'm not at all sure what I would use to lubricate typical Chinese use of gears in small lathes and millers but I would like the sludge worn from the gears to settle at the bottom rather than circulate and grind the gears down further. I'm inclined to use grease on the back gears of my boxford and oil on change wheels and gearbox etc. I have been a bit naughty on change wheels I should use ISO 32 but use a GP oil.

I've not looked at Chinese lathe ball/roller bearings but suspect just as when the Koreans were the source of smaller lathes that some wont be hardened. From memory ArcEuro have some pages on changing NVG bearings. I've used molyslip grease on bearings for some time. My lathes have been relatively low speed in terms of what typical greases can handle. Of late because it's available I use a high speed one that ArcEuro sell. Believe it or not it will extend life. It's important to not add too much grease of any sort to bearings of this type.

Plain bearings - Myford etc really do need to use the right lubricant if they are to last. I'd hazard a guess that ISO 32 hydraulic oil meets the spec for these as well - a highly refined mineral oil.

John

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Some simple tool grinders, more aimed at sharpening really are based on the tangent angle of a chord of a circle being proportional to it's heigh above or below the centre of the wheel. I've actually used one but can't remember how it was arranged to sharpen things like morse taper reamers even though it was demonstrated doing just that.

It was set up by measuring the diameter of the wheel and then setting the height from it's centre to obtain the desired angle - via a built in scale. Probably way too simple for many on here.

Bulk removal is a different problem and I am happy doing that by hand.

John

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You wouldn't catch me using motor oil. There is a post further down lubricating a mill. Same applies to a lathe.

John

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Thanks Peter. I did know about the back emf aspect so now I know where to look for suitable circuits. It's odd really as the old electronics magazines printed designs regularly but I don't see any on the web. I did work on electric vehicles some time ago but not on this particular aspect.. There is another control - the field windings if motors have them available. Trouble is that this can make them rev so fast that they may explode.

John

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Edited By John W1 on 03/06/2015 16:37:45

Out of curiosity what max revs does a car windscreen wiper motor achieve?

On speed controllers one interesting aspect is giving more or less constant speed with load. Usually applied to mains voltage universal motors but in principle should be possible on low voltage dc too. I spent some time looking for a circuit and came up with nothing.

John

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Edited By John W1 on 03/06/2015 10:22:19

i started using slideway lubricating oil off ebay some time ago. It does it's job well. Little is needed and it's stable and hangs around for a long time with no noticeable fuming. It's obviously from the state of the bottle it's kept in that it doesn't absorb moisture etc from the air either. Can't say the same thing for my cutting oil but I only use that sparingly.

I've used moly grease for a very long time. I was a little concerned about it's speed rating but haven't had any problems. ArcEuro started selling a high speed type some time ago so now if something needs grease I use that. In the past it could be difficult to get hold of it and despite what some people think it does extend life. Ford have been known to start using it on some parts that aren't making it through the warantee period. These days there are some incredibly expensive greases available.

Some people use a hydraulic fluid for spindle and general lubrication especially to replace oils mentioned in older lathe literature. Like those these are generally highly refined mineral oils.

I used to use all sorts of things when my lathe was in the garage including wd40 to prevent rust. It didn't take me long to realise why I developed a cough. Then there is the problem of hand contact - engine oil isn't intended for that and does smell. It's also intended for use where it's very hot for extended periods.

John

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Edited By John W1 on 03/06/2015 09:45:21

Edited By John W1 on 03/06/2015 09:46:57

At that size you might manage to unscrew it with electronic type pliers - they have longish pointed noses. Or you might be able to make something with 2 dowels sticking out / hand filed. I'd use silver steel and harden and temper it - dark straw.

Somebody I believe mentioned a carbide drill - wish you luck. The favoured way is spark erosion. I have heard of stellite being used but suspect it wont do the hole much good. The drills are also expensive.

Real stainless is a pig. The free cutting stuff which is slightly magnetic is a lot easier. The real stuff, marine grade seem to work harden. Last time I used it 3 drills to drill 2 holes. One went ok the other didn't and none of the drills were any good when I had finished it.

John

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