Member postings for Ajohnw

Part 2

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Myfords. Well plenty of use will result in more wear on the edge of the bed rails than many modern prismatic beds as the contact area is small - smaller than people might think as the wear progresses. This seems to cause more upset with things like parting off and even finish than some other lathes that use a similar arrangement.

I've hardly seen any plain bearing ML7's with shims still under the bearing caps allowing more rescraping as they wear and they are often worn going on the ones I have seen. Ok if some one can use a bearing scraper and keep the spindle level with the bed. Several people have mentioned that these lathes can drill a bigger hole than an S7 if that's head stock bearings are set correctly. Many people seem to have problems once they play with these. The person I bought my ML7 from had overtightened the countershaft belt to try and mask the problem but it still becomes apparent with various depths of cut. It later went S7 so I do know about the bearings on these. Myford made some spindles especially for me as the one in it was worn which would have made rescraping the bearing cone tougher than need be. I would have probable requested a new cone actually but my Boxford turned up.

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Raglan. Nothing bad to say at all really. Moderate wear on the side of the rails didn't cause any problems at all. I suspect it's down to the width of the bed compared with Myford. It did produce some taper as a result but finish was still good. Mine made an odd noise. The machine tool dealers did point that out and asked if I was sure i wanted it. Lathe fever - turned out that one side of the variable speed pulley was cracked but I did manage to make another on it. However when I used the saddle rack feed to add a key way to the bore the feed gear broke right at the end of the work. Turned out that a couple of teeth had been snapped off in the past and repaired with dowels filed to shape. Some one made a new gear for me.

One shaft was supported oddly, just one bearing on one end. I decided to replace the bearing - dropped and cracked a pulley hence repairing it on the Peatol. I should have left it alone.

I did have the bed strips reground. I found some one who was prepared to clock up the unworn part of the inner edge of each one exactly and then regrind the outer edge. it will only be thou's. When I reassembled using the same location dowels it was perfect. They also reground the bits and pieces that fix to the saddle and run on the rails. I'd still have this lathe but for various reasons wanted to move into the house. Not possible with this one.

The headstock bearings would have been the next job. I'd imagine that they are a standard size but the people who did the rails offered to regrind them for me. They do take steps to remove the inaccuracy that may exist in their universal grinder and often did this job for others.

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Various old dogs intending to do them up. These have had spindles running in cast iron so need real bearings adding.

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Pultra - still sorting it out but I have seen the level of finish these can provide if all is ok. A major problem with them can be belts especially for under drive. They appear to have used one of the L series belts and that size isn't available any more. Mine is also kitted out for 10,000 rpm. I need to knock that back ideally some how. 5k would be plenty and allow the bearings to last a lot longer.

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ML10. well the one I have shows that they can be found in good order. I'd wonder about the ones where the spindle runs in cast iron though. It wont go where I need it to go so at some point will be sold. The main flaw on these is the width of the bed against the length of the saddle. It has to be like this the way they have done it but they can do decent work if the saddle is set up a touch stiff. Long ago I seriously considered a new Speed 10 from Reeves. Crowd of Myford 7 owners in muttering why can't they change the headstock bearings on theirs as easily as they can be changed on the Speed 10. Not that simple really comparing perfect with perfect but as it has turned out the Speed 10 would have probably copped with everything I have made since. There might be a couple of exceptions but nothing springs to mind.

John

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Bad luck Michael.

More normally.

The travelling steady on a Boxford isn't suitable for a modern tool post. It can be used but it's positioned for lantern holders so access right up to the chuck can be tricky.

It's reckoned to be the most economical South Bend clone but in real terms the only one that is "better" is the S&B Sable mainly down to some proportions and heftier lead screws if I remember correctly.

The spindle doesn't project out of the back of the change wheel cover enough so when swarf is pushed out that way to avoid getting it in the chuck it can get on the change wheels. If these have been set correctly for quiet running the stud gear shaft may bend if the gear gets swarf on it.

Only some models have spindle locks for unscrewing chucks. This can lead to bull wheels loosing teeth.

Some spare parts have to be bought from John Ward. True of other older lathes as well.

They were popular with pro home turners for batch work. Read most peoples normal working hours. Tough life for any lathe. They would normally sell on when bed wear reached a point where the taper was too excessive to meet what they needed to be able to do. Headstock bearings too.

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Any Chines lathe I have looked at - cross slide travel is always too short. That covers a lot. Also Wabeco 4000's.

The Wabeco saddle hand feed wheel size wise is a joke. It has the usual chuck fixings fouling problem but the spigot is a light drive fit into the chuck. The bolt heads can be used to lever it off with the same spanner so it's a good idea to use bolts to hold things in place. The spigot size is unique. The motor housing / cover prevents the saddle from going completely along the bed. This may hinder shallow face plate work without tool overhang.

Swarf will drop directly on the lead screw. The 4000 isn't supplied with a lead screw cover.

It uses 2 T slots at the edge of a thin saddle. Often these saddles can tend to distort and jam up if they are used to hold things down. They also hold the compound slide down and that has a lot of overhang as a result.

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There is something really weird about Viceroy head stock bearings. In one case, lathe not owned by me they wouldn't stay in adjustment. This one was near new. Bought new actually at a college. In the one I owned they just wouldn't adjust. These too can finish up being used by home turners, Mine had wear on the V's up by the head = 0.010 taper mostly due to that over circa 4" or so.

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Early Chinese 3 in 1. Nice finish turning, noisy gears, oil leaks and the worst general alignment I have ever come across even down to the hand scraped tail stock. Also not possible to turn up to a centre as the centre distance had been increased by 2" by removing the tail stock nose. A number of Chinese lathes have had this problem. Some may still have.

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Hobymat. Not bad as small lathes go. Pretty good really and can do accurate work. Dog clutch needed a file running over it after any serious amount of screw cutting. Often messed up by miss use of the push pull bolts used to set the saddle fit. This was the screw cutting Hobymat. They now do 2 models. Going on next owner ones that use a tool post where tools are clamped directly onto the top of the compound over pressure can crack the compound slide casting.

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Unimat. Fine for what it is. Pass on the model with 2 round rails. I just changed the bearings. They need that from time to time due to how they are used but the method works really well.

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Peatol / Taig. An amazing amount of work can be done on these if fully kitted out. Very accurate too even for roundness but eventually the head may bend spoiling it's alignment. It did on mine but perhaps I asked too much of it really. 6" diameter aluminium with the riser block on din't cause any problems. Fixing a cast iron pulley did. Turning one side of a V off and replacing it with a steel plate and recutting the side of the V. I've been told that this distortion will spoil the initial accuracy eventually what ever is done on them but bear in mind the initial accuracy is very high. They are also surprisingly rigid after a fashion so finish can be truly excellent.

I'd wonder about the motor they fit now. Mine had a normal AC motor. There was plenty of power available and a decent speed range.

John

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Brian's lathe seem to get on a lot better once some one noticed that the lead screw didn't line up with the bed. That had caused a lot of problems. How that happened is a mystery. Some chance that the lathe had been changed at one end of the lead screw or maybe the wrong part had been fitted. Personally I feel that anyone who sells them should give these lathes at least a bit of check over. On this one if the saddle was adjusted it was rather stiff in places as it was forcing the lead screw to bend - that resulted in so much force being used at the handle that the parts pushed out.

One of the problems with Chinese lathes is that they produce models to suite price brackets so an Opti Baby bears little resemblance to say an Opti Mini lathe and so it goes on up the range on all of them who ever makes them. Doesn't really matter what people think about them but at some price break industry are buying and using them. Another aspect of that is many models state hobby use, not suitable for continuous use etc. Hobby in practice can result in some one spending a high proportion of their free time using them. It seems some can take that.

One claim Opti make on one model is that they do season the bed. Unique as far as I am aware. They also make statements about the bearings they use. It might turn out that an Opti mini lathes are fine. It might not. Who knows, no one until they actually buy one same with other brands. Same for the next model up etc but it's pretty clear that they do get industrial at some point well past what people might want to spend.

John

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It's funny how that problem often comes along Rod. It sometimes does seem to waking up one day and wanting a lathe. I'd guess you obtained a much better idea of what it's all about and what you need via the Zyto.

John

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The 3 in 1 isn't a myford. Maybe a mod will remove my post and the 3 in 1

John

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Sounds like the thread was binding or however the backlash is set up had worked itself too tight. Unless of course the barrel was extremely tight when the screw and etc was removed but I wouldn't expect that to be very loose. i doubt if I could push the one out of my lathe easily by hand as I can feel stiffness via capstan arms about 150mm long which gives a fair amount of mechanic advantage via the rack and pinion it drives.

Sometime Brian I suspect you need to think more before jumping in and figure out how this works before doing anything to it.

I reckon brass should  be ok with some grease but may not last as long as steel.

John

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Edited By Ajohnw on 18/02/2016 13:02:15

Edited By Ajohnw on 18/02/2016 13:10:48

That may not be fair Brian. It seemed to me that one glaring problem caused others - the lead screw mounting. It might be a baby lathe one off, a really bad one and it could also be that the problem doesn't exist on other models.

That's the problem - until some one buys one there is no way of telling.

John

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The trick with Hylomar is very little well spread Brian. They don't like leaks but there is one version that uses them.

I still wonder if too much heat is part of the problem because if the displacer gets too hot along it's length I feel they will have problems working. Perhaps it would be worth trying a candle like this one, or a much thinner wick.

It might make an interesting project for Brian at some point. Mix of hand work and finding some way of holding parts on the lathe to enable the use of a slitting saw. It's by J Jonkerman. There is a bit of milling as well but I suspect that could be don on a face plate really or a vertical slide of course. Plans are on the web.

John

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Yes. Should have looked further down the page, It has tapered gib strips on the cross slide so some one may even have kept it properly adjusted.

I should have said 2hp for normal mains sockets. Not sure about 2hp through an inverter.. I did have a Viceroy for a while that had a 2hp single phase motor.

I've taken 0.4" plus off 6" diameter aluminium in one cut on a Taig. I doubt if it could be done with indexed tipped tools though. Main problem eventually was being able to see the lathe and the dustmen spotted the sward and said industrial waste and wouldn't take it away.

John

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Edited By Ajohnw on 17/02/2016 21:10:15

I'm all right Jack, I mean Jason I'm more or less happy with my 5". I mean boxford.

Lathes co reckon all 2000 are 6 1/2 ".

It's rare to see something like that with all of it bits - except a collets.

Having looked again though I suspect it needs gears to cut all pitches.

John

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Edited By Ajohnw on 17/02/2016 19:59:56

Edited By Ajohnw on 17/02/2016 20:02:23

If Gareth wants to look at what is available here might be a start.

**LINK**

Couldn't help linking to one I would go and try and it's in Wales. It also comes with it's kit. There are others on the same site. Usually known for rather high prices but in the areas that have been mentioned I don't think they are too bad now but buyer beware.

John

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Of course sticking a finger in the hole in the centre of a bearing would be a pretty stupid thing to do - that's why i said hold the centre.

John

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I seem to remember you saying you owned a CVA at one point Jason ? In many ways especially the gap bed model along with it's equipment the dream machine if it's in the condition the manufacturers intended and that's the rub. In some ways they are better than a higher end DSG and also smaller. DSG's look like they get worked to death to me. Personally I feel Jason made a sensible choice for what he does and he does clearly do a lot of it. Way more than many.

When buying machines like the ones mentioned one easy sign of use is the noise the gear head makes. Even with a moderate load the motor will louder and with no load they should be very quite, hardly any noise at all. No clatter. I wish the buyer luck in that respect especially with any Colchester. I have used a quiet Harrison that was pretty good. Bought for a workshop and not used a lot. Just odd jobs. That's the sort of lathe to look for. Boxford VSL's sometime finish up being used like that.

There are some makes about that no one ever mentions - maybe with gear heads it's best to forget the make and concentrate on the noise and hope the home electrics can provide the power. 3kw motor is usually reckoned to be tops for the normal mains sockets. I know from another area that if 13amps is taken for long periods many plugs and socket will have problems, Past that maybe disconnect the cooker or shower or pay the supplier to install 440 3 phase. That can be cheaper than expected sometimes as the phases may be close to the meter.

I wonder what will happen when we all have to go electric with everything especially heating where 20 to 30kw boilers are pretty common.

John

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Lighter fuel is still pretty easy to get in the UK. We have £ / everything should be cheap shops. Main problem with it is getting rid of it after use. Best way is a very small dish of some sort as not much is needed and then setting it alight. There may be a bit of a bang come pop when the fumes ignite. Unleaded should do just as well. Small bottle of that may be available from fishing tackle shops for Colman pressure lamps. Meths should do some like acetone.

You could run the bearings up on your lathe. Turn something to hold them via the centre only. Run the lathe flat out and stop the outer from rotating. I'd use my finger being me but a pencil or bit of wood etc should be fine. Another way with an air line and bearings that are open is to hold the centre and blow at an angle onto the balls. Apprentices and others then drop them and they fly for amazing distances if they land on their edge.

I've been looking at run on the hand types. One mentions that when the flywheel is flicked round firmly on it's own it should run for several minutes. A very light flywheel. It use 2 683 stainless steel degreased and demagnetised bearings. 3mm bore, 7 odd and 2 thick. They show shields on one side in one somewhere. If the bearings have metal shields on both sides I've managed to get one out and put it back in the past, usually with care and a pin.

I found a good description of relubing a 7HT but they are after creating a certain amount of drag. Interesting way of getting oil in though.

http://hwee_surfcast.tripod.com/LubricatingBearings.htm

I've seen some designs where the bearings are held in recesses in each end of a short piece of bar. I'd hope that people would make and use a mandrel to locate things before forming the recess on both ends rather than just reverse in the 3 jaw. I think that as the bearings are usually a light press fit I'd machine straight through and use a spacer.

John

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Edited By Ajohnw on 17/02/2016 16:13:27

Having looked around Brian Stirling Engine design is a bit like black magic / suck it and see. If the power piston is fixed I'd just check it's to drawing and look for other problems. One aspect that will be important is the fit. Drop through but not when a fingers is over the other end. That needs a very high surface finish and a close fit - more like an air bearing than anything else. The phasing of the two "pistons" should be 90 degrees. They all seem to be apart from some academic research which is still close to that. Many types also only run in one direction. I'd guess that the direction of the phasing sets that.

You could fix a block of ice from the freezer to the power cylinder some how but I doubt if that is your problem if it's a small flame near the end of the test tube. The displacer getting too hot along it's length may mess things up.

On the flywheel bearings I'd expect the flywheel to spin for a very very long time spun up on it's own. Many minutes. I'm a bit at odds with no lubrication in them but going on some styles of beach casting reels it needs to be a very light oil and very very little of it. On the reels people wash them out in lighter fuel then add the oil but they are after a pretty precise level of braking. The stuff that comes in the bearings is no good for that. They also free up considerably after several casts. They run at very very high rpm for some of a cast. They could be "run in" on a lathe.

I'm still inclined to feel you should drive it from your lathe for a while. Say an elastic band round the flywheel and a bit of bar come pulley in the chuck to get I don't know say 100 rpm or so.

John

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The main problem with a used ML10 or Speed 10 is having the parts that are usually needed at some point. 3 & 4 jaw, face plate, no problem so far and then comes a fixed steady. That can be a problem to find. The difficulty of finding all of these parts can vary according to the lathe - price too.

The other aspect is the earlier ML10 - best avoided due to the headstock bearings really or checked very carefully. ML7's have the same problem but much of this type of problem depends on how much finishing with files and emery cloth is acceptable. I prefer none. Super 7's can have similar problems as can all other lathes for very similar reasons but sometimes it's fairly easy to replace the bearings.

The seven series lathe beds don't take wear well. They are great if perfect. On curious aspect is that Raglans use a similar arrangement and don't have as much of a problem with wear. They probably do at some point but the one I owned had more or less the same amount of wear as an ML7 I also owned but it didn't cause any where near as many problems. This was just a few thou on the width of the rails. The ML7 was also a dog due to head stock bearing wear until it was fixed. No problem if some one can use a bearing scraper. Till that was fixed the machine had a built in chip breaker on many materials and bits flew all over the place.

The main advantage of some sort of gearbox as I see it is easy feed selection - not easy screw cutting settings. It's just handy for that.

Colchesters, Harrisons etc. It's pretty easy to buy examples that don't deserve the name any more really. Generally when they really do the ££££££'s creep up at a very rapid rate. Some models are more inclined to be used lightly than others. This is true of other brands as well.

Personally I suspect the OP would be better off looking at the Warco site. If he has the funds and wants a fairly flexible size I would point him at the smaller gear head that at the moment comes with dro. He could easily spend 3k on something else and finish up with a dog. If that is too much several people on here use the larger variable speed models. Jason mentioned recently that his 280 runs out of steam at circa 9" dia so needs smaller cuts, That's how I read it anyway. Not surprising really but I'd bet he could modify the pulleys if needed. Some one else bought a similar lathe and the low speed range had been reduced to circa 400max, usable but probably a bit irritating to some one who often works at higher rpm's - bigger cuts at larger diameters, other types of cut will just take longer. I think Jason's low speed range tops out at 800. They will have changed this to give lower speeds for screw cutting. Ok drives and motors have been known to let the smoke out on these but it doesn't seem to happen very often and spares are available. Where these machines may fall down is milling, no way to fasten a vertical slide. The main limit of milling this way is capacity but it does extend what can be made on a lathe rather a lot. A lathe used like this can often be more rigid than some cheap small light weight miller.

John

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The compression ratio of a stirling engine Ian is the ratio of the enclosed volume with the power piston at each end of it's stroke. And yes it does matter but pass on how much.

Actually - it matter rather a lot on the very low temperature differential types.

John

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Edited By Ajohnw on 17/02/2016 12:00:13

I was laying on a bit thick with the alignment of things Brian. It all comes down to clearance between them to some extent but there will be limits on that too. The alignment needs to be better than the clearance otherwise there wont be any.

The problem with ball races is that they have virtually no clearance between the running parts. The size of the hole this sort of size goes in is likely to need to be correct to very few 1/10 thou and also round to an even tighter tolerance. Your best bet may have been to bore or ream them together with the caps on and us a tiny speck of super glue in each half. Or nyloc type retaining fluid.

Not sure where you are putting the flame. I'd suggest small and not too far from the end. The power cylinder shouldn't be getting too hot to touch. The other aspect is adjustment. As I'm thinking of making one looking around suggest the displacer at it max stroke should go right down the tube to a point where the end clearance is more or less the same as the clearance around it's side. If the clearance is too small it wont work. The power cylinder isn't so simple. That seems relates to the compression ratio of the engine and the ones I have been looking at are all low temperature so that is extremely low. In your case you can probably vary it by say starting with the piston reaching the end of it's cylinder and the reducing the ratio by moving it back. Further back will reduce the compression ratio which in turn "should" reduce the temperature differential needed for it to run. I doubt if that aspect is as precise as the academics reckon but generally it seems to be correct.

Leaks seem to be bad news too and the pressure goes up when the things are heated. Adding a bit on that. The engine is likely to run a bit roughly until that settles down.

It looks like there are 3 pedestals on each side of the brass plate. Try just using the outer 2 on one side and the central one on the other. 3 point suspension shouldn't distort the plate. The way to make equal length pedestals is with a back stop in the spindle to finalise the length or by using the compound slide for sizing. Face the end with a parting tool and then cut to length. Or the saddle feed if the lathe has one as per myford.

John

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Edited By Ajohnw on 17/02/2016 10:24:01

Edited By Ajohnw on 17/02/2016 10:25:21

Yes Ian but a Harrison could cost anything from £1000 or less to £10k or more. Colchestes can be wonderful but often can have done way too much work by the time they hit the used market. If not they are going to be expensive.

The range of prices on a myford can be better. Anything from some hundred to maybe 6K.

Much of the work on forums like this one also needs a miller but a myford with a T slotted cross slide especially the long one plus various bits can do rather a lot in that line as well. I feel in some ways the main problem with Myfords relates to high prices that may be for a well worn machine. Bit like buying a clapped out Scaublin. Great name but what is really needed is a great lathe.

Some one may decide they want a lathe but most of us know that it's not as simple as that and in real terms more information is needed than the OP provided. Budget for one and some idea of interested for another.

We had another one recently, deep pockets, 5" (?) loco and a large scale traction engine. Poles apart and the traction engine really does push out the boat. Model steam engines can also push the boat out a bit as well but in a different way.

John

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New or used?

If used to you know enough about them to pick out a decent one?

John

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Edited By Ajohnw on 16/02/2016 22:21:10