Member postings for Ajohnw

When ever lubricants for aluminium are mentioned it should be pointed out that any form of lubricant will ease the chips progress over a tool and also cool on just about all materials not just aluminium which reduces cutting forces and helps reduce tearing BUT in aluminium's case something more volatile is better such as paraffin. Evaporation takes heat away.

The simple answer to aluminium is a more acute cutting edge that really is sharp and a speed which will depend on how well the cutting edge is polished and it's rake. A simple remedy - if it sticks to the tool reduce the rpm.

John

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Afraid not. It seems to have gone awol somehow. I did find the small lathe design in oct/nov 91, free pull out plan. I suspect that the design I am on about would be before or around that that time but can't really remember for sure. I don't think I have the magazine wrong. It was MEW.

Excellent & nice fresh - the doughnuts

John

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From a making it and accuracy it would need I feel I best say zero about that design. So no not that one.

I might still have the mag that had the other one in. My wife has bought some doughnuts so once they have gone I will have a look.

John

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Or very easily with no key at all.

John

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I didn't mention 2 maybe 3 basket cases Ian or 2 that need putting together to be sold, just the ones I intend to use.

The basket cases were intended to be small but bigger super adepts with a very big capitol S - if some wants to do that I feel it would pay to start with a better machine. One a small boxford precision lathe could have turned out really good but no tails stock has ever turned up for it. It did come for free because of that, I could make one but .......

John

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If it has the thread followers to go with the screw cutting attachment it is VERY reasonable. I've been looking for a 2nd lathe and noticed that these were selling for rather a lot, the attachment too. If they are with the lathe it would be worth adding a photo of them.

It could tempt me with those as screw cutting with followers really is attractive but having had that size of lathe before I know I would eventually put something way too big on it if the other lathe breaks or needs something that means it's unusable while I make and fit it.

I now have 3 lathes, excuse - the Pultra is something I have wanted for a long long time and it's the only one I have come across with a decent set of bits and pieces with it.

John

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Edited By John W1 on 23/09/2015 13:51:35

The threading attachment and bits to go with it are pretty expensive Ian. There were some for sale on Ebay recently, might still be ( worldwide).

What sort of price are you thinking of ? I would have thought a deal more than the lovely or stunning one that is on ebay at the moment.

I sold mine around 15 years ago for a couple of hundred via the unimat yahoo user group with lots of bits but not the screw cutting. That was the later one with a more conventional bed but some people seem to prefer the older model.

On ebay it may well be worth adding watch and clock making to the tittle. As odd as it might sound they are well regarded for that.

John

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Doing a quick conversion 3/8 AF spanner should fit perfectly. He might find that they aren't on metric threads. That sort of thing sometimes happens to suite the US market.

If a 3/8 af spanner is a little tight which is unlikely it could easily be relieved a bit with a file. If Brian doesn't have any files I would suggest a set of warding files - 6" 150mm as they can be very useful on a lathe anyway. He might prefer 200 - 250mm. I took a look on oz ebay and they seem to be into bastard cut especially for odd shapes. What's really wanted is 2nd cut, Bastard is more suitable for wood really.

There are oz stockists. Others found by searching warding files eg

**LINK**

I paid about £30 for a set of decent ones from Axminster but some might not be happy using files of this length near rotating work. The lathe should be run slowly when filing. They are Swiss and cut very cleanly as Stubs used to. I also bought a couple of 10in to go with them. I wouldn't like to use these for a lot of heavy bench fitting as they are too flexible. Files for that are curved and flatten when the correct pressure is on them but they are fine for shaping things and cleaning up machining / fine fitting etc.

John

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Maybe Neil will post the MEW boring and facing one as it must be pretty old now as a freebee. People could skip the facing aspect if they wanted. It will be in an early edition. I did take it for a while when it came out. The part I wasn't keen on is mild steel on mild steel for the facing collar. It could be lined with something else if concerned.

These are ideal for a DIY design really though. All that needs to be noted is the general proportions. The feed for facing is a trickier.

John

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I'd hope that the OP's concrete floor is sealed. Dust etc. Personally I would put doors on it and shelves inside.

I believe some of the blocks might have holes for rebars.

I bought a lathe recently and noticed some vibrations. I'm not mounting it the same way the owner but if I have problems I will probably buy a compressed 3'x2'x2" slab and semi rigidly mount it on it with raw bolts. The 18mm mdf pads for that are already fixed to the lathe.

Not appropriate for this because of the probably surface area loading if the miller has feet but I needed a strong bench so bought some 18mm exterior ply. Cut the bench top out and a lot of strips around 3in wide and glued and screws a lattice of them on the underside. In this case the screw heads showing on top didn't matter but it could be covered with all sorts of things. It would be even stronger if the bottom was covered and glued and screwed as well. I mounted that on 4 3in square legs and it's about 6'+ long. Afterwards I though mmmmm if it had to cope with very heavy load on it why not use blocks. As it is I at 95kg can jump up and down on it. Personally I don't much care if I have never seen some idea used some where. If life was like that nothing would ever change.

John

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This is the ME one.

The pins are struck by a see saw like attachment with a pin on each end. It misses them when the see saw is level and has click locks to hold it in place when it isn't. I haven't used it for some time and should have rubbed some oil on it before taking the shot. The slight tarnish looks much worse than it is.

The idea of the tool holder part is to allow it to be changed for say larger bores or what ever.

The one in MEW had a collar round it that was simply grasped when facing was needed and could be locked up out of the way when not in use. I don't think mild steel is really a good idea for that sort of use but if needs must.

I'd guess more recent ones don't use the hand to grasp it but lots did.

John

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Edited By John W1 on 22/09/2015 18:54:33

I'll note that in case I need the idea Bob because they are easier to use. The high density one are porous as well so might be some way in between. I've laid some for a garden wall some time ago. They are sized so that corner interlocking works out and the main problem I had was mortar between ends. Some one that could do it quickly said I should have used a bigger trowel. I found a pointing trowel useful - it's just a narrow strip of steel.

John

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If I used mdf I would also use double sheets at the back to brace the sides. If that sort of weight tips a bit sideways for some reason a thin back wouldn't be a good idea. Actually the fact that only the back was braced would bother me.

I think for low cost and strength I would teach myself how to lay high density concrete blocks - not forgetting to add what I vaguely remember are called reveals at the front - walls for an L shape and I would lay all of the way across at the back. These blocks are dead easy to cut with an angle grinder and are also load bearing. The super light ones are more for insulation. If the walls were under the millers feet you could simply lay a sheet of mdf across the top maybe with checker plate or steel sheet etc on it.

John

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There has been a couple of designs for boring and facing heads in the magazines. One I think in Model Engineer which use a separate part to provide the facing when needed and another in MEW that I feel made poor use of mild steel. Cast iron would be better. That one was conventional but lacked taper boring which is a bit specialed. The ME one could be fabricated, made a bit smaller, changed as required etc It's a very heft thing and designed to screw onto a myford spindle. It can be used for fly cutting too. They aren't that difficult to make but the MEW one would be more work.

Facing is useful when a part is being made where a surface is needed around a hole that needs to be square to it as it can be done in one setting . Useful if the work can't be put on a lathe.

John

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The easiest thing to do JA would be to remove the paint all together and maybe polish up the aluminium. There is no plastic at all. Be hard to do anything with the label though.

Wouldn't surprise me if I leave it as it is. I have several ideas for it to try over a period of time.

John

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It might have been based around 2 mosfets opposite polarities maybe with drive built in as they are diodes when reversed so if both are off should block ???????? I'd need several cups of tea to be sure.

There is very little about on separate excitation only power, speed and torque curves also showing that they can run at over the motors base speed. Also golf cart motors for separate excitation - those probably do regen sensibly but it's not to difficult on wet lead acid traction batteries because they don't mind being overcharged as much as some other types. Some others are a nightmare when fully charged as they more or less go open circuit which causes problems when cells are in series. Others just don't like it full stop. People were trying to figure out by pass methods when I was involved. The old drives in things like milk floats were really crude.

Some years ago people were doing strange things with old fashioned starter motors and dynamos. Trouble is that they run at rather large currents and low voltages. I'd guess this was pre web but their might be some info somewhere. There was this wheel chair about at work that was way too fast to ever go on the market controlled with a joystick and sep ex.

John

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I bought these Jason. They should arrive a bit quicker than ordering from the UK as only a few grades of 125mm dia seem to be stocked in the uk so I was quoted 6 weeks. Green grit is available with a 20mm bore.

**LINK**

Postage isn't too bad, 1 euro for an extra wheel. I did look at axminster but no suitable wheels. I've used their 6in white aluminium oxide ones before and they are ok on HSS but the 2 grades they do don't seem to have much effect on removal rates so thought I try a much coarser and finer ones.

I might get a green grit at some point for something I haven't done for a long time. Regrind a braised tip carbide parting off tool for screw cutting. They stay sharper longer but I recently ground up one in Tantung G so will see how it lasts.

John

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Thanks Michael. I tried my usual trick and searched grinding and obtained several german words but none of them would isolate them. That one came up zero results. I had to wade through the general term they use which brings up flap wheels and other things but found some 125x20x20 which I have ordered. I decided to try a very coarse 46 grit and a finer than usual, 100 grit. In corundum which seems to be a form of aluminium oxide from a search.

Made in Germany which in my experience can mean either good or bad and often not in between.

I'd guess metric ones are thin on the ground here because the grinders last so long. I should be able to get a green grit if I need one though - maybe when carbide got more popular some bought new grinders.

John

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That would really be good for some types of battery Bob. It gets a lot more complicated than that to do it properly even on wet lead acid batteries.

John

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CVA's can be amazing too but £25000 in the 80's a touch expensive. Cheap used but I shudder to think what replacement bearings would cost. Some might not need other work but everything tends to wear a bit what ever they do. These with a gap bed also have a very large swing in them. It really is large compared with other machines with similar normal swings. They built some on a spinning bed. It's a massive thing.

My choice would be a DSG, the one they did a diamond turning attachment for. Better spec than some common cylindrical grinders of the day had. Oh for the super thick concrete floors needed and the cost of them if they were new.

Finish is all about rigidity including the headstock bearings and cutter grinding. Rigidity mean a certain weights for a given size for the simple reason that when a very high quality finish is achieved minor vibrations will cause micron deep marks to appear in the work as metal flexes to some degree as minute as it might happen to be. Go far enough and the ripple from bearings that have rolling elements in them become a problem.

John

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Edited By John W1 on 21/09/2015 14:51:13