Member postings for Ajohnw

**LINK**

That's the link to the first image going back from here Neil. I know the others are the same because they wouldn't show until I logged into modelenginemaker.

John

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LOL Now I am logged in I get fixed sized images that just fit in the normal thread width.

John

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The images are actually on modelenginemaker so in my case as I'm not logged in on this browser I just get an empty box.

John

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Your problems might just be a bit of binding due to things not lining up Brian. That sort of thing showed up when you ordered new ball races. For those to work as they should the pockets they fit into need to be perfectly axially aligned and square to each other. Same with the con rods. In that case the holes in each end need to be on the same axis, same distance apart when there is 2 on the same journal and their sides need to be square to the holes too. This sort of thing is why asked if your drill table was square to the drill earlier. Few are worse luck. Usually it's possible to square them up one way and the other may need some thought as to how the work is set in a vice and it can be impossible to do that. If this is one of the problems the easiest solution would be to easy the holes a bit and if possible ensure that the holes in the 2 are the same diameter and the same distance apart.

This sort of problem has cropped up in some model engineer mag projects in the past and if extreme they have suggested drilling in the lathe. There are 3 ways of doing that. One is holding them on the face plate but that needs the face plate balancing. That's not too bad on small light things as one clamp will hold the work and another can be fitted just to balance things. The other is a drilling plate in the tailstock. I've been looking for one for years. All that can be bought is cross drilling jigs and they are too small to hold things down on. They aren't much good for cross drilling either really, no clamp and the V is usually too small. The other way is some sort of holder in the tool post. It can be fly cut from the chuck to get it square on. I have done this at times using a lash up to allow me to jig bore pretty accurately using the cross slide.

The other aspect which you probably have thought of is to make matching parts in one go. Take the double con rod. Drill ream one end of each, fit a tight fitting dowel and then do the other ends together. If these are the problem you might cure it by simply relieving the holes a bit.

If I used any oil on these things I would get hold of some watch or clock oil but it can't be used on any really hot bits.

That long hole on the displacer shaft is a good idea. The way to view the length of holes like this is how many diameters of the shaft they carry long are they. More diameters means less tip for the same amount of clearance. If say they are 1 dia long rather than say 3 there will be something more akin to point contact at each end of the hole which in practice is likely to cause more friction in a case like this. Too much clearance will have a similar effect.

John

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There is a person in the Ukraine selling various hobs pretty cheaply on ebay uk and usa. He has 0.8mod, other sizes and some of the usual gear cutters as well. Russian work at it's finest going on some I bought.

John

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A common way of getting more precise speed control with dc motors is to arrange for them to run at the required rpm at 180V with no load and drive them from 240v via certain circuitry. That way as the winding resistance causes problems when the load and current increase the extra voltage that is available can be used to maintain the correct back emf for the speed required.

This is usually applied to universal motors driven from AC but the same principle can be used with a dc drive. On AC the 180v is the rms value of the wave form, only part of the mains cycle is allowed to drive the motor. The same sort of thing would be true of DC drive.

In practice so that the control loop can be control fully from no load to full load they generally never see the full voltage.

John

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Those plans that Dave mentioned can be found on the web. Some of the links that are about are dead.

**LINK**

There are video's of it on his youtube channel.

John

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Coke is really good for cleaning up copper based coins. Some people wont drink it when they see what it does.

While at school a friend who knew that I had cleaned a car asked if I was interested in going car cleaning to earn some pocket money. It went well. One person had a rusty bumper so I told him we had some special chrome cleaner but it was expensive. He made an offer so I took it along and he was very pleased with the result. That lead to a number of them being done. Eventually some one asked if they could smell it. Ok and he said he could smell Vim.

I'd mixed Vim, water and a detergent called something like Ticket that was used to get wax of cars and used it to remove rust not chrome. Rather like rust on cast iron. Rust is soft. The base metal isn't. Only problem really is that chrome rusts through pin holes but regular waxing helps with that.

Suddenly no one would let us clean their car so I was left with rather a lot of TurtleWax shampoo. We tried coach cleaning for a while but the pay was low for the time it took and was too much like hard work.

I'm a long way from Sutton now Chris.

John

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Edited By Ajohnw on 16/02/2016 10:12:08

I visited him Chris. Can'r remember which road but he said he made a living mostly renovating lawns plus some garden work, He had a "rusty" lathe in the garage. Quotes as it looked rather dark and crusty. When he told me what he did I wondered why the hell I worked so hard.

I can't even remember why I visited him or how long ago but pretty sure it was Sutton not Streetly, much of that is way too posh. It was a middling area. It was a long time ago. Can't think of anything to tie it down, not even what car I was driving. Might have been more Wylde Green or even down towards Pype Hayes.

Actually I'd wish anyone luck even removing 1/10 thou with those cloths. Curious how cleaning anything discussions go. I'd stick to paraffin what ever is used as often there will be either oil or gum from it under the rust.

Not keen on molasses. It clearly attacks in some fashion, probably the carbon in the steel. It can leave parts bright but others even areas that take longer turn a pretty disgusting blackish colour.

John

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Edited By Ajohnw on 14/02/2016 23:16:45

Edited By Ajohnw on 14/02/2016 23:17:38

I don't think the scouring cloths I've used have carborundum in them. It would make a right mess of aluminium and other things my wife cleans with them.

John

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Toolstation is in Wicks round here. Not sure how normal that is. Since I selected the local store it shows me how many of the items I look at are in stock in that store. They seem to be working on the basis of keeping a few of everything were as the local Screwfix has lots of people in it and is pretty big which must up the costs.

I generally buy power tools via brand name now and use mail order. I did buy some B&Q power pro stuff but that doesn't seem to be an option any more. It was fairly decent stuff hence giving trade users a more restricted guarantee.

John

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Edited By Ajohnw on 14/02/2016 20:05:25

The person that started Screwfix up sold it to the B&Q stable. He kept prices down by being careful about what he stocked. After he sold it he started up ToolStation. Same basic idea. Looks like the Wicks stable has bought that now.

I had heard from a friend who it seems has talked to him that he is going start up another.

John

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Out of interest I discussed lighting with a swedish lighting engineer who happened to be around when the topic cropped up. Seems that only warm white led lighting is available there. I wonder why, no point in repeating myself. That's what IKEA sell too. I reckon that they are a touch cooler than the usual tungsten lights. Most fluorescent tubes are warm white too. I've fitted some that should be suitable for colour work according to some standards but I'm not sure I like them so I guess the tubes I bought will last for a very long time. Mind you they should stop me from suffering from SAD. Not that I ever have.

The led lights I linked to use 15 or so led chips over an area so none of the point source problems.

John

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I'd have to read back through a number of posts Brian but didn't you fit a bigger heavier flywheel?

I have a strong suspicion that would upset a Stirling engine as it need to accelerate it's mass on every stroke.

John

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It's not unusual these days to hear an American accent in Birmingham city centre so not so sure about the triangle. I wonder if one day we will be dressing in blue overalls, cloth caps and clog dancing while swigging real ale and waving shovels about. Industrial version of morris dancing. The real ale would really help with that.

I think it might be best for Rob to pick out what he wants to see and stay some where based on that. A search for uk tourist attractions brings up lots. One for London would too and as mentioned there are all sorts there. Most cities have something or the other to offer. Problems may be things that also interest the wife and or kids. London should meet that easily. Others probably not so well.

What may be missing from the usual ones is places like this which in this case might be of interest

**LINK**

This forum should be a good source of links to this sort of thing and other interests. There are a number of them. That link was handy as I intend to go there in the spring.

In order to visit Doncaster from London my immediate thought would be by train. It will cost more than fuel and may need a taxi but the time scales are likely to be both shorter and a lot more reliable. The location could be miles from Doncaster's actual centre. This means thinking about where transport links are but all UK cities get totally clogged up at some times in the day. That can involve rather a lot of time getting in or out of most of them. I'd guess it's the same in the USA, maybe worse in some.

These days when I am going somewhere even on holiday I use google street view to look at the destination, as well as my gps to get there. Google will also give trip times by car, train or even bus in some cases. Road works often mess up the car times and a single solitary accident can easily add an hour or two to motorway travel times in particular - over very short distances too.

John

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The idea is to remove rust not polish it. Machine tools such as this one were made to a pretty high precision. Polishing mops etc an easily mess thing up. It doesn't take long to do it by hand anyway.

John

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Those kitchen scourers I mentioned are way way short of scotch cloth John. I spent a lot of time hanging around a used machine tool dealers. What they do will work out but it need some care - they don't rub hard with the emery at all. It's more like wiping with a scrubbing pretty action. I pulled a face when I saw them doing it and they showed me that there wasn't any dimensional change.

There used to be a gent who lived in Sutton Coldfield that cleaned up rusty machines. Really rusty ones at times. He wouldn't tell anyone how he did it. Sad as he probably isn't around any more. One thing is certain he rubbed something or other on the rust with his finger and the stuff flaked off. Very slow, maybe months and he seem to work along a lathe bed - or appeared to. My guess is that it was something that caused a electrolysis to occur at the boundaries. No idea at all what it was but he seemed to keep it in the kitchen so people tried all sorts of things that are usually kept in there.

Where I have used water as one of the things to remove rust and any oil I spray it with a water displacer as soon as possible. WD40 or duck oil etc.

John

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Edited By Ajohnw on 14/02/2016 14:55:15

The travel on the cross slide is 115mm according to the spec. They always seem to be a bit mean in this area compared with the swing.

Less the hole in the centre the effectve diameter of the work for the part that needs to be faced is 210mm so it should be possible to face that in one go if the toolpost is set up for it.

A suitable tool and toolpost setting should also allow the od to be turned.

If the motor housing limits saddle travel and that causes problems more tool overhand should help.

If you need a touch more cross slide travel you might find that there is a stop which screws into the end of the leadscrew but be careful.

It struck me on a similar lathe that if the lead screw was extended and stand off was made for the dial and handle flattened over the top so that it could pass under the cross slide these problems disappear. I haven't looked at it in detail but it could be possible to get an extra couple of inches of cross slide travel in an outward direction on some also curing the other strange one that can crop up going inwards when the compound slide and tool holder are in certain positions. It would have costed them peanuts to do this from new - many many lathes use this technique including earlier chinese ones. If it already has a stand off it could be made longer.

John

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I wouldn't use jenolite on it. It's good at generating a key for subsequent painting. All rust removers seem to be like that. Cement cleaner has a similar effect but rust comes rapidly after it's removed and the metal finishes up grey. Some people have used the reverse electrolysis method on lathe beds. The fluid is in some rag and a steel plate placed over it. This suites some beds more than others.

I would be inclined to take a tip from used machine tool sellers who often have to cope with rust. Paraffin is essential. The reason being that at some point it will have had oil on it and there will still be a bit or some gum there. It also prevents what ever else is used from clogging. For a fist try I would use one of those usually green kitchen scouring cloths, about 6" square and sometimes stuck on one side of a piece of sponge. It's a sort of weak scotch cloth. Wire wool would be ok too. The chances of removing any significant cast iron with either is remote. Rust comes of much more easily but may leave a bit of pitting. Usually using either of these just leaves a patina. Some people foolishly might use a diamond hone. That will remove cast iron so can be useful for sorting out machine slides. Some might use a polishing mop, that will too. A brass brush may be useful too but sometimes these are plated steel which will be a bit more vigorous. Very unlikely to do any harm though providing it's just used to remove the rust.

The dealer would get right down to it and use something like grade 200 to 280 emery cloth or wet and dry. Sounds drastic but they take care - they just remove the rust and don't try to get a high polish.

Personally if I ever found a southbend clone like that which seemed to be more or less unused I would have it like a shot.

John

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There are plenty of free plans about on the web. Just search Stirling engine plans. Also some cheap ones. The quality of the drawings varies though.

Noticing Ian's comment about ratio's I have been slowly digesting this

**LINK**

It's possible to request 2 free plans from the many he has elsewhere on the site. They are pretty good but I always wonder why many people who provide plans for models don't number parts in the GA as well as naming them.

I have the plans for his low temperature engine and am likely to give it a go wondering if I can do better. No ice bucket.

John

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Edited By Ajohnw on 14/02/2016 12:17:07