SHED MATTERS 2

[Stanley]

Today's job is making the valve so into the drawing office and do some measuring and calculations about the throw. I am on the right track, there will have to be some adjustments but I have just about enough room. First thing is to find some stock and make the blank.



I looked in my jar of brass ends and found a candidate. It's only small but it is going to be 1/2" deep.



There's not much sense in having a T&C grinder sat next to the VM and crashing on with what could be a dull cutter so I dressed the stone and did a really careful job on two 3/4" cutters, one of them the multi-flute because it makes such a nice job when run at speed.



It may seem like a waste of time but it isn't.... The first thing is to make sure the stock is perfectly square on all faces. You can't measure accurately until this has been done.



It'[s a while since you saw me on the HM but I remembered that Mick and John had brought me some brand new slitting saws! It cuts like a dream, I shall have to study the configuration of the teeth and apply that knowledge to my other cutters..... I soon had the stock reduced to close to size. Much better than elbow grease!



Here we have the blank ready for milling to exact sizes. I have to be as accurate as I can because I know there isn't any room for error. It struck me that the blokes who made the original had no such problems, this model is 1/12 scale and so my tolerances are all divided by 12!



This gives you an idea, that 3/4" cutter looks enormous! You can't see on here but I lowered the head so as to give the minimum amount of extension on the quill. That way I have the best chance for finish and accuracy.



Here it is sat in the steam chest. I can see that I am going to have some fun getting enough room for the throw! There is going to be some more filing in the aperture! Also, don't forget that there are three more milling operations to do on this tiny piece of bronze. I am going to have to give the matter very careful thought! But that's for another day. The Abu Dubai GP beckons......

[Stanley]

My first job this morning was to file as much as I dared out of the aperture in the steam chest to give me ample room for the throw of the valve which is 1/10th of and inch! (Ridiculous isn't it, plenty of scope for error!) Then I did some more very careful measuring and drawing reading, I wanted to decide on the hole in the steam chest. It's 3/32 of an inch and off centre. Once I had done that I addressed the valve itself, I need a 3/32" slot in it for the valve rod. Luckily I found a 3/32" mill cutter in my treasure chest.



Once I had the valve marked for line and depth I mounted it in the vise and used a point the get the exact line. Then I locked the axis and changed over to the cutter.



I took the first cut, so far so good but all this had taken 90 minutes. I know, it's slow but it's got to be right! The cutter is working OK on a very light cut, I have no feel for it at all with it being so small so that's how I will have to go on until I get my depth. So I decided to knock off and come to this fresh in the morning!

[Stanley]

I was at my bench shortly after 08:00 and the first job of the day was some very careful milling with the 3/32" cutter. Lots of patience and very small cuts. I must have done something right because here we are about half an hour later with a perfect slot.



The next job was some careful measuring and marking on the base of the valve where I have to mill out the relief for the exhaust to get to the port. There is no room for error at all and remember I don't see too well!



Some more high risk milling and we arrived here. I have it milled out .040 deep. It doesn't sound much but it will be perfectly adequate for the passage of the exhaust.



Another trip into the drawing office. I want to make and fit the driving bar for the valve. Once again I haven't much metal to play with because it has to be deeper than the slot for the valve rod without breaking through into the milling under the valve. That would be a bit of a disaster! Remember I am making this up as I go along because there are no clues in the drawing as to what was intended. I decided to aim for a 1/8" slot, that will give enough thickness for the thread on the valve rod. Any thicker and it wouldn't look right. I had cut the exhaust passage on the bottom of the valve with the 3/32" cutter as that would give me tight corners, no need to open them out any more. So I had to fit an enormous 1/8" cutter for the next operation. I can see immediately that depth is going to be a bit of a problem. I shall have a root tomorrow and see if I have a longer 1/8" cutter but somehow I doubt it.
Once again, not a lot done but what I have done is good and there are no mistakes! Nothing worse than cocking up when you have invested so much time and thought into a part......

[Stanley]

I started where I left off yesterday, cutting the deep slot across the valve for the driving plate. Less stress with this 'big' 1/8" cutter!



Here it is, cleaned up. My smallest files had to come out!



I got my brass ends jar out and found this piece of bronze, an off-cut from another job, that will do nicely.



I soon had it milled to the right thickness and fitted in the slot on the valve.



The driving plate marked out and the position of the tapped hole for the valve rod marked. I am not cutting it yet, it will be easier to hold to drill and tap the hole for the valve rod while it is this enormous size. (It's all relative)



After a bit of research I decided that 6BA would do nicely for the 3/32" valve rod. First I made sure it fitted in the long slot on the valve.



Next job was to find the tapping drill, 6BA tap and 6BA die ready for making the driver plate and the valve rod. Once I had all the tools ready it was knocking off time.....

[Stanley]

The first job was to drill and tap the hole in the valve driver, 2.3mm tapping drill and a 6BA tap. I'm glad I didn't cut it out first, this is a lot better!



I think you might like this idea.... I have to admit I'm quite pleased with it. I secured the driver in the valve using a 6BA set screw and a tiny washer. Then, holding it by the excess I cut it out using a Junior hacksaw.



I left the edges slightly proud and then cheated, leaving it firmly held by the set screw I cleaned it back to size on the side of the grindstone.....



Looking good! Now I have to address the small matter of the valve rod gland (and I mean small!) There isn't enough meat for me to do my usual pattern screw in gland nut, I am going to make an old fashioned one.



The first job is to open out a 3/16" hole for the gland and packing. Note the insulting tape depth gauge. I was incredibly lucky here because I forgot to back the edge of the drill off, it grabbed and only my fairy godmother stopped it from going too far! Then put the Taylor chuck on Mrs Harrison and after a measure up and another drawing, a bit of tiny turning.



Here's where we ended up at closing time. The gland nut fits and the 3/32" drilling is dead in line with the steam chest. I need to drill and tap for two tiny studs to draw the gland up tight. I'll put a bit of shape into the gland once I have the holes drilled and the corresponding holes drilled and tapped in the chest..... That's the first job tomorrow......

[micktoon]

Fantastic work Stanley ! ,
You can really see how small the parts are in some of them photos, micro surgery . Glad the slitting saw worked well and I liked your method of cutting the small brass section while held in place too.
Looks like this engine is doing its job of keeping you busy and your mind off other matters as much as possible too Just watch you dont drop any of these bits as you will never bloody find them !!!
Cheers Mick

[Stanley]

I remember the story about the watchmaker's apprentice who, when he saw a 1/4" drill said "I didn't know they made them that big". A 1/8" drill is enormous.... I think I'm getting used to working slower and to finer limits. I'm quite enjoying it! Slow but sure......

[Stanley]

First job this morning was to run a 3/16" slot drill in the gland to get as much depth as possible and a flat bottom. Only a tiny cut......



Then I turned my attention to making the gland nut fit the hole. I drilled it for the studs and then marked the steam chest and drilled and tapped it for 6BA. I have temporarily fixed the nut with two small 6BA set screws so that I can mark it for the flat that needs to be milled on one side so it will clear the body of the cylinder. The other side doesn't matter as the steam chest lid will increase the depth and anyway, having the nut shaped like this makes it quite clear which way it should be mounted.



Some careful milling of a tiny part with an enormous cutter!



Here's where I had got to at closing time. Ready to make some studs now for the gland nut. Doesn't look a lot but there was a lot of activity with the comms that held me up. We have moved forward a tiny step without making any mistakes!

[Stanley]

I decided to leave the stud making until I have to make the ones for the steam chest and lid. First thing I did was check I had the gland right and study the drawings to find where the steam inlet goes. Not as easy as it looks off these drawings so I went to the video of the engine running.....



I decided not to make a gland for this side as I can get away with a straight piece of pipe. I decided on 1/4" bore pipe which is 3/8" x 26tpi. A bit of careful measuring first and then poke a hole in it.



Here we are with a hole drilled and threaded. The next job is to decide on the location of the holes for the studs that will hold the steam chest on the cylinder. Again, not as easy as it looks so some more careful measuring and hole marking! I think I have it right, they are going to be 6BA again.....



It was knocking off time, I am all set up for drilling the steam chest. I'm drilling it tapping size so that it can be used as a template for marking the cylinder. It struck me that I must make the steam chest lid sooner rather than later..... But that's for another day.

[Stanley]

I remembered that I had already made a lid for the steam chest but then realised it had to be bigger. That's it on the pad. So I had to get the jar of bronze ends out and have a root. I soon found a piece that would do nicely.



A quick mark up and I milled it slightly over size. I can do the final adjustments when I have the chest fitted up and on the cylinder.



Here it is, ready for drilling. Note I have popped a witness mark on the gland end.....



A small toolmaker's clamp was just the thing..... I adjusted it so that it was central and I could still get to all the holes. Then into the drill press and get it set up.



Relatively simple with a bit of care....



Knocking off time, it was only when I got to this stage I realised that I had made a small slip up. The two holes at the gland end are almost beyond the valve seat. I can live with this and will make allowances when I fit the chest and lid. Next job is to transfer the drillings to the cylinder and I shall use the lid as a template for that. But that's for tomorrow....

[Stanley]

Prospects for the shed aren't looking too good at the moment.... The morning is being eaten up by urgent comms, household tasks and cooking! I shall do my best but if I miss, have patience!

[micktoon]

More good progress Stanley This engine keeps looking smaller every time I check on it !! At least any mistakes will not have wasted a huige chunk of brass anyway.
I am sure you will be back to it as soon as other matter allow Stanley, I think you have the bug for it again

Cheers Mick

[Stanley]

I have but yesterday was a very big day with Janet. I shall be in there this morning waiting for the news she is safe home.

[Stanley]

This was my first plan but as you can see it wouldn't do, no clearance for the quill so I had a rethink.....



I decided some shaft lock would do the trick and while it set I harvested the bronze chippings for John and had a good clean up.....



Here it is ready for shaving.



It worked just fine so I moved on to tapping the holes....



I'd been wondering about releasing the shaft lock but when I started tapping the problem went away!

[Stanley]

This was my first plan but as you can see it wouldn't do, no clearance for the quill so I had a rethink.....



I decided some shaft lock would do the trick and while it set I harvested the bronze chippings for John and had a good clean up.....



Here it is ready for shaving.



It worked just fine so I moved on to tapping the holes....



I'd been wondering about releasing the shaft lock but when I started tapping the problem went away!



The next job after tapping was to drill the lid and the chest for clearance.



Close of play. One thing to mention is that the tip of the tap broke off in the next to last hole and I never noticed it, not even when I tapped the last hole.... It's stuck in there so I shall live with it! We aren't running 300 looms! The two end holes at the gland end where I had made my mistake marking out are also defective so the net result is that only 5 holes out of the eight are perfectly tapped. Luckily there is a good thread on each side of the one with the broken tap in and the two at the end are well supported by the others so there will be no problem, I shall wing it and the chest will seal OK. A coat of paint will hide the errors...... I'm into progress, not punishment!

[Super_7b]

Hi Stanley,

You could remove the tap by dissolving it. The recommended method in brass/bronze seems to be alum. Here is a discussion I found about a similar problem to yours:-
http://www.model-engineer.co.uk/forums/ ... p?th=66592

BR

Mick

[Stanley]

I don't see it as a problem Mick. The chest will seal and the engine run.....

[Stanley]

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You will be forgiven if you wonder what the hell this has to do with the cylinder. Quite simply, nothing at all! I got diverted. I have been given this Protector lamp (which by the way is a GR6S, the Rolls Royce) It was a bit dirty inside and I wanted to clean it. There is a problem, these lamps are made so that once locked, they cannot be opened down the pit. The most common cause for wanting to do this is if the lamp is dropped and goes out. This is a Deputy's Lamp and is what they call a re-lighter. It has a mechanism which allows it to be relit without opening it. In addition they have a lock on them which can only be opened using a very powerful magnet. I have two lamps (The other is the bog standard type S) and this morning I determined that I would open them. The two steel blocks on the tablecloth are two incredibly strong permanent magnets and I was successful. I got it open, dismantled it and cleaned it and put it back together again.



Here it is in all it's glory. I am so chuffed with it! Now, let's get on with the main event!



Here's where we are at the moment. In case you hadn't realised we are getting very close to a functioning steam engine cylinder here.... I needed to have a study of the drawings, do a bit of thinking and decide where we go next. By the way, you may have noticed that I haven't bothered with the incredibly complicated system of drillings in the casting for the drains. I've mentioned before that this casting is short of metal, there isn't a lot to play with and I have ditched the drains. This is a table top piece and will only ever run off compressed air so I can live without the drains....
I need to make the piston the piston rod and the valve rod. At the same time I want to rationalise the old-fashioned tiny Whitworth threads specified in the drawings to BA which are just as good and easier to handle because I have no need to make bolts and nuts. So I have sorted out the drawing, done a fag packet drawing of my version and had a furtle in the treasure chest for a piece of bronze stock for the piston. I shall make the piston first because the lathe is clean and the chips easily harvested. Then I'll go on to steel and make the rods. I know exactly where I am going now and have checked all my sizes.



Here we are at closing time. All my ducks in a row and ready to go forth with purpose!! But that'll do tomorrow. No rush....

[Big Kev]

I am loving the lamp

[Stanley]

It's a cracker Kev and totally authentic. I am over the moon with it, such a generous gift......I found a good site for Protector Lamps, full of information. I thought they were paraffin lamps but they are not. They use special fuel but lighter fluid is a good substitute.

[Stanley]

I was a bit late in the shed, I wrote an article.... The job was to make the piston so I got cracking on the lathe. Not my finest hour.... I should have cut the piston ring groove before I parted it off but forgot so I had to improvise and the gap isn't quite central but it will be OK, it'll seal all right.



As you can see I gave it plenty of clearance, the packing in the piston will easily take care of this.



Knocking off time. Some fitting left to do but we'll leave that until I have the piston rod made.

[Stanley]

Have a gander at THIS to see John running the engine I made for Debs on steam......

[Stanley]

You may remember when I was boring the cylinder I commented that it wasn't the best I had ever done. I deliberately made the piston a snug fit even though I want the end result to have plenty of clearance, the packing will make the seal. Luckily, many years ago I laid my hands on a bunch of adjustable reamers. Not the easiest in the world to use because of the straight flutes but with care they can do a good job.



Bleeding obvious tip because someone reading this may not know. Always turn in the cutting direction, even when withdrawing the reamer. Never turn it backwards..... A couple of passes taking very light cuts solved the problem.



Then I put my home made flapper up the bore from each end. It looks OK now and the piston is a nice free sliding fit Now to address the piston rod!



I have plenty of 3/16" rod so I cut a length off and polished it up. I need to reduce 3 1/16" of this to 5/32. 0.156" as near as makes no odds. I can't support it with a centre and there is no way it will turn without deflecting. A bit of a problem.....



Time for one of my treasure chests. This one holds the odds and sods that are seldom deployed but when they are, they are a godsend.



Here's what I was after. It's a tiny cutter that incorporates it's own steady rest, the brass bush which, if you haven't got one the right size, you make yourself to suit the stock. I was lucky, I already had a 3/16" bush. I think you can see clearly how it works. I buggered up my first attempt because I forgot that for it to work properly, you have to make your reduction in one cut as otherwise, subsequent cuts aren't on the same diameter stock. Obvious really but I forgot, scrapped the first attempt, resharpened the cutter and had another stab at it.



Here's the result, not perfect but I crept up on the diameter until I had it about right. Took the cut and dressed it with a new fine file.... It will do. I have an even smaller cut to make on the other end for the 6BA thread. I shall sharpen the cutter with more rake and practice on a scrap piece until I have it set just right.



That was quite enough punishment for one morning. I knocked off. BTW, the design calls for a slot to be cut in the 5/32" part for a cotter. I can see now that this is going to be a taper pin!

[Big Kev]

It's a cracker Kev and totally authentic. I am over the moon with it, such a generous gift......I found a good site for Protector Lamps, full of information. I thought they were paraffin lamps but they are not. They use special fuel but lighter fluid is a good substitute.

They had 3 miner's lamps on one of those celebrity antiques tv programmes the other evening, they were quite excited by them.

[Stanley]

I saw one sold on Flog It! The postman called yesterday. He brought this, a very rare book, less than 60 pages but well worth the £20 it cost me, I shall enjoy reading it and learning more. He also brought the steam valve for the winding engine and 4 tiny drain cocks. Too small for me to make!