Making a piston valve engine from mainly junk materials

[sandy_ACS]

 

Hi PD's,

I tried to post this last night, however, I was having problems with the PD's server, which would not connect...... maybe Eddy was uploading to many video's or some such.....    :music

Anyway, why is it when you start a job, something always happens to make it a much bigger job?

As some of you know, I am in the process of upgrading the domestic galley area..... took the old wall units down earlier in the week.... you geussed it...half the B****y ceiling and a good chunk of wall plastering came away with them....... result... a further weeks work to get back to where I started......        :  :twisted:  :rant

Looks like ACS are going to be down for a while longer than anticipated......  such is life.
Kate is not very happy either.... no sense of humour some people....  

John..... good to see you are progressing well with the engine design, I particularly like the way you have achieved the steam transfer passages.... certainly saves a lot of deep drilling and plugging of holes afterwards.

On the subject of deep holes.... I attach some notes which may help any of you who may be following John's build, especially those who may be first time builders.

In no way should they be considered as any form of criticism of John's most excellent article, but merely as helpfull tips towards getting the job done successfully, and with as few tears as possible.

As John has already stated, the purpose of his postings was to pass on the design as a whole, along with general processing methods, rather than a blow for blow acount of how each piece was/should be made.

Having already mentioning the deep drilling issue in an earlier installment, I felt it would be helpfull/usefull in this instance to enlarge a little upon the subject at this point.
 
There are, of course, many ways of achieving the deep hole required, these notes are just one possible method, and one which should be achievable by most of you.


I am eagerly awaiting John's methods on the manufacture of the piston valve bobbins, and his method of timing the valve gear.  :respect2


OK BACK to the KITCHEN..... I know my place....  :twisted:  :    

Best Regards.

Sandy.    

[bogstandard]

I would like to thank Sandy for the post on deep hole drilling, very informative for everyone. My problem is that I have all the correct tooling and machines to carry out all the machining with ease and I keep forgetting that novices will not have access to the type of equipment that I posess, like most of my drills are precision four facet ground, plus I also have a set of metric drills specifically for drilling brass where the front face has been ground vertical to give a zero rake. To buy all these items at the beginning would cost a fortune, so purchase the best you can afford, you will find they will last a lifetime if correctly looked after. Most of my machine reamers came from the scrap man, who also clears out industrial workshops, and bought by the kilo. the last lot I bought were all brand new small metric (smaller than 10mm), solid carbide. I paid £20 and got about 25 reamers. The cost for one would be at least double this from a tool specialist. So if you really want to it can be done on a tight budget, you have just got to search about a bit.
Many thanks again Sandy for your input.

John

[bogstandard]

Now we are cooking on gas, starting to get it looking like a finished engine.
There is no need for a sketch for this post as it is done with piccies and superglue.
Pic 1 shows the size of the blanking plate for the end of the piston valve block, mine are made from the same material I used for the block support plate, 2mm thick brass, but I suppose they can be made of steel or ali, just don't go too thin as they are blanking plates for the steam control ports. I stuck mine together with double sided tape to allow me to machine all of them in one hit. You will only require two if you are making one engine but twelve if you make six (confusing isn't it).
Once you have the plates made, carefully superglue them to one side of the piston valve block and spot thru the block mounting holes with a 2.5 drill, this will give you the marks to drill all the way through the plates, you should end up with plates as in pic 2.
This time stick the blocks to the main piston block (the big shiny one), (too many pistons in this game, I'm going home) and carry out the same manouver by spotting thru with a 2.5mm drill. This again will give you your drill marks. Drill these holes with a 2mm drill 7mm deep and tap to 2.5mm.
By the way, the reason I always drill and tap so deep is that I am lazy. By drilling so deep it allows me to use a taper tap and get about 4mm depth of good thread, rather than drilling 4mm deep and having to use both taper and plug tap. At my age time is precious.
********** WARNING *********
Look at picture 3 and you will see the lower holes marked as a danger area. The reason for this is that when you drill these four holes they will penetrate the remnants of the holes that were drilled for the plate mounting screws, so unless you want to keep the DIY stores in business by selling you 2mm drills, take it VERY slowly and steady after you have penetrated about 2mm.
I will post a sketch tomorrow for all the hole locations if you do not want to spot thru. The reason for this is a fellow member of P.D.'s has kindly offered to draw up the plans for this engine, and this sketch will be needed. So hopefully after the end I should be able to upload a good version rather than all my grotty sketches.
Back to the build. Now you should have two plates drilled and deburred, and one main block with four holes extra in each end, that is eight all together, any less and you need to check again, any more and you are in trouble.
We now need to join all the bits together, so I thought I would give you a choice, one is rather expensive, the other is dirt cheap if you know any stainless steel welders. The first option is to buy some long 2.5mm bolts (I bought mine on a visit to Germany many years ago) and use those.
The second option is to use 2.5mm studding. I made these yesterday (Sunday), and I thought to myself 'Where can I get 2.5mm stainless studding on a Sunday', in fact where can I get it period. Then it occurred to me that a friend had given me some stainless welding rod a while back, I measured it up and it came out to 2.37mm or near enough for what we want. I needed about 350mm of the stuff, so lathe into very slow back gear, out with the  die stock and die, and having about 75mm sticking out of the chuck at a time with plenty of cutting compound, within 10 minutes had what was needed (miles quicker than making individual studs with a thread at each end). See pic 4.
I cut these into 26mm lengths and joined all the bits together, see pics 5 & 6. I am lucky, because I am building two engines I can have both, but I suppose you could mix and match if you were that desperate.
Next time the engine will be built up again and I will be making the eccentric straps and the piston valve control rods (a bit of high precision turning), but by now these will be a piece of cake with all the experience you have had so far.
These might take a couple of days for me to make and draw up so don't hold your breath.

John

[sandy_ACS]

 

Hi all,

No problem John, I had a feeling you would see where I was coming from.

Like yourself, I am surrounded by similar large equipment and have many options/methods available to me in achieving a particular end.
I also tend to sometimes forget that others are not necessarily so well equipped and might find a particular process, second nature to us, quite daunting, especially when the main machines available may be a small lathe and a small bench drill. It was for such people that the added notes were intended.

On the subject of tapping holes, I use a slightly different approach, but for much the same reasons, I am also lazy, getting old and time is precious, so, like you,  changing from taper tap to plug tap is not on.... I use spiral fluted taps, which are magic for blind holes and only one type is needed, namely the plug equivalent, which will tap a full thread right to the hole bottom.
The other advantage of these is that they throw the swarf out of the hole as it tends to climb up the spiral flute rather than falling to the bottom of the hole.

A small point on the availability, or not, of 2.5mm bolts, especially in the UK..... substitute with 7BA (use a 2.05mm tapping drill followed by a 7BA tap) which are readily available in hex headed form, even in stainless steel, from many of the model engineering suppliers.

Ok thats my lot.

Best regards to all.

Sandy.    :vacat  :computer

[bogstandard]

Hi Sandy,
Little would you believe it I have loads of the spiral flute taps, exactly as you said. But my problem in the frantic rush at the scrapmans emporium when a new load of tooling came in and I saw all the small metric sizes I snatched his hand off fairly quickly. Anyway a couple of weeks later I came to use one of the taps and just looked to see what size it was and noticed the word HELICOIL on the side. Never used them yet, but did manage to get a load of inserts just in case.
By the way, the design I will be using for the 'bobbin' valve (I would in fact call it a spool valve, from my days in pneumatics) is the one you told me about, being drilled from one end with an outlet hole just below the lower spool. I have the machining sequence already tried out and seems to work ok, can be tackled easily by anyone and should produce a good valve. Thanks for the design idea, it has saved me hours working out porting to get from top to bottom.
Sorry if this post has baffled anyone, just a quick explanation on the word helicoil. Helicoils are usually a steel thread insert put in to either repair or make more hard wearing a tapped hole. The taps are marked up as say 3mm, but in fact they cut a lot larger to allow the insert to be fitted to bring the hole back to 3mm size. So the ones I bought were no use for tapping standard size holes - DOH!!
Now you see the reason for my signature.

John

[derekwarner_decoy]

Goodness PD's.... the sight of grown men  :mrgreen: rushing down stairs @ 6.00 AM to the  :computer to catch the latest renditions from John & Sandy........  :post ......thank goodness the   is on

With all this talk of   tapping things.... you may wish to confirm to PD's on the current best practice fluids for this tapping process.... as my references are from the First Fleet only [1878] & I am sure there must be some advancement since then  

For aluminium a small drip of kerosene only, for aluminium bronze we couldn't afford anything, for red brass...one little drop of RocoiYel, for steel....one little dollop of that green slime TREiFolEX

Don't you just love our inherited language.......like what is the difference between a  small drip .....a little drop and .....one little dollop :?:  :idea:    :music

[bogstandard]

Hi All,
I will just answer Dereks question first. When tapping I tend to use Rocol cutting compound for almost anything except for cast iron which I always cut with no lubricant at all. Machining metal is a totally different process, and as you said, paraffin for ally, standard water soluble cutting oil for almost everything else. BTW for cutting copper (one of the worst materials to try to machine, it is like trying to machine evostik glue) try cows milk as a lubricant (if you can get the cow past the wife without her noticing), I suppose Derek could use his famous Ozzie goatsmilk, but I think the smell would be a bit offputting.
BTW I see you rise late in Oz. By 6am I have done the 3 Sh's, walked the dog about a mile and sat down to weetabix, coffee and a fag, in that order. Then its usually time to read the new posts.
That brings me onto this post. Only one pic tonight (the drawing mentioned last time will come later), the engine built up as far as I have reached with a pile of raw material to carry out the next task. That is to make the spool valves, and the eccentric straps.
The crankshaft is already timed for running, with pistons and eccentrics in the right positions (or so close it will not matter). If you remember when I showed how to make the eccentrics and I scribed a line on the back when I drilled the thru hole, well the trick worked a treat, you can align everything very accurately by eye rather than having to use a DTI to find max lift. So if you can, put that line on, if you need to know how, just ask.
Now the bad news. For the next week or so I am going to be very busy outside of the workshop and won't have time to prepare the posts. So what I intend doing is to get in the shop as much as I can and get the engine to a running state (no control valve, just fill it full of air). Once that is proven I will catch up with posts and pics. This part of the engine build is the most critical bit and hopefully should go fairly smoothly as I have already planned most of the machining stages, making the bits is easy, it is the fine tuning to get them to all run in unison that takes the time.
I will still be reading the posts and can answer any questions you may have.

John

[Eddy Matthews]

I have to admit that I initially thought the engine looked a bit ugly - Sorry, but thats the honest truth.... I realise a lot of the engine is designed to make it a relatively easy project for a newcomer, and we were looking at bits and pieces rather than a finished product.

However, now that it's coming together I'm starting to like the look of it more and more.

So you must be doing something right John!

[bogstandard]

Hi Eddy,
I love it when people give their truthful thoughts about something, there is absolutely nothing wrong with that.
If you remember at the beginning I said this engine would be functional and totally ugly. I think I have achieved that with gusto, but I must admit it does grow on you when you see it every day in the workshop, screaming to come to life, I can't wait to give it a few more bits, and it should look even better (but still ugly).

John

[Eddy Matthews]

Thanks for being so understanding John - My comments certainly weren't meant to be offensive, just an honest opinion....

However, as I said, the engine is definately growing on me as it progresses - Though as Walter Snowdon and Bob Golder (two fellow clubmates) would probably tell you, I do tend to like slightly quirky and unusual models, so it's perhaps not surprising that your engine is having more and more appeal as a potential first project!

[derekwarner_decoy]

Hi PD's...glad for the clarification on the new renamed ROCOL product John - it appears that TREFELOX is actually scrunched up OZ green locusts... hence the   smell oh well..

You had previously noted that a kind PD had offered to commit all of your all of your sketches to Drawings....would this be in an electronic format :?:  

Talking with a few colleagues :gather  & one suggested... if yes in electronic format, would be simple to redesign

1) the base plate to place the crank to piston axis on a 30 degree diagonal to the horizontal
2) the cylinder mounting block as above
3) the bigend bearing blocks similarily modified [so the oil didn't fall out] both North or South of the Equator

& hey presto  a :no1 paddle engine

The same bright spark also suggested he had a source of 4 & 5 mm diameter Torrington needle bearing needles

Anyway contrary to comment we people in OZ think the engine looks tough enough :yeah for our harsh OZ conditions & the manufacturing text is  :news for anyone considering a build

But   , your engine MUST have a name & here is my entry

"The J*** No1 V S******D"....what do you think PD's :?:    :music

Edited to add a V for......the opposite to H = horizontal or......different from D = diagonal

[bogstandard]

Hi Derek,
I thought you lot ate all these creepy crawly things, not mashed them up to make lubricant. otherwise the Bushtucker man is telling us porkies.
It is still in the early stages yet but I think he is doing it in CAD, so supposedly it will have the facility to be modified. The problem is that he cannot visualize some of my sketches so I will have to redraw them.
I definitely considered turning this engine into a horizontal, but the sheer width of it has put me off the idea. It would be better, if you can imagine it, cut the main cylinder block in two, and rather than having two steam control blocks just have one between the now sawn in two cylinder block, with a dual eccentric in the middle of the crankshaft. Doing it this way a saving on width of at least a third could be achieved. But there would have to be a redesign on the crankshaft to get it into a narrower package and I think this would be, for the moment, beyond the skill of the people this article is aimed at. But if they manage to complete one of these with such bad sketches, I'm sure that with a little bit more encouragement they could trespass into the realms of one piece cranks (not from a single billet, but built up as these are and silver soldered together).

Lets get this one finished first.

John

[derekwarner_decoy]

Hi PD's & a few points of clarification John...Q=question, C=comment, A= answer, R=response

Q)  thought you lot ate all these creepy crawly things, not mashed them up to make lubricant. otherwise the Bushtucker man is telling us porkers
A1) what.. do you think we are all silly  :nose :!: .....we wouldn't eat that crap
A2) we don't have  a "bushtucker" person in OZ - rumor is that your version is a Scot via a non deplume  :music

C) It is still in the early stages yet but I think he is doing it in CAD
R) well thats good

C) the problem is that he cannot visualize some of my sketches so I will have to redraw them.
R) if he cannot decipher your scrawl from the first sketch who will provide the second sketch :?: ...the Dog :?:

C) I definitely considered turning this engine into a horizontal,  but the sheer width of it has put me off the idea... lets get this one finished first
R) acknowledged &  :news....you have just got-a-laugh  

[bogstandard]

Hi Derek,
I admit defeat on all your answers except one, why drag my gifted friend the dog into the argument, I told you before, he's the maths expert, the cat is the artist!!
But you must admit since I robbed my grandsons ruler and pencil (I must stop all this contact with convicts, I'm turning out just like them), the sketches have got slightly more decipherable, in fact the dog has no trouble reading them at all, once he puts his contacts in  :shock: .

[bogstandard]

Hi All,
Ever since Sandy did his post on here about deep hole drilling it has been gnawing on what little mind I have left about the difference between hand and machine reamers, and I should have mentioned it without someone else having to remind me.
So I have decided the easiest way is to show you where you can get machine reamers at a very reasonable cost.
It is here - http://www.tracytools.com/reamersassorted.htm
The pic I have posted shows my imperial set that I obtained from them, 1/8" to 1/2" in 1/32" increments for about £70. They aren't all the same design but they all are good quality and function well. I think they do metric machine sets as well. The best way to order is to give them a call and tell them what you need, as the website is a bit confusing at times.
Another thing to note when you are just starting out is that the machine costs are negligible compared to the tooling costs. Only buy what tooling you require to do the job and over the years you will eventually end up with everything you require to complete most jobs. Car boots and private ads are a good way to buy tooling. A chap on a boot sale was selling brand new metric milling cutters (I didn't ask where they came from), various sizes for £1 each, I offered him £30 for the box and ended up with over 100 cutters. Went to a model boat show and a chap was selling what he thought were 2mm resharpened solid carbide drills for £1 for a pack of 10, they were in fact HSS 2mm slot drills, I bought the three packs he had left (some of his previous customers were in for a shock when they tried to use them for drilling). So keep your eyes open all the time and your machining can get a lot cheaper.
By the way, the engine is getting very close to running, will post a vid as soon as.

John