Making a piston valve engine from mainly junk materials

[bogstandard]

Now for the second part of machining the piston blocks.
Just a word of warning, you have to make an opposing pair, so mark everything up so you don't ruin your day.
The first part of the sketch shows you the position of two slots you are going to mill out, they are to join the main piston valve ports to the ports on the main block that go to the top and bottom of the pistons.
I would suggest you bury the cat, superglue the dog in its basket, give the kids some money to go out and treat the wife to a girlie dvd, you do not want to be disturbed while machining these slots, go past the line and you are having a bad day, unless you are good at rebuilding with silver solder.
They should be 2mm deep and up to 3mm wide, I have made mine 2mm wide. if you look at pic 1 it shows how I marked them up.
The lines are marked from the same datum as we used to drill all the holes in the previous post. The top and bottom marked lines are absolute limits, do not go beyond them, I would stop about 0.2mm from the line.
Once you have done one, mark up the second to give you an opposing pair and machine to the same criteria as the first. They should look like the ones in pic 2.
Once you have your pair, now for a bit of cosmetic machining to make it look a lot better.
The second part of the sketch shows what is to be hacked away.
In pic 3 it shows the hatched areas to be cut away, nothing too critical but try to make the height the same as the main block just to keep it looking neat.
Pic 4 shows what you should end up with.
There is a bit more to do on this block but it is to do with a gland seal like we have on the main piston rods, but that can wait until later. I have to finish the posts now until sometime next week as I have a couple of commissions to prepare for delivery.
On the next one we should be able to get the block joined to the engine and make all the bits to connect to the eccentric. Once this is done we can get some air to it and time the lot in. After that it is just a matter of getting the pipework and control valve done, so we are fairly close now.

May the force be with you.

John

[derekwarner_decoy]

Hullo PD's .....well.... we can see John is progressing at a great rate of KNOTS  , but how optical illusions still occur via computers

In '3 Custom Rods .JPG'.....we see the three lightening holes in the cranks for engine 2

In '1 Blocks marked for the maxcut.JPG'.....I thought I noticed  the alternate set of cranks for engine 1, however which had been   milled for the length of the throw to create an inboard sculptured appearance.... so talking with :gather  a few OZ colleagues  & a   we all agreed they appeared a very attractive rendition over the lightening holes

Then one smart ar..e [who is really only a 1/2 baked KIWI] said   ...it is only an illusion... look at the transition toward the big-end......  :rant  & ....but it still looks good [neo-classical] :?:

[bogstandard]

Hi Derek,
I think I have the gist of what you are talking about, the rods on engine 1 are in fact just turned parallel, and what is seen is in fact an optical illusion, most probably caused by the angle the photo was taken from (I think it is called parallax error).
The custom rods again are turned parallel but the three equi distance holes are of different sizes, namely 3.5, 3 and 2.5, to give the illusion, from a distance, of a tapered conrod.
On engine 2 I will be doing some taper turning on the columns, but I didn't want to complicate things for this basic engine.

John

[derekwarner_decoy]

OK PD's...... when John mentions - "I will be doing some taper turning on the columns"... reminds me of Tubal Cain early steam component construction......beautiful  :bow neo classical [non necessarily functional :nah ] but still  :no1

Eighteen months ago I incorportated a basic element of this style of   construction in the arched support for my JMC3H engine...... as per earlier postings

[bogstandard]

Just for Derek
Here is a little poser for you and your mates in Oz. seeing you spend more time looking into the background rather than at the piccies themselves.
You must have seen this little item in the background of some of my pics.
I designed this myself and it saves me hours of grief and stops those bad day blues.
It isn't going off topic because I use it all the time in making these engines. Usually a few times a day.
The four rods are a specific height from the base, and are sized 3,4,5 & 6mm.
It is used in conjunction with other pieces of equipment (I've most probably given the game away now).
I hope this will keep you occupied until I post again.
And it isn't a mini capstan for people with different sized hands.

John

[Eddy Matthews]

Well you've got me baffled John, but it doesn't take a lot to do that!

My vote goes for a 1:24 scale capstan for crew members with different sized hands

[bogstandard]

Hi Eddy,
You said exactly what I thought they would say, you must have posted at the same time I was editing my post to tell you it wasn't a capstan.

John

[derekwarner_decoy]

Hi PD's............... & yes John ... it was a very my    grandfather who suggested that I must look VERY deeply into the background prior to making comment re the current..........

With respect to your "four column height/length gauge" .... we convicts used these as toys on the  voyage :vacat to OZ for over sized or undersized marbles  [when the deck was steady]  

[bogstandard]

Way off

[derekwarner_decoy]

OK PD's  :rant  :nose  ... lets play John's guessing game  :hmph  :music

1] the column has four sides - each face does not exhibit pressure marking as being held in a vice or four jaw chuck - similarly the top face is not centered so would also suggest as not held between centers

2] each face has a different diameter shaft on what appears to be = height axis on center from the base
3] the lengths of the four respective shafts to the block faces also appears to be equal {however this is a RED herring..I think}
4] the ends of the respective four shafts are flat so are not used as a scribing reference

I previously   blundered as a 'four height/length' column... however this was adjudicated as incorrect

Is it a jig for holding components which have holes of 3,4,5 & 6mm diameter pre drilled? whilst completing further machining processes?

People from OZ are tough :yeah .. we never give up.. time to help cook the Sunday roast & have a   +   more  :rant

[derekwarner_decoy]

:nah ... Oh PD's ... as resourceful as we are... try & search for the "metal to size and marked up.JPG" dated sometime in this year of our Lord............ but I won't tell    :music  :luck

[bogstandard]

Nearly there, wrong on the machining. Another process follows.
The picture you found tells it and shows it all, except for one vital piece.

[derekwarner_decoy]

OK John  :nah .... see how you like the return quiz  but .....[I booked a community call to  Sandy & Walter & TBJ... as these members [as I] had professional  :nose training in t**ing in music all those years  ago
 
So my final answer is "t**e, "t**e, "t**e is on my side":......by Jagger & Richards........ :music  :music  :music.........

If I am again incorrect PD's .... I promise no more   :hmmm   guesssssssssssssses        

PS..... Kate won't let Sandy respond on the PC    as he hasn't  finished the new kitchen      renovations

[bogstandard]

T**E has definitely run out for you my man.
I thought you would get it straight away when you found the other picture with a square right next to it.
The solution is shown on the piccy.
It is used to set up anything with a standard size hole (and even non standard sometimes) into my toolmakers vice so that I can tap the hole using my vertical tapping stand perfectly square to the bore. It only takes seconds to do, and by the way the jig is removed from the bore before tapping.
I have finished my commission jobs so I will be posting very soon.

John

[derekwarner_decoy]

Well PD's,,,,,,, we know John is a self admitted no nonsence   task master.....but how do I explain my $500.00 AUD [to Karina] telephone bill to Mick & Keith when TIMING was not the answer

But remember ....we people from OZ are tough    .. others  eat MARS Bars......we eat IRON ORE crumblings on our weet BIX   ....we never give up  

Edited------ yes ....I can see the jig-function in easy setup John......etc