High Pressure Steam Table Engine

[Alyn Foundry]

I haven't been allowed near it yet.  The only thing I had spotted was the larger of the two gears is not there. Why do you think it is a replica? 

In the mean time I'm still making chainsaw chips 

Jo

A slight misunderstanding, obviously one of mine. It is, after all a half scale replica of the Gardner size 0 circa 1907.

Meanwhile the inspiration from which the range of Gardner horizontal engines came from is nearing completion.
The Robinson HA Oil engine, in 1/3rd scale. Circa 1895.

  Graham.

[Jasonb]

You have posted pictures of those jowitt castings before so should know what they are

Yes Grahams HA is looking good, waiting for mine to drop on the mat along with another little project

[Jo]

A slight misunderstanding, obviously one of mine. It is, after all a half scale replica of the Gardner size 0 circa 1907.

Thanks Graham, knowing the history of this orphan I had my suspicions that you might mean "someone" had been copying your castings 

Jo

[Jo]

You have posted pictures of those jowitt castings before so should know what they are

But they weren't Surus' then. In the meantime there was tales of them having been sold to someone else  until they reappeared about 6 months ago at which point someone has been trying to wrap him round his little trunk until it finally worked and I was sent to recover them before Eric's workshop gnome stole them again. I think something is missing 

Jo

[Jo]

Back to the boring bit... I had noticed that the cylinder was getting rather hot while boring it. On inspecting the carbide tip I found it had lost its edge  I turned the tip round and did another bore and concluded that it was too hard for this cheap Chinese carbide tip and it was time to dig out a Sumitomo tip. This cut through it like butter and left a rather nice finish 



The late start in the workshop I am blaming on Dave visiting (and the Robins/Chaffinch needing multiple feeds before they would let me out). While Dave was visiting I spotted that when I JB Welded on the square washers on the bottom of the column they had not gone on square  Time to warm them up using my heat gun and turn them slightly 



With the cylinder finally bored I have taken it off the faceplate and am looking to mount it on a mandrel. Why is it that every time I make an engine it has a different sized bore  Having looked around I found a piece of 28.5mm steel which was a tight fit but not ideal. The best I could find was a piece of aluminium which is 28.8mm or I can make another 2 washers for my 25.4mm mandrel 



  I'll think on it, there is no rush. After all I am retired so there is all the time in the world  so I need to make some more workshop time in my busy schedule and decide which to make before then  .

Jo

[Jo]

Ok so I wasted a couple of hours in the workshop  In the end I went back to my first plan and made a couple of washers

So ready to actually try to do something tomorrow 

Jo

[Roger B]

The orphan look quite interesting with a side block with both inlet and exhaust valves ( or have I missed something completely  )

I went to the opticians today to pick up my new distance and reading glasses. Both were to the distance prescription, copy paste error    This will be corrected free of charge but i have to go to the next town again. 

[Jo]

Hi Roger  I think that is the inlet but I am likely wrong. Graham is the man who knows all about Gardners.


First thing this morning I milled 1mm off of the top of the cylinder. Having retightened the nut on the mandrel it is now set up between centres on H and has had the bottom of the cylinder milled to 47.2mm square. I then started milling the port face to find it was too hard for the HSS cutter I was using so had to change over to a carbide. This meant that I no longer knew the cutting height so had to check using a feeler gauge against the known height:



I'm just about to mill the two top 'ears' before I work out how to do the trickier bits on this cylinder 

Jo

[Alyn Foundry]

The orphan look quite interesting with a side block with both inlet and exhaust valves ( or have I missed something completely  )

Hi Roger.
That’s the inlet valve chest. One valve does air and the closet to the camera does the gas. Both operated by a single rocker arm. The engines speed is controlled by an inertia governor probably best described by the accompanying video. The exhaust is carried under the front of the cylinder. Commonly known as a 3 valve gas engine.

<a href="https://www.youtube.com/watch?v=rhACUBzEGB4" target="_blank">http://www.youtube.com/watch?v=rhACUBzEGB4</a>

  Graham.

[Jo]

The two top vertical surfaces have been taken to width and then it was time to check, check and triple check the position of the three 12BA screws  that are used on the model to secure the two side frames.



In the end I decided where looked right on the side frames and drilled appropriately but I suspect using the side frames as a drilling template may be more reliable.

The port faces are much easier to do if you can see what you are doing so I first put some marker on the face:



Then I had to work out where to put the stud holes for the cover. The drawings suggest 12BA  I think 10BA nuts look better:



I have also moved the bottom two nuts in from where the drawing shows because that is how the original etching is. Drilling commenced and then I realised 



Some idiot has been in my workshop and hit the abs/inc button on the DRO and it has off set  Time to fill those:



before redrilling 

Now for the really challenging bit 

Jo

[Mike Bondarczuk]

Wooops  :wallbang:Jo, but seems a good fix to repair

Mike

[Jo]

Thank you Mike 

Now for the new to me experience  I decided to start by milling the top of the exhaust way so that the outside was circulair and it had square edges:



Then I used the pointer to find the centre of the exhaust way. I found it was 1mm lower than on the drawing - this is not a problem. Before milling the grooves I decided to look at the cover. A piece of 1mm thick would be easy enough to roll into a circle but would not provide much to secure the exhaust flange on to. A piece of 1.6mm thick would be harder to roll    Then I spotted a piece of tube which was a slightly smaller diameter which could be opened up to fit  So a 12.7mm wide piece was sliced off and faced.

Now to start the new to me bit  I have calculated that the wide groove has to be 2.5mm deep  but decided to start with a 10mm wide slot all the way round:



By doing this I can now mill on just one side of the cutter when I take the slot to width, rather than full width which tends to push the cutter away from the centre line. A spot of lunch then for the really exciting bit 

Jo

[Jo]

Mill either side of the slot to leave the slot 2.5mm deep and wide enough so cover fits:



Then mill 4.5mm deeper for the exhaust way, only to find 



     Keep going... Square up the corners of the top slot:



Drilling the holes through to the valve face was fun  The one at the front I could see, the one at the back needed a mirror:



The ring was split and cut to length using the "sticky tape method" to get the length right:



It will need screws in the corners to hold it down but not today 

Jo

[Admiral_dk]

Great to see that you still are progressing and making fine parts Jo   

Per

[Jo]

Thank you Per, it is nice to see someone following along 

Fitting the screws was a bit of a challenge. The Stainless tube I had chosen was a piece of hardinium welded stainless exhaust and my drills did not like it Then drilling into the cylinder without breaking into the bore was a bit  To make it even more exciting I had to hold it in place with a clamp to get it to sit tight against the cast Iron while I drilled and tapped it:



Time to find the centre and drill the four mounting holes:



And I am pleased to say that having opened the holes up to the correct size  it fits:



Now to work out how to hold the top cover as they seem to have forgotten to provide a chucking piece 

Jo