Stuart No 1

[Jo]

Thanks Stuart, hopefully it will provide a bit of a modern view on Andrew Smith's original book which described making this engine on just a lathe 


The valve was just on dimensions  So it had to be machined very carefully to leave the sides of the valve square. The slot on the top of the valve was already over 4mm wide but the bottom of the slot was tight enough for the nut. Then the hole for the spindle can be drilled. The later drawing show the hole at 4.76mm diameter    the earlier one as 5.5mm, we need the hole to be bigger than the spindle as we want the valve to float like a butterfly.. If it is tight you will either get the fault that the valve will not follow the port face or that it stick too far out 

The valve pocket is also tight  and the original drawing show it being cut with a radius. I could see no value in the radius so I went for a normal slot drill cut pocket and squared up on the valve pocket size.

We can now check the fit of the valve in the steam chest and as you can see it is too tight so the inside of the chest needs to be milled out. We can then try the fit on the side of the cylinder to check if the movement of the valve hits the chest at all.

Jo

[Jo]

Some of you have mentioned that I failed to do anything yesterday  sorry I will try to do better. To that end Eric has challenged me to take along this engine to see him next Wednesday so we can have an engine running session so I will be back in the workshop today trying to get some progress 


In the meantime any one visiting should be aware that Surus is camped out by the front door in case I get any 'visitors' who he suspects might have wine/chocolates and castings for me 

Jo

[Stuart]

Haven’t you received it/them yet

Tell Surus that they may be soft so do not squeeze them to hard


Happy Valentine’s Day

My birthday is tomorrow 72 times round the big ball , people ask me how I feel I tel them I do not not how I should feel I have never been this old before

Have a good valentines machining day

88’s

Stuart

[Jo]

Haven’t you received it/them yet

  I am having to resort to opening a box of Jaffa cakes to eat on my own 

Thanks Stuart, have a nice Birthday for tomorrow 


Starting from the bottom surface I machined the 8 degree slope on the bit where the leg needs to go. Then turned the cover over to do the top.

I thought it was prudent to check the alignment once more before drilling the hole at 8 degrees. The drawing shows it is 7.14mm for a 6.35mm thread so there is a bit of wiggle room 

Having checked the distance between the soleplate and the bottom cover it is time to start on that leg 

Jo

[Jo]

The starting point on the leg is to get it to length and to check it was right before any shaping up.

In case anyone missed it I repeat again: these forged bits from Stuart are horrible to machine  Turning the taper left a finish like an old gramophone record, which had to be finished by rotating the rod and using a file 

Mounting the leg up in Tgs indexing head meant it was possible to mill the two sides parallel and to width. Leaving two holes to drill at the correct spacing in the end.

The only problem I can see is that the standard size nut for the thread on the end of the leg won't fit so it will have to be made smaller.


That was the last bit of machining...there may be a little fettling to go, the cladding and an adapter for the compressor so there is nothing for it - it is studs and their nuts time

Jo

[b.lindsey]

Almost there now. Its looking great too Jo. The studs and nuts shouldn't be an issue for you 

Bill

[Jo]

Its a shame Bill I can't pick up the cladding for another week so it won't get finally finished just yet 


It might be time to start negotiation on the next set of castings   

Jo

[b.lindsey]

Ummm….would that be from Surus' stockpile or are you bypassing him completely

Bill

[bent]

Well that was quick!  Looks darn good, too.

[Jo]

Thanks bent,

Bill I had hoped that at least one casting set might have been dropped off for me today but  The visit to my supplier next week may bring the odd set to light but I doubt it so we are back negotiating as to what I might be allowed

Jo

[Jo]

Some more pics from Eric 

Jo

[Roger B]

That leg is really quite a tricky bit to get right  It was quite a common feature though, maybe it was easier/cheaper than a A frame casting (is it a or an  I've been away too long).