A Stuart Williamson build

[Sanjay F]

The port face is marked for drilling tomorrow, and then the steam passages which are at 2 different angles due to the position of the port face on the cylinder. Needs to be done with a fresh pair of eyes and a clear head 

[Sanjay F]

Ports and steam passages made and glad to to get them out the way! I'm confused by the drawing and wonder if its a mistake? The exhaust turns through 90 degs within the cylinder and to make this you drill a hole into the exhaust port then another which intersects it and finally you silver solder a plug into the original hole - all good, so far but why does the dimension provide say the hole is 3.7mm x 1/16" deep to meet the cross hole as that is not remotely deep enough?

If you look at the 1st photo you can see where I have marked the position of the hole and how far it has to go to meet the crosshole OR maybe I've read it incorrectly and its a 1/8" hole and just the end is opened up to 3mm or 0.145"?

[Jasonb]

1 5/8" total height. Cross hole 9/16" down means the other hole goes 1 1/16" up

[Sanjay F]

Oh I see........... and its an odd diameter 0.145"? The diagram (blue circle) seems to indicate that both diameters (vertical and horizontal) are the same if I'm reading it correctly

[Jasonb]

Nothing odd about the diameter when you have a set of 0.1mm increment drills  and even if you don't have a full set it is the common 4BA clearance size so most would have that or  a No27 which at 0.144 is close

Blowing up the blued circle the vertical hole is overlapping the horizontal so definately bigger, gives the engine a bit more breathing room.

3mm dia in from the port face

1/8" or 3.2mm dia horizontally in from the side to meet the 3mm then plugged

3.7mm up from the bottom to meet the horizontal 1/8" hole.

[Sanjay F]

Thanks  - I followed it as you described and as per the drawing 

Several operations for the top cylinder cover which not only has the recess for the piston gland, but is also the fixing point for the crosshead guides. It was easier to make a little mandrel/fixing in order to accurately machine the various surfaces; still a few to go!

[PaulR]

Coming along nicely 

[Sanjay F]

Thanks Paul

I'm glad I didn't pause the build whilst waiting for our friends in China to print the new colum; this engine has lots of fiddly little bits. The cylinder top cover and piston gland are now complete and need to be fitted to the cylinder

[PaulR]

Yep, that's quite a fiddly little piece, nicely done though 

[Sanjay F]

Making some progress, this is what has been done so far, flywheel, cylinder, valve chest & cover, piston gland, piston & rod, slide valve. Annoyingly the valve gland was a new casting and was faulty, but Stuarts will replace that I'm sure; it sent the drill off centre as you can see.

I'm quite surprised by how small this engine is, but I guess all this has to eventually fit inside the column! 

[Michael S.]

The issue with the valve stem seal is annoying. If necessary, it can be remade from round stock.

Good progress 👍.

[Sanjay F]

The connecting rod looks 'interesting' - I'm wondering the best way to set this up in order to machine between centres, these are the smallest lathe dogs I have and again same problem as I had before which is to set it up and drive them. I'll need to make centres at either end then taper from one end to the other as per the instructions .......any ideas welcome

[Jasonb]

Leave it a bit overlong at the big end end so you can put in a ctr drill hole that won't interfere with the half round hole when you come to form that. Hold by the small end in the 4-jaw as there is no real need to do it between centres and the chuck will provide the drive.

When it comes to that half round hold the rectangular stock in the mill vice with a bit of scrap steel either side so that you don't burst out the side and damage your vice jaws.

For the slots drill them out first then plunge with a milling cutter moving along very small amounts per plungs, you may need to come in from both sides. Finally file then to get the square corners, a needle file that has been ground down to fit the milled slot will have smooth edges so won't make the slot wider, just longer.

[Sanjay F]

Thanks Jason - certainly looks like a new challenge for me. The wedge and cotter arrangement is something I've wanted to get used to making 

[Chipswitheverything]

Hi Sanjay, you are making good and quite rapid progress on this interesting Williamson engine, it's a nice project.  ( One that, if I'd been a bit more on the ball, I might have had a go at, as I could have bought a boxed Henley set of the castings from a dealer friend , back in the mid eighties, for £35 ....!  But I bought the boxed up set of the triple castings , that I have tinkered with lately, from him , for the same price.  I was daft not to upend my piggy bank for the other £35, but I needed money for my first mortgage back then, which was at an interest rate of 14% ...!)

Anyway, just to endorse Jason's ideas on the procedure for the 'rod.  As the component is fairly small, I think I might find a longer, maybe bigger section, piece of steel stock altogether and give myself a couple of inches or so of parent stock to hang onto at the big end, for the milling vice and the chucking.
Maybe, also, some bit of overlength at the small end too, which can all be trimmed and rounded later on. I like to have a few more options on clamping and manipulating the stock that the component is appearing out of!

 At least , in the case of this slightly tricky component, only some easily obtainable stock of quite small section is needed . In fact, it could be made from 1/2" ( ?) dia . BMS bar rather than necessarily needing a square section, and the facets and holes sorted out using a dividing head. Dave