My AJ Reeves Bolton Triple Expansion Engine

[simplyloco]

I've completed the port drilling. Valve chest holes and studs next!

[simplyloco]

_{The Cross Drilled Exhaust Ports}



I'd forgotten about these! Very very important if I want the thing to work!

There are two exhaust ports in the main body, and this is a straightforward drill/tap exercise. I don't have the specified 26tpi taps, but 32tpi will be quite adequate for my needs!







The HP cylinder is connected to the main body by bolts, and these two recesses alow one to get one's nuts tight...







The exhaust (in the centre) ports have to be connected to the outside by another daft and dangerous cross drilling exercise!









The two 3/16" holes in the HP cylinder face go right through the body and connect to a cross drilling, which in turn connects to the exhaust port. Got that? 🙂







That thread in the HP cylinder is at both ends of the cross drilling, and will be sealed with a 7/32" plug.







You can see the port connections here. Two in the HP exhaust and one in the IP port. Clever stuff!

[simplyloco]

Valve Chests Completed

For this drilling job I donned my 2022 hat and drilled all three valve chests this afternoon without resorting to marking out, centre popping or spot drilling, relying completely on the DRO co-ordinates. I have to say that new technology rules OK…

[simplyloco]

Hooray! The workshop is open for business!


I have to make hundreds of studs, and to keep costs down and my sanity up, I've ignored the 7BA spec. and bought three metres of M2.5 stainless studding at very sensible money. However, there is no way I am sitting there hacking them off using a six inch rule and a junior hacksaw! There is a better way, as the following pictures will show..



First of all, one needs a bench shear of some description, with hole drilled in one side to accept the M2.5 studding. I made this one earlier...







Erect a stand for the stop. There are three holes in the shear base to facilitate cutting differing lengths. A sharp push down on the lever and they come off straight and clean, and all the same size!







I bought a ER16 chuck just for this purpose. The spindle stop is set to stud length, and the finishing tool set to the bed stop or DRO.







The tool is plunged into the work, and the stud thread touched up with a small file to ensure the nut engages easily.







NUTS! These are mass produced rubbish M2.5 nuts. My nuts will be much prettier...

[keith1500]

It was around the 22 December some one else, an American, famously said NUTS!

Keep the build going.the photos are great

Keith

[simplyloco]

Nut Mass Production - but not quite!

Now I've got a method for the studs I put that to one side and looked at making prettier nuts than those offered by the trade. I was successful, IMHO, and if I only had 20 or 30 to do I would use this method, but it is time consuming, and boring!.

I will purchase a large quantity of one size smaller steel nuts from a machine shop and just face them off to look like the ones produced today. Here's a few pics of the method, using my two lathes!



Set up in the Cowells for drilling using a self spotting PCB drill. The 1.25mm parting tool was used as a length stop, and then wound in to achieve a 2.75mm nut thickness. I have to say that the Cowells is a delicate, joy to use machine on jobs like this, but I'm not sure it will stay the course with me!







Tapping using my freehand chuck on a spigot, and parting off to length







Place the nut on a 2.5mm stud that is already held in the collet on the EMCO V10P. and plunge to the set depth.







Sample nuts for appraisal. I think my nuts are prettier than the mass produced ones!







Another view. These are mild steel, but I might go for stainless ones in the bulk order.

[chris vine]

Hi John,

Your own nuts look better than the bought ones, but I think they shouldn't be chamfered all the way across the end face.

Most nuts, of good quality, have a faced off end, with a chamfer across the corners, which just breaks into a constant line around the face.

Very tricky to describe!!

Enjoying watching your progress...

Merry Christmas
Chris.

[simplyloco]

Dec 22, 2022 17:38:03 GMT chris vine said:

Hi John,

Your own nuts look better than the bought ones, but I think they shouldn't be chamfered all the way across the end face.

Most nuts, of good quality, have a faced off end, with a chamfer across the corners, which just breaks into a constant line around the face.

Very tricky to describe!!

Enjoying watching your progress...

Merry Christmas
Chris.

Hi Chris. Yes, I know about nut profiles: I just like the convex shape!
Merry Christmas!
John

[chris vine]

That is the beauty of this wonderful hobby!!

Chris.

[Midland]

You are all bloody nuts!!!!!! Ran the No 60 on air yesterday and she runs very smoothly. No need to make nuts she has them already!!
D

[simplyloco]

Tapping the Stud Holes


This is a procedure that many newcomers shrink from, for fear of breaking a very small tap in a piece of very expensive bronze! 

I won't post any more on this procedure as it is just repetitive. It's also time to break out the Gin for the holidays!



I used the HP valve chest as the template for the first set of tappings. I stuck it on to the cylinder block using Loctite 510. It was lined up on parallels to ensure that the top face was exactly flush with the cylinder body.

edit: This is the IP chest for demo purposes only.







Once it was dry - about 15 minutes- I spotted the holes to a depth of 0.5 mm using a 2.5mm drill. The Proxxon has a handy depth stop feature. If you use the tapping size of 2.2mm the resulting hole could be out of position as the drill can wander about in the clearance hole!







The valve chest was removed - knocked off!- and you can see the spotted holes which the tapping drill will have no trouble following.







The 2.2mm PCB drill was set to 5mm depth and the holes drilled freehand without problems. I then tapped them all, again using the Proxxon.



Success! Fits like a glove and the top face is flush!

[simplyloco]

Joining the Cylinders and Blending the Sides


Holidays are over and the workshop calls! This job involves blending the main casting and the HP cylinder into one homogeneous shape. To achieve this, one has to machine some pockets in the side of the main casting to facilitate joining of the cylinders. As it happens it was tricky, even with the pockets, as there was no room for a spanner so I had to make some special slotted nuts to enable me to tighten them sufficiently. I've blended just one side today, and also cut some 26g Titanium cladding to see what it looks like. I'll do the other side tomorrow. Here's some pics.

[simplyloco]

Completing the blending



All done, and soon on to the next jobs, which are the valve chest and cylinder bore covers. I'm delighted with the progress thus far, but In the mean time, I'm having a little rest...😇

[simplyloco]

OK, I had a little rest this afternoon, and after a glass of beer I felt refreshed enough to do the three cylinder covers. Well chuffed with the result!

[simplyloco]

Valve Chest Covers



One down, one to go! I'll get it shot blasted to restore the cast finish. The drawing doesn't specify a radiused finish, but the real thing I'm sure would have had one. This was done with a miniature router bit on the FB2 at 2000 rpm!

BTW, thanks for all the 'Likes', we are starting to look like a ME forum again!
John

[simplyloco]

Fitting the Valve Chest Covers and do I need nuts!


Here's the completed valve chest covers, apart from the inlet connections. I'm quite pleased with them, but I am now on the horns of a dilemma over the use of nuts!


I have two choices:

To make 2-300 studs and nuts, preferably in stainless steel, taking many hours out of what's left of my life. OR


I use these stainless socket head screws throughout, which in my view look great, are just the right size, are available in quantity at sensible money, and would save me a great deal of work!


If I was making a modern engine I would use these screws, so as it's my engine, I'm going with Option 2, and the rivet counters can go whistle!

[millman]

Socket heads look fine to me, nuts and studs in stainless is a lot of work for little gain and at our time of life we have to get our priorities right. Very impressed with your progress so far.

[chris vine]

John Lennon painted his Rolls Royce pink. After all, it was his Rolls Royce.
On that basis, you can use whatever fasteners you like!
It will still look great and will be a precision made model.
You may have to test it on steam rather than compressed air: steam retains its pressure better than air as it expands so it will run much more smoothly on steam…
Chris

[simplyloco]

Dec 30, 2022 21:19:23 GMT chris vine said:

John Lennon painted his Rolls Royce pink. After all, it was his Rolls Royce.
On that basis, you can use whatever fasteners you like!
It will still look great and will be a precision made model.
You may have to test it on steam rather than compressed air: steam retains its pressure better than air as it expands so it will run much more smoothly on steam…
Chris

Hi Chris. Unlike my Major Beam, I have every intention of running this on steam. I recognise the fact that triple expansion engines don't like compressed air at all!
Happy New Year!
John

[mbrown]

Absolutely agreed that it's your engine and your choice - and the cap head screws do look very neat. However, the argument in favour of studs that tends to convince me is that you can go on removing and replacing the covers without wearing the tapped holes in the (expensive) castings. Dealing with a stripped thread would be distinctly challenging - whereas once studs are in, they can stay in for ages and be replaced if their threads eventually wear.

This may be a slightly academic point on most models, but after weeks of work on my cylinders, I decided to go for a plethora of 10 BA and 8 BA studs and nuts just to give me peace of mind.

But I can appreciate you not wanting all that faff!

Keep up this lovely work!

Malcolm