Entablature Steam Pumping Engine

[Rivergypsy]

Just as a quick post, with a lot of help from Pete, we now have a photograph of the original engine. From the accomanying article, it turns out that George Gentry didn't actually design this engine, but instead produce drawings of an existing engine, thought to be unique and dating back to around 1830. The original engine, once restored, was shown at the London Model Engineering Exhibition in 1922, so if my plans hold up, then it'll debut there again 92 years after it's first visit ;D

 

[Rivergypsy]

JWCNC - Many thanks, and I'm glad you like it

 

[Rivergypsy]

Here's the latest progress - the lower plinth is well on the way now, with just some stainless inserts to set into the side pockets, and the trims for the box base are slowly getting fitted. They take a lot of fettling and testing to get right, but I'm loving the look of them against the teak ;D

 

[idahoan]

It’s looking real nice!

Have you started fettling the flywheel and pulley? After they had come off the mill it was hard for me to see how much hand work was left to do. I’m curious to see how they turn out.

Thanks for the update,

Dave

 

[Rivergypsy]

Thanks, Dave!

No, I haven't yet. I've been focussing on the bottom end of the engine, as once these parts are complete, then everything else I make can be fitted once and for all. I'm still aiming for completion by January, so it's all a bit manic at the moment!

It has to be said though, I have been doing some hacksaw and hand file work on the flywheel to remove the machining lugs ready to get it up in the interact next week for its finishing ops. It's been difficult to leave them alone lately, but as they're the last parts to be fitted in the assembly they can wait for a little longer...

I've managed to get a few more bits done today, luckily - there's the stainless inserts for the pockets around the lower plinth, the lower trims for the box (in need of much fettling!), and some brass M8 inserts for the lower plinth, which will allow a pair of bolts to be used to secure it inside a case for transit - there's no way I want this bouncing around inside a packing case

Thanks again,
Dave

 

[Rivergypsy]

And here's a bit more - the base with the first of the lower twims in place. And, compared to the upper trims, they are a very long winded job to fit, the slightest bit too much taken off in the wrong place makes a huges difference.

Btw, Dave - the flywheel is in the Interact starting its finishing, and I've broken out the needle files on the pulley

 

[Rivergypsy]

Finally!!! The flywheel ran on the CNC from Monday lunchtime until early Saturday am, so this morning it was ready for a quick hours skimming to true the OD, the bore, taper the hub, and radius the external ellipse - now on to the filing, papering and polishing
woohoo1woohoo1woohoo1

It has to be said also, that it's a damn sight easier to manage with 15kg of swarf removed *beer*

 

[idahoan]

Wow it sure looks nice Dave,

But really; the Interact ran for almost 5 days on this operation? or is this a typo?

After a few hours of fettling it is going to look as nice as the rest of the engine.

On the lower filler pieces for the base you commented that they were a challenge to fit; were these parts machined? I was just wondering what made them hard to fit into their spot?

Thanks for the update and I'm still enjoying your wonderful work.

Dave

 

[Rivergypsy]

Hi Dave,

Thanks - I'm very pleased with it too ;D

No, it's not a typo, but there's reasons behind it. Firstly, as it was running lights out I didn't want to come back in the next day to find a scrapper in the mill, so the feeds and speeds were wound right the way down to around 600rpm and 40mm/min, and I think it worked out to be nice and gentle on the cutter too, as the same TiCN coated two fluter did the whole of the roughing and finishing.

Secondly, we have only one full 3D Gibbs seat in the building, which unfortunately isn't on my computer. So whilst I can use it, for jobs that needs adjustment or tweaking I tend to use the 2.5D seat on my machine to save p*ssing off the user of the 3D seat, which by giving it the outlines and the 3D model, produces results that are good enough for hand finishing. But, the real downside with that is that you lose the full control over the profiling operations, so the cutter tends to spend a reasonable amount of time in fresh air... Still, it got there in the end!

Lol, just a few hours

With the trims, I'd got the corners mounted first, and then machined the convex and concave profiles milled as lengths. But to ensure a good fit to mate to the vagaries of my filing and polishing on the corners, each length of trim has been hand filed and fettled to the correct end profile to mate with the corners. It probably sounds like moaning, but they have to be filed very carefully and gently to try and ensure no gaps. Drives me nuts to be honest!

Thanks again,
Dave

 

[Rivergypsy]

Here's the latest progress - the feed pump lever is now pinned to it's shaft with a 1/16" tapered dowel, so that's up for final fitting tonight, and I've made a little more progress on the governor valve. We're getting there ;D

Finger's crossed that by tonight there should be a final build of the plinth, with the lower bedplate and pillars going on top of it for good...

 

[Sshire]

Hot stuff! That is one exquisite engine. Magnificent detailing. Bravo!!

 

[idahoan]

Beautiful as usual Dave!

Can you tell me a little about the construction of the governor valve? Was it drilled from each end or?

I'm surprised that more people don't comment on this amazing piece of craftsmanship?

Thanks for posting,

Dave

 

[Rivergypsy]

Stan - many thanks, and I'm glad you like it!

Dave - thanks again! The governor body was CNC'd from solid, working from two sides and leaving a boss on either side of where the valve shaft runs through. I drilled (very gingerly!) from either side until they met, and then gradually opened the bores up to 4mm - the last job on those bores is to re-drill using a 4mm ball nose cutter to clear the radius out, and thankfully these arrived today. To be totally honest, the only part of this I've modelled yet is the body, so I'm tending to develop the valve, etc on the fly

More progress last night too - I finally got the plinth finished, and was able to get it base of the engine assembled with the lower bedplate and pillars. It has to be said, the sight of this coming together is making all the hours of work worthwhile.woohoo1woohoo1woohoo1

Oh, and I've just finished another 21 of the square headed bolts before
near terminal boredom kicked in again :wall:

 

[jwcnc1911]

Wow! This is looking so good! And it has been looking good since 2001!

Just kidding, I guess I don't know a single soul who sets the date on their camera!

 

[Rivergypsy]

Lol, I didn't like to own up to this being such a long-term project, JW

Well, with the aim of showing this in January still in mind, I'm having a real push to try and get this done, and here's where we're up to -

The stand for the governor bell-crank is done and ready to fit, the cylinder cover is turned and semi-polished ready for drilling and finish boring, the lever for the governor valve is roughed out ready for radiussing and polishing, and I've worked out how to laser etch a Moore & Wright logo onto oak for a little parallel project to go with this

 

[Rivergypsy]

And some more ;D

Here's the milling for the governor bell crank, with a lot of fettling to do, plus the lever for the governor valve mounted, and the cylinder cover now drilled. Time to cool down under the air-con for a while, lol.

 

[jwcnc1911]

I'm curious... how many hours do you have in sanding and polishing? More than machining I'm sure.

Looking good!

 

[Rivergypsy]

Hi JW - now that's a question!! Sometimes more, sometimes less - I radiussed and polished the bell crank last night, and that took an hour compared to a couple of hours machining, so not too bad. Other parts, such as the crosshead, that have internal corners are a different story... Sometimes it's a pain, but when you've got the polished part sat in your hand it all becomes worthwhile!

 

[Rivergypsy]

And some more progress. Things have been a little delayed due to my partner having her appendix out, but here's where we are now - the base is closed up once and for all, with the governor bell crank inside, and finally the cylinder, piston, cover and crosshead are in place.

Things are a little tight at present, not due to any particular component, but just a general accumulation of friction, but better this way than too loose, and at least it'll bed in to a nice running fit.

Next job is the entablature bedplate, and then the upper motion can start to be assembled ;D

 

[Rivergypsy]

ps - and no, the allen bolts aren't staying, but better to use them and check fits until I get the real ones made, lol