Chris's Holly Pumping Engine Build

[crueby]

Yes....looks supurb  . ...

However I still believe the check valves in the upper plate are of different internal construction  to check valves in the lower plate

The lower check valves open under vacuum, an admit water to the volunetric capacity equalling the swept volume of the water piston

So, could the upper plate check valves be bi-directioal? ........[free floating ball]......which would fall under vacuum of the suction stroke, and also allow water to enter the air chamber, but this is limited in water height by the stroke/volume of the water piston

Then, during the pressure stroke the lower check valve closes, and the bi-directional upper check valve also closes so sending the pressurized water on its merry way, leaving the water [level previously explained] trapped in the air chamber?
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The bi-directioanl check valves would look externally to be identical, but internally have different porting or the omission of a spring in the ball chamber....so is there anything hidden in those original drawings ?

Derek

You are over-thinking it - the valves are the same on upper and lower plate. Both operate under pressure differences between the upper and lower sides. When the suction is applied from the plunger on the upstroke, there is lower pressure between the plates, and higher pressure below the lower plate and above the upper plate. That will push the valve up on the lower plate and down on the upper plate. On the downstroke of the plunger, there is now higher pressure in the space between the plates, which pushes down on the lower valves and up on the upper valves, opening the upper/closing the lower. Also - key point here - there are springs on every valve to help close them.

This may help too - here is a picture of one of the 'beehives' of valves that I had described in an earlier post. Each beehive is covered with rows of valves, 15 in all. The hive is hollow, and sits above a hole in one of the plates.


Each valve look slike this. On the left is an exploded view, right is the assembled view.  The green part is a metal base, with openings for the water to flow through. Above that is a rubber gasket piece shown in purple. Above that is the valve plate in orange, that is held down by the spring above it. At the top is a post with adjusting nut, that post screws into the bottom base, and retains the spring/valve plate. The plate is free to slide on the post, but held down by the spring.




This arrangement works the same on top and bottom plates, the valve moved by the pressure differential during the pump strokes. Hope that helps?
  

[kvom]

So water passes between the purple and orange parts when open?

[crueby]

So water passes between the purple and orange parts when open?

Thats my understanding - the rubber piece, in purple, has the openings in it to let the water through, the orange plate is pushed up the post by the pressure. The pressure needed to open the valve could be adjusted by the nut above the spring - that was probably adjusted periodically as the rubber piece wore over time.

[crueby]

And more reassembled - got the lower frames back on with the flat plates on top. Those plates will hold the three large base plates for the engine proper, with the crankshaft and supports for the upper engine frames.

[cnr6400]

 

Great looking subassembly! 

[crueby]

Great looking subassembly! 

Thanks CNR, got to be the most involved base for an engine I have ever done!

[crueby]

Yesterday I got the big gate valves for the intake pipes designed and 3D printed, painted and installed this morning. Very important valves, since these pipes drew water from the lake, and were below the surface of the lake. There is a little building out in the lake where the intakes and initial screens/filters were. One thing I noticed on the real engine was that the shutoff wheels are not reachable from any of the catwalks, but they did have portable ladders scattered around that would reach them.


Speaking of catwalks, that is one of the next items to be made, the lowest platforms. These sit on top of the intake pipes between the pump chambers. There will be several other levels of catwalks higher up on the engine.

The railings are simple shapes, but I will need a lot of them, the upper catwalks have them too. Going to be yet another jig to make...  Also, I'm turning down the stock for the pump plungers, then will attach the blocks on top of them to take the connecting rods that go up to the crossheads. Pictures on that later.

[cnr6400]

Re the railings- the "joiner" or "connector" pieces look like three variations -
1. one hole vertical, one hole horizontal
2. one hole vertical, two holes horizontal at 180 deg  apart
3. one hole vertical, two holes horizontal at 90 deg apart

Might be a Shapeways bronze part job, with variations in the horiz hole pattern to make the 3 variants. 3D metal printing would allow a nice looking spherical joiner body, simulating a cast original shape (or whatever shape it was). Bronze would allow you to soft solder the railing rods (maybe they are brass wire or tube?)  to the joiners for a nice robust railing, against the pokey overscale fingers of observers, or to withstand elf gymnastics. 

The gate valves and operating gear look great! I wonder what the full size gate weighed, inside the existing valves?  probably close to a ton, or more. Glad they had a gear reduction and leadscrew to operate those!  Couple of    needed after a shift wrestling those valves.

 

[crueby]

Hi CNR,


Casting those connector pieces would cost a fortune given that I'll need dozens of them. More fun to set up a couple jigs to make them from brass bar stock anyway. The straight sections of the posts as well as the railings will be stainless rod. Some serious mass production of parts. And don't forget the bases, to attach to the floors.


Those gate valves must have been heavy, 36 inch diameter, and heavy enough to take the pressure.  The plans show the size and location, but no internal details. Either that page is missing or it was an off the shelf part from another maker. They made all the other valves, so maybe that page was just missing.

[cnr6400]

Hi Chris, I had not thought too much about costs with Shapeways. If you need lots of the connectors, yes it could get costly. Is the shape of the connectors spherical or jam-jar 'cylinder with shaped ends' shape? Either way not hard to make a batch from bar stock when all set up. Do you have a toolpost drill spindle accessory for the Sherline, or a Dremel mount bracket? this might speed things up by enabling the (eventually) horizontal holes to be cross-drilled while the bar / connector blank is still chucked. Just food for thought.

Now mind you with as many elves as you have in your shop, they may get through the cross drilling pretty quickly!       

[crueby]

Hi Chris, I had not thought too much about costs with Shapeways. If you need lots of the connectors, yes it could get costly. Is the shape of the connectors spherical or jam-jar 'cylinder with shaped ends' shape? Either way not hard to make a batch from bar stock when all set up. Do you have a toolpost drill spindle accessory for the Sherline, or a Dremel mount bracket? this might speed things up by enabling the (eventually) horizontal holes to be cross-drilled while the bar / connector blank is still chucked. Just food for thought.

Now mind you with as many elves as you have in your shop, they may get through the cross drilling pretty quickly!       

I don't have a toolpost drill setup, at least yet!  These post tops are a lot like chain link fence connectors are today, pipe fits in bottom and side holes of the fitting, a rounded top. Pretty simple shape to make. The way I have done cross holes on round rod in the past is to drill a hole on a block the size of the stock, then turn the block on its side and drill a second hole the size of the rail stock. Then can insert the bar for the fitting, use the block as a drill guide for the cross hole, no spot drilling or flat milling needed. Swap to the lathe, shape the end and part off. Repeat over and over. The parted off fittings can be chucked in the lathe to drill the blind bottom hole. Fiddly to make so many, but simple quick steps that the elves can do. With frequent cookie bribes!

[cnr6400]

    Sounds good Chris! Are you at making / buying 100 dozen cookies a week yet to keep production levels up?

[crueby]

  Sounds good Chris! Are you at making / buying 100 dozen cookies a week yet to keep production levels up?

Only 50 dozen... 

[crueby]

Started in on the pump plungers, turned from some stainless steel. The top of them tapers in, and will get a rectangular block attached that will have the long rods up to the crosshead attached at each corner. Waiting on some bar stock for those blocks, so after this will skip over to making the jigs for the railing posts.


The three plungers set in place in the pump chambers - each chamber has an o-ring in a shallow groove at the top, with a compressing rin bolted down over it. Tightening the bolts will squeeze the rings if needed to expand them, they are a good sliding fit with the rings just tight enough to hold them like a piston ring groove.

As I recall, the throw on the pistons is about 2", so these plungers will have that much travel.

[MJM460]

Hi Chris, it might be a very complex base plate, but at least when you finish the engine, you won’t have to wonder what to drive with it in order to put it to work.

Do you know by any chance the diameter of the intake and how far the pipe goes out into the lake?  The “Y” fitting that branches to the headers each side of the engine looks like all three flanges are equal size, but there may be a reducer from say a 48 inch inlet line.

MJM460