Chris's Holly Pumping Engine Build

[steam guy willy]

Hi this is all coming together really nicely,  lovely work...

Willy

[crueby]

Bearing block number three is fitted, one more to go:

After the last one is fitted, I can start notching them to take the bearing caps:

Still lots more shaping to do on these blocks - notching for the caps, drilling for the mounting bolts, taking them to width, and shaping the bosses on the sides, as well as boring the bearing holes through the whole assembly. The shop elves would go on strike, but its going to be a scorching hot day outside!

[RReid]

Continuing to impress, Chris! A time lapse video of that thing growing from the base up would be fun to watch. Not that you need anything else to do!

[cnr6400]

 

[crueby]

Continuing to impress, Chris! A time lapse video of that thing growing from the base up would be fun to watch. Not that you need anything else to do!

Darn, the camera on my wayback machine is broke!   

Neat idea - wish I had done that from the start, take pictures from a fixed point throughout. I did that on some boatbuilding projects years ago, though never animated them together.

This morning I have been playing in Fusion, doing some more on the Allis engine plans, converting them to a CAD model like I did for the Holly. Long term background project! So far have the foundation blocks/bolts, and the lower pump valve chambers. This eninge has a very different pump arrangement, one intake on the left, one outlet on the right, rather than two inlets/two outlets, and just one set of check valves per side rather than two. About the same volume of water delivered at the end.

[crueby]

Got the last bearing block slotted to fit over the side rails. Here they all are, with the centerline of the crankshaft measured out and marked in:

Started laying out the notches for the bearing block caps...

The center sits down 1/4" into the bearing block, then later the ends of the block get shaped down into curves leading to the bed rails. First things first though, getting the caps fit to the blocks then drilling the mounting holes, which go all the way through the caps, blocks, and frame rails. That will hold everything secure for the bearing hole drilling/boring steps - those holes are centered on the bottom of the caps, and do go into the side rails a ways too.

[cnr6400]

 

[crueby]

So today started notching in the tops of the bearing blocks for the caps. So satisfying when it snicks into place!

and one down

and a two

[RReid]

So satisfying when it snicks into place!

Few things are better than a good snick.

[crueby]

And the last two are fitted in (snick snick)

so started on drilling the bolt holes through the bearing blocks and engine beds, using each cap as a drill guide. Took some careful measurements to get the cap centered on the side rails properly, the sides of the bearing blocks will be trimmed in later. I dropped in some cap screws in the holes as I went to ensure the cap did not move while drilling the rest of the holes.


One cap down, three to go...

[Kim]

Very nice progress, Chris!

On those bearing blocks, I don't remember seeing that big chunk hanging over the bed plate.  Does it?  Or will it be trimmed back eventually?

Kim 

[crueby]

Hi Kim,
Those blocks still need a lot of shaping. Right now, they stick out like the red outline in this:



They will be trimmed back flush with the rails at the outside and just stick out in the center like the blue arrow is pointing at. The width of the cap is the final width of that center protrusion, the stock the blocks were cut from is a little wider than the cap still, and a lot wider than the side rails of the bed. The notches I cut in the side rail kept the stock on the sides of the bearing blocks thicker, and prevented any feather edges from forming as I trim them back to final shape.
On the top of the bearing blocks, they will also be trimmed back in a curve under the cap to blend with the top of the bed.

[Don1966]

I am interested to see if you line bore these or just bore them one at a time. Are if you will leave play for alignment purposes if you bore one at a time. . I noticed a split shaft arrangement if I am correct. You are one metal carving machinist I can say that much about as good at it as your wood carving. Always great work Chris….


 
Don

[crueby]

I am interested to see if you line bore these or just bore them one at a time. Are if you will leave play for alignment purposes if you bore one at a time. . I noticed a split shaft arrangement if I am correct. You are one metal carving machinist I can say that much about as good at it as your wood carving. Always great work Chris….


 
Don

Hi Don,


There's no way to line bore all four at once, since the outside end bed rails come up above the centerline of the crankshaft. I could line bore the center pair, but I don't have a setup or tools for that anyway, and the other two need to be done one at a time. Plus, there is just enough tolerance stackup in the lower frames, with 21 parts, that I can't just clamp up the bearing blocks, even ignoring the fact that the top of the siderails need to be part of the bore. The bed frames and bearing blocks add up to 3.25" wide which is too long for normal boring head tool.

So, long-winded way of saying that I need to bore them separately!  The other day I sketched out a jig to use on the center bed frame, to get those two holes aligned, will show that when I make it. Then, will make a pair of tube guides to fit those bores and hold a long drill or point to mark the outer two bearing blocks for boring.


May not come across in text well, but all fairly straightforward with a couple of jigs to do the alignment work. Stay tuned this coming week to see my thinking.


 

[Elam Works]

Given that the loading will not be that high, could you 'pot' the bearing shells or housing in something that would setup while all the bearings were held in alignment with a straight piece of ground shafting? Sort of a variation of pouring Babbit bearings in-suti using the shaft as the alignment tool. 

-Doug