Chris's Holly Pumping Engine Build

[gary.a.ayres]

Wow - it just keeps on coming!

[crueby]

That's a lot of frame pieces there, Chris!  And you get to do 2x the number of those end caps   

Pretty fun to watch you work

And hey - I just read my latest Live Steam mag (yeah, I'm a few weeks behind!) and really enjoyed your first Shop Elf Corner installment on nickel plating.   Great work on that too. Looking forward to reading more instalments of the shop elf corner

Kim

Probably good that you are running a little behind on reading your Live Steam issues, was talking with the editor and he mentioned that the next issue will be out slightly late, the design department got backed up and are running behind a little (they do a number of different magazines). No problems, just a little behind.

[Kim]

Good to know!  Now I have an excuse for my slow uptake on my periodicals!
Kim

[crueby]

This morning I finished broaching all the holes, so the inside corners are all square. Then started milling out the remaining chunk in the middle of the mortises. The tenons project out square to the base, at a compound angle to the rails, so the mortises are vertical, no compound angles to worry about with them.


The pads are all the same, top and bottom too, they just get flipped over for the different rail ends. Here are the first four pads with the mortises cut and fitted to the rails (just a couple swipes of the file needed in a couple places).

As you can see at the bottom of the photo, the tenons dont come all the way through the pads, yet. The pads will be cut thinner and narrower to final dimension, and they also get their top edges chamdfered, and holes drilled in the corners for the mounting screws. To fasten them all together, I am thinking that the joints will get some loctite and be cross pinned. Some epoxy putty will be used to form fillets in the inside corners to match the castings.
Here are the first two rails set in place on the base plates to give an idea of where its all going. There are a couple of the pads on the lower ones to keep them from tiping over, they almost balance upright but not quite!

Pads for two rails down, 10 more sets to go!

[cnr6400]

Looks like the engine designer has a leg to stand on, now!    

[crueby]

Looks like the engine designer has a leg to stand on, now!   

The elves have a pair of really tall crutches too!

[gary.a.ayres]

An engine is beginning to suggest itself...

 

[scc]

                Terry

[Kim]

Very neat, as always, Chris!

So, all this angled mortise & tenon joinery - is this how it was done in the original?  Or is this just how you're fabricating something that was cast as a single piece?

Kim

[crueby]

Very neat, as always, Chris!

So, all this angled mortise & tenon joinery - is this how it was done in the original?  Or is this just how you're fabricating something that was cast as a single piece?

Kim

On the original, the rails were hollow, and cast as one piece with the pads/tapers at the ends. Massive castings, just making and positioning the cores must have been a lot of work. Same with the base plates, those were one piece castings, according to the plans. Making the rails from one piece with the pads would have needed much larger bar stock, much wider and thicker, to get the pads and the angles shaped in - piecing it up for the model is much more practical for me.  The plans are a lot of fun to look through, they have notes on common patterns that made parts for different machines, where they just moved certain add-on bits of the mold.

[Kim]

Very neat, as always, Chris!

So, all this angled mortise & tenon joinery - is this how it was done in the original?  Or is this just how you're fabricating something that was cast as a single piece?

Kim

On the original, the rails were hollow, and cast as one piece with the pads/tapers at the ends. Massive castings, just making and positioning the cores must have been a lot of work. Same with the base plates, those were one piece castings, according to the plans. Making the rails from one piece with the pads would have needed much larger bar stock, much wider and thicker, to get the pads and the angles shaped in - piecing it up for the model is much more practical for me.  The plans are a lot of fun to look through, they have notes on common patterns that made parts for different machines, where they just moved certain add-on bits of the mold.

OK, that's kinda what I thought, but then I started getting lost in the pretty joinery and just had to ask.  Doesn't take anything away from the cool square-cornered mortises you're doing - that is super cool, as is the angled Tenon jig.   

The plans must be fascinating!  It is so great that you were able to get a set of the original plans! That must have been quite the thrill to get those!
Kim

[crueby]

Very neat, as always, Chris!

So, all this angled mortise & tenon joinery - is this how it was done in the original?  Or is this just how you're fabricating something that was cast as a single piece?

Kim

On the original, the rails were hollow, and cast as one piece with the pads/tapers at the ends. Massive castings, just making and positioning the cores must have been a lot of work. Same with the base plates, those were one piece castings, according to the plans. Making the rails from one piece with the pads would have needed much larger bar stock, much wider and thicker, to get the pads and the angles shaped in - piecing it up for the model is much more practical for me.  The plans are a lot of fun to look through, they have notes on common patterns that made parts for different machines, where they just moved certain add-on bits of the mold.

OK, that's kinda what I thought, but then I started getting lost in the pretty joinery and just had to ask.  Doesn't take anything away from the cool square-cornered mortises you're doing - that is super cool, as is the angled Tenon jig.   

The plans must be fascinating!  It is so great that you were able to get a set of the original plans! That must have been quite the thrill to get those!
Kim

I was stunned that he had found them in the building, and again that he let me have a copy of the scans - that is a very rare thing to get hold of. After the model is done, and assuming they get back to doing the annual tours, I'll have to take it over there for demos at the tour days, got to repay the favor!

[cnr6400]

For casting the original full size hollow frame cores, I would expect that many chaplets would be needed along each core to support them, both under the core and at the sides. The moulders probably used several individual cores to be able to make shorter ones, easier to lift and less prone to breakage. (and they would likely put Shaky the jittery handed moulder on pattern cleaning or counting flasks, the day they were moulding frames.) 

Chaplets are still available in many shapes and sizes. Link to one local firm carrying them is below. You can often see the residual imprint of one face of the chaplet where it didn't melt right into the casting if you look at big or long castings on old engines.

http://smelko.com/?page_id=395

 

[crueby]

For casting the original full size hollow frame cores, I would expect that many chaplets would be needed along each core to support them, both under the core and at the sides. The moulders probably used several individual cores to be able to make shorter ones, easier to lift and less prone to breakage. (and they would likely put Shaky the jittery handed moulder on pattern cleaning or counting flasks, the day they were moulding frames.) 

Chaplets are still available in many shapes and sizes. Link to one local firm carrying them is below. You can often see the residual imprint of one face of the chaplet where it didn't melt right into the casting if you look at big or long castings on old engines.

http://smelko.com/?page_id=395

 

What is a chaplet and how is it used? Never heard that term before. Chiclet, yes, Chaplet, no.   

[steamer]

This is going to be an epic build!
 
Dave