Chris's Marion 91 Steam Shovel

[Steamer5]

Hi Chris,
 Oh those shots of the inside look great! You better try & limit the elves cookie consumption, hot pipes on cookie filled belly’s wouldn’t be fun! 

Right I used standard black orings, last time I checked them they were fine...... I guess I better have a look as it’s been awhile since last check!

 Cheers Kerrin

[crueby]

Got the rest of the pipe connections made to the boiler today, also made up the ash grate dump handles that sit behind the boiler:

With the boiler wrapping up, time to start prepping for the steering engine. It will be made from 1144 stressproof steel like the crowd/slew engines were.

[crueby]

This morning I was doing some work on the display/transport base for the Marion when the 3D printed version of the steering engine arrived that I had ordered from Jawstech, figuring that it would be handy to have a reference while machining the real one out of steel.

Oh, my, but this is a small engine! It is 30% smaller than the crowd/slew engines, with the same basic design, sitting on a vertical stand so it can stand in one of the doorways behind the boiler. Here it is for comparison to the crowd engine:


With a ruler for size:

Cute little thing:

This is going to be a very interesting build - I may need to hire in George Britnell for this one. Double-acting slide valve engine with internal reversing valve and double-layer d-valves, all the palm of a hand...  Think I may dub this one the MarionTiny!

[Don1966]

Interesting Dog the size but hey bud not a big step since you have handled everything with ease so far. And did I say .........I.............like............




 
Don

[90LX_Notch]

You can do it Chris.  You have the right machines for going smaller.

FWIW: Small is a relative term. 

-Bob

[Steamer5]

Oh now that is cute!

It’s looking like the next generation elves have got a starter project! I’m sure the head elf will help to keep them on the right track!
Looking forward to the build......

Cheers Kerrin

[RonGinger]

I don't want to steer you off into a new track, but at this point I would have to fire the boiler and run all that is finished. Steering would be nice, but to watch all the rest of that machine work will be great. It would take to much discipline to keep me building when that close to a major run. 

[crueby]

I don't want to steer you off into a new track, but at this point I would have to fire the boiler and run all that is finished. Steering would be nice, but to watch all the rest of that machine work will be great. It would take to much discipline to keep me building when that close to a major run. 

I can (and do) play with it off the compressor at this point. Running the boiler means taking it outside, and I am still making the base for it. The model is too big, bulky, and heavy to just tuck it under my arm and walk through doorways... The display base will have bolt on handles and frames to lock around the tracks, but will still require two people to move. So, that is helping rein in the desire to run right away!

[crueby]

Oh now that is cute!

It’s looking like the next generation elves have got a starter project! I’m sure the head elf will help to keep them on the right track!
Looking forward to the build......

Cheers Kerrin

The elves have been studying the printed mockups, and have put in a design change request, to thicken the crank webs a bit. I agree with them, seeing it in printed form, the webs are too thin and may flex, so I will tweak the design to thicken them, which will require widening the crank bay on thw base the same amount. Also, the pockets that were broached in on the larger engines will be milled through from the outside and covered with thin sheet on this one, same end result in shape.

[crueby]

You can do it Chris.  You have the right machines for going smaller.

FWIW: Small is a relative term. 

-Bob

Thanks Bob, the Sherline is a good fit for this one, if not Bill can help with that nice little lathe he got last year...!

[90LX_Notch]

One bit of advice- use quality sharp tools if you are going really small.  Sharp equals less pressure on a dainty tool which in turn helps reduce breakage.  Clear chips regularly.  Make sure tools are running true in the spindle of the mill.

-Bob

[crueby]

One bit of advice- use quality sharp tools if you are going really small.  Sharp equals less pressure on a dainty tool which in turn helps reduce breakage.  Clear chips regularly.  Make sure tools are running true in the spindle of the mill.

-Bob

Good tip - most if not all of the crankshaft will be done with the parting tool with the part between centers, will need to sharpen that frequently especially. Things like the valve ports will need to be done with the micro (dental bur type) cutters, can't sharpen those but they come in packs of 5 so will use fresh ones.

Thanks!
 

[crueby]

Just finished making the changes to thicken the crank webs up a bit, went to update the plans and saw that I had never gotten around to adding all the dimensions to those sheets.... So, I know what I am doing today...

[cnr6400]

Hi Chris, I wondered whether the broach tool would be adaptable to the smaller engine as soon as I saw your 3D printed model pic. Through the side on the smaller one will likely be far less involved. Good luck with the detail dimensions today. Hope the elves don't get miffed about the thicker webs. Must be an eye-straining job sharpening all those tiny cold chisels every day while they hand carve out a crank from solid ....

[crueby]

Hi Chris, I wondered whether the broach tool would be adaptable to the smaller engine as soon as I saw your 3D printed model pic. Through the side on the smaller one will likely be far less involved. Good luck with the detail dimensions today. Hope the elves don't get miffed about the thicker webs. Must be an eye-straining job sharpening all those tiny cold chisels every day while they hand carve out a crank from solid ....

The side of the recess is so thin that it will be quicker to just cut through and cover it with some shim stock, though the broach setup would work as well.
The elves got hold of my credit card and started sending the chisels out to Sharpen-While-U-Wait till I saw the next bill....      Lazy little swarf-heads!