Chris's Marion 91 Steam Shovel

[Elam Works]

The Stanley stuff ought to be split off into a separate post. Until then here is an idea, why not just spilt the cylinders laterally (see attached)?

These 3D printings were some 1/4 scale proof of concept(s) that I did a few years back. Yes, everyone has an idea of doing a scale Stanley engine! The idea was the upper and lower half would be furnace brazed together. Perhaps with a little weight on the assembly in the furnace to get a tight (and the strongest) joint. It would require some potentially onerous lapping of the valve seat face after the fact, but on the positive side would make machining the steam passages easier. At that time, I created four registration pins in the corners of the valve chest, which you can see in the parts at the top of the image. But since then I think a better way would be to leave the cylinder bores solid and plant the registration pins (which could be large and further from the center) in that area. They would be drilled away when the cylinders were punched through. Perhaps ball milling a gutter down each side just in from the finished bore so the flux and spelter would have a place to ooze into, and relieving the center so the joint lay tight where the spelter would be. That way the upper half would not float on a entrapped area of flux. Could whip up a screen shot if that is not clear.

Models were based on several original engines that passed through the workshop for rebuilds. And yes, the commercial available plans are not 100% correct, but more of a 'stylized' 20hp engine mostly based on the 735/740 series. 1907 20hp cylinder on the left, and a 1913 20hp cylinder on the right (before they had truss rods from the cylinder block to the rear axle.)

-Doug

[Fix typo. 12Mar19. -Doug]
[Fix another typo. 17Jul19. -Doug]

[crueby]

Looks like a good start on the chests and covers for the shovel Chris.   

Don't forget to order your 45 gallon drum of Brasso! 

No brasso needed - they will be painted to match the steel parts! (sorry Don!)   

[crueby]

The Stanley stuff out to be split off into a separate post. Until then here is an idea, why not just spilt the cylinders laterally (see attached)?

These 3D printings were some 1/4 scale proof of concept(s) that I did a few years back. Yes, everyone has an idea of doing a scale Stanley engine! The idea was the upper and lower half would be furnace brazed together. Perhaps with a little weight on the assembly in the furnace to get a tight (and the strongest) joint. It would require some potentially onerous lapping of the valve seat face after the fact, but on the positive side would make machining the steam passages easier. At that time, I created four registration pins in the corners of the valve chest, which you can see in the parts at the top of the image. But since then I think a better way would be to leave the cylinder bores solid and plant the registration pins (which could be large and further from the center) in that area. They would be drilled away when the cylinders were punched through. Perhaps ball milling a gutter down each side just in from the finished bore so the flux and spelter would have a place to ooze into, and reliving the center so the joint lay tight where the spelter would be. That way the upper half would not float on a entrapped area of flux. Could whip up a screen shot if that is not clear.

Models were based on several original engines that passed through the workshop for rebuilds. And yes, the commercial available plans are not 100% correct, but more of a 'stylized' 20hp engine mostly based on the 735/740 series. 1907 20hp cylinder on the left, and a 1913 20hp cylinder on the right (before they had truss rods from the cylinder block to the rear axle.)

-Doug

Hi Doug,
Those are some nice patterns, shows how complex the original parts were!  The drawings I have are not commercially available, got them from someone who was redrawing an old set from a museum collection. They were not taken from actual parts, and I have found some minor errors in them, but they appear to be pretty close. A friend of mine has an original engine in his collection, can use that for details if needed.
I am looking to make these parts from bar stock rather than castings, so that will influence the direction I take on making them - don't have any foundry resources or skills myself, do have the equipment for silver soldering and small lathe/mill (sherline). Splitting the whole cylinders off as their own pieces would allow me to turn the bores on the lathe, which would help a lot.

As you show, ideally they would be cast and machined like the originals, but that is beyond what I am able to accomplish. They must have had some interesting setups for lapping the valve faces, yet another factory to visit if we can ever get that time machine working!
Thanks for the pics, and keep the ideas coming! Later on this year I'll start up a thread on the Stanley build, for now its definitely on the back burner. Actually on one of them, there are always a few background projects here!
 

[Elam Works]

I don't have a foundry but I do have a CNC mill, so my thought was to surface mill the two halves from billet. The inner features are sort of prismatic, so not too much difference between the end results whether one manual or CNC machined them. The steam ports would likely be simplified into an orthogonal s-bend where as with CNC it could be a nice curve closer to the original; but the differences would not be too great. Externally though, it would be a tedious bit of nibbling away to sculpt it on manual machinery. Not impossible, as various model engine build blogs using that approach have shown, but it would consume a lot of time.

The commercial drawings I was thinking of were the full size set published by the Stanley Museum in Kingfield, Maine.

The valve faces can be cut with a single point tool in  a shaper, just. Some sort of lapping to smooth out the planning marks was likely done.

They were an incredibly light engine for the time; perhaps a little too light and the rod frame is about as rigid as wet pasta and prone to breaking. Some of the design details were really bad engineering practice. I mean, even things the Victorians already knew not to do! They were constantly evolving as things broke, and seemly changed about every fifth engine. There are innumerable detail variants. Some of these can make modeling easier, or conversely more challenging.

-Doug

[gary.a.ayres]

Chris - how big will the Stanley car be?

gary

I do have a set of plans for a small car, but the main project is a scale engine only. The boiler style for a Stanley is quite different, not that suitable for a model. I am more interested in the engine, not sure yet how big it will be, maybe in the 1:4 scale range.

I was kind of hoping you would say you were going to build a full-sized car!   

[crueby]

Chris - how big will the Stanley car be?

gary

I do have a set of plans for a small car, but the main project is a scale engine only. The boiler style for a Stanley is quite different, not that suitable for a model. I am more interested in the engine, not sure yet how big it will be, maybe in the 1:4 scale range.

I was kind of hoping you would say you were going to build a full-sized car!   

I am leaving that to Ye Old Steam Dude over on his thread!!

[crueby]

I don't have a foundry but I do have a CNC mill, so my thought was to surface mill the two halves from billet. The inner features are sort of prismatic, so not too much difference between the end results whether one manual or CNC machined them. The steam ports would likely be simplified into an orthogonal s-bend where as with CNC it could be a nice curve closer to the original; but the differences would not be too great. Externally though, it would be a tedious bit of nibbling away to sculpt it on manual machinery. Not impossible, as various model engine build blogs using that approach have shown, but it would consume a lot of time.

The commercial drawings I was thinking of were the full size set published by the Stanley Museum in Kingfield, Maine.

The valve faces can be cut with a single point tool in  a shaper, just. Some sort of lapping to smooth out the planning marks was likely done.

They were an incredibly light engine for the time; perhaps a little too light and the rod frame is about as rigid as wet pasta and prone to breaking. Some of the design details were really bad engineering practice. I mean, even things the Victorians already knew not to do! They were constantly evolving as things broke, and seemly changed about every fifth engine. There are innumerable detail variants. Some of these can make modeling easier, or conversely more challenging.

-Doug

They did have a number of variants, got hold of drawings for their spool valve version, don't think they sold any of those.

[crueby]

Got out the rectangular drill  and cut out the center of the steam chest blanks... 


The inside corners will need to be filed square...

[Ye-Ole Steam Dude]

Hello Chris,

I might have ask you this question before, but when you are milling Brass do you over cut or under cut? All you milling looks so clean.

Have a great day,
Thomas

[crueby]

Hello Chris,

I might have ask you this question before, but when you are milling Brass do you over cut or under cut? All you milling looks so clean.

Have a great day,
Thomas

Some of each. These cuts were with a new cutter so nice and crisp. Also, recently stumbled into a sale on Butterfield Union cobalt mills for about $5 each, they cut wonderfully. I normally use undercut, but do final pass at same depth overcut which leaves nice finish. On some steels the undercut direction often embeds chips around the back after the cutter goes by and the final overcut takes that off.


Its usually the end cuts taking a flat surface down that leaves the most toolmarks.


Oh, and these steam chests are in stress relieved brass, which for whatever reason cuts smoother. I have mentioned before about baking the 360 brass at 500F for an hour to stress relieve to prevent warping when taking material iff the sides.

[cnr6400]

Great work with the rectangular drill Chris. I like Butterfield cutters as well. Side note - I have some Butterfield taps in my toolbox that my Grandfather bought for the garage in the 1940's-1950's, possibly 1930's even, that still cut steel beautifully. No idea how many thousand holes they have tapped or at least chased out, on all manner of automotive junk. I've kept them as they are rarely used oddball threads. One is a left handed 1/2" British Parallel Pipe thread for example. More than once some odd piece of machinery will arrive for a repair at my shop, and sure enough there will be a tap from Gramps' Butterfield collection that fits a thread on it!

[Roger B]

As ever struggling to keep up with your rate of progress, looks amazing     

[crueby]

Little more done this afternoon, between projects for our boat group. Got the rest of the steam chests milled out in the center, and the overhangs milled into three of the sides. The last side gets the bosses for the valve and throttle rods, want to do some measuring on the o-rings before I shape those in.

And started drilling for the mounting holes around the rim of the chests and lids:

[scc]

Hi Chris,  Just received my April copy of "Old Glory"   There is an article on "The Granite Rock Co" and a great picture taken in 1911 of a Marion model 50 steam shovel working in Logan Quarry. You probably have the picture in your archive anyway, but it was good to see.
Terry

[scc]

Just reading the article and it seems they operated a 1 1/4 yard model 20 prior to the model 50.                Terry