Chris's Marion 91 Steam Shovel

[crueby]

This gets better every post!   I cannot comprehend the speed of progress.   I MUST get some elves



Well Done Chris

Helpful shop elves are a must. It takes a lot of time and cookies to convert shop gnomes to shop elves, but its worth it!


 

You have to be careful the gnome layer is always there and if you don't watch close and keep there training up (and the cookies and treat plentiful), they revert quickly.

Gerald.

PS The quality control on the cookies is very important, Thus most of us who have Elves tend to be on the portly side, and you have a tendency to have a beard.

True on all counts! 

[Firebird]

Hi Chris

Ok I need a couple of shop elves

Where do I find them

How do I catch them

 

Cheers

Rich

[crueby]

Hi Chris

Ok I need a couple of shop elves

Where do I find them

How do I catch them

 

Cheers

Rich

The trick is to convert your existing shop gnomes, who steal parts and tools, into helpful shop elves. Start leaving out plates of mint chocolate chip cookies to draw them out, some shiny bearings as bribes maybe... 

[crueby]

... been doing some measuring and sketching on the valve rod area, think the best approach is to hang a guide bar off the end of the steam chest with a slider attached to the clevis bolt, like how a lot of locomotive engines do it. Will draw it up in fusion and post pics later today... This way the guide moves with the steam chest when disassembling rather than more screws buried between parts attached to the floor.

[Admiral_dk]

At this point it is slightly annoying to discover that you didn't spot the guidebar earlier - but compared to the bad feelings that it would have provoked much later, after something had happened ….. I'm sure you're glad to have to correct it now 

Great build as usual from you 

[Roger B]

Every time I look in there is so much more to see    Is that a Proxxon drill your Elf is using a few pages back?

[crueby]

At this point it is slightly annoying to discover that you didn't spot the guidebar earlier - but compared to the bad feelings that it would have provoked much later, after something had happened ….. I'm sure you're glad to have to correct it now 

Great build as usual from you 

Yeah, even knowing now that there should be some kind of guide, its really hard to spot in the phitos, dim lighting, lots of overlapping parts all covered in diet. I will put up a pic of it in a little while, hard to spot even in person. Wish I could get in there at will but glad to have any access!

[crueby]

Every time I look in there is so much more to see  Is that a Proxxon drill your Elf is using a few pages back?

Yes, thats the proxxon drill press, handy for little stuff, stalls on larger drills in metal but great for small parts and wood. I got it years ago for the ship model work. Comes in handy for drilling holes in the floor plates, it can go to the model, and can swing the headstock over to the side to get over other parts.

[crueby]

Okay, just to record the locations (partly for my own reference later), here are some shots of that valve slider area.
This is looking from behind the engine (am standing at the boiler smokebox), looking at the right side hoist engine cylinder. The cylinder itself is at the upper right, behind the lube pump. Looks like the valve rod slider is in a housing coming off the back of the slew gear upright, which is at the upper center and left. The housing goes behind the lube pump, which is driven from that lever in the center just to the right of the word "slider".

Here is another view of the same thing, taken from over the top of the slew drum. Just a little bit of stuff packed in! The stuff on the right half is the slew engine crankshaft housing, that is one of the con rods for it just under the word 'slew'. The valve rod slider is just visible on the left, the valve rod gland is between the words 'slider' and 'stephenson', well, at least the top adjusting nut is!


Then I was wondering why I did not see it on the left hand cylinder. Well, that has the large slew gear in the way!

They did not waste much space! just to get from one side to the other you have to climb over the slew engine and the backstay rod (which supports the main A-frame at the turntable). 105 tons in a 50 ton box! 
So, on to start up Fusion and design up a slider/holder for the end of the valve rod. I thought originally it didnt need one, but I was used to engines with a very long stephenson link which minimizes the rocking movement of the link. As Admiral-DK said, glad I found it know rather than after running at speed and having something bind and bend!

[crueby]

Okay, a little playing in Fusion, and the slider support arm bits are laid out. I will bolt it to the back of the steam chest base, and the screw through the clevis at the reverzse link will hold the clevis to the slider. The slider has a wider flange at the back of the support arm to keep it from moving horizontally. Should do the trick, basically a mini crosshead trunk. The new parts are the darker solid grey ones, the existing parts are the mottled gray ones. Well, except for the stephenson link, that is also darker gray. Whoops. 

The bolts to hold it to the steam chest base are offset from the center of the arm, this is since the steam chest bolts are partway into the base right there, and this avoids them. I cannot put a bolt in the center area, or it would go into the steam passage to the cylinder. These positions should miss everything, and everything looks to clear the other parts of the gear train. The control arm for the reverse link is not shown, that goes on the near side, up from the floor to the horizontal bolt at the top of the reverse link.
So, that is the next couple parts to make! Simple shapes so should not take the elves long to knock out the pair of them. They also need to start making a bunch of elbows for all the steam piping... I better thaw out some more cookies!

[Don1966]

That’s some cool shit Dog, but I am curious about the slew engine. That will be a real nice fabrication work to make it. Not that you can’t handle it mind you just that it will be some interesting work......


 
Don

[crueby]

That’s some cool shit Dog, but I am curious about the slew engine. That will be a real nice fabrication work to make it. Not that you can’t handle it mind you just that it will be some interesting work......


 
Don

Oh yeah, the slew engine is a real doosy - it has a number of neat features, like the D-valves are double-layered with 4 ports in the valve face, and there is a center valve that is both throttle and reverse/forward, so there is only one eccentric per cylinder. Fortunately I found the original patent for it, which included a whole series of cross section drawings for all the internal parts and steam/exhaust passages. It does the reversing by swapping which passages are used for the steam and exhaust. I was able to piece up in 3D where all the passages went, and came up with a slightly simplified version that uses another d-valve in the center for the throttle rather than the original spool valve. Its going to be quite interesting to make - I need to make two, one for slew, one for crowd, identical, then one more at 1/3rd smaller size for the steering engine. I have never seen this valving used on any other manufacturers engine, Marion developed it and used it for years. It has fewer moving parts than a standard engine, and is more compact, but it did require some seriously complex sand casting patterns.

The two longer valve rods on top are linked to the eccentrics, and the center shorter rod is the throttle/reverse/fwd control rod.

More to come on this in coming weeks!

[Don1966]

Cool Chris my mind is already thinking on how to go about it very interesting and intricate work.....

 
Don

[crueby]

Cool Chris my mind is already thinking on how to go about it very interesting and intricate work.....

 
Don

I picked up a selection of the 1144 stressproof steel, figure it will be a good time to try it out, at minimum for the crankshaft.

[10KPete]

1144 responds differently than, say, 12L, in that it seems to say 'open' much longer than 12L. It doesn't seem to 'smear' and produce the shine as soon as 12L..

I've found that if I leave an extra thou or two, at the most, for a final polish I can hit the dimension and get that nice finish.

Sorta like removing the fuzzies or something. Can't really feel it either....

 

Pete