Chris's Marion 91 Steam Shovel

[Don1966]

Awesome Chris just awesome!


 
Don

[crueby]

Thanks Don!
One quick update for today, started in on trimming the top half of the track plates to size using the holding jig. Squared up the vise carefully on the mill, and clamped the jig in place. After a couple of trial cuts to get the left/right positions set on the table, started pumping the parts through to square up one of the long sides, then again to trim the other side to final width. Goes pretty quickly, just over an hour to do one side on the whole pile. One more batch to go, and I can rotate them 90 degrees into the narrow slot, and trim the short end to length (bar is 1.5", final dimension is 1.438"). That will all be done on one end since the sides of the raw bar were nice and square. After that, will start milling in the shape on the top surfaces, where it slopes down at the ends.

Yes, doing 80+ plates seems like a lot, but they go through each operation quickly - would be a lot longer if I did each plate to finished shape then started the next!

[crueby]

Got all the parts trimmed to width, have moved to trimming them to length, using the longer slot in the center of the jig (is slightly deeper than the wide one, so there are walls to hold the part in alignment on 3 sides). A couple more batches trimming off the end and I can start shaping the tapers on the top surface...

[crueby]

Next step is to taper the narrow ends. The holding jig was tilted up to 5.4 degrees using a protractor/ruler, and the depth set to take a .325 wide wedge off the top surface. Now its a quick pass back and forth, swap the part end for end, another pass, on to the next. So far I have about 2/3rds of them done, should have the rest in a couple more sessions today. Here is a picture of the setup, with a tapered part in the foreground to show where this is going. Its a subtle change, but will really improve the look, and make it match the originals.

[crueby]

All the tapers are done, and starting to round over the top edges on the ends, using a small (1/16" radius) rounding over end mill. Just removing enough to radius the edge, not taking it down completely flush on the ends of the arc. Quick pass on each end, on to the next. So far the holding jig is working perfectly, once I get the distances set on the first part, I can lock down the height and one direction on the table, and zip through the passes on each part (stopping the motor when changing, don't like to have fingers anywhere near that close to a moving cutter). A plate without the end cut done is sitting on the back of the vise to show the difference.

[zeeprogrammer]

 

[Ye-Ole Steam Dude]

Hi Chris,

I am curious, do you do an Over-cut or an Under-cut on the stainless and what RPM. You are making this sound fast and easy.

Have a great day,
Thomas

[crueby]

Hi Chris,

I am curious, do you do an Over-cut or an Under-cut on the stainless and what RPM. You are making this sound fast and easy.

Have a great day,
Thomas

I always prefer to do an undercut to remove the stock (if I have the term right, where the cutter comes up to the surface) and usually do a return cut (overcut, or climbing cut) without moving the depth, which gives a nice clean finish. This is 303 stainless, which is classed as a easy machining alloy like 360 brass is, with a tiny bit if lead in the mix. It cuts a lot like 12L14 steel, but doesn't rust like that stuff does.


 I don't know what the rpm is, have no scale, mainly go by sound and feel, its less than half max speed for sure, too fast and it gets too hot. These cuts are not that deep so they are going quick.  Some of the cuts later on the bottom halves will be removing a lot, and will likely be done in several shallower passes, staying within the limits of the small mill and nit wearing the cutter so fast.

[crueby]

 

[Ye-Ole Steam Dude]

Thanks Chris, I appreciate your help.

Thomas

[crueby]

Thanks Chris, I appreciate your help.

Thomas

Anytime!

[crueby]

And one more set of edges to round over, the long ones on the top. Reset the holding jig down flat from the 5.4 degree position it has been, and switched the part to sitting so the long edge is out. Reset the height and table position in a few tries, sneaking up on the sweet spot, locked it down, and started making passes there. Not taking a lot off, just enough to knock off the sharp edge. After this, next big step will be using a ball end mill to undercut the long edge so it fits over the hinges on the bottom half of the track segments.

[Steamer5]

Looking good Chris!
Every time I tune in it seems the space time continuum has been warped again!

Right onto load tracker.......hope that truck of  turns up soon!


Cheers Kerrin

[crueby]

Looking good Chris!
Every time I tune in it seems the space time continuum has been warped again!

Right onto load tracker.......hope that truck of  turns up soon!


Cheers Kerrin

 


Just looked back, only been a couple of days so far on the tracks. Not bad!  But, this has been the easy half so far, the bittom half of the track is the complex bit. The jig is working great, well worth making.

[Craig DeShong]

Great progress Chris.  You must be working those elves overtime.  Sure hope they don't unionize, might set you back a bit