Author Topic: Chris's Marion 91 Steam Shovel  (Read 290548 times)

Offline Farmboy

  • Full Member
  • ****
  • Posts: 118
  • England
Re: Chris's Marion 91 Steam Shovel
« Reply #585 on: January 25, 2018, 09:53:31 PM »
Interesting bit of fabrication on those dipper booms. I'm glad you're making good progress as usual because I'm anxious to see how the dipper is located in the main jib so that it can slide and swivel while maintaining good contact between rack and pinion  :thinking:

No rush, because I like to try to imagine how I would do it, then see if I was right  :noidea:

Mike

P.S.  Actually, I think I've worked it out except for some details
« Last Edit: January 25, 2018, 10:08:45 PM by Farmboy »

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #586 on: January 25, 2018, 10:23:31 PM »
Interesting bit of fabrication on those dipper booms. I'm glad you're making good progress as usual because I'm anxious to see how the dipper is located in the main jib so that it can slide and swivel while maintaining good contact between rack and pinion  :thinking:

No rush, because I like to try to imagine how I would do it, then see if I was right  :noidea:

Mike

P.S.  Actually, I think I've worked it out except for some details

This is the key part - it rides between the two sides of the dipper handle, with its top plate on top of the booms and the small gears engaging in the flat gear rack on the bottom of the booms. The axle through the gears extends out and holds the large gears you see on either side of the main boom (which is also made with two narrow side rails). That axle is held to the main booms with a pillow block. So, the dipper can pivot on that axle, and is driven in and out by the gears. The large gear is driven by a small gear on the crowd engine, located just below the large gear on the main boom.

Were you right?

 :cheers:

There are two green arrows - the upper one points at the top of the plate in the drawing above, the lower one to the axle on that same fitting.
« Last Edit: June 16, 2018, 08:53:25 PM by crueby »

Offline zeeprogrammer

  • Full Member
  • *****
  • Posts: 6372
  • West Chester, PA, USA
Re: Chris's Marion 91 Steam Shovel
« Reply #587 on: January 25, 2018, 10:50:34 PM »
Wow, what progress!

It's really interesting to see people develop models straight from the real thing.

At this rate, you'll be starting the Stanley this weekend. Right?  ;D

Enjoying the show!  :popcorn:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Farmboy

  • Full Member
  • ****
  • Posts: 118
  • England
Re: Chris's Marion 91 Steam Shovel
« Reply #588 on: January 26, 2018, 12:14:41 AM »
Well, I was close enough to deserve the :DrinkPint: I treated myself to after dinner, but I assumed there would be some sort of roller guides on the top of the boom instead of the sliding plate. I guess the weight of the dipper arm would be almost enough to keep the rack and pinion engaged, so there perhaps wasn't too much pressure on that plate  :shrug:

At first I thought the loading on that axle would be too great for it to be the pivot point, but then I realised most of the heavy lifting is handled by the chain and the main jib.


My late father worked for a year in the Ruston Bucyrus factory as part of his engineering degree course way back before WW2, on dragline excavators I believe. He taught me a fair bit about machinery maintenance at 1:1 scale, although his career was in civil engineering. I have great memories of helping him strip down a couple of tractor engines for a de-coke.

 :cheers:

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #589 on: January 26, 2018, 01:03:38 AM »
Wow, what progress!

It's really interesting to see people develop models straight from the real thing.

At this rate, you'll be starting the Stanley this weekend. Right?  ;D

Enjoying the show!  :popcorn:
Well, I've been looking at the plans for the engine, they are out on the back table. I also have plans from Germany for a model of the car, but cannot figure out some of the views. The engine plans were drawn from a full size engine, would need to scale them down a bit. Still an old favorite!

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #590 on: January 26, 2018, 01:07:55 AM »
Well, I was close enough to deserve the :DrinkPint: I treated myself to after dinner, but I assumed there would be some sort of roller guides on the top of the boom instead of the sliding plate. I guess the weight of the dipper arm would be almost enough to keep the rack and pinion engaged, so there perhaps wasn't too much pressure on that plate  :shrug:

At first I thought the loading on that axle would be too great for it to be the pivot point, but then I realised most of the heavy lifting is handled by the chain and the main jib.


My late father worked for a year in the Ruston Bucyrus factory as part of his engineering degree course way back before WW2, on dragline excavators I believe. He taught me a fair bit about machinery maintenance at 1:1 scale, although his career was in civil engineering. I have great memories of helping him strip down a couple of tractor engines for a de-coke.

 :cheers:
Seems like there would still be a lot of force on that axle, but as you say the chain on the bucket takes the worst of the load. There were some shovels that used rollers on that top plate, seen it in one of the patents, but Marion didn't put them on this model.

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #591 on: January 26, 2018, 03:46:44 PM »
Some more done on the dipper boom (depending where you are from, also known as the dipper stick, dipper arm, dip stick, etc - varied by region and country) parts. Laid out and drilled the holes for the bolts at the end which will secure the oak block spacer between the two arms.

Also milled up the oak block and drilled its matching holes, and cut some 5-40 threaded rod for the cross bolts. The lower forward end of the block is angled to match the end fitting. The block still needs to be trimmed back to length.

I am going to need to go into production mode for both rivets and the threaded rod/nuts for the rest of the boom. The cross bolts/rivets will be installed first, then will drill the holes for the vertical ones that attach the top/bottom rails.
But first, off to the dentist in a little while, had a crown on a back molar decide to attempt an escape, need to go get that glued back in - hope he is not reading this thread and decides to use rivets!   :Lol:
« Last Edit: June 16, 2018, 08:53:43 PM by crueby »

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #592 on: January 26, 2018, 09:15:13 PM »
The dentist went really quick, just a quick clean up and re-glue of the crown!   :cartwheel:

So, back in the shop, been doing version 87.5 of the flippers for the turtle sub (keep learning new things with the materials and having to change the design of the mechanism, will report on that once it settles down, looking promising this time).

Also, got started drilling the holes for the rivets in the side rails, good chance to test the machinist jacks that followed me home from LMS at the Cabin Fever show (along with some vises, etc).

As I mentioned before, the outer ends of the holes will be countersunk slightly to give the rivet heads a place to expand into while keeping the surface flush.

Also, my order from Midway showed up with the bottle of DuraBake Enamel matte black paint. This is a bake-cured paint, thin coating, intended for the gun market so it should be durable. Comes in a couple dozen colors, mainly earthtones and camo colors, couple reds/blues too. It normally needs a 15 minute bake at 350F, but will also work with a 3 hour bake at just 185F, which means that I could redo the bucket paint and not have to worry about the soft solder I used to fillet the inside corners - also, being paint rather than a chemical blackener, it works the same on whatever the metal is.
It is meant to be sprayed or airbrushed on, but I figured I'd give it a tough test and brush on a thin coat and see how it holds up - there are a lot of small parts coming where it would be a pain to have to set up/clean out the airbrush over and over and over, so if it works okay for brushing that will save time in the long run.
Rather than strip the bucket down for the test, I gave the bucket door a light brush-on coating. Seems to cover pretty well, dries to the touch in 10 minutes or so, no nasty smells despite the solvents it uses - typical paint smell, but no where near as bad a lacquers. After a 15 minute dry time, then hung the part in the oven at 350F (preheated), then left it to cool.
Here it is set on top of the bucket shell (which is still the original paint).

Seems to be a good hard surface, first test was rubbing hard on the sharp corner of the brass lid with a fingernail, left no marks at all - did the same on the lacquer the shell is painted with, and it scraped off a strip. So, first impression is quite good. As I've noticed with other paints, ones that are supposed to be matte when sprayed come out glossier when brushed on instead, but that is fine. It went on thin enough, and without runs, so the lever mechanism still works, may give that surface a rub with a abrasive pad to get quick motion back, though it may just need a little oil.

I'll give it some more handling time, and if no issues develop I'll strip the other paint off the bucket and coat that as well. Instructions say that if needed additional coats can be applied and the part baked again, that is probably going to happen on some parts. For the shell, I'll try spraying it on. I got it in a 4 ounce bottle, they also have a larger size, plus spray cans - most of the reviews and resellers warn of needing to replace the spray nozzle after a couple of uses though, so I'll stick with the liquid bottles, and make sure I clean the airbrush ASAP after spraying.

So far, looks like a very promising paint for parts being handled a lot.
« Last Edit: June 16, 2018, 08:53:52 PM by crueby »

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #593 on: January 26, 2018, 10:37:00 PM »
Got the first side beam drilled and countersunk both sides, going to need a lot of rivets!

« Last Edit: June 16, 2018, 08:54:02 PM by crueby »

Offline kvom

  • Full Member
  • ****
  • Posts: 1957
Re: Chris's Marion 91 Steam Shovel
« Reply #594 on: January 27, 2018, 02:25:37 AM »
You don't want it to look too pristine.  A working machine after all.   :popcorn:

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #595 on: January 27, 2018, 03:24:31 AM »
You don't want it to look too pristine.  A working machine after all.   :popcorn:
I agree - the brush marks give it some texture, but for large surfaces like the bucket shell the brush tends to leave thin streaks that are hard to fill properly, too much texture. The airbrush should work fine on those areas, hopefully this stuff cleans out well, otherwise its just brush work. It does seem to give a nice tough finish, much better than the normal paints do, seems to stick much better to the bare metal. True test will be all the handling/bumping/scraping it will get in the next weeks when assembling the rest of the dipper boom to it.

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #596 on: January 28, 2018, 05:58:11 PM »
The first dipper boom side has had its horizontal rivets installed - took a bit of experimenting on the first half dozen to narrow in on exactly how long to cut the rivets so they would come out nearly flush when peaned over into the countersunk holes in the beams. Once that was determined, cut a dozen or so at a time and installed them. Once they were all done, took it down to the carving/sanding booth (bank of muffin fans behind a furnace filter, with some plexi panels out front to help corral the dust) and used a small drum sander on the rotary tool to smooth off the rivets that were still a little high, then finished with a flat file. End result is a smooth set of faces that wont catch the main boom or the slider in the center. Same to do on the other dipper boom, then I can start on the top/bottom rails.

It may seem like a lot of work to get a rectangular bar, but I am trying to make as much as possible just like the original, and this way also keeps the bar straight and light. The outlines of the rivets should shadow through the paint, just like they do on the original as well.
« Last Edit: June 16, 2018, 08:54:16 PM by crueby »

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #597 on: January 28, 2018, 11:06:34 PM »
Second boom now riveted like the first, can now start on the top/bottom panels of the booms.... Running a bit low on that size round bar, had to order some more to be sure I have enough for the main booms, going through a lot of it.

« Last Edit: June 16, 2018, 08:54:23 PM by crueby »

Offline zeeprogrammer

  • Full Member
  • *****
  • Posts: 6372
  • West Chester, PA, USA
Re: Chris's Marion 91 Steam Shovel
« Reply #598 on: January 28, 2018, 11:21:11 PM »
Wow.

I'm beginning to understand the power of your cookies. Sugar = energy.
Is one of the ingredients caffeine as well?

What are the rivets made of?
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

  • Full Member
  • *****
  • Posts: 8684
  • Rochester NY
Re: Chris's Marion 91 Steam Shovel
« Reply #599 on: January 28, 2018, 11:38:58 PM »
Wow.

I'm beginning to understand the power of your cookies. Sugar = energy.
Is one of the ingredients caffeine as well?

What are the rivets made of?

No caffeine, just peppermint! 

The rivets are 303 stainless steel rod - definitely harder to pean over than brass rivets, but working quite well. There is about 1/32" sticking out above the surface either side at the start, and it winds up nearly flush when the tops are exapnded into the shallow countersink at each opening - several hits with the ball end of the hammer to expand them, do that both sides, followed by a few with the flat end of the hammer to draw it all tight.