Author Topic: Chris's Marion 91 Steam Shovel  (Read 573501 times)

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3465 on: March 18, 2019, 06:32:07 PM »
It's just as well that you enjoy this pastime then.... :Lol:
Oh yeah, glad my hobby is not sitting in waiting rooms or on jury duty!!   :paranoia:

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3466 on: March 18, 2019, 06:38:34 PM »
This morning I got a start on the big end bearings. Since these have to go on in the middle of the crankshaft rather than slipping onto the end like most of the others, making them as a two part bearing. Started with a short length of bearing bronze, and sawed it down the middle. Clamped in the three jaw (two jaws on one half, third on the other) it seemed to hold well, so went ahead and drilled/bored the end for the crank pin diameter (hoping for a snug fit that can be lapped to fit rather than a loose fit), and then turned the outside to be a snug fit in the con rod. The OD fit can be checked while on the lathe, the ID can only be done by measurement, so I will not be surprised if I have to remake one or two.

Then slipped on the conrod and used a small hacksaw to part off the bearing from the parent stock. A little filing on the side and it should be good to go. Here are first two:

I'll check the fit on the crankshaft, and if good will loctite the bearings in place, and then can lap them to final fit if needed (expecting that to be the case on most if not all of them). Only had time to get this far before heading out for errands, back at it this afternoon...

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3467 on: March 18, 2019, 09:28:25 PM »
Rest of the split bearings are made - on the last set I had to switch to the 4-jaw, since the halves kept slipping in the 3-jaw. It worked fine for the first 4 bearings, but the last two no go, so switched over and finished them up. Only one set was too large an ID, rest are just right or a hair snug, will lap in fine I think. So, went ahead and loctited them in place. I did not want to risk glueing the cap to the main part, so I used a bit of flat bar and a clamping rig, just slipped the parts over the end and tightened the cap screws to hold it to set up.

After they have set overnight, I'll file the edges flush and lap them to the crankshafts. The small end bearings will be simple tubes since they get held in place in the crossheads by a shoulder bolt through them.

Offline Don1966

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Re: Chris's Marion 91 Steam Shovel
« Reply #3468 on: March 18, 2019, 11:35:15 PM »
Still with you Dog keep it coming!.... :ThumbsUp:


  :popcornsmall:
Don



Offline Robert Hornby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3469 on: March 19, 2019, 12:12:47 AM »
Chris, I have been following your superb build with great interest and admiration. So many components (probably in the thousands  :headscratch:) with, when they all come together, a masterpiece worthy of inspection by the most critical engineer on this planet. Well done - and more to come.  :pinkelephant: :pinkelephant: :cheers: :cheers:
Robert
Age and treachery will always overcome youth and skill

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3470 on: March 19, 2019, 12:32:14 AM »
Many thanks guys, much appreciated!


Robert, the complete CAD model lists it at a little over 3000 parts, not counting a lot of the small nuts and bolts. I tried getting the shop elves to count the parts, but Guinness impedes counting...   :embarassed: 


Before the slew and crowd engines it was weighing in at 74 pounds, with 3 engines, boiler, and cab still to go. Very involved, but its been like a series of smaller models on a big theme, am enjoying it a lot!

Offline ddmckee54

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Re: Chris's Marion 91 Steam Shovel
« Reply #3471 on: March 19, 2019, 03:55:20 PM »
but Guinness impedes counting... 
Enough of that stuff and it's hard to remember that eleventy-twelve comes after eleventy-eleven.

Don

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3472 on: March 19, 2019, 07:10:17 PM »
but Guinness impedes counting... 
Enough of that stuff and it's hard to remember that eleventy-twelve comes after eleventy-eleven.

Don
:lolb:

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3473 on: March 19, 2019, 07:29:18 PM »
Not much shop time today - did get the first pair of bearings lapped to the crankshaft, but the loctite red I used did not hold well at all. Maybe I should have used the green retaining compound version? Parts were quite clean and dry, but surfaces are very smooth. Maybe roughen up the mating surfaces and try the retaining version next...

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3474 on: March 19, 2019, 08:23:18 PM »
Not much shop time today - did get the first pair of bearings lapped to the crankshaft, but the loctite red I used did not hold well at all. Maybe I should have used the green retaining compound version? Parts were quite clean and dry, but surfaces are very smooth. Maybe roughen up the mating surfaces and try the retaining version next...
Did some experimenting and settled on filing a couple of tiny wicking notches across the steel under the bearings, and silver soldered them in. The loctite sticks great to stainless and 1144, pops right off bearing bronze.

Offline gary.a.ayres

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Re: Chris's Marion 91 Steam Shovel
« Reply #3475 on: March 19, 2019, 10:01:53 PM »
Fine work on those bearings. I watch and learn.

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3476 on: March 19, 2019, 10:12:03 PM »
I am learning too, this is the smallest split bearing I have ever done, first without the overhanging lips on the sides of the conrod too. Might have been easier to make the whole conrod from bronze, may do that on the steering engine later, which is same design but 30% smaller. Glad I am building to this scale, any smaller would be tough!

Offline Steamer5

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Re: Chris's Marion 91 Steam Shovel
« Reply #3477 on: March 20, 2019, 05:19:17 AM »
GUINNESS!

You are on a slippy slop there sir!  :DrinkPint: :DrinkPint: you gotta get in the kitchen & get that cookie baking underway....& way more than one tray! If your elves get a taste for  :DrinkPint: you build will slow to that of the rest of us!

Keep up the good work, always fun check in & see what you, errr the elves...., are up to

Cheers Kerrin
Get excited and make something!

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3478 on: March 20, 2019, 05:55:00 PM »
GUINNESS!

You are on a slippy slop there sir!  :DrinkPint: :DrinkPint: you gotta get in the kitchen & get that cookie baking underway....& way more than one tray! If your elves get a taste for  :DrinkPint: you build will slow to that of the rest of us!

Keep up the good work, always fun check in & see what you, errr the elves...., are up to

Cheers Kerrin
Still have a stock of cookies in the freezer, no worries there! And the elves... I me I... am still busy in the playshop!

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3479 on: March 20, 2019, 05:57:46 PM »
Got the rest of the big end bearings lapped today, used some Timesaver compound on them, spinning by hand and tightening the bolts down a bit at a time, them finishing with the crankshaft in the chuck and spinning it faster before cleaning them out and oiling. Then made up the small end bearings, which are simple tubes pressed into the con rods. These will ride on shoulder bolts through the crossheads.

Looks like next up will be the crossheads themselves, made out of bronze...

 

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