Railroad Line Forums - Slater Creek Railway
Railroad Line Forums
Username:
Password:
Save Password


Register
Forgot Password?
  Home   Forums   Events Calendar   Sponsors   Support the RRLine   Guestbook   FAQ     Register
Active Topics | Active Polls | Resources | Members | Online Users | Live Chat | Avatar Legend | Search | Statistics
Photo Album | File Lister | File Library
[ Active Members: 2 | Anonymous Members: 0 | Guests: 181 ]  [ Total: 183 ]  [ Newest Member: mm0047 ]
 All Forums
 Model Railroad Forums
 Logging, Mining, & Narrow minded
 Slater Creek Railway
Previous Page
 New Topic |   New Poll New Poll |   Reply to Topic | 
Author Topic Next Topic: Nye, Inyo & Esmeralda Railroad
Page: of 88

Coaltrain
Fireman

Posted - 03/29/2021 :  10:46:21 AM  Show Profile  Reply with Quote
I wish I had more to report on, too busy finishing off the rest of the basement / train lounge.

The latest thing I am working for the Shay is the crankshaft. I have been dragging my feet a little because I was not exactly sure how I was going to do it. I purchased a couple PSC crank shafts to ruin, I mean experiment with.

The PSC crankshaft is the correct size but I needed to get a spur gear mounted to it. The spur gear has a 0.0625" bore and the PSC crank shaft has about a 0.080" bore. I could have attempted to drill out he spur gear but I would run the risk of it being off center, besides it did not solve the issue of mounting it. Brain Bond took a Bachmann shay crank shaft and spliced two together to make a 3 cylinder model, so I thought about using his method, but I didn't what the journals to be as big as there were going to be once I made brass bearings for them.

In the end I decided to cut the crank shaft up into pieces and take advantage of the resin prints ability to resist heat and make a solder fixture to reassemble the crank shaft.

The first step was to saw out all the areas were the crank shaft main journals were, leaving the rod journals intact. I then designed drill jigs to hold the pieces while hand drilled new shaft holes. Resin cuts really easy so to make the drill jigs stay accurate I lined the holes with brass rod, steel would have been better but these are not production jigs. The jigs worked great and I had perfect holes in every part.



here is the eccentric drill jig. one half of the jig holds the eccentric, guide pins keep it aligned.





the crank journal jig required two different ones because one of the three journals has and eccentric mounted to it. The crank jig has an ejection hole in one end so I can push the part out of the jig. these jigs are tight to keep alignment and without the ejection hole it would never come out. I piece of wood is used to keep the crank spread when drilling.



http://www.railroad-line.com/forum/data/coaltrain/2021329103737_SHAY 8-75.jpg



with all the pieces cut and drilled I now had to put them all together. I used a 0.0625" brass rod as the main shaft. I designed a fixture to support all the parts in places so the spacing and orientation is maintained. Resin parts do not melt with the soldering iron so I soldered the crankshaft together on the jig. I coated the shaft with TIX and used a 40W solder iron to quickly solder all parts and the universals to the shaft. For now I am leaving the shaft run through the crank journals so I can test the final assembled drive. Once the drive passes test I will saw out the shaft for the main rods, this way I will know if any rough running is caused buy the shaft being twisted or not.







what little moments I have away from the bench I have been final detailing the cab and tender. with any luck I am a week or so away from printing all those parts, then things will really start looking like something.




Country: | Posts: 1429 Go to Top of Page

jbvb
Fireman

Premium Member


Posted - 03/29/2021 :  12:51:26 PM  Show Profile  Visit jbvb's Homepage  Reply with Quote
I'm glad it's working out well. Is the PSC crankshaft cast in one piece, or individual cranks pressed onto shafts?

I'd have felt confident about drilling out the .0625" spur gear with any of my old machines: Walker-Turner drill press, Atlas lathe, Clausing/Atlas mill. The Dremel that came with my tiny drill press doesn't run true enough and I rarely use it. 'Wiggler' center finders are inexpensive & accurate, but without one, you can just watch how a drill in that diameter range bends when it touches the existing hole.


James

Country: USA | Posts: 6897 Go to Top of Page

Coaltrain
Fireman

Posted - 03/29/2021 :  1:53:56 PM  Show Profile  Reply with Quote
quote:
Originally posted by jbvb

Is the PSC crankshaft cast in one piece, or individual cranks pressed onto shafts?




no, you can see in one image the PSC part as delivered, cast one piece, that is why I ended up cutting it up and just changing the shaft size and not drilling out the gear. By reducing the shaft size it left more "meat" in the crank case to make the part stronger. If I kept the casting shaft diameter then the bearings would have been so big that the 3D printed crankcase would have had really thin walls.



Country: | Posts: 1429 Go to Top of Page

quarryman
Fireman



Posted - 03/29/2021 :  1:54:26 PM  Show Profile  Visit quarryman's Homepage  Reply with Quote
Jeff-

I thought your new layout space was off limits for the foreseeable future. Are you prepping the space?

Mark Chase
Richmond VA



Country: USA | Posts: 1208 Go to Top of Page

Coaltrain
Fireman

Posted - 03/29/2021 :  4:21:43 PM  Show Profile  Reply with Quote
quote:
Originally posted by quarryman

Jeff-

I thought your new layout space was off limits for the foreseeable future. Are you prepping the space?

my layout space is currently an efficiency apartment for my son. his plan is move out this summer but the house market is nuts and it may take longer than he thought, and I am not rushing him to make a stupid decision, trains are not that important. The space I am working on is the rest of the downstairs. I am adding a bathroom, a room for my wife to "do her thing", a bar area, and a TV area. The list makes it sound huge but it is all pretty modest, but it I wanted to have it all done because when my son moves out it will TRAIN TIME!!! I don't want any house projects to get in my way.

Mark Chase
Richmond VA




Country: | Posts: 1429 Go to Top of Page

CNE1899
Engine Wiper

Supporting Member


Posted - 03/31/2021 :  1:26:03 PM  Show Profile  Reply with Quote
Mark,
Been peeking at your thread now and then trying to catch up.
Very impressive! Love the 3D modeling, the jigs, problem solving, etc, of your modeling.

Scott



Country: | Posts: 290 Go to Top of Page

Coaltrain
Fireman

Posted - 04/06/2021 :  11:35:51 AM  Show Profile  Reply with Quote
a little more progress, the cab and tender are printed. next I will move on to assembly of all the parts, it should get more exciting soon.

the cab and the tender are two separate pieces, they have a tongue and grove seam that will keep them in alignment, screws hold the parts to the frame. the coal load will be a separate piece as well. these days like to make the coal load on my locomotives removable (just like a freight car) so I can access the decoder without removing the shell. I guess if I really wanted to be clever I could make more than one load so I could swap them out in different photos to show it in different stages of use, but for now I like to have access the the decoder.

One thing about a project like this is that you can sure learn a lot. I thought I pretty much new my way around a shay but this project showed me that there are interesting details lurking around in the shadows. for instance, I did not know about that small little U-pipe that you can see on the rear tender deck. The U-pipe is connected through the top of the tender deck to straight pipe that goes all the way through the tender and is bolted to the floor, where a steam water syphon is connected. The water syphon allows the shay to pull up to a stream, throw a hose in the water and fill the tender. The water is lifted with the steam pump and pushed up the vertical pipe inside the tender and then back around on the outside the tender, then back into the tender. this method allows the water to be filled to the top of the tender, which is important because shays do not carry much water








Country: | Posts: 1429 Go to Top of Page
Page: of 88 Topic Next Topic: Nye, Inyo & Esmeralda Railroad  
 New Topic |   New Poll New Poll |   Reply to Topic | 
Previous Page
Jump To:
Railroad Line Forums © 2000-2020 Railroad Line Co. Go To Top Of Page
Steam was generated in 0.64 seconds. Powered By: Snitz Forums 2000