Building the 2.5" Scale Shay

Where users can chronicle their builds. Start one thread and continue to add on to it.

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jcbrock
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Location: Oregon

Re: Building the 2.5" Scale Shay

Post by jcbrock » Mon Jul 27, 2020 11:00 am

Soot n' Cinders wrote:
Sun Jul 26, 2020 5:03 pm
One option I’ve considered is machining out the existing blocks and soldering in commercial bushings to be machined off into split bearings.
Interesting idea Tristan. This would be by far the easiest/cheapest solution, so it probably won't work.
John Brock

Soot n' Cinders
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Re: Building the 2.5" Scale Shay

Post by Soot n' Cinders » Mon Jul 27, 2020 11:25 am

jcbrock wrote:
Mon Jul 27, 2020 11:00 am
Soot n' Cinders wrote:
Sun Jul 26, 2020 5:03 pm
One option I’ve considered is machining out the existing blocks and soldering in commercial bushings to be machined off into split bearings.
Interesting idea Tristan. This would be by far the easiest/cheapest solution, so it probably won't work.
Lol! I like your logic. Definitely shows you’ve been around these beasts for a while. I think I’m going to give Babbitt a shot, I’ve got a friend with some and it doesn’t seem to be much harder than soldering in a bushing. Plus it’s a much softer material than bronze
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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Greg_Lewis
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Location: Fresno, CA

Re: Building the 2.5" Scale Shay

Post by Greg_Lewis » Mon Jul 27, 2020 1:25 pm

Soot n' Cinders wrote:
Mon Jul 27, 2020 9:40 am
...
I will definitely check it with a run out gauge and my V blocks before cutting it in case what they sent me is 3 sided.
A wise move. Never trust the catalog specifications. There is an old saying in the journalism profession: "If your mother says she loves you, check it out."
Soot n' Cinders wrote:
Mon Jul 27, 2020 9:40 am
Hopefully someone else can learn from my adventures here!
Tristan, we don't make mistakes. We do "research and development."
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

Rwilliams
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Re: Building the 2.5" Scale Shay

Post by Rwilliams » Mon Jul 27, 2020 5:02 pm

Years ago at work we needed a new piece of shafting ground for standard dimension pillow block bearings. There was dissension in the ranks as to what grade of precision to buy as management was always wanting to go cheap as possible. Management won out with the cheaper material being ordered that still fit the specifications for the shaft material. Soon the material arrived and once removed from the 8 foot long 6 inch diameter cardboard shipping tube, the surface appeared to be well executed. Management was ready to get things put together as it was already a week behind schedule in production on the new line. A few checks with a micrometer checked out, but one of the pillow block bearing sleeves confirmed that something was wrong big time. The material was set up in the new lathe where it barely fit between chuck and live center in the tailstock. There were high spots that were located in a slow spiral down the entire shaft when checked with an indicator. Management was not wanting to return the shaft and wait for another piece of shafting. The slow spiral high spot was marked out with Black Sharpie marker and everyone got a turn at attacking the long spiral high ridge with files and coarse emery cloth. Then fine emery cloth was used to improve the finish until the indicator needle was happy and the bearing sleeves would slide down the shaft from one end to the other. Took most of 3 shifts to remove the problem. From then on, management realized that a higher quality of material was often going to be the best choice to save much shop time. Was a serious lesson for the entire crew that lasted many years.

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ccvstmr
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Re: Building the 2.5" Scale Shay

Post by ccvstmr » Mon Jul 27, 2020 7:27 pm

Well Robert...once again, someone had to prove to management how expensive being cheap can be! In business terms, that would fall under the "cost avoidance" category!

Most people already know the saying...pay me know, or pay me later. All pays the same for the maintenance staff. How easy it is for management to forget how much machine downtime actually costs them! In your case, all for the cost of a cheaper piece of shaft material. Been there, done that! Carl B.
Life is like a sewer...what you get out of it depends on what you put into it!
I don't walk on water...I just learned where some of the stepping stones are!
I love mankind...it's some of the people I can't stand!

Soot n' Cinders
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Re: Building the 2.5" Scale Shay

Post by Soot n' Cinders » Wed Aug 05, 2020 9:45 pm

Well, 3 of the 5 shafts have been turned for the new crankshaft. This chrome plated rod is tough stuff! I have to skim it with a carbide bit almost like getting under the skin of an iron casting. But even once Im under the chrome the steel is still plenty hard, about 25C Rockwell. The carbide cutter is taking it just fine though so Im able to move relatively quickly. Whats slowed me down is I had to junk my 5/8in 5C collet because it doesnt run true, and rather than wait for a new one Im just using my old reliable 4 jaw chuck. Also slowing me down is the fact I have to skim off the chrome before I can cut the rod to length, otherwise the blade just skates on the chrome. The real fun is going to be trying to cut the woodruff key seats in these rods. My key cutters are only high speed steel so Im going to have to take some time to figure out how to ease them through the chrome and even the steel underneath without tearing anything up.
Also, my babbitting supplies arrived today. Got a nice #2 ladle, 2 pounds of grade 2 4X nickle babbitt, and a pound of damming compound. Going to try melting the babbitt soon, supposedly my little coleman propane stove should be enough to do it but I can always add the blow torch to that too if needed.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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NP317
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Re: Building the 2.5" Scale Shay

Post by NP317 » Thu Aug 06, 2020 10:30 am

Good fortune on the Babbitt pour.
I just received 22 lbs of the same Babbitt: RotoNickel 4X Grade 2 alloy. We will soon be pouring two new crankshaft bearings (3" diameter) for a 10 ton steam traction engine.
Remember that this grade of Babbitt has a higher melting temperature of about 460 F. and a pouring temp close to 750 F. I don't remember the exact values provided by the manufacturer.

Fun times ahead.
I'l be reading here of your progress and success.
RussN

Soot n' Cinders
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Re: Building the 2.5" Scale Shay

Post by Soot n' Cinders » Thu Aug 06, 2020 2:12 pm

NP317 wrote:
Thu Aug 06, 2020 10:30 am
Good fortune on the Babbitt pour.
I just received 22 lbs of the same Babbitt: RotoNickel 4X Grade 2 alloy. We will soon be pouring two new crankshaft bearings (3" diameter) for a 10 ton steam traction engine.
Remember that this grade of Babbitt has a higher melting temperature of about 460 F. and a pouring temp close to 750 F. I don't remember the exact values provided by the manufacturer.

Fun times ahead.
I'l be reading here of your progress and success.
RussN
Yep! That’s exactly the same stuff! I’ve got an infrared thermometer to check my temps as I go. The number I saw for the pouring temp was closer to 800F. Not that thats much high than 750F. I’m assuming you’re using the crankshaft or a dummy shaft with the pour? I was just going to fill my blocks solid and machine out the 5/8in ID for the journal
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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NP317
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Re: Building the 2.5" Scale Shay

Post by NP317 » Thu Aug 06, 2020 5:04 pm

Yes, we will be pouring around the actual crankshaft, after coating it in carbon and heating everything with BIG torches.
It would be SO much simpler to pour a block and machine it to spec. But the engine-side bearing gets poured in the actual engine frame. On a 45* angle, too.
Way too big for us to mess with. So we will pour the old fashioned way: lower bearing half first, then the upper halves.
The hollow oil cellar bottoms of the lower bearing halves makes life difficult for us too.
RussN
AT bearing sml.jpg

Soot n' Cinders
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Re: Building the 2.5" Scale Shay

Post by Soot n' Cinders » Thu Aug 06, 2020 7:56 pm

NP317 wrote:
Thu Aug 06, 2020 5:04 pm
Yes, we will be pouring around the actual crankshaft, after coating it in carbon and heating everything with BIG torches.
It would be SO much simpler to pour a block and machine it to spec. But the engine-side bearing gets poured in the actual engine frame. On a 45* angle, too.
Way too big for us to mess with. So we will pour the old fashioned way: lower bearing half first, then the upper halves.
The hollow oil cellar bottoms of the lower bearing halves makes life difficult for us too.
RussN
AT bearing sml.jpg
Ah yeah, I’ve seen some videos of how that stuff is done. With my stuff being so small in diameter and all of it removable from the engine, it’s gonna be easier to just machine to spec rather than try to pour that thin layer and scrape it to finish.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

Soot n' Cinders
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Joined: Wed Jun 27, 2012 5:24 pm
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Re: Building the 2.5" Scale Shay

Post by Soot n' Cinders » Sun Aug 23, 2020 1:13 pm

Well, rebuild is well underway. The new shaft is complete and straight within a half a thousandth. The chrome plated shaft is really really hard. I burned up 2 corners on my carbide insert turning the shoulders. I figure if it’s that hard to machine it’ll be really hard to wear.
C7383CA3-BB21-4CA6-9EEE-9F236CAF1B95.jpeg
Babbitting is also well underway. The shells were machined 1/8in oversized so I’ll have 1/16in of babbitt all the way around. I clamped on some sheet metal to make dams, and used some damming compound to plug the oil holes. From there the shells were poured full and then the excess machined out. The chips were remelted and used again.
8AE30A09-143F-495A-9152-867C6E976942.jpeg
11149110-DB2D-4495-9DDA-68F56357D4ED.jpeg
6C0C2137-22BD-4628-B758-A4B07F7FD215.jpeg
B6C94C36-B789-4679-97AE-7D0D02F7071A.jpeg
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

Glenn Brooks
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Location: Woodinville, Washington

Re: Building the 2.5" Scale Shay

Post by Glenn Brooks » Mon Aug 31, 2020 12:01 am

Tristan, Iam researching a different gauge track and wheel set for drives and rolling stock.

Curious what size diameter drives you are using for your 2.5” scale Shay?

Thanks
Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

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