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

Post by Soot n' Cinders » Thu Mar 05, 2020 8:45 pm

Berkman wrote:
Thu Mar 05, 2020 8:32 pm
Looks awesome! What's next to do after the cab?
Step boards and domes. Other stuff is in the works as well. I need to source a decent sounding bell as well.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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

Post by Soot n' Cinders » Sat Apr 18, 2020 10:29 pm

Been a while since Ive updated this, but the cab is officially varnished and bolted down! Now on to the windows and maybe the hatch for the roof vent.
014785d5d11ae71e946be4d1629af9bfd60c81096f.jpg
Keeping in line with my last post, does anyone have any leads on a good 2.5in scale bell? Doesn't seem to be too many options out there, but I'd like one that sounds decent even though theyre small.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

jcbrock
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Re: Building the 2.5" Scale Shay

Post by jcbrock » Sat Apr 18, 2020 11:12 pm

Looking nearly done Tristan, wish I could say the same. Amazon has a lot of ornamental brass handbells for cheap - I saw a 2.2" one for example so there are some smaller ones and it was $10. I was thinking about getting one of those and then either sanding or turning the decorative casting off the outside and whacking the handle off. Solder a threaded stud to the top, Kozo up a yoke and call it good. Just an idea at this point, I've not tried it yet. A 2"-3" bell is never going to sound like a 12" bell, so I'm going more for scale appearance.
John Brock

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

Post by Soot n' Cinders » Sun Apr 19, 2020 10:57 am

jcbrock wrote:
Sat Apr 18, 2020 11:12 pm
Looking nearly done Tristan, wish I could say the same. Amazon has a lot of ornamental brass handbells for cheap - I saw a 2.2" one for example so there are some smaller ones and it was $10. I was thinking about getting one of those and then either sanding or turning the decorative casting off the outside and whacking the handle off. Solder a threaded stud to the top, Kozo up a yoke and call it good. Just an idea at this point, I've not tried it yet. A 2"-3" bell is never going to sound like a 12" bell, so I'm going more for scale appearance.
I have thought about doing something like that. Get a musical bell about the right size and modifying it to fit in a standard cradle. I know it won’t sound like a 12in bell but at least it would have a clear tone to it. Some bells out there get some weird overtones going and just don’t sound good
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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Fender
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Re: Building the 2.5" Scale Shay

Post by Fender » Sun Apr 19, 2020 11:00 am

Some years ago, I found a “school teachers” bell at an import store that looked remarkably like a scale locomotive bell. They had several in stock, and I rang each of them, then picked the one with the lowest tone. This is not exactly the same bell, but you get the idea. One thing I learned is that the tone goes lower the thinner the sides are. So you might be able to machine it thinner from the inside for a more realistic “clang”.
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Dan Watson

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makinsmoke
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Re: Building the 2.5" Scale Shay

Post by makinsmoke » Tue Apr 21, 2020 11:39 am

Years ago I bought a “Christmas” bell at Hobby Lobby. It looked about the right size for my 2-1/2” scale goose.

It doesn’t sound very prototypical, but has a good sound and looks right. You can make your own clapper and buy acorn nuts in various sizes.

Brian

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makinsmoke
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Re: Building the 2.5" Scale Shay

Post by makinsmoke » Tue Apr 21, 2020 11:41 am

And yes, very similar to the one in the photo.

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

Post by Soot n' Cinders » Sun Jul 26, 2020 5:03 pm

So it’s been a while since I’ve posted anything, it’s been quite a year so far with graduating, COVID, job hunting, etc.
Work on the shay continues, I have a bell on her now and work continues to finish out the cab. But there’s been a major set back in the running gear. The wrist pins started knocking last year and the take up wedges for the crank pins are almost completely drawn in. After some tearing down, I’ve found that my crankshaft and wrist pins are wearing just as much, if not more, than the bronze they ride in. Only thing I can figure that happened is I mustve gotten some 303 stainless instead of 316. 303 is much too soft to be used as shaft material which is what’s led to such premature wear. So now I’m looking at making a new crankshaft and renewing the bearing surfaces.
For the shaft I’m looking at using chrome plated drill rod since it is so hard. I’ve seen old mills and lathes with chromed ways that still look new so it seems like a good way to be done with shaft wear for a long time to come.
In addition to that, I’ve also been looking at ways to make renewing the bearing faces easier. One option I’ve considered is machining out the existing blocks and soldering in commercial bushings to be machined off into split bearings. The other option I’ve looked at is going back to old fashioned Babbitt. Some friends I know who have worked with the stuff recommend 4X nickel Babbitt, which is just grade 2 tin Babbitt with a little nickel added for extra strength. With the right fixtures, new Babbitt could easily be cast and then finish machined to suit.
Does anybody else have any thoughts on this? As many shays that are currently being built here, I’m sure this won’t be the last time someone will need some info rebuilding one.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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Greg_Lewis
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Re: Building the 2.5" Scale Shay

Post by Greg_Lewis » Sun Jul 26, 2020 8:47 pm

Be careful with drill rod as shaft material. I once spent $30 for a piece of 1-inch, noting the specifications for accuracy only to discover that it was tri-lobed by several thousandths. This did not show up with a mic because of the triple lobe issue — only after it was put in v-blocks and checked with a DTI. I'd look for some precision ground shafting instead.
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.

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

Post by Soot n' Cinders » Sun Jul 26, 2020 9:23 pm

Greg_Lewis wrote:
Sun Jul 26, 2020 8:47 pm
Be careful with drill rod as shaft material. I once spent $30 for a piece of 1-inch, noting the specifications for accuracy only to discover that it was tri-lobed by several thousandths. This did not show up with a mic because of the triple lobe issue — only after it was put in v-blocks and checked with a DTI. I'd look for some precision ground shafting instead.
That’s what I meant. The stuff McMaster has is precision ground drill rod
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

Harold_V
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Re: Building the 2.5" Scale Shay

Post by Harold_V » Mon Jul 27, 2020 1:08 am

Soot n' Cinders wrote:
Sun Jul 26, 2020 9:23 pm
Greg_Lewis wrote:
Sun Jul 26, 2020 8:47 pm
Be careful with drill rod as shaft material. I once spent $30 for a piece of 1-inch, noting the specifications for accuracy only to discover that it was tri-lobed by several thousandths. This did not show up with a mic because of the triple lobe issue — only after it was put in v-blocks and checked with a DTI. I'd look for some precision ground shafting instead.
That’s what I meant. The stuff McMaster has is precision ground drill rod
You apparently have no experience with centerless grinders. That their shafting is precision ground doesn't exempt it from being three sided, although it should. A centerless grinder will create a perfect circle when properly operated. It takes little error on the part of the operator to crate three sided parts, or if the material being fed isn't dead straight, it, too, is often not round.

Your material selection for a shaft was in poor judgement. If you wished to use stainless, you should have pursued something in the 400 class, which is heat treatable. The difference between 303 and 316 would be negligible, and, if anything, 303 would have made a slightly better bearing due to the sulfur (or selenium) contained within. In reality, though, none of the 300 series of stainless make for good bearings. They are all simply too soft.

You could have also selected something like 17-4 PH, which is also heat treatable, and would make a respectable choice. The easiest of all would be to machine the shafts from 416 stainless, which is a joy to machine and heat treats well.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

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

Post by Soot n' Cinders » Mon Jul 27, 2020 9:40 am

Harold_V wrote:
Mon Jul 27, 2020 1:08 am
Soot n' Cinders wrote:
Sun Jul 26, 2020 9:23 pm
Greg_Lewis wrote:
Sun Jul 26, 2020 8:47 pm
Be careful with drill rod as shaft material. I once spent $30 for a piece of 1-inch, noting the specifications for accuracy only to discover that it was tri-lobed by several thousandths. This did not show up with a mic because of the triple lobe issue — only after it was put in v-blocks and checked with a DTI. I'd look for some precision ground shafting instead.
That’s what I meant. The stuff McMaster has is precision ground drill rod
You apparently have no experience with centerless grinders. That their shafting is precision ground doesn't exempt it from being three sided, although it should. A centerless grinder will create a perfect circle when properly operated. It takes little error on the part of the operator to crate three sided parts, or if the material being fed isn't dead straight, it, too, is often not round.

Your material selection for a shaft was in poor judgement. If you wished to use stainless, you should have pursued something in the 400 class, which is heat treatable. The difference between 303 and 316 would be negligible, and, if anything, 303 would have made a slightly better bearing due to the sulfur (or selenium) contained within. In reality, though, none of the 300 series of stainless make for good bearings. They are all simply too soft.

You could have also selected something like 17-4 PH, which is also heat treatable, and would make a respectable choice. The easiest of all would be to machine the shafts from 416 stainless, which is a joy to machine and heat treats well.

H
Harold, you're right on my experience. Im basically a self taught hobby machinist so I've never even encountered a centerless grinder in person before. Im not sure how McMaster's shafts are ground, though what I have ordered this time around is listed as rotary shaft material. 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. That should allow me to work with their customer service about getting a replacement piece.
I agree that my material choice probably wasnt a good one. I cant find any record of ordering shaft material for the crankshaft though, so I dont know where the material came from or what it is. Either way, lesson learned, always verify critical materials like this. I did find an order for the shaft on the trucks so I know its ok. Ive got an invoice for 3ft of 3/4in 440C shafting so at least the trucks should be fine, and I cant feel any slop in those bearings yet.
Hopefully someone else can learn from my adventures here!
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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