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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Fender
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Re: Building the 2.5" Scale Shay

Post by Fender » Thu Jun 16, 2016 6:33 pm

Marty Knox had a great idea for attaching a separate smokebox to the boiler. You machine matching 45 degree bevels on the rear of the smokebox and on the front end of the boiler barrel. Then, weld four square nuts set on edge into the inside of the boiler barrel and in a corresponding place on the rear of the smokebox. The nuts on the smokebox are drilled out to clearance size for the bolts that will hold everything together. When the bolts are tightened, pulling the nuts together, the bevels keep everything aligned. A small amount of high-temperature sealant between the bevels will form a good seal.
You may have to use socket-head cap screws (which have smaller heads than hex bolts). Goop up the threads with a generous amount of anti-seize.
Dan Watson

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

Post by Soot n' Cinders » Thu Jun 16, 2016 8:30 pm

Fender wrote:Marty Knox had a great idea for attaching a separate smokebox to the boiler. You machine matching 45 degree bevels on the rear of the smokebox and on the front end of the boiler barrel. Then, weld four square nuts set on edge into the inside of the boiler barrel and in a corresponding place on the rear of the smokebox. The nuts on the smokebox are drilled out to clearance size for the bolts that will hold everything together. When the bolts are tightened, pulling the nuts together, the bevels keep everything aligned. A small amount of high-temperature sealant between the bevels will form a good seal.
You may have to use socket-head cap screws (which have smaller heads than hex bolts). Goop up the threads with a generous amount of anti-seize.
That's a good idea! That would definitely pull tight and make everything square and air tight.

Another thought me and my dad have had is machining shoulders on the smokebox and boiler barrel and then either screwing or hot riveting the smokebox back into the barrel.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

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PeterCraymer
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Re: Building the 2.5" Scale Shay

Post by PeterCraymer » Fri Jun 17, 2016 8:53 am

Tristan,

I just formed a ring out of 1/8" x 1" HRS that was a good snug fit into the boiler side. I set the flue sheet back from the end of the boiler pipe about an inch or so (don't remember exactly) so I could weld everything and then the ring was tack welded in a bunch of places around the OD of the ring. Small recessed welds so they wouldn t interfere with the smokebox. My smokebox is made from the same pipe so the ID was a perfect match and can be adjusted with a grinder. There are screws that are in the line of rivets around the back of the smokebox that hold boiler and smokebox together. The ring is drilled and tapped and the smokebox has clearance holes. Just another option.

Peter
Attachments
small front flue sheet.jpg
smokebox attach.jpg

tomc
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Re: Building the 2.5" Scale Shay

Post by tomc » Fri Jun 17, 2016 9:32 am

Hi Tristan, I think your rode in #9 as 12 is parked and not run anymore.

Tom C.
tom_at_srclry_com
Lost somewhere in Michigan!

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

Post by Soot n' Cinders » Thu Aug 04, 2016 8:15 pm

Time for another update. Not a whole lot of progress to report but its something. Got both trucks complete and also got the frame painted. Brushed the paint on the frame because of all the corners and the finish didnt come out as good as the trucks, but once it gets a coat of grease and oil on it, nobody will be able to tell the difference.
IMG_0235.JPG
Also decided to throw the decking boards and boiler barrel on the frame just for grins and chuckles. Makes it start to look more like a locomotive!
IMG_0236.JPG
IMG_0237.JPG
-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 » Tue Aug 30, 2016 9:58 pm

Work on the shay continues! Albeit slowly since school is now back in session for the semester.
Got the support bracket for the johnson bar welded to the frame.
IMG_0238.JPG
The tumbling shaft arm made and brazed on to the shaft.
IMG_0239.JPG
The johnson bar shaft and johnson bar made and connected to the the tumbling shaft through some nice ball end from McMaster-Carr.
IMG_0240.JPG
And just started on machining the quadrant, the notches should be interesting to machine.
IMG_0242.JPG
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

Jawn
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Re: Building the 2.5" Scale Shay

Post by Jawn » Wed Aug 31, 2016 1:17 am

Looks like good progress.

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John_S
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Re: Building the 2.5" Scale Shay

Post by John_S » Wed Aug 31, 2016 7:14 pm

Soot n' Cinders wrote: And just started on machining the quadrant, the notches should be interesting to machine.
IMG_0242.JPG
If you've still got it in the rotary table, cut the notches. Use a file to square out the bottoms after you pull the part off the mill. This will allow you to have perfectly machined notches to match the radius you've cut.

kvom
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Re: Building the 2.5" Scale Shay

Post by kvom » Thu Sep 01, 2016 6:48 am

Or mount rotab vertically to index. Notches will be milled square.

Pontiacguy1
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Re: Building the 2.5" Scale Shay

Post by Pontiacguy1 » Thu Sep 01, 2016 11:33 am

Or put the rotary table vertically and mill them out using a slot cutter or slitting saw. You could also use your fixture that you have and clamp that in the vise and use a slot cutter/slitting saw to make those.

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

Post by Soot n' Cinders » Thu Sep 01, 2016 11:51 am

My rotary table will go vertical and the plans call for the slots to be 1/8" wide so I was just going to use an 1/8" end mill to mill the slots out. That's this afternoons project so should be interesting.
Then it's on to the latch hardware.
-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 » Fri Sep 02, 2016 1:41 am

Soot n' Cinders wrote:My rotary table will go vertical and the plans call for the slots to be 1/8" wide so I was just going to use an 1/8" end mill to mill the slots out. That's this afternoons project so should be interesting.
Then it's on to the latch hardware.
Not a good plan unless you happen to have a very short end mill, as opening the slots will be somewhat troublesome. Deflection, even breakage, will be the enemy.

If you must use an end mill, you'd be best served to use a 3/32" to open the slots, then go back to take them to size and to achieve proper location. The first pass will have deflected and not leave a great finish, nor will it be on location. By using an undersized end mill, when you take finish cuts you'll be able to take a climb cut on both faces, yielding a uniform finish. The roughing and then finishing operations provide the added benefit of permitting locating the slots in the proper location.

Assuming you have clearance, using a slotting saw for this operation would be in your best interest. You might also consider the use of a Woodruff cutter, which would be a great choice.

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

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