An O.S. Porter Journey

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

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mikeyg
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Joined: Tue Jun 26, 2007 4:31 pm
Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

These frames have lots of angles and brackets to hold things together. All good stuff to add detail with as well as tie the frame together. We’ll carve most of these out of brass so chunks o’ brass are on the way…

The first steps are the small internal brackets which will assist with aligning everything in the center. We mill out the center of each piece while it is still on the bar, shape the sides and cut it off. This leaves one side to finish plus drilling of the holes. Holding it for the back side work involves squeezing it in the vice with a fixture in the middle to keep it from crushing. The pattern for the holes comes right from the drawing and the bolt sizes do too. These are 2-56 with a #41 clearance drill. Aligning them to the wood pieces, the beams are match drilled as well.
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Carving
Carving
Cut off
Cut off
Drill fixture
Drill fixture
Assembly
Assembly
Done!
Done!
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mikeyg
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Joined: Tue Jun 26, 2007 4:31 pm
Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

Now for the cool part…

The little side beams (only 5/16” x ¼”) are angled to fit into notches on the end beams. These notches are angled inward to hold them in under longitudinal compression of the frame. Those old guys were geniuses! We want to duplicate this too, so with a little careful milling and carving we come up with a compression joint which actually works in 1” scale.
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Rough assembly
Rough assembly
Notching
Notching
Compressed
Compressed
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mikeyg
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Re: An O.S. Porter Journey

Post by mikeyg »

Next, we look at the rear coupler which is relatively simple to machine and assemble. The basic idea is to use a 1/8" ball mill to carve out the backside shape, but we have a finish problem during the initial work so we consult with friends. Answer: speed up! Small 1/8” ball mills need the speed. This piece is machined on both side to reflect the Baldwin drawing.

There are three pieces in the pocket including the base, the curved cover and the little pin boss on the top. All are machined and silver soldered together. Sorry, no pictures of the whole process. Curving the outer piece was easy. I just put it inside of a piece of pipe, placed the back side on the horn of the trusty American Eagle anvil and gave it a whomp. Once curved, I pinned it to the back piece with brass wire for soldering. We’ll blast it too. Then match drill the beam. Pocket done! We also radius the bottom of the beam per prototype and mock up the assembly with temporary 3-48 bolts. This piece will be attached to the frame with the longitudinal compression rods all the way up to the forward drawbar piece but that comes later.
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Machining
Machining
Raw
Raw
After blasting
After blasting
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mikeyg
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Joined: Tue Jun 26, 2007 4:31 pm
Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

One more for today...

The next pieces are much more complex…and I forgot to take any pictures during the process. These pieces rest above the rear truck springs providing them with a load path into the frame. They are very cool, but difficult to machine with multiple setups and dimensional checks along the way. For example, the side frames are about .010” different in dimensions from side to side so we make each of them to fit a specific location. I figure .010” difference between sides isn’t too bad when using the table saw.

They have a radius on the back side which needs to be let into the beam too. Some simple trimming with an Xacto knife helps.

And...we've blasted all of the pieces to date for a nice finish. And they look like castings too!

Next week we'll have the rear center pin and some wire EDM work for the side supports to share.
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Rear truck side support
Rear truck side support
Blasted
Blasted
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mikeyg
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Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

Another week's progress...

I’m always thinking of sequence of assembly when I put these things together and I chewed on this for the frame too. I want to get the main frame tied together so the outside frame supports seem to be next. But rather than slog through machining all of the six pieces, I decide to ask a friend to cut the center core out using wire EDM. So I’ll send off a dxf file to him and see what else he needs. After review, friend Doug wrote the wire program and I prepped the pieces by drilling holes for starting the wire. We’ll move on to other things while we wait.

Describing the image below, it shows a piece of 3/8" x 5/8" brass from the top with holes and profile shapes located. I manually drilled the holes on the mill and Doug did the rest!
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EDM file image
EDM file image
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mikeyg
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Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

I need to determine the height of the frame above the trucks so I decide to work out the rear cross pieces and bolster center supports. The rear truck springs in this design rest on those side supports we just made so I can lay the frame on the truck and confirm how tall the center pins need to be.

The frame mounted center pin is both simple and kind of cool with the radius on the pin and an internal radius on the back side to match. Of course I duplicate this for no reason other than it's fun. But I may use the back side depression which results for mounting a nut or some other form of retainer for the truck pin. I drill the center for 6-32 clearance thinking that might be a good size. Once again, I forgot to take pictures while it was on the lathe, but the simple description is that I cut a piece of 1” square bar and held it sideways in the four jaw to machine the pin. I went with a 3/8” pin so I could reverse it into a collet and machine the back. Then I cut off excess, zoom it on a sander and drill the mounting holes in the mill. Easy stuff. I also zoomed it on a wire wheel to smooth the edges then off to the blaster for some texture and cleanup. Lots of zooming. Of course I drill it too for 3-48 clearance.
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Drawing
Drawing
Bottom
Bottom
Top
Top
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mikeyg
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Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

Last one for today...

The bolts for mounting this thing go through the center boards of the frame and on top they have these cool square washers. They size out at ¼” so I’ll use square brass in the square collet to drill and shape. But I decide to thread them and fake the bolt on top so we can keep a very low profile. One interesting thing about Baldwin tenders is that there is a lot of hardware sticking above the frame tops. The top planking is apparently relieved underneath to clear them. I may pick up some brass 3-48 nuts for the top and shave them down to reflect the low profile on the prototype drawing.

More next week!
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Sitting on the frame
Sitting on the frame
Square washers
Square washers
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Love4Steam
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Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by Love4Steam »

Amazing detail Mike. Keep up the great work!
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Dick_Morris
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Re: An O.S. Porter Journey

Post by Dick_Morris »

Nice work on the tender.
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mikeyg
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Joined: Tue Jun 26, 2007 4:31 pm
Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

Thank you for the comments!

Now for the truck bolster piece. (Actually two as we need a similar piece for the front truck) We see it’s tapered on the vertical piece and the base isn’t square, but we again choose 1” square bar as a start. (I always forget to take a picture at this point!) Center it in the 4-jaw, mark the center, drill for the retaining bolt, bore for the pin and outside tapering are easy. Parting it off in the saw is too, but now we need to hold it from the tapered end so we can clean off the bottom. I make an internal expanding mandrel for the 3/8” + bore which fits the center pin we just made a little loosely. The mandrel goes into a collet and onto the lathe. Then repeat for two.
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On the lathe
On the lathe
Expanding mandrel
Expanding mandrel
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mikeyg
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Joined: Tue Jun 26, 2007 4:31 pm
Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

I use the same inside mandrel in a collet and hold for the drilling part of the operation.
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Drill 1
Drill 1
Drill 2
Drill 2
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mikeyg
Posts: 70
Joined: Tue Jun 26, 2007 4:31 pm
Location: Garden Grove, CA

Re: An O.S. Porter Journey

Post by mikeyg »

Last one for today...

Now we have two tapered pins, one for each truck bolster. Which I failed to mention are now made of the same wood as the frame. Those steel ones were not terribly attractive so off we went to the table saw.

We match drill the bolster for the bolts and put a center hole for the Allen wrench to fit into for the retaining bolt. We’ll paint or stain the wood later.

I'm not sure if I'll post next week or not as I've been distracted with the repair of a Juliet for a friend. Plus, I'm waiting for hardware from our favorite model bolt supplier. But maybe I'll have some time in the shop.

More soon!
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Fresh bolsters
Fresh bolsters
Bolted in place
Bolted in place
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