Bobber Caboose

[jbodenmann]

And after a bit more metal removal, remember...just remove everything that doesn't look like an fulcrum casting. The trick is holding the part, so the last thing, is to cut it off of the big piece of stock. Another tip is to utilize the technique of climb milling when machining a long skinny part like this. That way, any deflection of the work piece forces it away from the cutter instead of grabbing it and pulling it into the cutter. I hate it when that happens!

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[jbodenmann]

There is a little raised rib around the slot that the equalizer pivot pin works up and down in and this is what is being made here.

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[jbodenmann]

Here our little raised bit has been roughed out and will now get a good working over with files to round the edges. Then it will be stuck to the fulcrum with tiny screws and soldered in place. This is only a tiny detail, but is important in that it really gives our little part the look of a casting.

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[jbodenmann]

And here is the raised bead soldered in place. There are actually two, one on each side. The size of the fillet can be easily controlled by how much solder is used. Silver solder is wonderful stuff!

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[jbodenmann]

Here is the base for the fulcrum being machined. Here the recess for the rubber spring-damper is being cut.

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[jbodenmann]

Here is the photo of the fulcrum, the equalizer and the rubber spring-dampers. Later four wheel cabooses dispensed with the equalizer and dampers. I guess they just weren't worth the trouble.

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[jbodenmann]

Last one for now. Here you can se how the whole mess fits together. Fulcrum, equalizer, pedestal and axle box. Time to send them off to Brad for investment casting. All will be bronze except for the long skinny equalizer which will be cast steel. Never had a cast steel part made before, too much fun!
See ya' later..
Jack

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[alanstepney]

Another excellent example of superb workmanship.

Plus an interesting photo sequence showing how it is (or should be) done.
Thanks.

[Shawki Shlemon]

Alan not many model engineers I know ( including myself ) can do what this gentleman is doing , he must be one of few that can do what he does , I admire his work and am always on the look out for his thread . One can learn a lot from him but not necessary can do what he does . He is an inspiration in our hobby .

[qreidford]

These posts are fantastic, inspirational and motivating and I look forward to each posting.
I will never be able to achieve this level of precision and finish but that doesn't prevent me admiring this level of expertise.
Please keep them coming.

[jbodenmann]

Hello My Friends
First off I must thank you for the lovely compliments, you are most generous. Here are a few more photos of the caboose project. The frame is made of birch hardwood, and will be held together with square head nuts and bolts and truss rods. In this photo the frame is upside down.

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[jbodenmann]

Here the frame members that the pedestals will mount to have been added.

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[jbodenmann]

And now right side up, and the planks for the end platform have been made. Some of the nuts and bolts have also been put in place. I fiddle around a lot putting things together to have a look and check the fit. And then disassembling to fit and add more pieces. On something like this I won't bother to make any real drawings, just some scribbles on 5" x 7" note pads. Get R' done.

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[jbodenmann]

One more of the frame showing the buffer beam, the ogee washers and the square nuts (#8-48 thread). All this little baloney adds up and is eye candy for the viewer. As with most of what I do, if broken down into manageable bits it's really nothing difficult. But it does require a lot of energy and my hammer headed stubbornness!

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[jbodenmann]

Here is the start of the sides. 5 MM birch plywood. The prototype caboose had timber framing with steel rods run vertically from the top of the side down through the frame with a washer and square nut on the bottom. Then all is covered with tongue and groove siding, vertically on the outside and horizontally on the inside. The timber framing is completely covered so as I see it, it would be a complete waste of time to do this on the model. But you will see the rods and square nuts sticking out of the frame underneath the car. In the background of this photo you van see a full size rendering of the caboose side on a piece o card stock. This was made mainly just to prop up on the frame, and then stand back and have a look....

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[jbodenmann]

Now for the vertical steel rods. They will actually hold the body down to the frame. But there is no way to drill a long hole through the plywood for the rod to pass through. So we will start with the hole and build the side around it....what? Here you can see that the car side has had some slots cut in it with the table saw and there is a rod laying in one of the slots just to have a look and make sure it fits. The windows were drawn on to the plywood with a pencil to make sure the rods didn't interfere with them. The rods also had to miss some frame cross members.

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[jbodenmann]

And here is what I mean about building the side around the hole. Now that all the slots are cut a piece of 3MM plywood will be glued on leaving a long hole for the rod to pass through.

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[jbodenmann]

And now here are the sides and ends being glued. Some white glue was thinned down a bit with water and a thin coating was brushed on both pieces of plywood, put together, carefully aligned and then put on the steel table under another thick piece of plywood and weighted down with anything heavy I could lay my hands on. When dry they will be trimmed as they are a bit oversize. Next up will be to make all window sash and door frames, then the openings in the body panels will be cut to fit. It is much easier to fit the holes to the frames rather than the frames to the holes. The windows will have four panes of glass each and will slide up and down just like their full size counterparts. The doors will have raised panels and two panes of glass, a functional door knob and perhaps even a tiny skeleton key so you can lock up when away to keep the hoboes out! Too much fun..
Jack

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[jbodenmann]

Hello My Friends
Here is some progress on the bobber caboose. As stated earlier the doors will be functional with tiny knobs that can be turned to open them, (well not really that tiny as this is 1-1/2" scale) and a dead bolt lock with skeleton key so you can lock up when you are away to keep the hoboes from nicking your lunch.

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[jbodenmann]

This photo shows the latch and all the tiny bits that make up the mechanism, except the springs.

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