Author Topic: 7/8" scale railroad baggage cart  (Read 1119 times)

Offline Dan Rowe

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7/8" scale railroad baggage cart
« on: December 08, 2019, 07:43:20 PM »
On a scale RR forum the challenge was to construct a model using popsicle sticks. I chose to build a baggage cart.



Checking the web I found a full scale rebuild:

http://www.tarheelpress.com/BaggageCart/

Catalog data suggests the platform is 10' by 40" wide with 28" wheels. I have some SS tube 2" od with a 1/16" wall for the tires.

Here are the main frame timbers.


The first end beam fitted to the frame timbers.


These are the photos I used for a reference


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Now I have a bunch of metal work starting with the wheels. I took a 2" section of stainless muffler pipe and used a muffler pipe expander in the lathe to trim the end.



Then I moved the muffler pipe expander to the vice to cut off a wheel rim with the hand hacksaw.





Then to the 6-jaw bezel chuck to trim the length.



I worked out the rest of the wheel design and a fixture to drill the rims that will also be used for the final assembly.
The hub is a three-piece design. The outer rims of the hub will be identical with a 1/4" bronze bushing in the center.

Here is a photo of boring the recess for the 1/4" bushing. The stock was 3/8" brass cut to 7mm with a radius on the lathe tool.


Note in the photo a steel ring with an internal bevel is acting as the depth stop for the part.

I made up a 24 pin index wheel for the Micromill and tomorrow I will drill and tap 6 holes in each outer rim at an 8 degree angle.

Here is the Micromill set to tap the 6 holes 1.4mm. The steel ring is again used as a depth stop for the part. The center and tap drills are the first two steps.



This was a snap to do with the Micromill it makes a fine drill and tapping stand. The hand feed lever allows the tap to be locked in a collet and the drawbar handle works for sensitive feed just flip the drive belt off and tap away.

The last step for the outer hub rims is to part off the 7mm chucking piece.

Time to drill the tires the drilling fixture is recessed to hold the tires and a 1/8" stud and nut holds the halves together. The stud will center the hub when I silver solder the spokes.




Cheers Dan
ShaylocoDan

Offline Dan Rowe

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Re: 7/8" scale railroad baggage cart
« Reply #1 on: December 08, 2019, 07:55:14 PM »
I am using flat head 1.2mm screws to bolt the plates. I have wood screws and machine screws with square nuts for the braces. It took me a while to figure out why the movable bearing plate has a thicker section. That is so it can be tapped for the rod that bolts the axle.

I tapped this section 1-72 for a scale 1" tie rod.



Here is one of the 1.2mm wood screws in place.





I bored the wheel fixture for the hubs then took an 8 degree cut on the face to clear the spokes. I used white-out to prevent any silver solder wicking down the spoke. Here is the first one ready to bolt on the other half of the fixture.



The white-out worked to block the silver solder.



I threaded more spokes for the next wheels and took photos of the thread roller taken apart to show how simple the design is. If a rod is broken while rolling simply take it apart and reasemble it on a flat plate. Try fixing a tiny cutting die.






To thread a spoke I simply put one in a drill chuck and used the roller by hand. The spokes were beveled on the lathe and it takes a bit of pushing while turning to get it started but for just a few quicker than the lathe.

I needed a way to attach the main tie rods to the frame members which are about 5mm wide so not a lot of room. I made up some special thin nuts with wings.

The front tie rod is 2-56 and I heavily modified a T nut to secure the 2-56 all thread for the center tie rod.


The rear tie rods are 1-72 and I made similar wing nuts from brass.


All this will be covered by the lolly stick deck.

Here are the rear wheels with paint.



In order to finish the steering gear, I needed the handle. It took several tries to get all the bends in the correct place. The rebuild photo series does not show the handle very well so I used the first photo in this thread for the model. Here is my final version.


To make the forged handle I used a Bell System crimping tool. The dies were removed by grinding the rivets and I made a 5/16" tool steel cube for the anvil. It is held by a 3-48 screw with washers and small plates. The forged wire is .072" in diameter and is what I make all the tiny blacksmith tools seen around the anvil stump.

Here is a photo of smashing the second handle. The first leg is easy getting the second one in the right place is the real trick.



Here is a photo of the tool there are two styles, one has two small holes and the other one has a single larger hole.



I found the two-hole one under a telephone pole when I was a kid and I have been smashing wire with them for a long time.

Cheers Dan

ShaylocoDan

Offline Dan Rowe

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Re: 7/8" scale railroad baggage cart
« Reply #2 on: December 08, 2019, 08:03:52 PM »
I have spent a bit of time looking at the photos and I realized that all thread usually comes in 3' lengths so I took some wire and made scale 3' all thread to match the photo.





All the tricky metal parts are done and only one more color to paint......





I am getting close to finished the deck can be glued down now as all the needed bolts are in place.



The extra bolts are 1.2mm nickel silver optical screws that I have been using as carriage bolts after riveting the heads. For the blind carriage bolts that have to work, I smashed flats on the heads to make T bolts.



The counterweight for the handle is finished and after drilling 3 holes I found a working balance point. The bolts and threaded rod sticking up will get masking tape for the paint job.





It was a lot of fun setting up the matching photos to a full size build. Here is the finished photo.



Cheers Dan
ShaylocoDan

Offline Dave Otto

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Re: 7/8" scale railroad baggage cart
« Reply #3 on: December 08, 2019, 08:34:34 PM »
That is an impressive piece of work Dan!
Thanks for sharing.

Dave

Offline crueby

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Re: 7/8" scale railroad baggage cart
« Reply #4 on: December 08, 2019, 08:47:19 PM »

THATS how you get such nice models - your shop elves include both Bigfoot and Einstein!   :Lol:

...




Offline PJPickard

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Re: 7/8" scale railroad baggage cart
« Reply #5 on: December 09, 2019, 01:14:50 AM »
Love this, very nice work!

Offline Roger B

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Re: 7/8" scale railroad baggage cart
« Reply #6 on: December 09, 2019, 10:59:55 AM »
Wonderful  :praise2:  :praise2:  :wine1: That's a fine set of helpers  :)
Best regards

Roger