3/4" Scale J1e

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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Hello My Friends
Here is a look at the underside of the cab roof. The riveting is proceeding with the roof ribs being fastened in place.
Cab210.jpeg
Here is a close look at the rivet buck. This is just a short length of 3/16" cold rolled. The pocket for the rivet head was made with a small round nose end mill. The pocket should be very slightly shallower than the rivet head so as not to mark the parts being riveted. The edges of the pocket should be rounded slightly. As this tool is for soft brass rivets it needn't be hardened. My table used here is 1/2" thick steel and has some holes drilled and tapped 1/4-20. I have a variety of tools that fit into these holes and that is what is being used here.
Cab211.jpeg
Here
In this view most of the rivets are in place and now the #00-90 machine screws can be removed and the final rivets put in place. The cab roof can now be riveted to the sides and back. Riveting is one of those tasks that is relatively easy but requires close attention. Making sure that the rivet head is properly located in the buck is a must. If not the head will be de formed, or the buck may scar the material being joined. If this happens, and the scar is not too bad it can be filled with soft solder and metal finished.
Happy Model Building
Jack
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Cab213.jpeg
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Hello My Friends
Here are a few snappies of the cab. The riveting is mostly complete with just a few left. It's time to start fitting the half round. This will be made from 3/32" round brass. There is also a few things like some grab irons and a rain strip on the roof. Also arm rests in the cab window and wind deflectors at the front of the side windows. So far I'm pretty happy with the way it's coming along :D .
More To Come.
Jack
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Cab230.jpeg
Cab231.jpeg
Cab232.jpeg
Cab233.jpeg
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Hello My Friends
Here is something you may find useful. Steam locomotive cabs often had half round trim here and there. 5344 had this trim around the top front edge of the cab roof, around the side window openings , and around the top rear edge of the cab roof. I am using 3/32" round brass to make the half round. In this first photo we have a block of hardwood with a 3/32" hole drilled through. This hole should be parallel with the table. A length of 3/32" brass should fit through so as to slide smoothly, but without any slop.
HR1.jpeg
In this next photo you can see that there is a simple infeed guide, cobbled together from plywood scraps. This need not be fancy, but should guide the round stock parallel to the table.
HR2.jpeg
Here a .020" slitting saw is being used to split the round stock as it is being gently pulled through the wood block. I usually hold the round stock with some vise grips as is seen here. The cutter was spun at 200 RPM. I split a three foot length in about three of four minutes. You can use this method to both split material. or to put a slot in. It also helps to have a brand new slitting saw as if the teeth are bruised or damaged it probably won't split the round stock evenly.
HR3.jpeg
SteveM
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Re: 3/4" Scale J1e

Post by SteveM »

Ingenious!

Steve
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Harold_V
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Re: 3/4" Scale J1e

Post by Harold_V »

SteveM wrote: Mon Jun 06, 2022 9:20 pm Ingenious!

Steve
Yep! It's a great way to create long cuts in brass items.
One thing that wasn't mentioned is that the cut should NEVER be climb. If you attempt to climb mill, pretty good chance you'll destroy the material, ruin the setup and break the cutter.

Years ago, I had to cut a 45° x 3/16" chamfer on several strips of rectangular brass (free machining) about 36" long. I made a setup of parallels (and appropriate shims) that allowed the brass strips to be guided and move freely, but without any excessive movement. A solid backstop with a pair of parallels set with a thou clearance on the opposite face, one on each side side of a 90° countersink, plus a pair of cap parallels to prevent lifting was all it took. I could easily push the pieces through the setup. Again, no climb cutting.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Hello My Friends
Thank you SteveM and Harold. Yes climb milling in this situation would no doubt have disappointing results :oops: . Here is a bit more on working with half round. Our first photo here shows an offset that was needed where the center roof sheet overlapped the two outer sheets. This is a spot where the over scale thickness of the material really shows.
HR4.jpeg
To accomplish this offset the half round was first annealed and then marked where the offset should be. As the cab material is .040" a piece of .040" brass was used as shown here.
HR5.jpeg
Then a piece of hardwood was used as shown here and given a good smack with a large hammer. This was done on the steel work table.
HR6.jpeg
Here is the result.
HR7.jpeg
Here the half round is having the #000-120 x 3/32" screws fitted. The clamps used here work with Cleco pliers. Now it's time to form the radius to match the rounded corners on the cab roof.
HR8.jpeg
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

This radius was formed around a bit of 5/32" round brass. Here is the set up for this. The brass is first annealed and clamped down.
HR10.jpeg
Then the half round is formed around the round stock using a wood piece.
HR11.jpeg
.
And here it is in place on the cab roof. Screws are placed where needed as the half round works its way around.
HR12.jpeg
The same routine applies as the half round is applied to the side windows. This is much easier than the roof as the half round is only formed in one plane.
HR13.jpeg
Here is the set up for this. Here 5/16" round stock is used to form the radius.
HR14.jpeg
Sometimes I will use small vise grips with the jaws ground smooth so as not to scar the half round. First the half round will be marked where the screws should be. Then it will be tap drilled. Then clamped back in position and the tap drill will be spotted through the cab side. Then removed again and the half round clear drilled. The location of the next bend will be annealed. The cab side will then be tapped and the whole mess re assembled. Then the location for the next bend marked, dis assembled again and the bend formed. Re assemble and proceed. This is one of those times when put it together, take it apart comes into play. Put it together, take it apart, put it together.... :D
HR15.jpeg
Last edited by JBodenmann on Thu Jun 30, 2022 8:07 pm, edited 2 times in total.
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Here we now have the half round mostly in place and ready for soldering. I still have the rear edge of the cab roof to do. This is one of them fiddly jobs that I really enjoy. This half round trim really adds to the appearance of a model. As this is a very prominent detail neat and tidy workmanship really pays off here. This is not a difficult task but requires careful marking out and execution. Curved half round like we have here is actually very forgiving as the location of the curve can be adjusted after forming. If the curve is not exactly in the right location, it can be moved by straightening one edge and then putting it back on the form tool and bending the other end. Sometimes you will have to re anneal the part to do this as the act of bending will work harden it. Coming up, some tips on soldering the half round in place.
See You In The Funny Pages...
Jack
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HR16.jpeg
HR17.jpeg
HR18.jpeg
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Hello My Friends
Here is something you may find useful. This is a flux pen that was purchased from McMaster. It's a water soluble flux for soft soldering. Works great!
Cab250.jpeg
This flux was used when soldering the brass half round in place. The half round was all removed from the cab and everything was cleaned with alcohol. Including the screws. Any brass not shiny clean was brightened up with scotch write. Then the half round, the screws, and the cab were fluxed and re assembled. Remember...put it together, take it apart...a large part of model building. As mentioned before I like to use rosin core electronic solder for this. It has a low melting point and also has good wicking characteristics. Small pieces were snipped off and set in place as we have here. The cab was orientated so that gravity held the solder in place.
Cab251.jpeg
Then the cab was heated from below with a propane torch. Don't apply heat directly to the half round or it will expand more than what it's sitting on and lift. Here is the roof after soldering. The challenge is to use j u s t enough solder...Not too much as it will need to be cleaned off later.
Cab252.jpeg
This corner has way too much solder. It obscures the crisp edge between the half round and the cab sheet and looks sloppy. After all was soldered the cab was given a good scrub with scotch brite and Ospho metal prep. A stainless steel platers brush was used around the rivets and half round.
Cab253.jpeg
Here the excess solder has been removed and it looks much better. A Dremel with a pointed burr, and files were used here to remove the excess solder.
Cab254.jpeg
Last edited by JBodenmann on Tue Apr 11, 2023 3:34 pm, edited 2 times in total.
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JBodenmann
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Re: 3/4" Scale J1e

Post by JBodenmann »

Here is a bit about finishing the half round. First Everything is scrubbed with metal prep and dried. Then the screw heads are snipped off with a flush cutter. Then what remains of the screws if cleaned up with a 4" smooth file. To smooth out the half round I will make a sanding block like shown here. It's just a piece of soft pine. The half round we are smoothing here is 3/32". The groove in the pine was made wit a 1/8" dia. end mill. This will allow clearance for the sand paper.
Cab256.jpeg
Here is the sanding block in action. There are also other little sanding blocks with a square end for removing solder next to the half round. I also use a stainless plater brush a lot. It will brighten things up like around rivets and such.
Cab257.jpeg
Now here are a few just for fun. Soon that big empty space under the cab will be filled with a stoker engine and some other cool baloney.
Cab258.jpeg
I especially like this one looking up into the cab.
Cab259.jpeg
Just one more for now. There are still a few little details on the cab roof. There are rain gutters over the side windows, and a rain strip further up on the cab roof from front to back. Also some grab irons and little adjustable wind wings at the front of the cab side windows. Having fun here :D
Jack
Cab260.jpeg
Last edited by JBodenmann on Thu Jun 30, 2022 8:08 pm, edited 1 time in total.
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NP317
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Re: 3/4" Scale J1e

Post by NP317 »

Your extraordinary work reminds me of mountain climbing:
"Why? Because it's there..."
RussN
Steam Engine Dan
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Re: 3/4" Scale J1e

Post by Steam Engine Dan »

the cab is looking fantastic jack. we ran our 5344 for 18 hours last weekend and really put the miles on her. here is a video from our spring meet last weekend. https://www.youtube.com/watch?v=O31WFNgnIGo
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