Another Pennsylvania A3 Switcher

[Roger B]

Looking good     

I like your painting system 

[JCvdW]

Thanks Per, Kim and Roger for checking in!

The tender frame was completed today and is ready for painting!





The vertical slide was used on the lathe to drill and tap the holes in the ends of the sidle sills. This worked quite well, but in hindsight, the drilling jig used by Blondihacks is probably a better and safer idea.





The only part that had to be fabricated twice was the rear coupler pocket. The first silver solder attempt came out skew, due to too much heat on loose mounting screws.

With summer holidays around the corner, painting will have to wait for next year...

[redhouseluv]

That spray booth is seriously cool - I have a cardboard box 

I bought a rotating cake stand make things easier to turn, but need to get something rigged like yours

[crueby]

Frame and trucks are looking great!!

[Kim]

That looks great, JC! 

With the frame it starts to pop into 3D and you really start to get a feel of the size of the tender.  Very nice work!

Kim

[JCvdW]

Thanks Sanjay, Chris and Kim for checking in!

I finally had some time to paint and finish the tender frame. I am still pondering whether to paint all the screw heads.





Time to start with the tender tank proper!

[Roger B]

Nicely done  Do you have a length of test track you can try it on?

[Kim]

Your tender is looking great, JC!  Nice paint job! 

As for the screws, I don't know what to tell you.  I ended up just using a permanent Sharpie to cover the shiny screws, but I didn't paint them.  It's not perfect, but it made me happy! 

[JCvdW]

Nicely done  Do you have a length of test track you can try it on?

Hi Roger, Thanks for checking in. No test track yet. The local club track is about 30 km away. Will have to take it there soon to at least see if it fits!

[JCvdW]

Thanks Roger and Kim for checking in. The permanent sharpie is something to remember!

In the last two month time in the workshop was very intermittent, but some progress has been made.

Given the price of brass, I took Kim's lead and made the tank floor out of 304 stainless steel plate. This machined more easily than what I expected.

The wooden former and backing plate for the copper side plates were made with my home made CNC router.



I also used it to cut out the copper profile for the side plates and to separate the two halves after forming. I have never used the router to cut metal before, but it seems to handle brass and copper sheet quite well. It is going to be very handy for all the sheet metal work to follow.



The bottom horseshoe member was carefully mounted to the floor to ensure proper alignment with the side plates. The top horseshoe member was then formed to mirror the shape of the bottom member.



The vertical board was mounted to the bottom horseshoe member to provide a good reference for the rest of the parts of the coal bunker.
This required endless assembly/drilling/tapping/disassembly/drilling/assembly operations, adding one or two screws at a time, until everything was screwed together.





I used the sheet metal function of Fusion 360 to create the profiles for the verge board and top strip, and then cut those with the CNC router.



It is always very satisfying to see how well the parts then align after bending.



The coal bunker turned out to be quite complex, and I am very glad that I first studied how Kim and Blondyhacks approached it. This definitely allowed me to avoid quite a few pitfalls!

I decided to defer all soldering until all the sheet metal parts of the tank are made and screwed together.

[Kim]

Very nice looking!  You did a great job forming the copper sides AND the horseshoe bend parts.  Those cause me no end of grief! I had to do that upper horseshoe member a couple of times to get it right.  But I'm glad I did, because that cool shape of the tender is part of the charm of the A3!

Looking great! 

Kim

[matthew-s]

I missed this build. Great progress.

I’m building one too, I chip away where I can.
I very much enjoy the process. It looks like you are too!

Kim and BlondiHacks have been a great help to me. Although I suspect I’ve been working on mine longer, and I’m way behind them!

 

[JCvdW]

Thanks Kim and Matthew for checking in. Your interest and comments keep me motivated!

The sheet metal parts for the tender tank were cut out with the CNC router. As always sequence of operations are important, and the top plate had to be made twice. Trying to do the top bend after the man hole opening was cut, resulted in a warped top plate.

An embossing tool was made following Kozo's instructions and lots of fake rivets embossed. I followed Blondihacks method to first print the location of the rivets on paper, to ensure that rivets aligned on all edges.



Sourcing small screws locally to join the sheet metal turned out to be a problem. Luckily, a local optometrist turned out to be an excellent source of small screws. He had some small stainless steel M1.6 screws with heads exactly the same size as the embossed rivet heads.

I used my Dremel mounted on the milling machine (https://www.modelenginemaker.com/index.php/topic,12280.0.html) for drilling and tapping M1.6 holes to fasten the top plate to the side plates.



All the tender tank parts ready to be fluxed and screwed together for soft soldering:



And after soldering, pickling and a bit of Scotchbrite (this short sentence belies a marathon session of fluxing, assembly, soldering, pickling and re-soldering!):





Quite a few of the screws did not solder, even after pickling all the parts and screws before soldering. Pickling probably did not clean the screw holes well enough. An ultrasonic cleaner may be the answer. Rather than trying to get the screws soldered in, I decided to fill and seal the holes with JB Weld instead.

I also found (by luck) that reheating a soldered joint and then only applying some flux, will more often than not 'pull' the solder out from the joint to form a fully soldered joint.

And finally, with the dummy side plates attached, it now really is beginning to look like  a tender:





There are still some small dents here and there on the curved edges of the copper side plates which happened during forming, which I hope can be filled and levelled with etch primer when painting.

Now I only need to make the coal stopper, to finish the tender tank section before moving on to the man hole.

[Kim]

That is beautiful!  You're doing a bang-up job on the tender, it's coming along wonderfully! 

Kim

[Admiral_dk]

Looks good  and a LOT of work ....

Per