Pennsylvania A3 Switcher

[WearyParticipant @weary]

I have been wondering how you are getting-on so was very pleased to see that ‘works are progressing’.  It looks really good!  Am looking forward to seeing it progressing.

Baz, As Mark mentions, Blondihacks on youtube, is currently doing a build thread.  Other build and similar ‘A3’ threads are available on youtube.

Phil

[DalboyParticipant @dalboy]

Great to see that you are able to get back onto the switcher build. I do enjoy seeing how people approach their builds. So far an enjoyable build

[BazParticipant @baz89810]

Thanks Phil I will take a look at YouTube and Blondiehacks.

[Mark Elen 1Participant @markelen1]

Many thanks Guys, for your kind comments. As my friend and I were joking about just lately, I seem to be spending a vast of time either tool making or jig making, and, not a lot of time model making.

The next big sub-project on this build is the sheet metal with the fake rivets. I have already made the punch and die, and hardened and tempered them.

I still need to make the jig for punching the rivets at the correct spacing from the edge, and decide how exactly I’m going to lay them out. Right now, I’m thinking of going ‘full blondiehacks’ and buying a copy of the software she was using.

thanks again for your comments

cheers

Mark

[Mark Elen 1Participant @markelen1]

Kozo’s books are amazing. Every one has so much detail, that, even if you aren’t going to build what he is detailing, there are so many set up ideas, you just go…. Why didn’t I think of that?

After I got the A3 book, I bought the next one. Then the next. And the next.

I’ve got the lot now. Including the 2 latest  K27 books.

All of them are works of art in their own way.

 

[Graham TitmanParticipant @grahamtitman81812]

 

Very nice keep it up watching with interest.Graham

[Mark Elen 1Participant @markelen1]

Many thanks for your kind comments Graham.

I have managed to get a bit more done this week, another of the parts of the build that I really wasn’t looking forward to. Embossing the rivet detail on the Tender Tank.

I made up the punch and die quite a while ago and hardened and tempered them.

I milled out a pocket in my ‘use it for everything’ jig/mini-pallet block, then made up a fence:

I cut and milled a couple of lengths of 1mm brass sheet to width before cutting them to length and milling out the 1mm offset for the verge board

I also spent quite a while testing exactly how much pressure was required with the punch to create a reasonable rivet. I think i may have drilled the die a little too deep, as with too much pressure on the punch, it will punch a hole in the sheet. Some of these were done before I made up the fence, some after:

I also bit the bullet and bought a copy of Infinity Designer, and went through the learning curve of new software – I found the spacing on this was incorrect – they were too close together, fortunately, i used the offcuts from each side sheet as test pieces and ran through the whole process with these, to get a bit more comfortable.

On to riveting…

And this is where we are now. I need to drill out a few of those rivets for fixturing screws and bend the plates, but overall, I’m happy with how this turned out

Cheers

Mark

 

[Mark Elen 1Participant @markelen1]

Lots of work in the last few days, but not much to show for it.

I filed off the dummy rivets where the fixturing screws were going:

Then drilled out the rivet 1.1 mm, I have found that 1.05mm (the correct tap drill size for 12BA) to be really tight on the teeny tap, especially in the 6.35mm brass bars. Then drill the matching part, tap, then drill out the brass plate to 1.3mm (clearance for 12BA).

10 of these on each plate. Plates on, off, on, off, then all off to drill and tap out the horseshoe member.

Then finally, i have cut down the vertical board and filed and sanded it to shape

Cheers

Mark

[Mark Elen 1Participant @markelen1]

Bit more done.

Starting with squaring off the top sheet and bringing it down to dimension width wise using my Blondiehacks inspired sheet metal clamping system:

I then printed out a rivet spacing sheet and spray glued it to the back of the top sheet, after annealing the sheet.

i did the rivets for the first 20 or so, then did the bend for the bottom:

The next step is to bend the top, cut the top back to meet the sides that are already done and cut out the curved section for the horseshoe and Verge Board, then I can space the remaining rivets, so that they all meet up and look about right.

Cheers
Mark

[Author]

Posts