Pennsylvania A3 Switcher

Lovely work Mark, a pleasure to see, going to be a lovely engine, please keep us up to date on your progress.

Dave

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Thanks for the kind comments.

I got a bit more done this week. Starting with the tender frame. Not very exciting, just drilling holes and getting the stock to length. The bit I wasn't looking forward to was drilling and tapping the holes in the long side members. At over 15" they were too long to go in either my mill, or drill press. I ended up making a 'drilling jig' as a tight sliding fit on the end of the side member, then after drilling, I opened up the holes in the jig, to allow me to use it as a tapping jig. It worked a treat.

There are still some holes to drill in the end sills, but it is mostly complete.

With that, on to something a lot more interesting, fabricating the front steps

I cut up some small .04" strips and set them up to make the slots. Kozo shows using a vertical saw, I set mine up horizontally and took it really steady

Then got all set up and silver soldered the first step

I got the other one done to that stage as well. I was very happy with the silver soldering as I'm still a very novice beginner.

This is where it all went wrong. I had miscalculated the measurements for the slots in the steps somehow, and instead of them measuring 5/8" external at the tops, mine were 5/8" internal.

So, I started again, this time making double sure I got the slots in the right places

I'm now waiting on some 1/16" brass sheet to finish the backs of those, so have moved on to making up the rear step. Photos later

Cheers

Mark

I seem to have got a load done over the last week. Helps that I'm not having to go to work at the moment. While waiting for the 1/16" brass sheet to arrive, I got on and made up the rear step:

When the 1/16" sheet turned up, I got the steps silver soldered:

Then started cutting and filing to shape:

There is still some work required to file the fronts to shape, but as its going to be 'freehand' I'm putting that off until I get some inspiration.

I then got on and made up a 'grooving tool' to take a hacksaw blade:

Then got the pins made up for the bolsters:

I also made up the little brackets to hold the front steps:

I had to make up that D bit as even my smallest countersink wouldn't fit

With that, the front end is complete, just the freehand filing to do.....

I then got on and made up the rear coupler pocket:

I then had to radius the rear to 3/4". I was originally going to set it up somehow on the rotary table on the mill, but as I had decided to make up a holding fixture for it, I decided to use the 4 jaw on the lathe:

I then used the same fixture with a 50 degree angle block to mill off the bottoms:

With that done, I got on with the tender tank floor, cut out of a sheet with a fret saw, then milled to dimension and test fitted:

Cheers

Mark

Beautiful work!

I stand in awe of your patience and skill!

Howard

Nice fabrications - coming along very nicely Mark.

Regards,

IanT

Top notch work Mark!

Thanks gents for your kind comments.

I got a bit more done this week, starting with some woodwork. I cut out the former from a block of oak that I got from e-bay a few weeks ago. I also put in 3 registration pins along the centre line, shamlessly stolen idea from Kim's build log here: Link to Kim's Build Log

With that made up, I started rounds of annealing and hammering using my plastic faced mallet. It didn't go too badly, just one corner that I messed up a little, after a few goes with a pair of pliers and some more annealing and hammering, I managed to get it reasonable:

With that done, I got them separated and made up a block that fits the table on my mill to line up the top. I used the edge finder on this block to set up and square up the bottoms:

I'm now waiting for some 5/16" square brass for the bottom fixing for these, but have got a bit more done in the meantime. I'll update later

Cheers

Mark.

Well I started to read the other guy's blog there for a minute or two Mark - but thought I'd best stop and watch your progress here instead. ( No Spoilers then - although I have read the book! )

I like the idea of the locating pins and making the symmetrical sides in one go (instead of two pieces). I'm sure that will come in handy sometime.

Anyway - Great stuff as usual !

Regards,

IanT

My first look at this thread - making models is not my thing - but I would recommend anyone making something, to manually turn the spindle, to make something based on a wheel. No chance, if you forget to remove it, of a flailing handle which may go into orbit as it is clearly very unbalanced. On a safety scale, I’m afraid I wouldn’t rate it.

For slow turning, such as threading, a balanced manual handle could be left in situ - if one is careful.

Even more important if your lathe motor is not soft start, at the very least. Downright dangerous, potentially, IMO.

Hi Ian,

I have spent hours going through Kim’s build log, it is a great reference with loads of tips. Many thanks for your comments. There is another build website that I’m following, I’ll link to that with my next post detailing the bending Jig that I’m in the process of making.

NDIY, many thanks for your opinion.

Cheers

Mark

Evening all,

Whilst waiting for the side 5/16" square bar to turn up, I have been working away on making a 'bending jig' for the horseshoe parts. I bought the 20mm plate of ali a couple of years ago with the intention of making a mini pallet for the mill, in much the same way as the one I made for the rotary table:

I just didn't get around to it. With the horseshoe parts to bend, I have been looking around at other peoples build logs to see how they approached this. Pat Hucheson's build log gave me some inspiration and it also prompted me to start on the mini pallet. Link to Pat Hucheson's Build Log

One of the annoying things with the rotary table pallet is that the holes are never in the place where I want them, so with this one, I'm just going to drill and tap the holes as I need them:

In the above photo, you can see that I have scribed some lines in the top of the pallet, I did this with a scriber tip held in a collet and used the DRO to scribe where I wanted the lines

I got the bars made up and ready to bend:

Then, with a couple of 1 1/2" dies made up, bent the first bar

Reading Kim's build log, I followed his lead and annealed these bends 4 times during the process of bending

It worked really well and apart from a couple of small tweeks, it looks like its going to do the job. The plan is to make up a set of dies for the other bar and also a couple of longer ones to bend the sheet, I'm also going to crib Pat's idea of a 11.6 degree block to bend the verge board as well.

The other thing I'm going to use the pallet for is as a holder for the die block for embossing the rivets, more on that later.

Cheers

Mark

Great progress!

How does the switcher compare with other 3.5" "starter" engines?

It looks capable, and I want a 0-4-0 for reasons of flexibility.

Hi Roger,

I'm afraid I can't answer that for you. As this is my first foray into engine building, I don't know how it compares. What I can say is that Kozo's instructions are excellent, with the dimensions specified being absolutely spot on so far. I'm learning a lot of new techniques and am growing in confidence with every piece that fits. I can see why the tender gets built first now.

I have got a load more done yesterday and today (helps that i'm not working at the moment, but that is going to change next week, so this build will slow down considerably)

The 5/16" square for the side plate brackets turned up, so i got it to length, drilled and tapped the holes for holding it down to the bottom plate and then nicked Kim's idea of using a wood router bit to radius the ends (same router bit used for rounding the wooden former, so it should end up pretty close)

I then made up a piece of aluminium to use as a jig to hold the bottom horseshoe in the vice, then spotted and drilled and tapped the holes using the DRO to set the dimensions:

I then decided to set up and drill out the fixing holes for the side brackets and the horseshoe on the bottom plate. In the end, I decided to drill out all of the holes in the bottom plate, I was going to drill out the holes as I needed them, but its a pain to keep swapping between vice and table, so I did them all in one go. There was a bit of clamping gymnastics, but in the end, I managed to do all of the holes in 2 set ups.

I blued and scribed out the set up as a sanity check and was very pleased that all of the holes came pretty much spot on my scribe marks:

That 12.7 PCD 3 hole took me ages to get set up for on the DRO, until I realised that 0 degrees is actually on the x axis, lots of head scratching...

All drilled out and ready to go:

Then it was moment of truth time:

I was pretty chuffed with that, they all line up and the horseshoe is pretty square:

I made up the front little bits and the rear corner member, then had a trial fit of the sides:

Then got one side drilled, tapped and screwed together ready for soft soldering. By that time, I had had enough today.

Cheers

Mark

Bit more progress on the Switcher:

I got the side panels soft soldered to the corner members:

Then got on and made up the punch and die for the fake rivets:

That piece of Gauge Plate is the holder for the die that will be fixed to the mini pallet.

I then got on and did the first bend on the upper horseshoe member, again, 4 lots of annealing and taking it easy with the bends:

I then made up a mandrel to fix to the pallet with the correct internal bend radius for the vertical bends (Kozo specifies the external radius)

Cheers

Mark

I may have missed something Mark - but is the end-shape of the clamping bar for a particular purpose or simply the shape of the material that was to hand?

Good progress btw.

Regards,

IanT

Hi Ian,

I have shaped it to accept the cut out section of the bend. If you look closely at Pat Huchison’s build photos (which is where I got this idea from) he has done the same.

I also cut that section the whole length of the clamp bar so that I can get it out once the two legs are bent up.

Cheers

Mark

Edited By Mark Elen 1 on 14/02/2021 15:13:21

Hello Mark,

Just wondering how this excellent project is progressing as you have been 'quiet' for a while.

Regards,

Phil

Hi Phil,

Sorry for the late reply here. Not much has happened since my last post. I did manage a little over Christmas last year that I didn’t document here, but I’m hoping to get back into this build soon.

Cheers

Mark