Hello and a part-built blowfly

[Lisa]

Did just a little bit more today, seeing as the humidity's gone away again. Just milled one of the bolting lugs, one to go.

Dad was not at all impressed by the sound of the mill cutting today (cutting beautifully, just noisy), and so spent some time sitting outside giving me grumpy looks.

[Lisa]

So today I worked on the smokebox, this involved the complex task of finding a knife so I could open the box, thanks murray!


So of course I had to stack the smokebox together with the saddle and chimney cap/base castings to see how it looks.

[Jim]

Wow! Amazing how a smoke box complete with door, sitting in place with the chimney suddenly turns a chassis into a loco. No holding you back now.
Looking good Lisa.

Jim.

[Deleted]

looking great Lisa....who can resist putting bits on just to see how things look?...I certainly can not....

Pete

[Donald G]

Me neither, I think it helps to drive you forward
Donald

[Lisa]

Not a lot has happened recently due to a variety of reasons, including drunk siblings and some storms from cyclone debbie drifting down this way and flooding the workshop several times (there was 9" of rain one day last week); no damage here, just can't work while standing in a stream!

But, a bunch of bits turned up in the mail today, including the material for the crosshead / little end pin, so the crossheads can be finished now.

Also, this length of 1¼" rod, which John at Hobby Mechanics was kind enough to supply faced and centre drilled for me (too big to fit through my headstock, and I don't have a steady for the sieg lathe, so having it already done simplifies things muchly), this will become the larger of two between-centres boring bars for the cylinders.

[Jim]

The weather has been shocking but on the bright side having Hobby Mechanics machine and centre drill the between centres boring bar is a nice gesture and a head start for the next job of boring the cylinders.

Jim.

[Lisa]

Today I finally finished milling the port faces and bolting lugs on the cylinders, next I'll mill the top surfaces of the cylinders which will also clean up the outside faces of the bolting lugs.

The top faces is also where the exhaust piping connects to the cylinders.

Then it'll be on to making up the bolting plate for the lathe cross slide, as well as the between-centres boring bars, before getting to boring the cylinders. Though I may finish the crossheads first, simply because I have all the materials now so there's no need for them to sit around half done.

Meanwhile I put the running boards / footplate on the loco, along with some of the brake linkage, just to look at it all:

[Jim]

That's starting to look like a pretty serious locomotive Lisa. It really gives you a boost when get to the point of being able to start to assemble things like the running plates and have the chimney/smoke box in place. You're doing a great job there. 👍👍

Jim.

[Lisa]

Thanks Jim, the whole lot's got to come off at some point though, as I need to make a couple of modifications to the frames... which will be extra fun with the chassis being welded together!

[Jim]

If the frames are welded together would you be able to carry out the mods treating the frames as a large single unit?

Jim

[Lisa]

That's the plan yeah, with a bit of luck I should be able to hang the buffer beams over the ends of the milling table with the chassis side-on, then do one side, flip it, and do the other.
Otherwise, hacksaw and file time, which hopefully won't be too bad.

[Deleted]

I have a similar issue, Lisa, I have two vertical elongated slots that need machining in the frames (one either side) for the sand pipes to pass through, no sign of this on the drawing of the frames but then you find it on the sanding gear drawing much later...lol
When I strip the frames down for painting I will then machine these slots with the chassis as one assembly on it's side, should be fun...not...

btw.. nice work on yours...

Pete

[Lisa]

I figured I'd get the crossheads finished before moving on with the cylinders, so today I bored out one of the connecting rod pockets.


Some sacrificial packing was needed between the crosshead and chuck jaws so as to machine the full diameter without chewing on the chuck. The actual machining didn't take as long as setting up, I had a pilot hole to start from, so spent a while with the DTI getting that running within half a thou of true.

Meanwhile the humidity's put a light coat of rust on the cover plate, I'll have to slather them in a bit more oil after cleaning that up.

[Lisa]

With the 4-jaw chuck back in working order, I bored out the connecting rod pocket for the other crosshead today.

These now just need the piston rod holes, and oil holes for the slides to complete. Plus the pin of course.
Also noticeable is the step on one edge of both crossheads, this is the result of using what I had to hand, material-wise. But I did position it such that most of it was removed by the cutouts on that edge, so it shouldn't have much if any negative effect.

[Lisa]

I wasn't well for much of last week, which resulted in me sleeping more than anything else. But feeling better now I had a bit of a poke about in the workshop this afternoon.
I was going to finish off the crossheads, but then realised I don't have the tapping drill for the piston rod hole... so that can wait.

Instead I just faced and centre drilled the smaller of what will be the two boring bars for the cylinders.

So I can get on with cross drilling these and grinding up cutting tools for them and such. Meanwhile I also need to machine the top faces of the cylinder blocks, then take the vice off the mill so I can make the bolting plate for the lathe cross slide. I can also make up the crosshead / connecting rod pins, and bushes for same; this I can do in the Taig lathe while I pull the saddle apart on the Sieg to drill and tap it for the aforementioned bolting plate.
I also need to search through the box of odd castings as I suspect I have some handy bronze bits for the glands. I should probably sell off some of those bits too, there's about half a Heidi II chassis laying around in bits, which could go toward a boiler at some point.

[Jim]

Sorry to hear you've not been well Lisa but from what you say you're now on the mend and back in the workshop for some restorative therapy.

Jim

[Lisa]

Thanks Jim, speaking of restorative therapy...

Today I milled the top surface of one of the cylinders flat, this both finishes the bolting lug to size and makes the face that the exhaust will come through.

The actual exhaust connection I don't have any real drawings for; the original design called for a tapped hole to screw an elbow into, but had small passages and sharp corners. The improved design calls for o-rings and studs and larger free-flowing pipes, but other than some sketches one is left to work it out fro one's self. Not that that's particularly difficult, and there's plenty of other areas in the design which are left to one's imagination anyway.

So, I just have to do the same to the other cylinder, then I can make the bolting plate, fixtures, and tools for boring.

[Lisa]

I've been busy with a little paid programming job I picked up recently, but decided to ignore it for a bit today as I wanted to do a little something in the workshop.

So I finished milling the top face of the other cylinder, so both are now to the same state and ready for boring.


So now I need to make the bolting plate for the lathe cross slide, which I have this piece of 100x10 frame offcut for:

It obviously needs some cleaning up, so I'm thinking of using a little of the money from this job to buy a 25mm end mill; the machine says 30mm is the max capacity for face milling, so 25mm will give me a bit of leeway I figure.
This will get 5 rows of M10 holes in it at 18mm centres (multiples of 1.5mm, which is one turn of the handwheel, so every hole will be at 0,0), plus clearance and bolting holes to fit to the cross slide.
I'm going for M10 as that suits the clamp kit I have for the mill, so I'll be able to use what I already have.

[Lisa]

I managed to get into the workshop for a little bit today, and had a look at what needs doing to the frames.

The bolting plate now has its its own thread here, but I'm waiting for some bits and pieces to arrive before continuing with that or the boring bars.

So the frames need some changes to them, and I wanted to see if I could do that in the mill, so I dropped the wheels out and brought the frames to the mill for a look; it looks like it's mostly possible:

The main issues were if the table had enough travel, if the handwheel was going to get in the way, and if the tool could get in to do the job without the buffer beam getting in the way.
As you can see the rear axlebox slot (I hesitate to call that the horns) is perfectly positioned relative to the handwheel to avoid anything fouling.
There is plenty of clearance for the tool to get in, the bufferbeam's not an issue at all.
However there isn't quite enough travel to do everything I want.

The two jobs that need doing are:
The ½" hole above the cylinder / valve chest cutout needs to be opened up to 16mm, and then slotted to the top of the frames. This is to suit the bigger exhaust piping for the improved drafting arrangements.
The cylinder / valve chest cutouts need enlarging a little, as while the length is fine, the height is a bit too narrow; blame this on the impatient teenager (me) who made the frames many years ago.

The exhaust hole can be done without issues, however the cylinder cutouts I just don't have enough travel for; but I figure I can do what I can and file the rest, which will at least be less filing than if I had to do the whole thing.
I could get all fancy and decide to bolt the front buffer beam on, then grind the welds off, which would mean I could mill the entire cylinder cutout; but I figure that's probably more messing about than just filing the bit that the mill can't reach.

Also, I advise anyone building a Blowfly to bolt the frames together, ignore the construction book/articles that say to weld it, you'll save yourself a lot of hassle even if you don't have to mill things later on.