Hello and a part-built blowfly

[Lisa]

Thanks Shawki, that's pretty much what I'm thinking of doing for the boring.

[Jim]

That's a very neat solution Shawki. I've added that to the 'Good Ideas note book I keep.

Jim

[Lisa]

Today I finished off the front cylinder cover I started the other day, besides the bolt holes of course; which will likely be done on the rotary table in the mill, once it's not full of cylinder blocks.

Dad was sitting at the tailstock end of the bench giving commentary as machined that; nothing particularly helpful, but he was enjoying himself.
The plans say to keep or remove the chucking spigot, whichever is preferred; I think leaving it on looks like the job's incomplete, so the inside and outside faces are essentially identical just to give a bit of shape to it.

Meanwhile the port face on the second cylinder is now at the correct height.

If the weather stays nice I'll mill it to length and width tomorrow, then work on the bolting lugs.

Once both the cylinder blocks are at the same state, I'll make the bolting plate for the lathe cross slide which is need for boring them.
Need to make a couple of between-centres boring bars too, which I suspect I'll need some steel for... I should check.

At some point I'll need to bolt the loco chassis to the milling table as well, if possible; there's a couple of changes needed for the improved exhaust piping, which I didn't allow for when I first made them. I think I'll be able to do this, if not then I'll just have to drill/saw/file/grind.

[Lisa]

I figured I might as well do the other front cylinder cover.

So now they're both to the same state, the pic also shows the slight difference between the inside and outside faces.
The rear covers I won't do till the cylinders are bored, as getting the alignment spigot a nice fit in the bore is a little more critical on those.

Next thing on the lathe will be to make up the between centres boring bars, though I won't have the steel for one of those till the week after next (hopefully).
In the meantime progress continues on milling the second cylinder block, which is gradually getting there as I distract myself with other things.

One thing I've been having difficulty with, is getting hold of material for the smokebox; there's a perfect size of steel pipe available (125mm bore, 5mm wall) which no one seems interested in selling a 4¼" length of (including those claiming "no job too small"). I also tried some places that might be able to roll it from flat, but so far there's been those who won't do small jobs, and those who won't deliver.
I've emailed a couple of ME suppliers to see if they can help, so fingers crossed.

[fostergp6nhp]

You could always do the smokebox from solid, but it will take you a while.

[Lisa]

Boring out a 5" diameter hole doesn't sound too appealing. That's if I could get a lump of bar big enough to start with.

[Jim]

Hi Lisa,
I rolled up my own smokeboxes from 2mm plate. The first was for the Burrell with a borrowed set of rolls that had the upsetting roll at the top so you had to make allowances for the flat bit. The Britannia's was done on a better set of rolls with the upsetting roll at the front so you didn't get a flat bit before the curve started.

Jim

Ps: I'll check I may have something

[Deleted]

shame that you're not in the UK , Lisa....I used M-machine metals for my smokebox, they used some 7" OD by 1/2" wall steel tube (stainless) for my smokebox tube, They machined it to size for me leaving the machined section on the stock so that I could check the measurement and part it myself... I'm sure glad that I didn't try to machine the whole part myself, my lathe is too small for such a lump, I can swing it but difficulty getting a tool on the work, as for boring...forget it....

Pete

[Lisa]

Thanks Jim.

In the Blowfly series/manual (I do read it occasionally) it says the smokebox is 'simply' rolled to 5" inside diameter from some 3mm steel; however when I saw some suitable pipe was available, I figured that'd be a simpler option.
If I can't get the pipe, or somewhere to roll some plate, I'll look into rollers; there are some vice-mounted rollers that can apparently do 2.5mm steel, though I'm not so sure they're really solid enough for the task.

Mar 9, 2017 13:27:08 GMT @greenglade said:

shame that you're not in the UK , Lisa....I used M-machine metals for my smokebox, they used some 7" OD by 1/2" wall steel tube (stainless) for my smokebox tube, They machined it to size for me leaving the machined section on the stock so that I could check the measurement and part it myself... I'm sure glad that I didn't try to machine the whole part myself, my lathe is too small for such a lump, I can swing it but difficulty getting a tool on the work, as for boring...forget it....

The grass is always greener somewhere Pete.
I figure if I make up a spider, and use light cuts (or lighter than usual) I should be able to bore just enough to get a nice fit on the boiler. Possibly skim the outside too, with a right-hand boring bar, though that's not entirely necessary. Another option could be to clamp it to the milling table, and use a boring head; fortunately it's a short enough smokebox for this to be possible.

My last loco was designed with a steel boiler, the barrel of which was long enough to also form the smokebox, which greatly simplified things.


Speaking of the smokebox:
"The chimney is a piece of 1⅞" car exhaust pipe, and is silver soldered into a neat-fitting hole in the top of the smokebox shell."
No need for choke apparently... I've got a lump of 50mm bar I intend to turn it from, and some improved drafting drawings lurking around somewhere.

[Lisa]

So today I was going to make a start on the boring bars (or one of them), so I cut some 20mm* rod to length, then went to face it and centre drill it.
At this point I realised I'd have to change the chuck (can't fit 20mm through the bore of the 3-jaw, but can with the 4-jaw), and decided to finish off another task first in the 3-jaw.

So I finished off the main steam pipe tee. This first required deepening the pockets for the o-rings, and checking with a spare o-ring to ensure the pockets where actually deep enough this time (a spare because digging it out of the pockets inevitably damages it), then silver soldering it all together.

At this point it's just been lightly cleaned up with a wire brush, also the hole for the oil inlet re-drilled, as it got partially choked with silver solder.

Also I heard back from a ME supplier regarding the smokebox material, he suspects he's got some of that pipe behind his shed and will get back to me once he's checked... so hopefully that'll work out.

* I'm going to make a 20mm and a 30mm bar, as the smaller one will fit in the cast bore, and the larger will be more rigid for a finishing cut.

[Jim]

If you get stuck I have some plate I could roll up for you, I need to clear out some of the stuff I've collected over the years.

Jim

[Lisa]

Thanks Jim!
I might take you up on that, depending on how things go.

[itchyballs]

regarding smokebox material

just go to your local sheet metal place, they will happily roll the sheet and tack it together for you. I got one done last year for $25 complete from a mob around gosford. Got them from the phone book and paid cash, no receipt. Me suppliers too expensive. Just paid $15 for 50 8BA x 1/2 steel setscrews((( with postage $19.. Better of going direct to the UK.

[Jim]

Hi Lisa,
Deleted my last post and will send you a PM with some options that may help

Jim

[murray]

Hi Lisa

I have Blowfly smokebox you can have for the cost of postage from Melbourne:



It has the front ring and door with hinges and the screw type dart.  And a wee bit of rust!



I started building a Blowfly more than 20 years ago but never completed it.  If you'd like it you're more than welcome to it.  Let me know and I'll box it up and send it.  I'm guessing postage to Qld will be in the order of $20 or so.

Cheers
Murray

[Jim]

Hi Lisa,

Wow! Murray's offer is one you simply can't refuse and it would really give you a head start with your loco.

In the meantime if you ever decide to build a second Blowfly I've got the plate ready to roll.

Jim

[Greg]

What a really nice offer.

[Lisa]

Thanks murray, I've sent you a PM.

Sorry Jim, looks like you'll just have to get on with Boadicea's tender.

Thanks a bunch everyone that sent offers of help, publicly and privately, it is most appreciated.

[Jim]

Oh blow! I was so looking forward to getting my oxy-propane set all fired up now it's back to the boring stuff.

Looking forward to more progress on your Blow Fly.

Jim

[Lisa]

Well, here's a little bit more. Just finished squaring off the port face and was going to start on the bolting lugs, when the neighbour started working on (revving) his car, so I went and hid inside; petrol fumes, aside from the thick air that smells awful, tend to give me nose bleeds, which I can do without. Why can't everyone just stick with steam?