A Cracker locomotive

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Stilldrillin:
Nicely done Arnold. :clap:

Like the idea of centre pops, to hold off for silver solder penetration...... :thumbup:

David D

arnoldb:
Dave, Stew & David - Thanks chaps :beer:. Today's soldering wasn't quite as neat though...

David - the centre pops trick I picked up from other modellers - but it's good to show little bits like that for those that have not seen it or are newer members.

A bout of 'flu has kept me from being my normal self for the past week - so I spent yesterday in bed and slept most of it off.
This morning I felt quite a bit better, so started on the cylinder from a bit of 10mm hex brass stock:

I wasn't in the mood to make up a reamer to ream the cylinder, and the hand reamers I have are no good for a blind cylinder, so I used an 8mm end mill to run in to final depth - with a very fine feed both in and out this makes a pretty good finish in the cylinder - as long as the lathe's tailstock is very well aligned with the headstock; which mine fortunately (well, after a lot of work adjusting in the past!) is:

For the cylinder port face I used a bit of the same 4mm bronze the port block is made from - just poked some holes in the correct places and gave it a shallow counter bore with an 8mm slot mill:

Flipped it end-over end, and ran a 10mm ball nose mill over the back side to match the cylinder outside diameter:

And made a flange from 1mm brass plate for a light press fit over the step I left on the cylinder end. This will be used to bolt the cross head and piston gland to the cylinder. I also milled a small corner off the port face block to accommodate the flange:

Then I fluxed things up and used bits 'n bobs to hold it in place on a fire brick:

With a snipped-off bit of 1.6mm silver solder embedded in the flux on the "other side as shown in the last photo" along the cylinder, I heated things with the blow torch from the viewpoint of the photo; not ideal, as the flux closest in view would get direct flame and burn off a bit (hence the reason for the large amount of flux applied!) I also added a dab of solder to the top behind the flange when things were hot; unfortunately a bit too much ::):

Not the neatest job I've done; but that's OK - my defence is "I'm still learning" :D - this was the most complex job I've tried in such a relatively small size.

After a bit of clean-up it looks better; not good; but OK for now:

I forgot to include scale; the screw in the last picture is an M2 and the holes in the port face is 1.2mm (0.01")

This might seem like a lot of faffing around... There's several reasons though. I want the cylinder block to have as little metal as possible on it - with a small live steam engine, it's crucial to keep the amount of metal down to a minimum, so that it can heat up quickly, especially with a small boiler. In fact, I'll be removing even more metal off both the cylinder and port block.
As to silver soldering the lot - ordinary electronics soft solder would have done for this job, but some of my future projects will require accurate and neat silver soldering on small complex parts, so I'm just practising!

I wanted to do a bit more today, but it started getting chilly again, so I went inside; hopefully I'll feel better during the week or next weekend.

Regards, Arnold

ozzie46:

Hang in there Arnold, Hope you feel better soon.

Cracker's coming along nicely. :thumbup: :thumbup:

Ron

DaveH:
Arnold,

Looks good to me, :thumbup: a bit of a clean and polish - perfect :clap:

Look after yourself mate, hope you feel better soon :D

:beer:
DaveH

Stilldrillin:
Arnold,
I love to see the adaptation of milling cutters. I do it a lot, when necessary. :thumbup:

Don't be too hard on yourself with the outcome. Looks very good to me! :clap: :clap:

Hope you are soon feeling 100% again...

David D

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