CONWAY 0-4-0 3 1/2" GAUGE LOCO

[Firebird]

Hi

Thanks Kim and Carl

My rotary table has a 4 jaw chuck permanently fitted so I mounted the mandrel in that to hold the wheels for drilling.

The 2 driving wheels have a 1/2" hole drilled opposite the balance weights



The balance weights have been drilled 3.3mm and countersunk, then used as a guide to spot through to the wheel.



The wheels are then tapped 4mm and the balance weights have their holes opened out to 4mm. The weights are attached to the wheels with 4mm countersunk socket head screws.



Cheers

Rich

[Firebird]

Hi

The wheels have been assembled with a little car body filler





Once set they are rubbed down and cleaned and have a coat of primer



Cheers

Rich

[90LX_Notch]

Nice work Rich.  I have been silently following along.

-Bob

[Firebird]

Thanks Bob

Cheers

Rich

[Firebird]

Hi

I have finished the outside motion brackets. I found the riveting of the small brackets difficult so in the end countersunk the holes with a centre drill



Peaned the rivet over into the countersink then filed flush



1 bracket has been primered, the other ready to be painted.

2 more stretchers have been made. Straight forward enough as per the plans. They double as stretchers and safety angles. In case of a de-railment they will help prevent damage to the motion



They fit here



Moving swiftly on to the horn blocks, I purchased the gun metal castings.

Unfortunately Martin Errors has struck again  . Completely threw me for a while



He has the height of the horn block as 2 5/16". Thats wrong As far as I can see it should be about 1 3/4"

The castings themselves are in pairs so maching a pair at a time should make them identicle. Seperate them after the machining is finished. There is very little room for error, the castings are only a few thou over size in places.

Just one shot of cleaning up and bringing to size



Cheers

Rich

[vcutajar]

Good progress Rich.

Vince

[zeeprogrammer]

Great work.

Loved the wheels too.

[Firebird]

Hi

Thanks Vince and Carl

A few shots of machining the horn blocks





The first casting came out ok, just enough material to machine but very tight. The second casting however was slightly undersize in a couple of places before I started. I couldn't find a decent enough straight edge to start from. whichever way I tried there was always something out  If I got the edges straight the oblong hole was out and vise versa. In the end I made the best of it, making sure the axle box part was true with the mounting. Because they are mounted from inside the frames very little can be seen and I'm not building this to be a show standard engine just something I can play with. Perhaps I should have sent the casting back and asked for a replacment. I think with hind sight I would be better off making them myself from steel or cast iron.

Anyway they are done



I have been looking at the boiler and trying to get things straight in my mind. I have some of the materials but need to order the rest so I have mocked up a rough shape.

A piece of plastic tube has a piece slit out and re-glued



I have printed out the various plates actual size and spray glued them to some card



Cut them out and roughly assemble









From this I have measured for the inner and outer wrappers with a bit of string to gauge how much copper plate I need.

Cheers

Rich

[Firebird]

Hi

Continuing with working out the materials needed I have come across another error.

Looking at the following section of the plans



Look at the dimensions in the lower right hand corner and it shows the firebox wrapper as 1/16" (1.6mm) but in the text it says 3/32" (2.5mm)



I'm assuming It should be 3/32". 1/16" sounds way to thin

Cheers

Rich

[Admiral_dk]

I see both dimension at the bottom right corner - 1.6mm on the inner and 2.5mm on the outer "sheet".

I don't know about you .... but I often look so hard that I overlook important parts / prints / dimensions 

Best wishes

Per

[crueby]

I see both dimension at the bottom right corner - 1.6mm on the inner and 2.5mm on the outer "sheet".

I don't know about you .... but I often look so hard that I overlook important parts / prints / dimensions 

Best wishes

Per

I think his point was that the drawing shows 1.6mm for the inner sheet, while the text says 2.5mm for that same inner sheet.

[zeeprogrammer]

Not knowing anything at all, or what I'm talking about...

Could that 1/16 in the drawing be that feature to the inside of the inner wrapper?
That is, the 1/16 dimension should be to the left?

The text talks about wrapping the inner wrapper around the firebox tubeplate and backplate.

What's the thickness of the firebox tubeplate and backplate?

[Firebird]

Hi Carl

they are the same 3/32" (2.5mm)



Gets confusing doesn't it 

Cheers

Rich

[Jasonb]

If in doubt check with boiler inspector or go with the thicker option. You will need to size for formers to allow for the extra thickness or machine down the 3/8" foundation ring material by 1/16"  (2 x 1/32") Think I would reduce the plate sizes rather than the waterspace.

[Firebird]

Hi Jason

I'm pretty confident it's another typo error. I can't see the firebox wrapper being as thin as 1/16".

Cheers

Rich