16mm IDRIS

Hi John & Dave.
Thank you both for your replies. I knew there must be a reason.
The Chemistry there makes sense as well.

Looks like I need to buy or make some square Phosphor Bronze.

You could machine 1/16" off one face of a piece of 1/2" round PB to give a flat surface to solder onto the boiler or do all 4 sides to get some square stock.

J

Water gauge bushes made. 5/8" Round PB made square.
Waiting on 3/16 Tap for the final bushes.

Looking good so far Alex....

Might have a go at making one myself...but mebbe I should finish the DeWinton version I started....?

Forgive me if this has already been covered....
I have an 18" length of 2" Copper tube.
Whats the best way to cut it ?
A Pipe Cutter will curl the ends in.
I thought about a Parting tool in the lathe with the tube held in cones.Could get Messy!
I have a Band saw but the blade is fairly corse.
I'm not the best with a hacksaw.

Thanks

Put a strip of tape or a cardboard collar around it and use it as a sawing guide. Use the finest toothed hacksaw blade you can get and go gently.

Neil

Alex,

Just cut with saw and true up with a file.....it's not precision engineering you know

Hacksaw it is then. Thanks

Hi Guys. Just had the latest ME drop through the door.
Martin makes Reference to www.brandbright.co.uk

Heading to the website, they are retiring and may or may not have the various required items available.
Can anyone suggest other suppliers of similar items ?

Have a look through this list of suppliers

What items do you need that they supply?

Not having access to the latest ME makes it difficult to help......(I've no intention of taking out a subscription before anyone suggests......)

Steven. This is my first Loco build and great fun it's been so far. I have made a couple of Stationary Engines. (Puddleduck and Dads n lads). This is quite ambitious for me.

I need:
Wheels, Axles, Cranks, Safety Valve are the items mentioned in this edition.
Wheels I can make if required. I have MS and Cast Iron. 1 1/2" flange. 1.323 tread.
Axles I can make - but have no drawing or details. Looks like they are 1/4 " dia from the Bush drawing.
Crank webs I can make.5/16 Throw - I guess that's enough info.
Safety Valve I'd rather not make.

Sounds a bit like I'm moaning, That's not my intention........

Alex.

Took the plunge and cut the Boiler tube tonight.
Drawing says 6.400"
My cut is at 6.470" less than 1/2mm to big. That'll do.

I mounted the tube on 2 cones on a bit of 8mm rod between 2 vices.
That way I could spin the tube to scribe square lines. I then did up the grub screws to stop thing rotating as I made the cut.


Overkill ?
Well I got a nice square cut very close to the correct length. I say it worked just fine.
BTW, The cones real life job is to hold my Milling Vice on the mill table.

I'm going to make the wheels. Cast Iron or mild Steel ? I have both in a suitable dia.
Axles will be Silver steel, probably 6mm rather than 1/4 " as I have loads of 6mm silver steel rod.

Just to let you know, at Jason's suggestion I asked Martin Ranson to look in on this forum but he seems to be away on holiday. I haven't managed to get him by phone or email since the end of March.

Diane

Hi Diane. Thanks for the update.

Alex, I would hope that there will be drawings for the wheels, axles and cranks in forthcomming installments so you should be able to make them. The saftey is something that can be bought from a number of suppliers, just hold off drilling and threading teh bush for it until its in your hand incase the thread is different.

Steel will be fine for the wheels.

Reference IDRIS 16 mm loco. From martin ranson, sorry for the delay but my old computer is dying. Farewell to the old tower with the lovely large screen. I am using my wifes laptop with a tiny screen. I do not know why Diane Carney has been unable to contact us, especially by phone. On most days one of us is in, sat very near the phone. I have said to Diane that I am very happy for her to give my phone number to anyone interested in the IDRIS loco. In this case, especially to Alex Collins. For us to start a technical discussion by Email will take a very long time. It will be far quicker by phone, any evening after 6.30 PM. Assuming both of us have the ME magazine open at the appropriate page we should be able to sort out his problems. Probably I will learn a lot as well.

ALEX COLLINS 19/3 ... using metric taps is perfectly OK and easy for things like the pressure gauge elbow. However for something like the stainless spindle in the gas supply valve be careful. Assume a thread of 3 x 0.6 mm was used it may change the characteristics of the valve opening. Using a size of 3 or 4 mm metric thread gives a choice of 3 different pitches. Using a size of say 5, 6, 8 or 10 mm diameter gives a choice of 4 pitches available. Be careful which one you use to match any particular ME thread.

ALEX COLLINS 24/3 ... using loctite on the rectrictor may be awkward if it gets too hot. Possibly use 2 nuts locked hard against each other, or silver solder one nut on the end of the thread. The thread sealer was intended for the thread inside the fitting. As regards the smooth point of the valve spindle I always use a smooth needle file and then some very fine emery. Try 400 grade then 800 then 1200 grade. A bit of oil on the emery helps with producing a smooth surface. If you do not think it is safe to do this on the lathe then try using a cordless drill instead. The fire tube inside the boiler should be as low as possible, just clear of the inside surface of the flanged boiler end. Your first guess for the water gauge bushes was correct, they are drilled through into the boiler. The 4 or 6 BA bolt used as a temporary clamp was deliberately rusty so it could be removed later. The top end was then plugged. As regards the slots in the burner tube, the 0. 5 mm slitting saw is better and quicker than my method with a small hacksaw ground down. Providing the saw did not have any sideways wobble the slots will only end up a tiny bit wider than mine, can I suggest that you fire up the burner in a spare bit of 22m tube and see what happens. I have always used bronze or brass for the tubes, what will happen with the copper long term, I do not know.

ALEX COLLINS 13/4 ... for a supplier try Roundhouse in Doncaster. tel 01302 328035 or www.roundhouse-eng .com. I wrote this article in the spring of 2014, I have since discovered that the wheels and axles started life in the Roundhouse factory. I have purchased more items from them very recently. Diane carney has my phone number on file. There must have been some mix-up with the number, I have said to her that I am perfectly happy for her to give the number to anyone interested in building the loco. Much quicker than endless Emails. I would love to talk about model engineering, sounds like I will learn something new.

DRAWING ERRORS ... issue 4506, figure 7, down at the bottom of the picture are the words "2BA thread" . Just on the left of this is a strange lump of metal with a left hand thread, I have no idea what this is, certainly I did not place it there. A computer gremlin has added it. Going up the drawing to the top of the lubricator body in the middle, there is the word "drill" .. just under it was an arrow pointing downwards to indicate the location of the small hole 0. 021 " diameter. This is drilled carefully into the crossbar. Lastly in fig 5 there is an error which is mine, very sorry. At the top there is a measurement given as "distance between flanges nominal 1.232 " The vertical lines show this as the measurement of the inner flanges, obviously it should indicate the outer edge, the bit where the wheels fit onto the track.

Regards, martin

Hi Martin and thank you very much for your comprehensive reply to my questions.
I can get on and complete the Boiler at this point.

Roundhouse certainly appear to have the Axles, wheels and Safety valve.
I'll get them ordered over the next few days.

Another Q for you.
The Gas Tank. Do you plan to provide drawings for that ?
They seem rather costly to buy and I have a spare ~5" length of 2" tube.....

Alex ... hopefully the editor will give my phone number to you soon ... much quicker ... the gas tank is a square shape ... coming up later in sketches 19, 20, 21, 22 ... it was a best fit for the space available ... next engine I make will have a round one ... much easier to make ... I am just cutting the frames for it.

Regards martin