Brian's 1" Minnie Traction Engine

Good question, I too assume it is a bit harder so less likely to strip the threads as well as being easier to form them in the first place.

Thanks Jason,

reason I ask is I'm about to make the pump pad on the side of the boiler

should I use copper or pb102, am I just over complicating things by mixing it up

Copper will be fine if you have it, I think thats what Mason used anyway.

Has anyone either found or put together a materials list for making a 1" Minnie from stock (excluding the boiler materials)? This is my next model engineering project and I would like to get all the materials from Midlands show...

Thanks in advance,

Mike

I've not seen one for an engine from castings or all stock materials. Making a list is a good way to aquaint yourself with the drawings.

The set of metric drawings that are on the web have a parts list which would be a start as you could just write the sizes next too each item.

Edited By JasonB on 05/10/2015 16:26:54

Hello All.

Can anyone help me with this one,

I need to drill the holes into the horn plates for the fire box stays,

are these taken from the template, so 1" up by 1" 1/8 across ?

Thanks

No see bottom of page 35 in the book

Had to read it a couple of time but understand it now..

Thanks Jason.

Hello Brian; I am hopefully nearing completion of my 1" Minnie boiler. My pump pad is in copper; as supplied in the kit of boiler parts purchased from Blackgates Engineering. I now need to add the firebox stays on the sides. I have so far found that the construction notes need very careful reading; for example the figure on page 30 showing the drilling template indicates "RH end​" in the top right corner. I will see if my interpretation is correct! I find it easier to cut fine threads in bronze than copper. I also believe that they will be stronger.

I have tried and failed (it seems very complex) to attach a photo of my boiler to date. Also found it impossible to paste my comment from a Word document.

Good luck with your boiler.

Ray

Hello Raymond, not sure to the reason for the problems you are having, but please percavere as it would be good to see another build.

Hi Brian,

It is possible that my latest attempt at posting a photo or importing text from Word, was thwarted by my using the latest upgrade to Microsoft 10 and the Edge browser. I have now transferred to my laptop which uses Linux Ubuntu. So, will see what happens when I try to attach three photos and import text from LibreOffice.

I would like to contribute, but only if the technology is helpful.

Best wishes

Ray

Looks as though it worked for the text; but unable to add the photos. Seems as though I have to put the photos in an album?

Well that worked. Long winded though.

hello Raymond, the reasons for the behaviour are two-fold-

1 It lets us limit the size of all pictures (I greatly upset the mods on another forum by embedding an 80mB image...)

2 HTLML in posts is disabled except in an embed media box, to help prevent abuses.

Glad you got there in the end.

Neil

Hello Brian, I have sent a message to your inbox. Regards Ray Griffin

Morning all.

Just for future use, what size should the boiler gauge be ?

.. 3/4" 0 - 80 PSI ?

Thanks in advance,

Brian

Mine is 3/4"dia x 100psi but 80 should do.

PB102 is a stronger material and yes holds threads better, does not tear like copper can do. Much more durable.

Thanks Both,

Hello all, happy new year to everyone, made an attempt and trying to solder by Minnie boiler this week, needless to say this has ended in disaster..tried several practice attempts using 424 with no real problems, after a few goes anyway, then tried to solder the firebox. Problem I seemed to be having was could not get enough heat into the job, I am using a standard sievert 28mm burner, can anyone advise what size maybe to try, 32 or 35 ?

Thanks

Brian

Bump: So that Brian's last post is not lost in the festivities. Happy New Year everyone.

Brian,

It looks like you find yourself in the same situation as I was about 40 years ago when I was attempting to make a Minnie boiler. No matter how I tried, I did not seem able to get the work up to temperature before I exhausted the flux, which was the correct high temperature type for C24, as it was then.

I still have the shell - throat-plate, barrel, thickening plates, and pump pad, which I managed to assemble and silver solder OK with some help at night-school using oxy / acetalene - (very scary - for me) - which gas do you turn off first?.

The firebox did not, however, want to be silver soldered by me with my propane set-up which was a Bullfinch 1250 / 38mm dia / 12.6 kw / consuming 907 grams of gas per hour and which also kept blowing out! I had a makeshift hearth with lots of coke (as suggested by Mr Mason in his book) to surround the work and conserve the heat.

I gave in and bought a boiler which may not be an option for you as the prices have increased quite a lot since I paid £25 at Reeves in the early 70's.

I did some research last year (Sievert and Bullfinch websites) into propane torches, hearths and methods in preparation for a second attempt. Apart from a lot of successful small test pieces, some more Sievert burners and remade firebox plates - no further progress.

Your Sievert 2941 / 28mm / 7.7 kw output is quite a bit smaller than I was trying to use. I'm not saying that this is not enough - I just don't know, those more skilled at this may say - why are you wasting so much gas.

Another bit of information to bear in mind is the maximum off-take possible from different sized bottles:
A 3.9kg bottle - 25000 btu or 7.3 kw :: 11kg bottle 50000btu or 14.6 kw. etc.

Silver soldering a boiler, even a small one, is a difficult and potentially costly skill to learn.

I hope someone will be along soon to offer some practical advice, which I will also gladly welcome.

Regards

Phil