1" minnie

Hello All..

A Friend of mine is wanting to start building the L C Mason 1" minnie.

The original plans are still avaialble but there also seems to be a metric version available.

Has anyone built from these plans ? wondered if they where any good.

Thanks

The metric plans have only been about for a couple of months so certainly none completed, I have read of a few other people thinking of starting one using the metric drawings but not seen any sign of work.

There are a couple of things that are not right on the metric drawing such as the cylinder studs protruding from the boiler, OK on full size where they could send a boy into the boiler through the manhole but in miniature you would never get the cylinder in place!!. I have e-mailed the source to make them aware of the error but have not seen a revised drawing. Its also still drawn to suit imperial DP gears not metric MOD ones.

Whichever version you decide to go for I would highly recommend you track down a copy of LC Mason's book "Scale Model Traction Engine Building - featuring Minnie" Its out of print and fetches a premium but worth every penny. There is also enough info in the book to build the imperial version so you would be saving the cost of a set of plans, thats how I built mine.

J

There are 3 or 4 on ebay at present, which means that prices may not get too high. As with all of Len Mason's work, the book is very comprehensive and well written.

Rod

I just found the drawings for the metric version. Browsing over them I noted that the boiler tube is 67mm, that is 2 ⅝" if I'm not mistaken, not a very common diameter is it? If this is suposed to be a metric version, why not make it 70mm on the drawing?!

Probably because a whole lot of mating parts would also need to be changed, meaning that 2 designs would need to be done. At the time the engine was designed I suspect the vast majority of modellers used imperial.

Andrew

There are two types of metric models those totally designed for metric from the outset and those that have had the imperial dimensions changes to metric with some rounding up or down to commonly available stock size this falls into the later catagory.

If you went upto 70mm then a new cylinder casting would be needed for example and the knock on effect would as Andrew says need a complete redesign.

Though at least 2 5/8" is readily available , not seen much 70mm stuff about.

I've looked around and can not find any 2 ⅝" copper tubing anywhere, got a suggestion where I can get some?

**LINK**

Thanks! I had hoped one of the more ME oriented suppliers would have it, since I doubt these guys would sent a short bit off to Sweden. And finding anything non metric here is very hard!

In that case if you are going to have difficulty getting the other imperial sizes you may be best to get a complete boiler kit which will have all the tube and sheet you will need, ask someone like this . Another option would be to roll from sheet or cut down the next size up and roll it down to size.

Good suggestions all three of them! Thanks!

67mm seems to be a common plumbing diameter albeit most i found were 1.2mm = 18swg and likely not an ideal copper type. If I recall correctly then i read somewhere it was used more in france at that diameter?

I recently was searching for CAD models on the GrabCAD website and found lots of useful information like a 3D Solidworks computer model of a 1" Minnie traction engine. The model was sent to a 3D printer.

Models are free to download after registering from grabcad.com.

Paul

Edited By Paul Lousick on 24/09/2015 23:49:28

Hi,how do you fill the boiler on a Minnie please?

The Filler plug is the square headed plug in the middle of the cylinder flange on the valve chest side, that can be used for initial fill when cold.

Thanks for that Jason, found it.

I need to pressure test this for my own safety and generally found out how to fire it up and maintain it.

Any ideas where I could find this info as Im sure you dont want to list it out lol??

Thanks.