Page 22 - NMRA Roundhouse January-February 2020

Locomotive Scratch Building
Eric Belshaw MMR Part 1
Patent Super-Garratt Articulated Locomotive - Beyer, Peacock & Co. Ltd., Gorton Foundry, Manchester
AP MODELLING ARTICLE
S cratch building begins with the So assuming you have decided on Scale, Before I begin my ramblings on my
need to make a working model. My locomotive building was driven by the requirements of
the Motive Power Builders section of the Achievement Program.
In that section you have to build 3 loco- motives or powered mobile machines. Each one must be capable of moving under its own power. One of those 3 models must be ‘Scratch Built’.
So, what are the limitations? Well you
can build anything you like, be it a copy of an original or a freelance machine. Most modellers have a ‘natural’ scale that they are comfortable with like O, HO and N etc.This will make you feel right as you make the parts and structures that form your machine. My natural bents covered HO, OO and O. If you don’t know what your ‘Natural’ scale is and you try to work from scale drawings, then the work will be much harder. I know because I started 2 projects in N and it was hard to imagine the compo- nents and their ‘Feel’ was wrong for me, so they didn’t get finished.
That was something like writer’s block really, not a skills issue.
Miniature Pillar Drill
Compound slide makes the pillar drill into a milling machine
Bench Vice
A large selection of small High Speed Steel (HSS)drill bits
Engineers centre punch and stainless steel rules in imperial and metric
you then need to select your prototype. My watchwords for the selection are: 1.The simpler the better
(especially for the 1st one) 2.Work within your skill and
available machine tools
3. Select your model building material
from those that you are comfortable with. If you like Casting Bronze and Mig or Tig welding Stainless steel while working to T scale but you can’t drill holes, then develop that which you are good at while minimising the things you are not.
You will have to step outside your com- fort zone eventually, that is what the AP is for, but you can make those steps easy on yourself.
I discussed my scratch building with a fellow modeller at a convention once, he had a grandiose idea of making a fictitious 2-6-6-2-2-6-6-2 Mallet Garret with walschaert’s valve gear. In the ensu- ing discussion it came to light that this would have been his first scratch build. Hmmmm.
Note Strangely, this was a real locomo- tive, I found the drawings online years later, see above title photo.
experience of building locomotives, I would like to suggest tools and machines that reduce some of the risks in building anything, not just locomotives.
When drilling holes in metals, the least repeatable device is a hand drill (pin chuck, bow drill or crank gear style). Their near neighbour is the handheld power tool (Dremel style etc) both of these types of item require drill ‘square- ness’ skills which make jigs necessary. Squareness issues are eliminated when a pillar drill or milling machine is used.
Eric Belshaw MMR
An Engineers Scriber either type will do. However the smaller your scale the sharper the scriber must be. Engineers Square and Dividers
ROUNDHOUSE - January/February 2020
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