Most of my model engineering output is in the form of lost wax castings which I supply to clients wanting the very best that their money can buy.
For the most part these castings are destined to become part of the model that the client is building.
This work usually requires me to produce a 3D drawing of the part , so that a pattern can be printed .
From this pattern a flexible rubber mould is taken , allowing the wax replicas to be made which ultimately become the castings.
However when I am on my own time my interest is in gauge one steam locomotives , and in particular the Merchant Navy Class engines which ran on the southern region of the British railway network.
It is not my intention to bore you with details of these engines , if you want further information there is plenty to be found on the net.
No , I rather thought that I would describe how I go about producing parts for the small batch of engines that I am slowly building , nothing will be new to the old hands but perhaps some newcomer to the hobby may find a useful tip or two.
As I started out saying I mostly make castings , mainly in copper based alloys , brass ,bronze , gun-metal and nickel silver.
I always try to design the parts that I require as castings because there is always room in a mould of customers work for a few bits of my own .
You might say that my stuff comes almost free , quite cheap anyway.
Right at the front of all engines are the buffers , these absorb the shock loads during pushing operations.
Some components are common to a wide range of engines and I make a very nice gauge one ( 10 mm to the foot scale) buffer stock.
I also make a buffer beam casting for the Merchant Navy class
Unfortunately , to save money on the laser cutting , I changed the frame steel thickness from 2.0 mm to 1.5 mm so the cast beams no longer fit , I decided that rather than modifying the castings it would be easier to fabricate new beams.
Which I did from 5/32 sheet brass , with silver soldered joins.
the short length of sprue left on the back of the buffer stock helps locate its position on the beam and keeps it secure whilst being soft soldered.
The beam is attached to the frames with countersunk head socket screws , with the restricted access these are easier to fit than anything else as they can be firmly held on a long series allen key.
The screw holes need to be very accurate , and repeatable between sets of frames so I use a jig made from a spare piece of frame.
The jig is positioned and clamped to the beam with a small tool-makers clamp and the first hole drilled.
after drilling the hole a second clamp is added alongside the first.
with the second clamp firmly home the first clamp can be removed and the second hole drilled
By using this method the beams and frames are interchangeable , hopefully if I can maintain this method throughout the subsequent builds should be like assembling kits.
to be continued
For the most part these castings are destined to become part of the model that the client is building.
This work usually requires me to produce a 3D drawing of the part , so that a pattern can be printed .
From this pattern a flexible rubber mould is taken , allowing the wax replicas to be made which ultimately become the castings.
However when I am on my own time my interest is in gauge one steam locomotives , and in particular the Merchant Navy Class engines which ran on the southern region of the British railway network.
It is not my intention to bore you with details of these engines , if you want further information there is plenty to be found on the net.
No , I rather thought that I would describe how I go about producing parts for the small batch of engines that I am slowly building , nothing will be new to the old hands but perhaps some newcomer to the hobby may find a useful tip or two.
As I started out saying I mostly make castings , mainly in copper based alloys , brass ,bronze , gun-metal and nickel silver.
I always try to design the parts that I require as castings because there is always room in a mould of customers work for a few bits of my own .
You might say that my stuff comes almost free , quite cheap anyway.
Right at the front of all engines are the buffers , these absorb the shock loads during pushing operations.
Some components are common to a wide range of engines and I make a very nice gauge one ( 10 mm to the foot scale) buffer stock.
I also make a buffer beam casting for the Merchant Navy class
Unfortunately , to save money on the laser cutting , I changed the frame steel thickness from 2.0 mm to 1.5 mm so the cast beams no longer fit , I decided that rather than modifying the castings it would be easier to fabricate new beams.
Which I did from 5/32 sheet brass , with silver soldered joins.
the short length of sprue left on the back of the buffer stock helps locate its position on the beam and keeps it secure whilst being soft soldered.
The beam is attached to the frames with countersunk head socket screws , with the restricted access these are easier to fit than anything else as they can be firmly held on a long series allen key.
The screw holes need to be very accurate , and repeatable between sets of frames so I use a jig made from a spare piece of frame.
The jig is positioned and clamped to the beam with a small tool-makers clamp and the first hole drilled.
after drilling the hole a second clamp is added alongside the first.
with the second clamp firmly home the first clamp can be removed and the second hole drilled
By using this method the beams and frames are interchangeable , hopefully if I can maintain this method throughout the subsequent builds should be like assembling kits.
to be continued
