fowler a7 traction engine scale model engineering mikes-models

Session 2 - 28th March 2008

I thought I would give the Mills a rest for a little while and have a go at the
Fowler for a change. Several issues arose from today's session. Firstly I need to
address the storage and work area to accommodate the Fowler. My idea is to
suspend it from the ceiling! It can be stored up out of the way then lowered
down and legs lowered to stand it on its own work bench. I am just designing the
system now.

Because of my disability I will power it with an electric winch. Basically I will
have two sets of rollers mounted through bearings and attached to the ceiling
joists. These would be the pulleys and wire run around them to the winch. This
will form a little one off project in its own right so if you want to know more go
to the one off projects page.

However, lets get back to the Fowler. Today I have gotten to the stage of
mounting the front wheels and axle. To get here I had to manufacture a securing
pin [photo1 below] and this was a simple and pleasant task where I wasn't
working to the very close tolerances of the Mills! This made a nice change and
only goes to prove that making very small items to accurate measurements is an
advantage when then going back to other projects.

To make the pin as per the plan [photo 2] I simply turned a piece of steel bar in
the 3 jaw chuck to a diameter of 0.250" for a distance of 1.250". I then took the
stock material over to the milling machine and milled an 1/8th or 0.125" from
each side. To ensure the two milled flats were parallel, I used the digital angle
meter to set the bar over. To be able to make a measurement I put a square bar
of brass clamped to the flat and mounted the angle meter on the brass.

Once the milling was completed it was back to the lathe to part the pin to length,
finally cleaning it up. When trying it in the slot cut into the axle mounting shaft, it
didn't seem to want to go through. I reversed the entry point and found it was
going in about the same distance. Looking further into the slot in the axle there
seemed to be a high point in the middle of the opening. A little filing was all that
was required to fit the pin [photo 3 ]into the slot. I wont fit the split pin yet as it
will have to come apart again no doubt before I am finished.

The wheels were then fitted to the axle and the fitting to hold the wheels on, fitted
first time. I still have the bracket to remake that holds the smoke door on and
secured to the side of the smoke barrel but once this is completed there isn't any
major work to be done on the front and she stands now as in picture 4 below, all
lopsided………..

Time today 3 hours: total time 3 hours 30 minutes