fowler traction engine ashpan model engineering mikes models

Whilst the build manual leaves the building of the ash pan until later I felt it would be
better done now so that she can stand on her wheels now. There are four pins that
have to be screwed into the foundation ring of the boiler and as you will see in the
gallery I made them of brass.

It is suggested that the ashpan be made of steel, or for a more durable solution,
copper. I have decided to go the copper route (the expensive option!) and therefore I
need to make a former to form the bowl shape.

I decided that I would use some mahogony that was left over from an extension doen
last year but as always, not the right size. So three pieces were araldited together and
two cardboard templates made for the first profiling.

I then found that the former would come up short so another piece glued on but since
it was the last piece some filling would be needed to get to the correct shape.

To help make sure the profile would be correct on the x and y axis I cut female
templates from sheet steel. These will ensure the profile remains correct. The work
though was extremely messy with tremendous amounts of fine sawdust produced.
Vindicating my decision of moving the Mk2 Jaguar form its garage and using that area
away from the workshop.

I won't get delivery of the copper until Monday or Tuesday next week which is a good
job and it seems to be taking a long time to get the former to shape!

To be continued....

6th December 2008

Well I finally felt well enough to get into the workshop. I now had the
copper and all I required to make the ashpan. I have achieved the shape
but I wasn't happy with the forming. The annealing went well but the
forming didn't. Too much metal became spare at the front corners. I did
try to form those first, as recommended in the build manual, but I must
have done something wrong!

In the end I had to cut slots and remove the surplus metal. The edges
will be silver soldered when it comes time to attach the top flange.

I have got the ashpan nearly there but the front radius is not the same
as the plan. The work though is not wasted as I believe I can get a
working result that will look ok after cleaning up in the end.

The next tasks will be to machine the 4 stainless steel support legs for
the cast iron grate, the damper, its hinges and the holes drilled in the
four brass pins. Then the hornplates can be attached.............etc. etc.......

7th December 2008

Todays session was spent by soldering up the four corners using the
highest temperature silver solder I had. The reasoning being that I
could use a lower melting point for the connection of the top edge to the
ash pan.

After the corners were done I decided to place the ash pan into the
pickle solution whilst I chain drilled the copper sheet being used for
the top edge. Once the drilling was completed the sheet of copper was
taken to the Proxxon bandsaw and the inside cut out.

The ash pan was then mated to the top edge and a scribe mark placed
around the pan so it could be located again when soldering. The silver
solder paste was then mixed and 'painted' onto both the edge of the ash
pan and the top plate.

To hold the ashpan in place a couple of heavy steel blocks was placed on
top and then lengths of silver solder cut and placed against the edge of
the ashpan and into the flux.

The ash pan itself was then heated with the propane torch, bringing the
ash pan to cherry red, where upon the solder rod melts itself and flows
between the joint.

It is important that the flame does not impinge on the solder rod itself,
melting it before the surrounding metal is ready. I started work on the
left hand corner, moving the flame around to the otherside when the
solder started to flow.

The ashpan unit was allowed to cool before placing it into the pickle
solution. After cleaning up a little, the ash pan was then placed onto the
up turned boiler and pleasingly the holes and pins were still aligned.

The next job will be to file up the inside edges of the ashpan top edge
then make the fittings for the grate and the damper plate, not
forgetting the holes to be drilled in the four pins for split pins to
reside it. It is the split pins that hold the ash pan in place and these are
pulled out if the fire needs to be dumped quickly, when in use.

A few words but a lot of work done..................

9th December 2008

Today the ash pan was cleaned up and the upper flange filed down to
match the inner ash pan. Work then started on cleaning up the cast iron
grate. The top side was faced off on the milling machine and then 4 holes
drilled and tapped 4BA.

I had need to use the tapping fixture I recently completed and I must
say it worked very well, just need a better quality tap holder to make it
even better.

It was one of those days whereby a lot of work requires little right up.
there is still quite a bit to do as the ash pan damper plate needs to be
attached to the ash pan including a bracket for the lever operating
system.

10th December 2008.

Todays workshop session was something of a mixed bag really. I satrted
with making the four legs for the grate to stand on for the Fowler 2"
scale traction engine. The simple procedue is the face off the bar stock,
turn down to size for the 4BA thread for the correct distance, then
thread, and cut off to size. This means that you have to change from a
cutting tool to a parting off tool. I made some time ago a toolspost system
where the tools have their own holders so setting for height is easier. So
this cuts down on tool setting work but as I say the tools have to be
changed. Multiply this by 4 legs and you can see that there are 8 changes.

Afte I cut the first bar down to size and threaded the end I needed to
move the bar out to allow the length to be cut. This is when the
'blindingly obvious' struck! Why not just revesre the bar and use the
same tools, resulting in less changes as when both endshave been threaded,
they could be parted off. Doh! But its something to remember for the
future. A 'put it away' for future use moment.

Feeling quite pleased with myself I fitted the four legs and using a depth
gauge got them all to the same size by filing. So the next task was to
make the damper plate. After studying the plans for a while I couldn't
see where the pivot blocks fitted. The answer was I hadn't finished the
top flange. I don't know how I missed the fact that the top flange
continues all the way around the ash pan. The pivots fit to the missing
flange. So a start has been made on the missing flange.

I had hoped to wrap up the whole assembly today but thats not going to
happen now. I think there are at least another couple of session before it
is finished. Drat!

To be contd......

20th December 2008

Got sidetracked with other 'projects' but today I managed to restart the
ash pan and fitted the flange to the rear of the ash pan. I started by
chain drilling the shape required and then used the Proxxon band saw to
remove the main central copper.

After annealing the copper bent smoothly into shape and then it was silver
soldered to the ash pan itself. After pickling and washing in clean running
water, the pan was cleaned up.

The next task was to file the outside to shape, followed by the inside.
That was enough for the session. Tomorrow I hope to complete the
bracket system and fix the pan to the boiler.

21st December 2008

With time running out for me to get the fowler onto her 4 wheels, a start
was made of the hinge pins and pivot blocks. The first task was to cut the
pin bases to shape with the two securing holes drilled into them. The next
task was to turn down some brass for the pins as I didn't have the right
size in stock.

The bases were then taken back to the milling machine for a slight indent
made for the pin to rest in when silver soldering the pin to base. When
silver soldering, the same procedures as earlier sessions were used. First
some powder flux was mixed with water. Small chips of silver solder were
cut and placed alongside the pin and heat layed on the brass base away
from the pin and solder.

Once the heat was sufficient the solder melted and ran under the pin. Once
cooled, they were put into the pickle for 30 minutes, before rinsing and
cleaning up. That completed the hinge part. The next task was to mill some
hex bar to a square block. Then two holes were drilled into the brass and
threaded 5BA as per plan.

Then some BA threaded rod was cut to approximate length they were soft
soldered in place. To protect the threads from solder running down them
some Carr's masking material was used to protect them. this was the first
time I had used the masking material and the solder paste. After warming
the threaded bar it was dipped into low solder flux before screwing into
the square block. Gentle heat was applied and the solder soon ran, without
coming down the threads.

So the masking worked fine. Once cooled, the threaded rod was cut down
to final size along with the square bar. The next job was to round over the
top of the pivot block and this was achieved with my 1" sanding belt and a
fine grade sanding block.

All that is left to do now is to drill a suitable hoe for the pin to locate in
and then fix the pivot blocks to the back flange, before making the damper
plate itself. The hinge part is riveted on and that hopefully will complete
this part of the build.

I must admit this has been a larger task than at first site, but I am very
glad I did it now. To complete the ash pan with the Fowler standing upright
must be a task indeed!

So I may be behind with the yearly target for the fowler but in fact I did
not plan on the ash pan so its a bit of swings and roundabouts..........

Hopefully only one more session will be needed to complete this sub
assembly. I can then get on with fitting the horn plates to the boiler. Then
the wheels can go on.......

To be contd.........