July 2020

during a couple of our meetings, he decided to make

a sextant. This device enables sailors (primarily) to

find their latitude fairly accurately by measuring the

angle of a celestial object (typically the sun) above the

horizon. (This would normally be at mid-day and you

also needed a set of tables to correct for the time of

year and some other things.) Referring to his picture

below, the telescope looks directly at the horizon

through the half-silvered mirror in front of it. Then, at

the top there is a normal mirror that can be pivoted to

reflect an image of the sun back towards the halfsilvered

mirror. (This has to be at the correct angle so

that both the horizon and the reflected image of the

sun can be seen in the telescope – so Stu’s needs

some adjustment.) The angle of the top mirror is then

adjusted until the image of the sun reflected by it and

the half-silvered mirror appears through the telescope

to coincide with the horizon. The angle at which the

top mirror is pivoted can be read on the scale at the

bottom of the instrument and this is calibrated to show

the angle of the sun etc. above the horizon. A

magnifying glass on a swinging arm is used to help

read off the angle accurately. The other essential

component is a set of filters between the top mirror

and the half-silvered mirror that can be swung into

place to reduce the intensity of the sun and protect

the eyes of the operator. Tony Koolen provided a

piece of mahogany to make the handle used to hold

the device. The spirit level came from an old box of

tools, but I am not sure that it is really necessary for

the operation of the device. Basically, the whole thing

is hand-held level with the horizon and I imagine quite

a lot of skill was needed to get an accurate reading if

the ship was pitching and rolling badly.

What Members have been “Up To”

This time Stu Brownlow was the first to respond with

some information on what he has been doing.

Inspired by the discussion we had on navigation

This is a picture I pulled off the web showing the basic

principles. (In this case it is showing an observation

based on a star and the “Horizon” mirror is the half

silvered one.)

To me, making a traction engine represents a similar

amount of effort to making a steam locomotive.

Basically, once you start you just have to keep

plugging away until you get it done. I did make a

small contribution a while back: Not long after I

bought my CNC mill, I made the horn plates for him.

These go either side of the firebox and support the

bearings for the crankshaft, reduction gearing, the

tender and a few other things. They seem to have a

gazillion holes, are not the same both sides and if you

get one hole wrong you have to start over. At least

with CNC you can write a program, try it out on a

piece of Masonite board and make any corrections

needed before doing the final job.

Tony Koolen has been doing more woodworking, this

time making 34 plaques for his granddaughter’s grade

8 graduating class. This is the one for his

granddaughter; Gillian Koolen.

Brian Lawson went along to look at Kasey’s stuff and

bought the spot welder he made (and brought along

to one of our meetings) along with a set of metric taps

and dies. The smallest is 1mm and he is afraid to

breathe too close to this in case it breaks.

I have been working away on some refinements to my

Sealion. I now have a fairly simple carburettor system

that allows the engine to start up and run quite well on

propane and it idles quite smoothly at ~2000rpm. The

main problem I have is that at very high speeds quite

a lot of oil gets thrown out into the exhaust. At some

point I will have to take the engine apart and check

everything over but I think the problem is likely that

the pumped lubrication system is just supplying too

much oil and the piston rings cannot cope. (There are

no oil control rings – they are very difficult to

incorporate in this size of engine.)

This is the propane set-up with the primary regulator

bringing the pressure from the small propane cylinder

down to ~ 5psi. The gas demand valve and a

proportioning/mixing device are then attached to the

original gasoline carburetor.

Picture Missing

One tends to forget that other countries carried out

major developments in steam locomotives. This is a

German video of a Streamlined (Stromlinien)

Locomotive. (The commentary is in German but the

pictures tell the story – Dave; how about eine

Übersetzung?):

https://www.youtube.com/watch?v=Su8QG_qpdok&fe

ature=push-fr&attr_tag=nPtSQl0ZN-b6dkUl%3A6

Then I found a series of three videos on the Stuart

Triple Expansion Engine:

https://www.youtube.com/watch?v=OdJEk6uNXNQ

https://www.youtube.com/watch?v=QYIFfu0XqnI&t=4

1s

https://www.youtube.com/watch?v=lqjVXRsi1oo

What he is saying about the breaking in (or running

in) process also applies to internal combustion

engines. I mentioned how stiff my Sealion was when

first assembled, now it is much less so. One

indication of successful breaking in is that if you try to

bring the piston up to compression turning by hand

then let go, the crankshaft springs back. This

indicates both that the piston rings are sealing to

create some pressure and that the surfaces have

become fairly smooth.

Drawings for model engines rarely indicate any

tolerances for the fits of parts but my experience is

that if the clearances are right the engine will be

“tight” to begin with then loosen up after breaking in.

If it runs freely to begin with, the clearances are

probably too great and things will start to rattle after a

while.

What Happens Next?

As mentioned earlier, when we can resume normal

meetings is really anyone’s guess. Bruce and I will

continue to monitor the situation and keep everyone

updated when there is something to report. One

event I did have some information on was the

Southern Ontario Model Engineering Annual Picnic at

the Hamilton Steam Museum. This was scheduled for

September 13th. It looks as if this too has been

cancelled but if it is a “go” I will let everyone know. It

is mainly outside so maybe they will decide it is safe

enough to go ahead.

Our Website

https://sites.google.com/site/bluewatermes/

John Lovegrove

The other thing I have been working on is the ignition

system, in particular trying to use those very small

commercially available igniter coils I mentioned last

time. In my 20s I got fairly seriously into electronics

and built a number of different things so I have some

background in the area. I am now trying to design the

electronics to “drive” one of these coils from one or

more sensors mounted on the engine. What I am

finding is that ~50 years on, the basics of electronics

have not really changed but there is now a vast array

of components available that were not available back

then.

Something I was lacking was an oscilloscope to look

at what is happening at engine speeds and in the kHz

range when looking at the operation of these

miniature coils. Kasey had a high quality but old

“scope” and I was willing to make an offer for that.

However, his grandson decided that he would like to

keep it. Having concluded that one would be really

helpful for what I am doing, I applied to senior

management for funding. This was approved so now

I have a not-too-expensive device that should do all

that I really need (and probably a lot more as well.)

I did say that pics of anything interesting that anyone

has acquired would be valid input for the newsletter

so I will apply that principle to myself.

This is a picture of the oscilloscope from the company

website:

What it also means is another learning curve to work

my way around. The capability of present-day

oscilloscopes is really amazing and the learning curve

has lengthened to go along with that.

A few Links that might be of Interest

This is something I found showing what was involved

in the routine maintenance of a steam locomotive.

https://www.youtube.com/watch?v=LC1BEc04i-0

(Not surprising that railway companies wanted to

move over to diesels.)

We were watching a television program where this

Lombard’s (steam) Log Hauler was shown briefly. I

looked to see if there was anything on YouTube…

https://www.youtube.com/watch?v=nFxXqr-6Sdc