June 2015

The June Meeting

Our treasurer was not present so there was no update

on finances (since we have not spent very much we

assume things are still OK.)

Hobbyfest was the first subject of discussion: This

will be on Sunday July 19th in Canatara Park, Sarnia

(the same venue as last year.) The city only allows

us 2 tables and no chairs. We have our own tables

so that is not a problem but for anyone coming;

something different has to happen otherwise many of

these shows will die.

John Sibbick asked whether the club locomotive was

for sale, the decision reached was that it was not.

After Ed Spencer’s request asking if anyone had a 21

mm tap and die, some discussion followed on weird

thread sizes and pitches. (Apparently the 21mm size

is available but at a price, it is certainly not a preferred

metric size.) Anyway; one of the weirdest pitches is

please bring a chair of some kind. I will send out a

that used on 1” – 2” National Pipe Threads, it is 11 ½

TPI!! (Why not 12? At least BSP uses 11 TPI for

similar sizes.) Someone raised the point that many

lathes will not screw-cut some of the unusual pitches.

The 2015 CNC Workshop (Allen Park MI)

I was hesitant to attend this time but I am pleased that

I did. The main reason for going was to find out more

about Mach4. That objective was mainly achieved but

a few other things of interest emerged:

Firstly it does appear that Mach4 is a significant

improvement over Mach3 and it is being well

accepted in the (lower end?) professional world as

well as that of the hobbyist. The mill version was the

first to be completed but now the lathe version is also

available so I think it is time to try it myself.

The MS Windows operating systems used by Mach3

and 4 has an inherent problem when it comes to

running a control system because normally, all sorts

of processes go on in the background that prevent

things being done properly on a “real time” basis.

However, Art Fenerty found ways around this and put

together Mach3 that enables readily available

Windows based computers to be used for machine

control. Mach4 is a much improved version of this.

Since CNC got started in the hobby world the main

alternative has been to use a control system based on

the Linux operating system. This is an open source

system and does not have the same issues as

Windows when used for real time control. It can be

loaded on to a PC in place of Windows but once that

has been done the machine will no longer run any

Windows applications. This approach has always had

an enthusiastic but relatively small following and the

main CNC control program was EMC.

I had previously regarded Mach3/Windows as the

preferred approach but I am beginning to wonder.

generally credited with this move. (One publication I

have seen actually credits them with inventing the hot

bulb engine.) Their first engine was produced in ~

1897 so they were not far behind Hornsby Akroyd.

A normal gasoline 2 stroke is not very efficient

because part of the fresh gasoline/air charge is lost

through the exhaust (also resulting in significant

hydrocarbon emissions.) In a diesel or hot bulb

engine this is not a problem because only air is lost.

On the plus side the simplicity of the engine results in

mechanical lower losses than a 4 stroke with its

associated valve gear.

Murray Bennell brought along some items to show his

toolmaking skills. He had a screw cut piece of steel

with a double start, left handed acme thread. He also

has double and triple start, left and right handed taps

that he had made to produce some similar,

corresponding female threads.

Murrays tools

Tormach, who are probably the most successful

supplier of CNC machines to the hobby/low end

professional market have gone away from using a

customized Mach3 system to a Linux based system

called “Path Pilot” that they have developed (or have

Another good feature (for marine use) was that by just

changing the timing of the fuel injection, the engine

would run equally well in forward or reverse.

Production of hot bulb engines took off in a major way

early in the 20th century and it seems that

(continental) Europe really dominated. In England,

quite a few companies got into making the engines:

Hornsby Akroyd, Crossley, Petter, Allen, Clayton and

Shuttleworth and Gardner were the better known

names but others I have found are Ailsa Craig,

Beardmore, Brooke, Invincible and Robey. I have not

heard of any Canadian manufacturers but in the US;

De La Vergne, Mietz and Weiss, Fairbanks–Morse

and Kahlenberg were names I had come across

previously. Others I have found are Missouri,

Remington, Seattle and Sumner.

In contrast, apparently there were several hundred

manufacturers in continental Europe and about 70 in

Sweden alone. Bolinder is the name most people are

familiar with which is not surprising because at one

time had about 80% of the world market for these

engines. After making some 4 stroke engines initially,

they changed over to 2 strokes, so with their share of

the market, that is the form of engine that was

dominant.

The Kahlenberg

Hot Bulb Engines (part 2)

After the initial invention, probably the next significant

development with these engines was going to the 2

stroke format. Meitz and Weiss in New York are

Before getting into applications, it is worth mentioning

another problem with these engines. It was that they

would not run at very high speed (300- 400 rpm

seems to have been the limit) and the useable range

does not seem to have been very great either. They

were good as stationary engines, driving pumps,

generators and general machinery. They were also

very popular in boats where they could run at a

steady speed. Also, being able to use heavier, safer

fuels and having no electrical ignition system that

would tend to give problems in a damp environment,

were distinct advantages. Their lack of speed

flexibility meant that they were not very suitable for

road vehicles but they were extensively used in farm

tractors.

The De La Vergne and Hornsby Akroyd in last

The Dan

popular engines fitted to UK canal boats in the 1910 –

1950 period.

BolinderEngine

This is a 4 stroke with suction inlet valves on top and

the exhaust valves below. (The valve operating gear

is missing from the engine.)

I will get back to some of more technical aspects next

time. Although the simple story usually told is that the

hot bulb engine was replaced by the true diesel, in

many cases it seems that it essentially morphed into a

diesel.

Our Website

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

Meetings Next Season

As a reminder, bookings for the room we use cannot

be made before early September and historically

meetings that month have not been well attended

(people still away on vacation.) I will discuss the

matter with Bruce before making the bookings but the

earliest will be late September, but more probably

early October.

John Lovegrove

Closer to home, this is a Kahlenberg engine made in

Two Rivers WI and is presently in the Coolspring

Power Museum in PA. These engines were used

extensively in vessels on the Great Lakes and had a

reputation for being very nicely made (lots of brass!)

The next engine certainly has a Canadian connection;

it was used for auxiliary propulsion on Amundsen’s

boat the Gjøa, which was the first vessel to

successfully to complete the Northwest Passage in

1903-1906. It was made in Denmark by a company

called Dan and is now in the Oslo Maritime Museum.