Today I decided to start work on the height adjustment mechanism for the blades or diamond cutting disc. The start or which was sourcing some suitable steel to make the quadrant. I seem to be well stocked when it comes to non ferrous materials but poor for steel and the like. I eventually came upon a piece of angle iron that was just under size but would do so using the bandsaw one side was quickly removed and the remaining piece cleaned up.
To cut the radius required for the teeth the rotary table was used on the milling machine. The only cutter I have matches the Myford gear profile and will be used to create the teeth both on the saw arm and the quadrant. The radius for the quadrant was decided upon by matching a Myford gear to the profile that will fit the available space. This method has the benefit of defining the number of teeth although I will only cut 90° worth I need to have the right dividing plate on the Vertex indexing tool. In this case the divisions need to allow for 55 teeth.
The saw arm will however require only division to be found for 28 teeth (again only 90° worth will be cut). To calculate the gearing I made use of two publications namely “Model Engineer’s Handbook by Tubal Cain” (3rd Edition) and Ivan laws useful book “Gears and Gear cutting” in the Workshop Practice Series (number 17).
As a side issue I have been putting together a spreadsheet using the formula in both books for my future use covering various situations such as number of gears, their size, and number of teeth etc that can fit within a given space. When the bugs have been ironed out I will put it on my website for downloading if anyone wants it.
About Mike Freeman
Hello, my name is Mike Freeman and I am a retired Chief Fire Officer from the United Kingdom with a keen interest in model engineering, silver caddy spoons and sea fishing. I live in the pretty fishing port of Brixham, South Devon, in the United Kingdom.
I am a sufferer of degenerative osteoarthritis, which impacts on the amount of time I can spend in the workshop, and is the reason why you will see seats and a stool in some of the photo's. I have only recently added the above sentence after a discussion with one of my Doctor's from the excellent pain clinic, based in Torbay. This does affect concentration one of the reasons why I double then re-double my measurements and set ups.
Before completing nearly 30 years of public service I and my wife Sandy, owned and ran, a small restaurant in Okehampton Devon. Prior to marriage I worked for my father in his various businesses, in the early days these were garages, which he bought in a run down state, then built them up before moving on, to start again.
I took every opportunity in those early days, to work in his workshop's
learning 'on the job' rather than as an apprentice. This, I suspect, is the reason why my building various model's in the early days, turned into model engineering, when funds allowed the required equipment to be bought.
My workshop comprises one half of a detached double garage. It has a
stud wall separating the two halves and unusually perhaps, its own
shower/toilet/washbasin compartment! (the true reason for buying the
bungalow - don't tell the wife!!!)
It is fully insulated with a ceiling and fluorescent lighting supplementing the one window. Several double electrical sockets are dotted around in
relevant positions.
Equipment consists of 2 lathes (1 Myford ML 10 and 1 Chinese variable
speed motor with etched glass DRO's), 1 milling machine (RF25 far East) floor standing pillar drill, Proxxon bandsaw, Warco bandsaw, 6" wire brush and polishing mop motor, 6" coarse and fine grinder, Proxxon mini drill, various benches and an engineers vice. I have just acquired a third lathe, a Myford ML7 which I am at present evaluating so I can decide which of the Myford's I will keep.
I have only just bought the Chinese lathe and had it fitted with DRO's prior to delivery. And what a bonus they are! So good in fact that I decided to buy another set for the Milling machine. Whilst my engineering experience can only be described as limited, I find the use of DRO's has affected my accuracy levels which have improved tremendously (although that's not saying much!) and would recommend their fitting to any model engineer.
Prior to retirement I built for my son's 17th birthday a Locost car. This
was a tremendous project and a great feeling when it passed its test. The book it was based on suggests it can be built for £250. Ours was nothing special in the sense of all new parts but still cost about £900 to build!
Thank you very much, your too kind. Mike