As part of my Seal engine build I need to inline bore the cylinder block. Whilst making the boring bar is relatively simple, setting the tool in clear increments of adjustment after each cut seemed a little more complicated.
I needed a method of moving the tip of the cutting tool in steps that were measurable and raised this issue on my blog website. One response received included an article by Eddy Rebbe, who described his double clamp system incorporating a screw that moved the tool point. The article appeared in the May/June issue of MEW (Model Engineering Workshop) 1994.
I liked Eddies’ design but thought it could be simplified, and the level of accuracy of the tool increased by the fitting of a micrometer head. So out came the drawing paper and some scribbled designs were soon made. I also wanted to use the design process to help me get to grips with CAD. Using the Alibre free package I soon managed to get something drawn up and then it was into the workshop to make a start.
By a combination of building, back to design then building again, I arrived at the final design seen in the photos. It has fewer parts than Eddy Rebbes, so should be easier to construct. My version was made from materials in the ‘waiting to be resized’ box (scrap!) the only item bought was the micrometer head from MSC/J&L (UK based) (reference SPU-12375H) and cost £17.87p. I have no link to this company other than buying the micrometer head from them but their delivery was swift and it is a nice item. No doubt there are other sources out there for similar items.
I got on to MSC/J&L from an advert they placed in the last issue of Model Engineer and if you order their catalogue be prepared to reinforce your table. It’s massive, and from memory around 1,800 pages! I don’t think there is anything engineering wise that they don’t stock! I must take my hat off to you professionals out there. Some of the prices of top quality tooling is frightening…
Now back to the tool. It didn’t take too long to make and when finished I thought it would be nice to put it in a box to protect it. Perhaps it’s the fact that it has a micrometer head that led me to make its box. Bearing in mind I don’t like woodwork you can see how much I wanted to protect it!
Over the next few days I shall get to use it and will post the results when I have them. If you want a copy of the plans please email me BUT they are my first attempt at producing drawings so be warned!!!
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!
