Today was the first session in the workshop for some time as my 'medical' difficulties have restricted my access to the workshop. Since I didn't trust myself to do anything of a 'critical' nature I just sat there smelling the oil as it were. Then I spotted an item recently bought and thought I couldn't do any damage if I were to 'play' with it so this short experience is all I can report to you at the moment.
I have a lovely certified granite block for marking out and keep it stored away in its box for safety. However on a recent visit to eBay I spotted a 'cheap' kitchen one. So I bought it and thought it would be a useful addition to my marking out section, for items that were less 'critical' than others.
It duly arrived and although it looked pretty good, I thought I would just run a dial indicator over the surface and see how true it was. Now bear in mind I work in imperial units and the measurements are very small, I was disappointed to find the DTI moved all over the place! Now to a chef 5 to 10 thousandths of an inch wont spoil his tomatoes, but it was too much for me. So if you think of buying one for the same reasons just bear in mind their surface is not as flat as it would seem. It was not only the range of difference but also where they were and I sought to find out if any section of the granite could be used. Of course the answer was no.
About to leave the workshop, I wondered if the underside was any better? It was not polished like the top but low and behold the underside is a lot better than the surface! So it must be the polishing process that makes dips. In the end I will be using it but not so much for marking out but as a 'relatively' flat surface for some assembly tasks perhaps.
Mine may not be representative of others but smooth in looks is not always smooth in surface.
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!
£220.70
I’ve heard the suggestion of using a granite tile/cutting board as a marking out plate. I’ve also heard of using plate glass, now that should be accurate because of the way it’s made.
Yes plate glass seems to be favourite with many people, I just don’t know of a local supplier of offcuts…..perhaps I will look out one….