Member postings for Bill Pudney

I recently made a couple of three ball handles for a small carriage and cross slide I've had underway for a while. To avoid the making of a ball turner, which would probably only be used twice, I adapted Guy Lautards method in one of his books. The process went something like......

1/ Draw the required handles in CAD, in my case TurboCad. Identify the max ball diameter as a datum.

2/ Draw a line parallel to the datum, 0.5mm away from it, record the diameter, and enter the number on a chart.

3/ Repeat stage 2/ until end of circle, thus creating a set of co-ordinates

4/ Set up dial indicator on carriage to measure diameter reduction

5/ Using a sharp, rigid parting tool, line up left side of cutter on the part datum, move slide towards tailstock by the appropriate amount, in my case 0.5mm, and plunge in the amount indicated. Repeat.

6/ Using a well chalked, sharp file remove the steps produced and polish with oily wet and dry.

7/ Repeat for the other balls. There are a LOT of little steps.

This is obviously a vastly shortened version of the real process. But I was able to make my two three ball handles in a morning. The CAD work and developing the process took a while though.

I will ask the Chief Photographer to provide a couple of pictures of the finished handles.

cheers

Bill

In the early 70s, I spent some time as a Work Study Engineer. We used mechanical digital stopwatches, where a full turn of the hand was one minute and the dial was calibrated in 1/100 of a minute. It was fairly easy to read the watch to 0.01 of a minute, very quickly and accurately. Of course the calculations "back in the office" were so much easier with decimal minutes. We also used slide rules as electronic calculators hadn't been invented yet, but that's another story......

cheers

Bill

Over the Christmas break I had to take my mini lathe apart. It seemed like a good opportunity to check and adjust the spindle alignment. I chose to use "Rollies Dads Method", as described by John Moran. This requires using a DTI to measure the out of truth of a suitable test bar.

My initial setup used traditional, fair quality (mixture of MW, Mitutoyo, Starret) DTI holders etc. Well what a performance, I was thoroughly confused with conflicting and non repeatable measurements. I came to the conclusion that the problem was flexibility in the DTI holding system.

So I made a special DTI holder, with reamed holes to take the DTIs, mounted on top of the compound slide using the thread which normally secures the toolpost. Both Indicators could be mounted at the same time. What a difference!

No more conflicting measurements, all (well o.k....most) measurements were repeatable, within a very short time I had the out of truth of the spindle down to acceptable limits, approx 0.04mm over 300mm both vertically and horizontally.

The acid test of course was the cutting test, which showed an error of less than 0.01mm (graduations on my best micrometer) over a 100mm test length. The actual error, given the equipment to measure it, would probably be between 0.004 to 0.006mm. Pretty good I reckon for a 12 year old, much used Chinese pre assembled kit!!

All provided by a rigid system!!

Happy New Year

cheers

Bill

Chris, being dopey, I prefer to think that AET have their own special fleet of couriers.........

Last Saturday 15/12/18 I placed a small order with ArcEuroTrade, expecting that delivery wouldn't be until sometime in the New Year, because of the silly season. Imagine my surprise when there was a knock at the door from the postie with my package!! I reckon 6 days from the UK to Australia is pretty good, especially when Australia Post seems to find it difficult to deliver a standard letter from Melbourne to Adelaide in under a week!!

So, not for the first time thanks ArcEuroTrade!!

Merry Christmas

cheers

Bill

Or try a lapidary shop, they use fine diamond discs to cut stones, rocks etc. They also cut composites which is why I got mine!!

cheers

Bill

Years and years ago, decades even, one of the young engineers pet projects was a thing known as a "Battle Torch". Machined from solid high grade al. alloy, with specially set up optics, and a ni cad battery. It was indeed an impressive piece of kit, very good light, very solid, almost indestructible, just what the Army wanted. At a bid review where it was announced that the cost, (the "cost", not the selling price) was over $500. One of the more cynical people plopped a metal torch on the table and said...."Bunnings, $20, it does everything the Battle Torch does"

Guess who got his nose out of joint.

Merry Christmas

cheers

Bill

I always wanted to be an Engineer. My boyhood heroes were Engineers like IKB, W. O. Bentley, R.J. Mitchell. It really does irritate me when Technicians are described as "Engineers".

Merry Christmas everybody!!

cheers

Bill

I had an MGBGT, did 110,000 miles on it in 11 years. Loved it. It only got sold because I couldn't do the 2 to 3 hours weekly maintenance because most of it had to be done on hands and knees, and my metal knee objected. Got an Impreza and rediscovered free time on the weekend!!

cheers

Bill

I changed the plastic gears for metal ones earlier in the year. The noise is bad, especially over 500/600 rpm in high speed. I'm seriously considering changing back to plastic ones, material and design faults not withstanding. The original plastic gears lasted close to 15 years and only broke when I was doing a fairly aggressive interrupted cut. Whilst it's a right royal pain in the neck to replace them, realistically it only takes a couple of hours.

cheers

Best of luck!!

Bill

British motorcycles

Other (good) motorcycles

Aeroplanes

History

Old engineering

Hate DIY

Hate gardening

cheers

Bill

Sorry if I'm about to introduce even more smoke into an already obscure topic. Where I used to work a 5 axis Makino mill was purchased. Cost was something over AUD$1,200,000, that's a lot of money in anyones language and it was about 15 years ago. The machine was set up at the factory in Japan, packed and delivered. On arrival a team of three or four Makino guys unpacked it, moved it to its' location and did all the installation tasks, including setting to work, making sure all the bits moved in the right order etc, this took about four or five days. Then another team of two people arrived who set the machine up, adjusted all the electronics so that the machine would achieve the VERY tight tolerances expected of it. This took another four or five days.

Then the machine was set to work, running two shifts with the third shift running unattended, "lights out", at the end of the second shift the machine was loaded so that it would run until it had finished, then switch itself off.

My point is that machines require setting up in situ, doesn't matter if they are a small benchtop manual lathe, or a big multi axis CNC mill.

cheers

Bill

Hi Steve,

In absolute terms I don't know, however the magnification is sufficient to make tiny changes to tool height to be VERY obvious. So, having used it (Opt Ctr Finder) more than 10 years, I'm very comfortable with setting it just below the horizontal line visible in the viewfinder, so I'm guessing that it's 0.015 to 0.02mm below. Tool height setting is now a very consistent process. After setting it's very gratifying to find that the tool parts off very cleanly, with no noticeable centre pip....except on cast iron, of course, which is a law unto itself!!

Mine is a Chinese one which was on sale at ENCO in the US, it certainly wasn't what I'd call cheap but it was priced way below what I've seen European retailing for. It's not often that you see multi use bits of kit!!

cheers

Bill

Some time ago I got an optical centre finder, it was on sale at the time. It has many useful functions, two of which are centre finding (that's a surprise!) and tool height setting, simply stick it in the tailstock chuck, and you can see the tool in scary detail. To my mind better than all the gauges, tools etc.

cheers

Bill

Where I worked in the 80s at a company making electronics for the defence industry, company standards insisted on using wavy washers, under every fastener, bear in mind these were all small fasteners under about M5. There had long been a feeling that wavy washers were a waste of time, but the standards stood. Then I saw an electronics box, full of PCBs and other stuff, all held together with an approved fastener scheme on a shake table. It only took a minute or so for the screws to start to release, and about 3 or 4 minutes for most of the screws to fall out.

We still had to use wavy washers though, but on final assembly we started using Loctite.

I will continue to put full size nuts on first, and locknuts last.

cheers

Bill

I hope that the contact people at Alibre now have better developed people skills than the manager of their Australian office a few years ago................

cheers

Bill

I have a Vertex 4" RT and it is very good. I'm sure that other makes are perceived to be better by many, but it's solid, reliable well made etc, and does the job very well. I have some other Vertex stuff (milling vice, collet chucks, collets, etc) All the Vertex bits I have are of good quality, not the best but absolutely better than most. Taiwanese stuff is generally pretty good.

cheers

Bill

Edited By Bill Pudney on 25/09/2018 13:03:49

Model Engineering as a sit com?.....why am I thinking of "Dads Army"?

cheers

Bill

Does anyone actually do hard anodising in the home workshop?? As far as I remember it's a far more difficult process than cosmetic or normal anodising.

cheers

Bill

Amongst many other things, I used to run an estimating section for a manufacturing division. Obviously we had all sorts of metrics available, but one that used to impress people was "...halve the tolerance, quadruple the time....". Sometimes it would be worse than that, when an "easy" tolerance could be achieved off the mill, whereas for the same feature but with a tolerance that demanded grinding, or even lapping, it could be off the scale......

To make things exciting some of our "draughtsmen" (Engineers on a CAD station) didn't have the faintest idea how any given part would be made. Good fun, I miss it like you miss the flu!!

cheers

Bill