Here is a list of all the postings Bill Pudney has made in our forums. Click on a thread name to jump to the thread.
|Thread: Mini Lathe Rear Tool Post|
My Sieg C3 (mini lathe) now uses an "oxa" QCTP also acquired from Arc Euro. The square, flat, spacer went straight into the "small bits" bin no doubt to return to dust there. Most of my tooling has 10mm x 10mm shanks Some time (years and years) ago I made a post and clamp, Norman(??) style toolpost (look in my Albums). This used an upside down parting blade, and obviously required the spindle to turn in reverse. Being a modern machine with a bolt on chuck, this caused no problems with the chuck unscrewing. Parting off with this set up was a breeze. Although parting off with the oxa is o.k. there are still knuckle whitening moments, I'm thinking of making a toolholder with an upside down blade, to try and improve things
I recently nearly finished a "chariot a vis" (Schaublin terminology) for a Schaublin 70 (again, look in my Albums). All machined on a 10 or so year old Sieg X2 mill. Gordon Bennett what a mess, but it does machine beautifully. Because my new chariot does not get used very much on the Schaublin, it occurred to me that for the small things that I make quite a lot of, The "chariot a vis" could be used on the Sieg C3 (after removing the carriage obviously). We shall see!!
|Thread: Blacking engraved lines|
Where I used to work, we made a lot of electronics boxes for the military. So it had to be robust and soldier/sailor/airman proof. There was a lot of engraving, one person used to do the infilling, he used Humbrol enamel, black, white, red whatever. After near obsessive cleaning the engraved characters were infilled with a small brush and the excess wiped off with a Humbrol thinners dampened cloth. Much like what has already been suggested.
Edited By Bill Pudney on 12/02/2019 02:20:33
Sorry chaps, should have mentioned the album...short term memory loss!! The leadscrew threads give the logical movement associated with the handle movement, i.e. clockwise moves the slide away, or forward. It took me a while to work out!!
cheers and thanks for the nice words!!
Some time ago I was fortunate enough to buy a Schaublin 70 turret lathe. It occurred to me that Schaublin proudly boasts that parts and assemblies are interchangeable, between, for instance their toolroom lathes and their turret lathes, so wouldn't it be a good thing to have a carriage and compound slide to use on odd occasions. So I looked around for a secondhand "Chariot a vis" (Schaublins terminology). The cheapest I saw was EU1,600 plus postage. So I thought "Crikey....I'll roll my own". Using data derived from on line drawings and manuals a series of drawings were produced, which represented a simplified but similar size assembly. Original features which were not incorporated are
1/ Pressure oiling, the original features a very complex network of oilways, all fed from a single point. Wonderful for a machine which is used a lot, but not so practical for occasional use.
2/ Taper gibs. Initially I couldn't see how to organise this. It wasn't until metal was cut that the penny dropped.
3/ The original used 6.5mm x 1.0mm trapezoidal thread leadscrews. I couldn't source appropriate taps and dies to do this, at least without eating for a year. So I used M6 x 1.0, I had to make 6 of them before I got two acceptable ones though!
So after about a year of drawing and machining it's almost finished, just a few odds and ends to do and it' ready to go. I have installed it on the Schaublin and it works quite well. All the machining was done on my Sieg C3 lathe and Sieg X2 mill. The four main bits were grey cast iron...Meehanite. The gib strips are silver steel, with pegs and lockscrews.
Edited By Bill Pudney on 17/01/2019 04:40:02
|Thread: ball turning|
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.
|Thread: Measurements from the past|
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......
|Thread: Mill tooling runouts|
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
|Thread: Merry Christmas Delivery|
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!!
|Thread: [Dremel or smaller size] Diamond Saw Blade|
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!!
|Thread: Making a torch|
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.
|Thread: Year of Engineering|
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!!
|Thread: New old 1950's Myford 7 Lathe still in the crate|
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!!
|Thread: Mini-Lathe Repair|
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.
Best of luck!!
|Thread: Interests other than Model Engineering|
Other (good) motorcycles
|Thread: Upgrade from SC3 lathe|
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.
|Thread: An alternative to parting-off|
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!!
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.
|Thread: Nut screws washer and bolts|
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.
|Thread: A Big Treat coming for Readers of MEW|
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................
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.