Member postings for Bill Davies 2

Sadly, these problems go back a decade or more:

http://modeleng.proboards.com/thread/3876?page=3

Thanks, Phil. I used to run an apprentice school in the 1970s, and taught mech eng apprentices more recently. The extent of down-skilling is quite scary. I had thick textbooks for each subject/unit I was taught in the late '60s, today a slim booklet covers all units. And it started before my time; the 1930s and '50s books I picked up from older colleagues were harder than mine. Plus those that worked and studied during the war has reasons and motivation to be well-educated.

And trained as a mechanical engineer, we were taught that electrics were things we didn't touch (three phase industrial voltages), although I did an HNC electrics/electronics unit, which covered quite a lot.

Bill

I'm no electrician, but I think I read that the ring main was introduced, post-war, as a cheaper solution due to the lack of copper for wire. The ring main has two routes for the electricity to reach the socket, until there is a failure in one arm of the circuit, when the entire current must follow the alternate route. This will not be as large a wire gauge as a spur, so may overheat. I'm not sure is there is a straightforward test for a 'broken' ring main without examining connections. Sorry, this is off-topic.

The gear rolling tester takes me back a bit ... Sorry to see inspection equipment so rusty (or any equipment, for that matter). You would require a master gear (or a very good one that's accurately concentric with its bore) to gave readings that you could interpret.

Making up a probe (a ball or a rack tooth) and test around the circumference of the gear would give you similar information. The clearance of the gear's bore with the central shaft would have an effect. Might not be useful for horological gears, though!

Spurry's rule rings a bell (some way back). I once had a hardwood rule with 'triangular' divisions, I think it was an NPL (National Physical Laboratory) design. A great rule but eventually was broken. I found it much easier to read than graduations of the same length (which I think are always too long). And I agree with all the previous comments about 1/2 mm graduations, but perhaps that's also the 'too long' problem..

Bill

Edited By Bill Davies 2 on 03/04/2019 21:48:49

Given that MT tooling will be pulled in using the draw bar, is there a risk that a de-tanged drill might be very difficult to eject? I'm presuming that these spindles don't have a slot for a drill drift. A morse taper tool, jammed in, in the usual way, can have a fearsome grip due to the wedging action.

Edited By Bill Davies 2 on 02/04/2019 17:13:33

I have it on a number of items. I bought several pairs of Lidl's Bresser binoculars several years ago, they are all tacky. A dirt cheap mains drill (from B&Q? a decade ago??), the body is hard plastic but other bits are artificial rubber (including the strain relief grommet) and all went tacky. They are now falling apart. Poor materials, or the future green world where everything is biodegradable.

I can remove most of the stickiness on the binoculars using washing up liquid, but not all. They are stored in their original boxes, perhaps this is bad? But the stickiness returns. I have assumed it was the plasticisers leaking out, and presumably the next stage is the plastic falling apart, just like the power drill.

I have also tried dusting with talc, but it doesn't look good, plus it is not a permanent cure.

I'd agree with the description as a lathe tool grinder. Many years ago, working on a tool grinding section, I used similar grinders for sharpening brazed carbide lathe tools, and one grinder had a diamond wheel, for finishing the tool. The trough is for water, although people seem to deprecate its use now. We didn't allow the work to get too hot before cooling in the water just to keep them cool enough to hold. No gloves were used for holding the tool. I think we had double-ended versions, and although hard to judge, the ones I used was larger (8 inch wheel?).

Perhaps my PC has a virus or malware, but the Boxford manual link asks me to install an exe file, 'ReimageRepair.exe' which my Norton Security flags as a file that could harm my computer. I attempted this twice, but did not download the file.

Bill

Hi, Ian. You've probably found these too:

Oxygen-hydrogen generator

Hydrogen generator polisher

A couple of manuals for potassium hydroxide electrolyte (different makes, using similar technologies):

Manual 1

Manual 2

I hope this is relevant and useful,

Bill

Some of us are still waiting for our copy, but I'm sure it will be enjoyable.

Thanks, John and Michael, that's useful info regarding my motor.

I have a similar freebie. I have a 3HP DC motor from a scrapped York treadmill. The controller was failed, and not thought economic to replace (excuse for new, bigger treadmill). It requires 180VDC which doesn't seem to align with any type of rectified 250VAC mains. I appreciate that a switched mode supply could run it, although nowhere near 100% 'on' ratio, close to 50% (340V peak, 680V peak-peak?).

I tried it on a 20VDC power supply, and it ran slowly with reasonable torque (like Maurice's test above). Is there a logic to the full speed voltage? Is half the waveform thrown away, then the voltage is chopped, or am I missing something?

Bill

I was running an apprentice school in the mid-70s. My company had a contract to build machines for the Kamaz lorry factory. The Russians could not pay entirely in Western currencies, so the company also took machines and wheat (!).

A Russian vertical mill arrived in my workshop, and used conventionally. However, there was power feed available by push button, which the British machines lacked. One 'enterprising' apprentice discovered he could rough cast iron blocks using the rapid traverse - this with reasonable depth of cut and a 2-ich end mill. The mill seemed quite happy with this. As Phil says, the Russian machines were very robust.

Bill

Some of the 'smaller' mills used at my college (long ago) used aluminium castings as the overarm. This was a box section. Probably not used on production mills (Young's modulus, wear resistance and all that).

Use by apprentices knocking out vee blocks and other practice pieces, including a few rare mistakes like work slipping in the vice jaws and 'climb milling' through the steel block, punching the HSS teeth into the steel as it went, and bending the 1 inch arbour. Needed a new arbour, but no apparent damage to the overarm.

Other mills (some may recall) used a pair of large steel bars for the overarm. However, that would need a new arbour support in this instance.

Bill

I concur with ega. The Maplin multimeter with capacitance I bought several years back could not cope with electrolytic capacitors used in simple power supplies. I can't find it at the moment so can't quote value. Motor caps will surely be much larger in capacity.

Bill

In the 60/70's, I worked for a firm that made large machines. We had 6 foot diameter phosphor bronze worm wheels in stock as spares. The accountants didn't like that, so a couple of my mates were given the job of hacksawing them up and throwing the bits in the scrap skip.

When the next customer broke a wormwheel, they were quoted many months for the part to be cast, weathered, turned and hobbed, then delivered overseas and installed. The customer said no, scrapped our machine and bought a German one. Needless to say, my old employer no longer exists. The German one still does.

Bill

BobbH, you would have finished at Brooklands the year I started! Or did you go to Kingston?

I'm not sure where the smiley came from, it was not intended.

During the first year of my apprenticeship, there was an EITB (Engineering Industry Training Board 'Black Book' of about 80 pieces. I have been looking for a long time for a copy. We also had to make a piece of equipment as a final practical exercise, which I think was assessed externally (by the EITB?). In my year, it was a set of small bench centres, and in two's we had the run of the training school workshop to complete it.

There are is a pdf of some US apprentice pieces knocking around on the web somewhere, don't know off hand where, but I may have a copy on my home computer; I'll check later.

Bill