Member postings for Bill Davies 2

Thanks, Vic. That's a lovely looking machine. I have a Britannia which must be a smilar vintage and shares some of the styling of the period and (before I painted it an inappropriate grey) a black finish. But a much less sophisticated machine, although it sounds similar when running.

Bill

Vic, I didn't make clear that I was referring to the slide at the bottom of the attachment. The surprising feature for me is the small worm and wheel, is there a ratchet that operates it? I can't see a micrometer dial to indicate the amount of travel.

Bill

As Pete says, and possibly other indexing operations. Presumably would require a verical milling head to make it usable? The spindle casting has an additional boss, so perhaps a home-brew made from existing parts or own castings.

The fine adjustment on the cross-slide is interesting. Seems overkill for adjusting depth of cut for gear teeth, or maybe its for grinding?

Bill

So you have two choices - grind dry or (periodically) wet.

If dry, then the 'temper' colours look unsightly, but unlikely to draw the temper. Retaining hardness at higher temperatures is the key feature of 'high speed steel' over the earlier plain carbon steels. Red heat is around the tempering temperature, so that's not forgivable, in spite of 'red hardness.' I find placing on the cold tool rest of the grinder takes out the excess heat quite quickly - I'm referring to smaller tool bit sizes.

If wet, then cool frequently. Do not allow it to get very hot as the thermal shock can induce tiny cracks, reducing cutting tool edge life.

Bill

That's amazing, Michael. Made up from so many photos stitched together.

What size printer could print it out?

Bill

Hi, Pete.

I think it may be off a capstan lathe, as you suggest. I operated one, too many decades ago, so my memory is a bit faded.

Bill

The 1/8" plunger has a CSA of 0.01227 in^2. Therefore, 100 PSI requires 1.227 lb weight, a ratio of 81.5. Hiraoka provides the following weights:

Plunger: 0.11 oz

Carrier: 4.80 oz (plus plunger gives 4.91 oz, i.e., 25 PSI)

25 PSI weight: 4.91 oz

50 PSI weights (x2): 9.82 oz

The chapter title says inch version, so perhaps a metric version was published elsewhere. All dimensions in the Heisler book are in US Conventional/Customary Units, including threads.

Bill

Or, as Duncan suggests, PM me with your email.

Bill

Hiraoka’s book, Building the Heisler, goes into great detail in building a deadweight pressure gauge tester. He includes making the gauge, which I guess John does not require. The essential detail is that he suggests a ground or drawn 1/8” rod for the plunger (or piston), into a reamed hole in the cylinder. His drawing calls for a smooth sliding fit. There is no seal, as this would introduce friction, but he says that the small clearance causes very little leakage, due to the oil viscosity.

The deadweights sit on top of the pointed plunger, on a carrier that has a clearance to avoid contacting the cylinder. The weights have masses calculated to produce the required pressure, based on the cross-sectional area of the plunger. The carrier represents 25psi, plus three weights for 25 and two 50 psi weights. Maximum pressure is thus 150 psi. He allows the the miniscule mass of the plunger! I can quotes masses, if rquired.

The cylinder and adaptor to suit the gauge are made from hex brass, with suitable thread and cone to seal, and the two parts screw into a block or manifold with a 1/8” hole, with a plug to seal the end.

I haven't posted images as I'm not sure of the copyright; can a moderator comment. My copy published in 1986. I can provide further detailes if required.

Bill

I did some work for Martin-Baker at Denham a few years ago. Lovely to see their work, impressive factory.

Beautiful model, Carl, very well done.

Bill

It's 30°C here in Cardiff, too. I'm sitting browsing the laptop, whilst a plumber, electrician and builder are all working hard on an extension. I'm providing cold drinks. All doors are open, so the house is soaking up the heat, and we will pay for it tonight!

Too warm for the garage/workshop!

Bill

Thanks, Chuck, your find is proving more interesting than you expected.

I read some years ago, perhaps when visiting the Ironbridge museum, that wrought iron isn't made any longer.

A brief search brought up: Wrought iron. I had expected that "old stock" might have been recycled, but they claim to be the only supplier in the world.

I recall seeing some large anchors at Portsmouth dockyards, with very significant grain visible.

I think that I read that sand or crushed glass was used as a flux, or was that blacksmith welds?

Thanks, Dave, for interesting details.

Bill

Robin, that looks in remarkable condition. I hope you get it working again, in both senses of the word.

Bill

Hi, Brian. Just a comment for others, that it is not to post personal email addresses, use a private message to send info to the recipient. Otherwise, you may end up with unwanted emails forever.

Good luck with the gear, old machines are nice to use and to look at, and deserve repair.

Bill

Would a diode cut 24 VAC to something suitable for a 12V bulb? RMS gives the equivalent DC power level, (filament) bulbs aren't too fussy regarding voltage, a continuous higher voltage giving reduced life.But this varying from 0v to about 17V rapidly, and filaments have a degree of thermal inertia.

Bill

Nigel's comment suggests he knows, but for others who may not, the "0x" numbers are in hexadecimal format, more readable than binary. They may be the codes representing the action produced by the key codes in column 3, or as Nigel says, the address that the command jumps to, to execute the code that performs the action.

Without seeing the labels at the top of the table, this is just conjecture.

Bill

Me too, Ed. The was discussion a while back about changing ownership, and the email says we don't need to do anthing, except note a change in customer reference number. The source of the email looks legitimate.

Bill

No idea,Paul.

It looks as though the ring is used to hold the base against something, presumably the work? The base clearly butts against the edge of something. Do you push the screw to force the blade out? Does the screw control the depth of cut?

Bill

Edited By Bill Davies 2 on 05/06/2022 16:54:56

David, I hope you get feel a bit better soon. Thanks for your contributions.

Bill

Hi, Christine, and welcome.

I think your decision will come down to how near you want to get to the practical aspects of mechanical engineering, and also the size of organisation you see yourself working for. It also is affected by whether you want a full-time or part-time course, be employed or sponsored, or pay course fees.

Following a degree course will provide you with skills to go into design, then progression into customer facing or management roles.

If you take an apprenticeship, depending upon your prior qualifications, could lead you into technician level part time Certificate or Diploma level courses, which supplement what you would learn in your workplace. Diplomas may tend to be full time courses. There are two levels, (Ordinary) National Certificate or Diploma and Higher National Certificate or Diploma (ONC/D, HNC/D).

If you seek practical wokshop skills, you may follow the ONC route or take a National Vocational Qualification (NVQ) which assess what is learned in the workplace, where your competence is certified by internal and external assessors.

You can search on these abbreviations to find more info, but note that Scotland and Northern Irelands qualifications differ in their details from England, I'm not sure whether Wales offer their own.

If you can add more info, it's possible we could offer more focussed advice. This is without adding that mechanical engineering covers general engineering, aeronautical, motor vehicle and many other specialised fields, for which the units you would study may differ.

Good luck,

Bill