Member postings for Robin Graham

I'm sure I'm not the only one on here who is deaf. In my own case it's congenital and started in my mid forties, so I've been using aids for over twenty years. Exclusively NHS for me. That's been OK until recently.

The main purpose of this is to ask if others have experienced benefits from going private after having had experience of NHS aids. I'm less interested in the 'bells and whistles' (Bluetooth etc) than (a) subjective improvement in hearing quality and (b) expertise and accessibility of audiologists. I'd be grateful to hear of any experiences before I splash out. I'm thinking either Boots or Specsavers.

Robin.

Not sure if you have your tongue firmly in your cheek Bill, but in case not the 'others I have seen link' (Myford aka RDG) advertises an LH tool with a picture of an RH tool. Scrolling down they show the corresponding RH tool with - erm - exactly the same image.

Robin.

I started a discussion about this a while ago. Might be worth a read. Shamefully, I didn't report the outcome for me - I did buy a cheap (~£35) device, but it wasn't great. I found that I could get the same sort of images or better with magnifying lenses and a mobile phone camera. MichaelG linked to PeplerOptics (sorry I didn't acknowledge that Michael, but I did read and digest!) They give proper specs and seem trustworthy. Entry level now on sale at ~£160.

Robin.

Edited By Robin Graham on 01/07/2023 23:55:01

The canny thing of course would be to lock it away in a very small safe and sell entirely invisible NFTs.

Robin.

Well, it sold for $63,750:

3D printed Louis Vuitton replica apparently:

I doubt that it would be my own first priority if I had $64k going spare, but astonishing engineering - something called 2-photon polymerisation printing. Shall have to look that up now....

Source: The Guardian.

Robin

Edited By Robin Graham on 29/06/2023 21:59:02

Another way, if you are confident that your tailstock is on-axis and you have a decent tailstock tool holder (eg a good drill chuck) is to is to hold the work in the (accurate) 3 -jaw at the headstock, not fully tight, support the other end in the steady and eyeball. Then bring up the tailstock holding a centre drill - it will draw a circle on the facing end unless you got lucky. Adjust the steady until the the circle reduces to a 'point'. Tighten 3-jaw fully, repeat at the other end if necessary. It works for me!

Robin.

To draw what I hope will be the final line under this topic I think I have at last sorted it out. Following the guidance of a forum member who has the same machine and PM'd me I was able to strip it down and eventually found four dodgy connections between armature windings and commutator segments. I re-soldered the connections and all is now well. For now at least! I shall never know if that had anything to do with the earth fault because I cleaned out the carbon dust from the brushes at the same time. Anyhow, the machine is back in service.

My thanks to all who have offered advice on this, and to the forum in general - the kindness of strangers heartens me.

Robin.

Thanks for replies. First, I don't think Emgee was suggesting that arcing was the only, or even the most likely, cause of the earth fault - just a possibility worth investigating. Given the intermittent nature of the fault it seems a sensible suggestion to me.

noel - I don't think it's the RCD. When I started investigating the fault I bought a 30mA 'local' RCD (the type that goes between the wall socket and the machine plug) hoping to avoid taking out the CU every time the fault occurred. Sometimes the CU RCD wins the race, sometimes the local one. I'm in the Derbyshire Dales near Matlock.

lee - thanks for your suggestion. I think I have some Servisol somewhere, if that's what you're thinking of.

Dave - I'm pretty sure it's not the socket. I have a socket checker (one of those things you plug in and lights come on to indicate fault conditions) and it passes. Also I can run my drill press (1/2 HP induction motor) from the same socket without any problem. But thanks for the suggestion.

I'll dismantle and give it a thorough inspection and clean before attempting to test the PSU / motor components individually as the consensus seems to be that is best first step.

old mart - testing with a multimeter gives >40 Mohms - the fault only occurs when the motor is working.

Writing that, something else occurs to me. I always wind the speed pot down to minimum before stopping the machine. In the past, when I've restarted it has started smoothly at minimum speed, but now it makes a groaning noise and I have to give the chuck a manual nudge to get it started. It seems likely (correlation) that the two things are related, but I can't see how!

Robin.

That did occur to me but all I did was take the brushes out and apply a (powerful) vacuum cleaner to the holes. Perhaps I should take the motor off, dismantle and give it a good clean? Worth a go.

Thanks, Robin.

A while back I posted about my WM14 mill intermittently tripping the workshop RCD. I thought I'd fixed it by cleaning out the tachometer, but not so - it's doing it again. I'm going to have to strip it down to find the fault.

A logical first approach is to separate the power supply from the motor and test each individually. Can anyone suggest a suitable dummy load for the PSU? The motor is brushed DC rated 500W.

Any advice would be welcome!

Robin.

This is quite fascinating. Much more complicated than I thought. Would I be right in thinking that if it could all be designed from scratch it would be possible to simplify? My house is maybe 200 years old and has seen many changes - the plumbing is crazy, lead water pipes in some places, dead legs all over the place and still after 7 years in here coming across lead gas lighting pipes. The electrics, though obviously more more recent, have clearly 'evolved'. Some black and red, some blue and brown. I suspect that it's a bit of a mess, though when I had the cellars wired up to make workshops the sparks tested the whole house and gave me a piece of paper saying it was OK.

In the picture below is the bulging out bit before the meter a conventional (ie it melts) 100A fuse? The leccy comes in through the connection labelled L1. Strangely the bulgy bit isn't secured with a seal - I can wiggle it and suspect I could pull it out.

Robin.

Edited By Robin Graham on 12/04/2023 00:11:16

Edited By Robin Graham on 12/04/2023 00:12:23

Edited By Robin Graham on 12/04/2023 00:16:12

Edited By Robin Graham on 12/04/2023 00:31:53

Thanks for your detailed explanation Stuart - very useful. I had assumed that the connections to the gas/water mains constituted a local earth in that the pipes are (or were) metal and buried in damp earth.

Robin.

As often happens here, a question is asked, an answer is given, then a more general conversation starts. Which I like!

I'm now wading my way through the acronyms (yeah, I know, initialisms if you prefer) in an attempt to understand how my house is wired.

The earthing is like this:

Ah, that's a bit truncated on the right, but gas meter goes to water main which goes to the CU.

The CU seems to be locally earthed via the gas/water pipes, but if I've interpreted the label (Earthing Terminal P.M.E. System) on the box connected to the supply correctly my local earth is bonded to the grid neutral at this point. Is that right?

Robin.

Edited By Robin Graham on 09/04/2023 23:46:54

Thanks. I think Willem explained it in the first reply. Annoyingly I was aware that a neutral / earth short can trip the RCD having had exactly the experience which John Doe 2 described, but didn't think of it before posting. Perhaps surprising that that there was enough neutral/earth current to cause the second bang, but certainly not impossible.

Doing this I had a minor brainwave when faced with the problem of threading the new flex behind the kitchen units. "Ha!" I said to myself, "join it to the old flex with a piece of that adhesive heat shrink tube and pull rather than trying to poke it through."  When my wife saw me making the join she asked " but how can you be sure that the red lines up with the red and so on?" I was tempted to mystify, but came out with the boring truth. Anyway, it worked a treat.

Robin.

Edited By Robin Graham on 08/04/2023 23:36:56

I wired in a new cooker hood today. The old one was wired to the mains via one of those fused wall switches with neon indicator. I prised the switch cover open enough to replace the old wires with the new and left it like that while I turned the power back on at the CU. So far so good, but when I (electrically) closed the wall switch there was a bang and some smoke, followed, maybe half a second later, by another bang and a bit more smoke  from the wall switch.. It turned out that the insulation on the wires to the neon indicator had failed resulting in a short, presumably when I prised the cover off.

When I went back to the CU both the MCB for the circuit and the RCD for that half of the CU had tripped.

My problem is that there were two bangs separated by far more than the reaction times of either the MCB or RCD. One or other should have shut off the circuit after the first bang surely? Any hypotheses about the series of events would be interesting!

Robin.

Edited By Robin Graham on 08/04/2023 00:49:01

Thanks - sounds like the clones are worth a punt. Your comment about the angling of the lenses makes sense of some negative reviews about the clones I've read on Amazon.

Torch looks good - the Donegan offering (advertised as xenon - presumably not xenon arc!) seems overpriced for what it does. Thanks for the link.

Robin.

I've been struggling too. I do have a headband magnifier, one of those with flip-down acrylic lenses, not one of the very cheap things (I think it cost ~£30) but it's not great. In particular I've been having problems soldering components to strip board. Because my eyes are 'unbalanced' I have problems with depth perception.

Partly on the basis of the glowing recommendations here I've splashed out on a genuine Optivisor. Night and day! Best for me is that I can use them with my varifocal prescription specs looking through the 'distance' part of the lenses. That seems to have eliminated the depth perception problem. I couldn't use the cheaper set with my specs on - physically possible, but harder to focus. No idea why there is this difference, perhaps someone who understands optics can explain!

Are the lenses supplied with the clones physically compatible with the Optivisor headset jaCK? I bought the x2.5 Optivisor, which is good for what I'm doing, but if I want other magnifications it would make sense to buy a clone with all the lenses provided that they are optically equivalent and physically compatible.

On other points, the headband on my one looks like PU 'leather', so perhaps will go mushy with time, but on the positive side it looks like Donegan have got the message about studs on the lens holder becoming loose - now secured with screws and nuts

Robin.

Edited By Robin Graham on 19/03/2023 23:58:34

Thanks all - looks like it's a press-stud setting tool then. Probably not much use to me at present, but you can never have too many tools and good to know how it works.

Maun pliers now on wish list!

Robin.

My wife returned from a charity shop scavenging expedition with this:

It is obviously some sort of eyelet or rivet setting tool, but I'm wondering how it would be used. I'm sure someone on here will know!

As an aside I had a look for Maun Industries and it seems that they started in 1944 making hand tools and are still a going concern based near Nottingham, though now making only parallel-action pliers. I think I shall get some.

Robin

Thanks for replies.

Joseph - thank you very much for your clear and detailed explanation. I now see what's going on and understand what the author of the article means by the diodes 'steering' the trigger pulse.

Bazyle - thanks for your reply, but Joseph explained it, so no need to dig out felt-tips!

Peter - thanks for your recommendation of Hemingway's books. Electronic Designer's Handbook is available used on Amazon for a mere £125.50 ! Plus postage. I shall try the library.

So far as intended use goes, I confess that I'm not entirely sure - it's more about the journey than the destination at this stage.

Robin

Edited By Robin Graham on 20/02/2023 23:17:37