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Member postings for Martin W

Here is a list of all the postings Martin W has made in our forums. Click on a thread name to jump to the thread.

Thread: Some quite astonishing ‘metal bashing’
18/01/2021 23:36:36

Michael

That is absolutely brilliant, the way that the plates are formed and laid out look like the muscles of the real beast; then there's the head which takes it to another level.

Thanks for sharing it.

Martin

Thread: Chester DB8
07/01/2021 16:09:55

If the DB8VS has the same arrangement as the DB7VS then the pulleys are plain V section and don't have teeth. The only reason for using a toothed V belt would appear to be to give it the extra flexibility to accommodate the motor drive pulley diameter. If so then the number of teeth per unit length is irrelevant.

Martin

Thread: In anticipation of the New Year ...
03/01/2021 00:49:35

Michael

If I could do that leads or batteries or what I would be a very happy man !! Thanks for sharing and it really shows the progress of technology to date. I remember a James Bod film where there was a tracking system that displayed the target on a visual display system and I thought "Yeah really" yet a few years later along came GPS and map tracking. I really wonder what the future holds in the development of technology especially with the introduction of Ai etc,

Thanks and stay safe.

Martin

Thread: Milling cutter
27/12/2020 11:19:20

John.

Message sent re inserts.

Martin

Thread: Rewiring Li ion battery
21/12/2020 16:46:25

It looks like a fairly standard 6 cell unit complete with the charge controller built in. This will include circuits to balance the charge across the cells to eliminate over charging/discharging any of the cells. Many of this type of board include temperature monitors to prevent charging/discharging the batteries if their temperature is excessive plus some form of current limiting, Dyson use a similar arrangement on their cordless vacuum cleaners and as you say the unit is fed from a standard DC PSU.

That said I would take on board all the warnings and advice given already as when these things go wrong it can be spectacular or devastating depending when and where they fail. Even the experts get it wrong as was demonstrated a relatively short time ago when several laptops burst into flames. Not a design problem admittedly but a flaw in the battery production. When fully charged they contain a significant amount of energy and can release this explosively. While these small domestic units are not in the same league we used to use large lithium batteries in remote locations and if these showed any signs of distress they were covered with dry powder fire retardant material and removed to a specified dry safe place well away from people and buildings etc.

If you are not sure then don't take the chance.

Have a safe and happy festive break that doesn't involve any of the 999 services.

Martin

Thread: Size question
20/12/2020 23:24:40

O Mart

I would think that an open apology would be in order after such an acidic post - perhaps the old advice of " If you haven't got anything good/constructive to say then keep quiet ". As others have said it was a perfectly reasonable question as tolerances can vary and the given measurement/dimension may only be valid under certain conditions i.e. straight runs of track or whatever.

Martin W

Thread: New scam to beware of
02/12/2020 18:39:55

I treat them as a bit of amusement. I try to sound like an old fellow who isn't quite sure of what is going on, at 77 I suppose it's not too far from the truth. Usually the computer is upstairs and switched off so a slow climb with much puffing then a long boot up time, oops forgot my glasses and they are down stairs so another lot of huffing and puffing. Next is finding they key they normally want me to press, very sorry can't see it so they try to explain where and what it is. By this time my wife and I are trying not to laugh loud enough to give the game away. Eventually I will get bored talk normally and tell them what they are in no uncertain terms or they break the call. The best I've had is about 25 mins having been passed from one supervisor to another and they can get quite annoyed when they realise that it is them that have been conned. One even phoned back to ask why I had wasted their time, needless to say he was told explicitly what I thought of him and reminded him that they had paid for any phone charges.

It amuses me to string them along and all the time that the lowlifes are talking to me they are not attempting to con someone that is vulnerable.

I find this site quite useful as anyone who has been cold called can leave the number that called and a description of the call plus a flag that indicates, in their opinion, the type of call from annoying through to dangerous.

Martin

Thread: grease for instrument control knobs
04/11/2020 12:48:12

Michael

Thanks for the reply, if you find the 'elusive product' then I would appreciate a heads up.

Cheers

Martin

04/11/2020 10:02:26

Some time ago I was servicing one of my microscopes and bought a tube of Nyogel from Ebay as it was suggested that it would be suitable for camera lenses etc. Once I had fully cleaned and re-lubricated the slideways, using said grease, I found that the controls were so stiff that the microscope was virtually impossible to use. I suspect that the relatively large contacting surface area coupled with the close fit of the slideways enhanced the 'grip' effect of the grease. Whatever the cause it meant a complete strip down of the microscope and rebuild after thoroughly cleaning and re-lubrication of the slideways with a different type of grease.

Unfortunately I can't find the offending grease so I am unable to give an indication as to its viscosity.

Cheers

Martin

Thread: Chatter
24/09/2020 01:17:32

The tool post looks to have chamfered edges which could explain the apparent gap between it and the cross slide. Looking at the reflection of the tool post on the cross slide in the enlarged picture it appears there are chamfered edges on the bottom of the tool post which could explain the gap but worth checking anyway.

Martin

Thread: Mystery parts
21/09/2020 10:57:33

It's odd in that it appears to have 2 sets of valve gear the one on top of the cylinder is disconnected. Might have been an improvement with the intent to give it a reversing valve gear.

Martin

Thread: HSS/Tungsten Tool Honing Machine
15/09/2020 17:34:05

That's an elegant design and the workmanship is brilliant. It's one of those pieces of equipment that 'looks right cause it is right'. Mightily envious of the quality of work that you have achieved.

Martin

Edited By Martin W on 15/09/2020 17:34:35

Thread: Surfaces of Platonic Solids
08/09/2020 12:02:45

Thanks for that Michael, thoroughly enjoyed watching it. You wonder why nobody has asked the question before even if they didn't have the wherewithal to solve it.

Cheers

Martin

Thread: Mystery post
02/09/2020 18:05:57

How about a timer for street lighting that had to be set or wound periodically prior to the days of light sensors and remote signal control. I look forward to finding out what it is, it's purpose and age. The fact that a nondescript tatty old piece of street furniture has caused so much interest must be a reflection of the members of this forum's curiosity.

Thread: Miracles do happen
29/08/2020 14:02:34

Several years ago dropped a smallish spanner in my shed and before I could bend down to retrieve it the Gremlins pounced and snaffled it, I still haven't found what they did with it and I reckon they are still chuckling about it. As for small fixings/parts etc. they must have secreted a hoard somewhere! Ahh the joys of fumbling fingers, poorer eyesight and not being able to hear when small things hit the floor seem to be the gifts we acquire as we get older/old.

Martin

Thread: Help needed in identifying inserts
28/08/2020 19:30:41

Jon

I have not seen the like of these either. However they look to have similar dimensions to the TCMT1102nn series of inserts. If it would help I could send you a sample insert that is designed for aluminium, tip definition - Aluminum Carbide Insert TCGT110204-AK--, to see if it would fit the insert bit bar that you have. While these inserts are designed for aluminium they will work on free cutting steels provided that one isn't too enthusiastic with the depth of cut or feed rate.

If your interested then contact me via the PM system on this site and I will get one in the post.

Cheers

Martin

Thread: Mini lathe blown fuses and Motor overheating
28/08/2020 00:25:55

Yes it is the last fuse that the energy supplier is responsible for but it is, as I said, the 1st fuse 'in the supply chain in the property' wink 2.

Cheers

Martin

27/08/2020 19:25:58

Martin

That is just the first fuse in the supply chain in the property which is then normally broken down into lower current circuits but it is the final safeguard. Yes I totally agree that it is sealed, is the responsibility of the energy provider and is there to protect the incoming supply.

As I had stated that I was looking at Fast Blow fuses I purposely did not include the Consumer Unit or any other fuse in the circuit and was giving just a general description as to the rationale re the fusing system and their purpose.

Cheers

Martin

27/08/2020 18:14:35

There seems to be a misunderstanding regarding the performance of cartridge/wire fuses and their rupture time. A quick blow fuse will run indefinitely at its rated amperage, which one would expect. However when the current rises above the rated value the fuse it does not immediately rupture. In fact, worst case figures, at 2 times the rated current it can take a fuse in excess 6 seconds to rupture and at 3 times the rated current it can take 0.4 seconds. The energy passed during this time is frequently enough to damage a semiconductor component.

Fuses are not there to protect the components or equipment but to limit the energy drawn by the device in order to:

a) To limit the current drawn so it does not damage the house wiring and potentially start a fire.

b) But primarily to ensure that the energy provider's cabling is not compromised.

Hope this helps.

Martin

Thread: Horological Tool Sale
11/07/2020 12:17:05

Hi

I have just been browsing a sale catalogue and noticed that they have sets of horological tools and lathes for sale. I have absolutely no experience in horology so no idea of the quality but the estimate prices look very low. For those interested, even just out of curiosity, the lots on offer can be seen here. Usual disclaimers re vested interests etc.

Martin

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