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Member postings for john halfpenny

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

Thread: Help: Cordless angle grinder keeps shutting down?
09/06/2022 19:02:33

I don't thnk you can 'know' that the battery is healthy when under load, notwithstanding a long charge and good voltage on a voltmeter Can you try another battery to rule out a fault with the grinder? Symptoms are those of a failing battery, as hinted.

Edited By john halfpenny on 09/06/2022 19:03:02

Thread: Fortis Vice
09/06/2022 15:21:14

The ovality indicates a rather hard life. My No.11 has superficial signs of very hard use, but no such wear.

Thread: Proxxon Micromot 60 Drill Went BANG!!!!
07/06/2022 18:35:26

Don't encourage him, please.

Thread: Fortis Vice
06/06/2022 17:49:52

I think Coventry is right. Mine is on my flogging/bashing bench, and has proved unbreakable under very considerable force.

Thread: Anyone know what these are called?
10/05/2022 09:23:42

Mine is called a lampshade

10/05/2022 08:33:56

A version with more angles.


Thread: Spindle depth stop
06/05/2022 09:02:43

A strip of masking tape wrapped around the tube will give you a perpendicular cutting line.

Thread: Lever operated tailstock for Clarke CL430/500M
05/05/2022 10:26:16

Yes Mike. I make a lot of kit, but no models yet. This one has a brass sleeve for my small taps with pointed ends. The crank may be better for larger threads where it is difficult to get a big tap wrench to turn in front of the chuck, and of course you have to stop the chuck from turning with the tap.


Edited By john halfpenny on 05/05/2022 10:29:53

Edited By john halfpenny on 05/05/2022 10:31:29

04/05/2022 12:50:44

I suppose the sliding tailstock will also allow a tap to advance in a workpiece held in the chuck -the chuck being turned by a crank like this one I made earlier. I have not tried this yet.


The wheel on the crank is a cheap 24 hole indexer intended for a wood lathe, and used with the spring loaded plunger shown in the second photo.



Edited By john halfpenny on 04/05/2022 12:51:34

04/05/2022 11:15:27

I did it because I can Mike. Scrap materials mostly - I bought two oilite bushes and two proprietary adjustable locking handles to finish the job. On the contrary, I expect it will give me more 'feel' for some drilling jobs, and allow rapid withdrawal for clearing swarf when drilling long holes. I think it's been worth my time to make (and an enjoyable project), and time will tell on utility.

04/05/2022 09:47:43

The recent thread by Hopper encouraged me to make this mod based on a mini lathe conversion I found via google photos. It works well and smoothly, and retains hand wheel operation by locking the barrel extension in the rearward position.



Thread: jiggered lathe
20/04/2022 19:03:44

Ford and Vauxhall used tufnol camshaft gears in the 1920s. Still good in both of mine. A good long lasting solution to quietening gear drives if engineered correctly.

Thread: Myford Lever Action Tailstock Design and Build
12/04/2022 09:29:24

Just looking at old MEWs. No.16 (May'93) has instructions and dimensioned drawing for making a version of just this. I have to say that yours looks much more professional.

Thread: Chester machine tool machines
10/04/2022 10:28:52

I have had a combination machine for 25 years, so I can speak from experience. The mill is perfectly usable, but you must go carefully, taking light cuts because of the obvious lack of rigidity - so milling is slow work. I now have a separate mill, which is certainly preferable. The lathe is fine for a bench top machine, and has no disadvantage for having a mill on top - the mill is easily removed if need be. Any four jaw chuck can be fitted; you don't need to use the makers version - just make a simple backplate with diameter registers to suit. My lathe has features which I like - a bolt on chuck, a tee-slotted saddle, fast and slow leadscrew feed, vee belt drive and a good swing- and some less good, like poor tailstock reach, no half-nut, and a slowest belt speed which is too high. Over the years I have remedied all the less good features, and it does everything I need whilst taking up little space. Yes, switching between functions takes about a minute, but is not a big disadvantage for a hobby machine.

Thread: Wiring and connectors
09/04/2022 09:38:03

Some widely advertised (cheap) brass bullets are too hard. They solder fine, but crack when crimped.

08/04/2022 13:51:56

I do a lot of auto wiring. If you can afford it, get a hex crimper and the appropriate bullets. These give a very strong, all round crimp. Otherwise, I would solder.

Thread: The ettiquette of sharing designs
02/04/2022 15:45:55

Peter has mixed up a few concepts. UK law has a specific exception for teaching, which is not Calum's intention. As Hopper says, the exception relates to an extract, not the whole thing or a substantial part, and the criticism aspect refers to the extract, not a modified version thereof (which is what Calum has generated). Non-commercial use is often mentioned, but is a not a defence - copyright infringement does not require commercial loss to be proved, though it may be helpful to the claimant and guide a damages award.

Sometimes it is better to ask forgiveness than permission, but perhaps too late for Calum now. John is right to draw a distinction between the drawing and an article made to a drawing, but it is a very complex area of copyright law.

Edited By john halfpenny on 02/04/2022 15:49:20

02/04/2022 12:02:41

Calum will not get a definitive answer to his complex issues on this or any other forum, so he needs practical advice, given the complexity of copyright law, especially as it relates to engineering drawings. This has a long legal history in the UK. Bear in mind that you cannot prevent an aggrieved person commencing legal action. So you must mitigate the risk by not copying features, or combinations of features which might be proprietary. Of course, 'old' features may be free to use if the relevant copyright has expired. This may of course require research. Generally speaking, the more effort taken to avoid third party copyright, the better the potential defence if a claim arises. Permission and/or attribution can further reduce risk.

In practice a copyright claim is rather difficult to prosecute, since the onus of proof rests initially on the copyright owner (unlike patents, which btw expire before full term if annual renewal fees are not paid). That is why reported copyright cases are lengthy and often ruinously expensive. Perhaps Calum's risk is low (maybe he is not worth suing), but he will never get a definitive answer unless the facts are tested in court. I would not rely upon custom and practice, or homespun opinion.

02/04/2022 09:33:03

Broadly speaking, if you take inspiration from one or more third party designs, and draw/dimension your design without direct reference to those other designs (eg on a clean sheet of paper in an empty room with no reference matter), you will have a defence to an action for copyright infringement because you did not copy. On the other hand, taking a third party design, and changing it so that it no longer resembles the original, is prima facie copyright infringement because copying was part of your design process.

This is necessarily a brief (UK) guide to a very complex legal construct, which varies considerably from country to country, and, as they say, each case turns on its merits (and lawyers can be very inventive and occasionally aggressive). Seeking permission is always a good idea, but not always practicable - it is your desire to publish which is the practical issue here.

Thread: April questions---for one day only.
01/04/2022 10:03:27

Very illuminating Dave, but surely only suitable for light machining.

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