By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Neil Wyatt

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

Thread: German Optics fo British Rubber
21/07/2018 21:42:47

Anyone else listening to Radio 4?

Apparently the exchange of British rubber for German binoculars was a genuine deal during the first world war.

greatwarproject.org/2015/07/20/a-clear-case-of-trading-with-the-enemy/

Neil

Thread: A beginners' guide to aluminium anodising?
21/07/2018 21:34:27
Posted by choochoo_baloo on 18/07/2018 18:22:55:

Forgot to ask, can someone recommend a dye supplier?

Try Gateros Plating, very helpful.

Thread: A New Way To Cut Gummy Metals
21/07/2018 13:10:47
Posted by Muzzer on 21/07/2018 11:40:16:

It certainly seems to relate to the behaviour of the material surface in the "vee" where the original material is shearing into the compressed chip. If that is the case, you'd expect the effect to be more marked for shallow depths of cut - for heavy cuts, what happens on the surface will surely have less impact on the behaviour deeper within the shear zone.

Unless the cranks rapidly propagate beyond the surface?

Interesting stuff.

Neil

Thread: Shingle bells
21/07/2018 11:11:50

I've thought about this recently.

Rather than being a forum about model engineering, it's a forum for model engineers in the broadest sense.

If a number of forum members are interested in a topic, then they should be free to discuss it (in the right topic).

What would be wrong is the unlikely situation that people who do not share our 'common interests' start using the forum as a convenient place to discuss their interests.

It's not the job of moderators to limit the topics of discussion (aside from those likely to spread disruption), but for forum members to vote topics up or down simply by deciding whether or not to participate in the threads.

We did, however, establish topics like 'Related Hobbies', 'Vehicle Restoration' and 'The Tea Room' for those of a particularly sensitive disposition.

Neil


Thread: A New Way To Cut Gummy Metals
21/07/2018 10:53:42

We mustn't condemn the research because of the way it's reported. The abstract gives more detail;

Soft and highly-strain-hardening metals such as iron, aluminum, and tantalum, often called “gummy,” are notoriously difficult to cut. This is due to their tendency to exhibit redundant, unsteady plastic flow with large-amplitude folding, which results also in macroscale defects on the cut surface and large energy dissipation. In this work, we demonstrate that this difficulty can be overcome by merely coating the initial metal surface with common adhesive chemical media such as glues and inks. Using high-speed in situ imaging, we show that the media act by coupling unsteady surface-plastic-flow modes with interface energetics—a mechanochemical action—thereby effecting a ductile-to-brittle transition, locally. Consequently, the unsteady plastic flow with folding transitions to a periodic segmentation-type flow in the presence of the surface media, with near absence of defects on the cut surface and significantly lower energy dissipation (a reduction of up to 80%). This mechanochemical effect is controllable and not material specific, with the chemical media demonstrating comparable efficacy across different metal systems. This makes it quite distinct from other well-known mechanochemical effects, such as liquid-metal embrittlement and stress-corrosion cracking, that are both highly material specific and catastrophic. An analytic model incorporating local flow dynamics, stability of dislocation emission, and surface-media energetics is found to correctly predict the onset of the plastic-flow transition. The benign nature and simplicity of the media suggest wide-ranging opportunities for improving the performance of cutting and deformation processes for metals and alloys in practical settings.

 

"Scanning electron microscopy images of chip morphology in Cu. (a) Characteristic mushroom-type structures on the chip free surface, a signature of sinuous flow, arise due to individual folds (yellow arrows) collapsing onto each other. (b) In the presence of an SA medium (glue 1), the flow transitions from sinuous to segmentation type, characterized by minor folding events in each segment (yellow arrows) and separated by periodic fracture surfaces (red arrows). The morphologies span the entire width of the chips."

Visit the link below, click on the images as the captions tell much:

journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.10.014009

The video shows a transition from treated to untreated, it also states that they are using high-speed imaging i.e. it's slowed down.

I think we need to try it in the real world before deciding it's bunkum.

In particular, I think their test is very relevant to tapping and die threading with soft metals.

Edited By Neil Wyatt on 21/07/2018 10:57:30

20/07/2018 20:12:45

Planning to machine some nasty aluminium alloy or some copper?

Coat it with Pritt or mark it up with a sharpie first!

phys.org/news/2018-07-metal-gummy-sharpie-science.html

I haven't tried this yet, but i will have a go next time.

Neil

Thread: Quality of back issues
20/07/2018 11:09:54

I think it's pretty much as Jason says, the main problem being that the older issues are physical scans of magazines, while the more recent issues are generated direct from the electronic data.

If the original drawings are less than perfect then scanning with reduction in resolution for monitor display doesn't help.

Neil

Thread: Hello from Dursley
19/07/2018 19:48:45

Welcome to the Forum, Beaker.

As in Professor Bunsen?

Neil

Thread: DC motors
19/07/2018 19:47:23

If I recall correctly electric motors in parallel will tend to balance current to run at the same speed, with motors in series if one is stalled and the other is free the free one will overspeed.

Thread: Eccentric's "Turnado"
19/07/2018 19:33:45

I complemented Gary on the choice of colour, and he confided in me that they just came out like that!

It is a lovely example of the patternmaker's/foundryman's art.

Neil

Thread: Todays Mystery Object?
19/07/2018 09:40:10

Momentum of a photon = frequency x planck constant

www.nasa.gov/mission_pages/tdm/solarsail/index.html

Edited By Neil Wyatt on 19/07/2018 09:45:07

Thread: Homemade Grinder Advice
19/07/2018 09:20:23

Another word from Cassandra - back in the day before cheap bench grinders MEW was always full of people suggesting using DC and 'universal' motors to make grinders.

These articles were always guarded with reminders about the hazards of overspeeding grinding wheels with non-synchronous motors.

It was, I think, 'Duplex' who presented a grinder with a friction pad to stop a grinder overspeeding with no load, probably one of the dodgiest designs ever featured in the 'hallowed' pages of Model Engineer.

Neil

Thread: Todays Mystery Object?
18/07/2018 20:35:12
Posted by Howard Lewis on 18/07/2018 20:21:18:

A light beam, reflected off the mirror has no measureable weight or inertia.

But it does have momentum

Neil

Thread: Microsoft Windows 10S - One to Avoid?
18/07/2018 20:33:07
Posted by Russell Eberhardt on 18/07/2018 19:18:53:

I've used Linux for over 15 years now and never phoned the help desk. Oh, there isn't one.

So that's why I've been stuck on hold for eleven years...

I hope it was a freephone number I dialled.

N.

Thread: Homemade Grinder Advice
18/07/2018 15:47:47

I found this:

www.ccohs.ca/oshanswers/safety_haz/abrasive_wheels/bench.html

The key issues with your design are lack of card washers and no undercut for the flanges, both of which you could incorporate, but I think you also need to check the proportions.

Be aware that the diagram is wrong as it doesn't show the fixing thread extending well inside the flange i.e. you wouldn't be able to grip an over-thickness wheel securely.

Note also that a fixed diameter setup like you propose will only be able to be used with one hole diameter.

Neil

18/07/2018 15:42:05

You should use fibre or card washers so there is no metal flange to wheel contact, also the gripping flanges are usually cupped so they grip the wheel well away from the edges of the hole.

The centre bore must NOT be a tight fit, which is why a resilient (typically plastic) plug is often used. This helps ensure concentricity. A tight fitting metal plug may expand with temperature and burst the wheel.

Neil

Thread: Should every machine tool be bolted to a concrete floor?
18/07/2018 15:29:21

My X2 mill, SC4, adept shaper and pillar drill are all bolted down either to built in benches or in the case of the SC4 to a matching stand that's attached to the floor. All the smaller machines (grinders and mini lathe) are free standing.

Neil

Thread: X2 Mini Mill - Motor Armature
18/07/2018 15:25:32

My UK X2 has a motor plate that reads DC 230V.

Neil

Thread: Milling for beginners
18/07/2018 10:23:36

Generally true, but there is less variation in the mill specifications.

Look for a brushless motor and large table.

Neil

Thread: Moped Restoration -NSU Quickly/Chinese scooter- constant rebuilds
18/07/2018 10:19:27

Welcome to the forum, Chris.

Neil

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Email News - Join our newsletter

Love Model Engineering? Sign up to our emails for the latest news and special offers!

Latest Forum Posts
Support Our Partners
Eccentric July 5 2018
Eccentric Engineering
Expo Tools July 14
Ausee.com.au
ChesterUK
Warco
Sarik
Allendale Electronics
TRANSWAVE Converters
Shapiro
SPG Tools October Seventeen
emcomachinetools
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

Visit the Model Engineer
Exhibition website

Model Engineer Exhibition