Member postings for Jon Gibbs

Another possibility is to use a rubber (boa) strap wrench around the bull gear.

Steve Jordon has a good video here that might be useful...

**LINK**

The wheels Harold uses are AlOx which are perfect for HSS.

If you want to sharpen carbide though it's pretty straight forward to apply the same principles to a set of diamond wheels of similar diameter such as those from ArcEuroTrade here http://www.arceurotrade.co.uk/Catalogue/Diamond-Tools/Diamond-Grinding-Wheels

HTH

Jon

Edited By Jon Gibbs on 10/10/2017 19:35:12

A cheap laser diode or any non-white light LED would be pretty close to monochromatic and as cheap as chips I'd have thought.

[Correction, LEDs are not monochromatic but I think Laser diodes are]

Jon

Edited By Jon Gibbs on 08/10/2017 12:49:30

Mine is more or less running true now since I dressed the inside.

...but before that I would say that one side of the cup was at least 1mm thicker than on other and so it couldn't run true both inside an outside at the same time.

Jon

Edited By Jon Gibbs on 04/10/2017 10:16:48

Hi Colin,

I thought that mine was probably the same but in fact my wheel had a slightly different spec.

It was a 100x40x31.75 8A 60KV Type 11 Taper Cup.

I probably should return it to Midland Abrasives but I've now invested at least a couple of hours into getting it trued up and it does seem to be running ok now.

Jon

I'm a very satisfied customer of m-machine metals.

Give them a try.

Jon

Well last night I spent some time with the DTI and realized that the inside and outside mounting faces of the wheel and the blotters were not parallel. The outside face was flat and more or less on-axis with the outside but the inside face sloped around 0.015" - 0.020" across about 2.25". So, I cut some paper annular shims, trimming and stacking them to take up the misalignment - finally trapping them between the blotter and the inside bush. It was a real fiddle to get them as close as possible.

Anyway, the upshot of this is that the wheel is now running much better. The outside rim has a TIR of about 0.005". Still not perfect but the vibration is within reasonable limits for me and I am able to dismount and remount the wheel fairly repeatably without too much trouble. I also ran the wheel for several minutes at full speed standing out of line and finally plucked up the courage to do some grinding. It worked ok.

I think that the dressing I did on the inside face helped even things up but there is still some difference is wall thickness around the outside of the cup which is responsible for the vibration.

Thank you for the comments

Jon

If you buy 16mm, 1/2", 12mm, 10mm and 1/4" collets, you can accommodate 16mm, 5/8", 1/2", 12mm, 10mm, 3/8", 1/4" and 6mm diameter end-mills and never have to tighten them more than 0.5mm.

Jon

Hi All,

Thanks for the comments and suggestions.

A new 125mm saucer wheel I bought at the same time and using the same style bushes runs beautiful and smooth.

Chris, I have added a new 1" diameter step trued up in situ on the shaft and the shafts run true within 0.001".

Jon

...but isn't it bad news?

Angela Merkel by contrast has a PhD in Quantum Chemistry and spent some time as a Research Scientist.

You're probably right about the other lot - Tony B's cabinet was just as bad - It's certainly not a recent phenomenon.

Jon

Edited By Jon Gibbs on 02/10/2017 17:12:01

As a follow-up to my gripe about PPE graduates in the Cabinet, here's a quick run down of the first degrees of Mrs May's current rogues...

• Theresa May – Geography
• Damian Green – PPE
• Philip Hammond – PPE
• Boris Johnson – Classics
• Amber Rudd – History
• David Davis - Molecular Science/Computer Science (1971)
• Michael Fallon – Classics & Ancient History
• Liam Fox – Medicine
• David Liddington – History
• Baroness Evans – Social and Political Sciences
• Jeremy Hunt – PPE
• Justine Greening – Business Economics and Accounting
• Chris Grayling - History
• Karen Bradley - Mathematics
• Michael Gove - English
• David Gauke - Law
• Sajid Javid - Economics and Politics
• James Brokenshire - Law
• Alun Cairns - ??? + MBA
• David Mundell - Law
• Patrick McLoughlin – Agriculture.
• Greg Clark - Economics
• Priti Patel - Economics, Sociology and Social Anthropology

So, apart from David Davis who studied Molecular Science/Computer Science dual honours, graduating in 1971 (pre-Intel 8080 and probably even PDP-11), there's no one with a scientific background except perhaps Liam Fox - a medic. Certainly no one with an engineering background.

I should single out Patrick McLoughlin who did agriculture and apparently spent a year or two down a coal mine. So, he's perhaps a tad more practical than the rest of his peers but still no engineer.

Jon

Blimey that's up there with some of the best conspiracy theories I've come across.

Cock-up theories always win hands-down for me. It seems much more likely that our parliament is full of PPE graduates (and Classics graduates if you extend it to BoJo) who found science a turn-off at school and are too ill-informed to realize that science and engineering are more beneficial to the economy than services.

I hesitate to raise the "B" word but suffice it to provide this link to the work of the European Commission that has been fostering R&D in the EU for many years and on which a lot of our Companies and Universities have been funded by in no small part until now... **LINK**

...but don't worry those PPE and Classics graduates will have all of the sovereignty that some of us voted for soon.

In the TV arena the public begrudge the license fee (thanks Rupert and friends) and so we get cheap celebrity television with high ratings to show value for money. None of our youngsters therefore see anything on the TV to get them interested in engineering or science and so the smarter ones read PPE or Classics or choose the City and the cycle is complete.

Jon

Hi All,

I've just bought a 100mm flared cup grinding wheel from Midland Abrasives to put onto my offhand grinder.

I'm following the procedure Harold Hall suggests in his two books "Milling a complete course" and "Tool and Cutter Sharpening" and have made up a new set of reducing bushes. The bushes run true and are within a gnats of being in-balance.

...but when I mount the wheel it runs way out of true with one side noticeably thicker than the other. I've tried dressing the inside of the cup to make the sides more or less the same thickness but the grinder still vibrates like heck.

Is this normal for cup wheels?

Jon

I'm with you Neil. Extended warranty is a form of Insurance which is all about statistical averaging over many individual policies to ensure that the insurer makes a profit overall all after all claims.

So, I never pay for extended warranty on principle and apply the statistics over all of my devices, appliances and white goods. If I get one dodgy item that dies before it should do, out of warranty, then I am pretty certain that I've saved enough by not buying the warranties on all of the other "good" products to cover it.

Jon

Q: How do you tell the difference between an extrovert software engineer and an introvert software engineer?

A: The extrovert software engineer looks at your shoes when he's talking to you.

I must admit I thought that washing machine drums were supposed to rotate off-axis when there's an uneven load?

I think it ought to effectively rotate around the centre of gravity of the drum if everything is working well.

Jon

Hi George,

I may be wrong but I think that the friction pads are there to grip the tow ball in order to help dampen driver induced oscillations. Fabric conditioners to me sound as if they will reduce the friction - especially since some contain silicone-like compounds these days.

Probably reduces squeaking but at what cost to functionality?

Jon

Hi Brian,

Jason kindly linked to this series of 5 schematics a while ago when I was interested in the same question...

**LINK**

I hope they help you as much as they helped me.

- Thanks again Jason.

Jon

Edited By Jon Gibbs on 25/09/2017 12:58:27

Last night I created the baseplate and mount for the cheap grinder to go with my HH Advanced Grinder rest. 30mm plywood base 600x300 with a 3mm steel plate for the mag mounts.

Swivel plate and minor accessories including single point dresser and 4-facet drill grinding set-up bottom left. I need to make the bushings for the grinding wheels next and then onto the end-mill accessory.

Jon

Edited By Jon Gibbs on 25/09/2017 10:23:17

My old ML7 has the flat oilers and a traditional rigid oil can spout (Cheap Faithfull) held flat over the balls can achieve an adequate seal for me.

I used to have to use a bit of open-weave cotton rag between the spout and the ball but my technique's improved a bit since the early days. I still have to use this method on the mill which has similar oilers and is supposed to use ISO-68 which is a lot thicker than ISO-32 for the lathe.

HTH

Jon