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How can I make an accurate 90 grind using a diamond whetstone?

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John Haine28/10/2021 10:26:03
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John, this has been an interesting if frustrating saga, both for you I'm sure and also the many people who have tried to help you. The big stumbling block has always come down to the fact that you want to do things that would be trivial with the right machinery but extremely hard with what you have access to. So here is a suggestion: find out if there is a "Makespace" reasonably close to you that has the right sort of machinery and join it. Or maybe an evening class, or a model engineer that will let you use their machines (under supervision) and help you with the tricky bits. Otherwise you will continue to stumble in the dark and get increasingly frustrated.

I appreciate that you want to do things under the radar to protect your ideas - you say "patent pending". Does that mean you have filed the patent application; or has it been examined so you know the scope of protection; or do you just have an intention to file? If you have at least filed and lodged claims then you do have a modicum of protection, but would no doubt still want to keep reasonably quiet about what you're trying to do. But you must appreciate that when you say things like "an angle must be exactly 45 degrees", or "an edge must be exactly square", if these are impediments to manufacture and people ask why and make suggestions, you might make faster progress if you can open up a bit.

Ian P28/10/2021 10:37:43
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+1

Rod Renshaw28/10/2021 11:57:24
346 forum posts
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+2 for John H - who clearly has a lot more patience than I have. And +! for Baz, I find these threads have an aweful fascination but I think I have had enough now.

Rod

Nicholas Wheeler 128/10/2021 12:02:49
769 forum posts
52 photos

The more you write about this, the more you prove how far over your head you actually are:

Novel and inventive, no equipment, no money and no experience at any of the processes involved make it very easy to dive into the wrong rabbit hole and dig enthusiastically.

Your insistence on precision finishes from what should be easy parts: if I was going to have 32x6x1mm steel parts(I'm inferring yours are a plate for the magnet to grab), they would be designed to be usable straight of the guillotine from commercial 6x1 strip.

Same thing for the tight tolerances: a watertight box needs the lid to fit accurately to work. An attached steel strip shouldn't. Or if it does, constrain it with other features like ribs moulded into the case.

Credible prototypes prove that the concept works, and illustrate the final aesthetics if they matter. One cobbled together on the kitchen table out of cardboard, string, hot-glue and a Stanley blade painted with £1 gloss black is credible.

That's also how you iterate the prototypes, quickly moving from the glue, through different materials etc, to a production part. Low production and mass produced in the millions parts are going to be very different, even if they do exactly the same job.

You're not iterating, but stalled. I suspect you know this, and have managed the next step which is to ask for help. The bad news, is that often the best advice is to bin your favourite parts of the design and redo them. Which is extremely difficult to take!

I hope that at some point you show us what this thing is.

duncan webster28/10/2021 13:47:53
3581 forum posts
65 photos

In production engineering, exactly has no meaning. If parts have to be square, and the right width, thickness and length to some very close tolerance (and made from unubtainium) they will be expensive, not what you want for a bit of office equipment. You can get better than a thou with a file, and some patience. I'd have made 4 to sensible tolerances in the time it has taken me to read this thread.

John Smith 4728/10/2021 15:12:43
271 forum posts
11 photos

John H
On the face of it your Makespace is a good one. Yes, I had been using them, however as you know it is crucial that I am not seen to disclose what I am doing in any public form or further patent claims & sub-claims will not be possible. Either way I have not been using them since the Covid-19 pandemic and with 1 million people infected with Covid right now, now is not the time to start.


Yes I have done multiple prior art searches and yes, I have filed patent claims.
But do I REALLY have to answer all your invasive questions?

Look is it too much to ask for you folks to just confine yourself to answering the simple questions that I have raised?

Why does everyone keep trying to re-design my product for me?

PLEASE just let me dig my own grave, if that's what you think I'm doing... but please can everyone keep their self-righteous egos out of my designs.

If, unprompted, you do choose to make design suggestions, that's up to you and in general I am grateful but the down-side is absolutely no way can I go into details about the reasons for my design decisions. So if that's frustrating please do NOT make design suggestions.

Nicholas Wheeler
Sorry Nick offensive as your personal attacks are, you simply have no idea what you are talking about and it would take too long to correct you. Yes I have done a lot of outsourcing where appropriate.

No, straight of the guillotine bends the plate. It curls on one side and rounds the edge on the other. We all know this. So why am I wasting my breath?
You don't sound like you have much if any experience of fine tolerance and strong magnets. Because if you did you would know that in practice, unbelievably small machining errors can easily cause a x2 change in magnet pull.


Final words
Okay that's it. No more person attacks, please. And no more re-design suggestions, please. If you don't enjoy reading threads that I have started... if you still want to make your personal attacks, if you still want to offer what is completely unsolicited re-design advice PLEASE GO AWAY.

Please can we all just stick to the materials, tools, technology and techniques... and stick to the topics in the actual question!

John Haine28/10/2021 15:54:40
4259 forum posts
251 photos

I give up. Some people just can't be helped.

John Smith 4728/10/2021 16:14:23
271 forum posts
11 photos
Posted by John Haine on 28/10/2021 15:54:40:

I give up. Some people just can't be helped.

There we agree.

Nicholas Wheeler 128/10/2021 16:42:18
769 forum posts
52 photos
Posted by John Smith 47 on 28/10/2021 16:14:23:
Posted by John Haine on 28/10/2021 15:54:40:

I give up. Some people just can't be helped.

There we agree.

Yes.

I still hope to see whatever is causing you so much hassle.

Ian P28/10/2021 16:49:22
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2533 forum posts
102 photos

I wish you good luck with your project but based on what I have gleaned from the various threads I would say its doomed to failure. I'm not trying to depress you or dissuade you from continuing but the reality is that to get the project to a state where it is protected by patent you will need to invest quite a lot of money (say compared with the tools and machines you have mentioned).
Unless you already have some sort of arrangement with a potential manufacturer bear in mind that many large companies have a deliberate and rigid policy of NOT buying in external ideas (damhik).

One observation, as you say the magnetic attraction between two parts can be seriously reduced if the parts do not fit together well and it sounds like its the 1mm wide face that is one of the abutting surfaces, It would need seriously strong magnetic force for your metal strip to stay at 90 degrees if whatever is attached to it is going to do anything useful.

I cannot understand why you thought Nicholas Wheeler's comments were a personal attack on you, he just summed up the situation perfectly.

Ian P

John Smith 4728/10/2021 17:45:39
271 forum posts
11 photos

> I wish you good luck with your project
Thank you.

>>>
...but based on what I have gleaned from the various threads I would say its doomed to failure. I'm not trying to depress you or dissuade you from continuing but the reality is that to get the project to a state where it is protected by patent you will need to invest quite a lot of money (say compared with the tools and machines you have mentioned).
>>>
Wrong. Like I have already said, several times in fact, this is well in hand and has already been done. [Shesh!]

Ian P, in the nicest possible way, I think your all of your strategic advise is doomed to failure.

>>>
One observation, as you say the magnetic attraction between two parts can be seriously reduced if the parts do not fit together well and it sounds like its the 1mm wide face that is one of the abutting surfaces, It would need seriously strong magnetic force for your metal strip to stay at 90 degrees if whatever is attached to it is going to do anything useful.
>>>
Wrong again. The magnets work absolutely perfectly. I'm actually serious.


Now, if you no further suggestions on the topic "How can I make an accurate 90° grind using a diamond whetstone" please stop.

JasonB28/10/2021 18:26:46
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I'm going to delete any further postings that do not directly answer the heading, so anyone else is best to move on.

Michael Gilligan28/10/2021 19:08:32
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19258 forum posts
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Directly answering the opening question … You already have the answer, John

My post timestamped 27/10/2021 08:25:56 refers.

If you insist upon using your existing whetstone then the process will inevitably be slow … but you have already identified the method for yourself.

Sincerely

MichaelG.

peak428/10/2021 19:09:53
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1537 forum posts
165 photos

John, Regarding the filing guide I linked to earlier in the die making video, I'm not sure how you would damage your files if you leave them in the toolbox, and use your diamond hone instead as you originally proposed.

Next idea, look up woodworker's shooting board, for inspiration.
Replace the plane with a square block of something, which holds your diamond hone vertical; possibly with a step at the bottom, just thicker than your hone, to act as a running surface.

A small hold down clamp for shaping the first edge, along the lines of those used in a finger plate, would secure the workpiece to the "shooting board".

After you have one long edge square and straight, insert a couple of dowels into pre-drilled holes, exactly 6mm from where the diamond plate will run.

Clamp the workpiece down again and finish the second long edge; assuming you've drilled the dowel holes in the right place, you will have a 6mm wide strip.

The square ends can then be made using the right angled fence.

Bill

Ian P28/10/2021 20:20:33
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2533 forum posts
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Posted by JasonB on 28/10/2021 18:26:46:

I'm going to delete any further postings that do not directly answer the heading, so anyone else is best to move on.

Maybe I'm being too pedantic but does this new rule apply only to this thread?

It is a serious question though

Ian P

'Best to move on' What does that really mean? 

Edited By Ian P on 28/10/2021 20:22:11

JasonB28/10/2021 20:31:00
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Just this one.

Those that feel that John is not listening to their suggestions would be better moving on to other threads where their input will be better received and using the ignore member option if they no longer wish to flog a dead horse, aid in what may be a commercial product development, etc.

As Neil said in another of John's recent threads

"Please can people stop mudslinging

The OP is happy to continue, but I suggest that just those making positive comments continue to participate."

 

Edited By JasonB on 28/10/2021 20:39:41

Frances IoM28/10/2021 20:43:59
1172 forum posts
28 photos
I have a ready supply of 0.5mm x 8mm x 48mm strips - one can indeed set a small magnet on the rear face of a strip laid horizontal then balance one strip on the 0.5mm face on the base strip and even balance a 2nd strip on its 0.5mm face on the other edge of this balanced strip - the strips are the lamination strips found in a low voltage transformer with the usual E+I arrangement - I now use them as packing strips under lathe tools - may a slight adjustment as to size will allow these accurately formed and magnetically suitable strips to be used in any demonstrator (The winding & E laminations were used in a demagnetiser)

Edited By Frances IoM on 28/10/2021 20:45:12

John Smith 4728/10/2021 20:46:25
271 forum posts
11 photos

Much appreciated, Jason.

Peak4 - Wow, "Woodworker's Shooting Board" is a genius concept. Yes very clever indeed, particularly the way it hooks onto the bench to stay in place and how the plane doesn't cut into the supporting structures. Thank you so much for pointing it out to me.

In my case, given the way that my diamond hone's diamonds go right tot the edges, as you say, I'd need to find a way to create a running surface in addition to to holding the hone vertical.

Fwiw, by way of fine-tuning, I suspect that think one would need a small trench so that the filings don't start to get in the way.

Many thanks

J


P.S. On reflection my slight concern is that the diamond hone seems to work much better with some lapping fluid on it, as this helps to stop the diamonds from getting clogged up with grindings.

There again, maybe if the hone is being held vertically on its side then to some extend gravity becomes one's friend and would help to pull them away, and the hone might work okay dry... What think you? [As I'm quite keen to not destroy my rather valuable diamond hone just yet!]

Michael Gilligan28/10/2021 20:58:55
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19258 forum posts
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Posted by John Smith 47 on 28/10/2021 20:46:25:

[…]

P.S. On reflection my slight concern is that the diamond hone seems to work much better with some lapping fluid on it, as this helps to stop the diamonds from getting clogged up with grindings.

There again, maybe if the hone is being held vertically on its side then to some extend gravity becomes one's friend and would help to pull them away, and the hone might work okay dry... What think you? [As I'm quite keen to not destroy my rather valuable diamond hone just yet!]

.

At the risk of repeatedly stating the obvious … A coarser hone would not clog so easily

MichaelG.

Michael Gilligan28/10/2021 20:58:56
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19258 forum posts
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[ deleted unintentionally duplicated post ] 

Edited By Michael Gilligan on 28/10/2021 21:01:01

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