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

[Ian PParticipant @ianp]

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 47Participant @johnsmith47]

> 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.

[JasonBModerator @jasonb]

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

[Michael GilliganParticipant @michaelgilligan61133]

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.

[peak4Participant @peak4]

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 PParticipant @ianp]

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

[JasonBModerator @jasonb]

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 IoMParticipant @francesiom58905]

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 47Participant @johnsmith47]

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 GilliganParticipant @michaelgilligan61133]

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 GilliganParticipant @michaelgilligan61133]

[ deleted unintentionally duplicated post ] 

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

[JasonBModerator @jasonb]

Water works just as well to keep the surface from clogging but best not used dry particularly on softer metals and even more so when using the finer grades

[John Smith 47Participant @johnsmith47]

Posted by JasonB on 28/10/2021 21:02:01:

Water works just as well to keep the surface from clogging but best not used dry particularly on softer metals and even more so when using the finer grades

Opinions seem to vary on that one. The Trend lapping fluid that I use does seems to get very good reviews overall, with a number of users saying that it actually improves cutting performance through lubrication and also avoids any theoretically possible risk of rust.

To get clear, obviously don't use the diamond hone if there is a lot to come off. For filing by hand, I have two sets of superb Bahco Engineers Files, one course set and one fine. The course is bit of a beast that takes a LOT of metal off really fast even after a history of quite a lot of rough use on random hard metals.
They weren't cheap but they are absolutely superb.

If I have the big heavy disk/belt sanding machine, then that is both more accurate in terms of angle and faster than hand files, although for small parts I have taken to regularly dipping them in water to keep the heat down to avoid burnt fingers. In my experience, were the sanding machine falls down is when a longer dead-flat surface is required.

But either which way, if I need an absolutely flat finish – which I sometimes definitely do – I still need to finish off using the fine side of my diamond hone, (which from memory is Sharpal 325+1200).

==> Hence this thread.

[Howard LewisParticipant @howardlewis46836]

Making up one or more jigs will allow the OP to attain his goal, but not as quickly as machinery.

The jigs may well take longer to make than filing / honing / machining to make the prototype, but will save time for larger quantities.

As an aside, a good fitter should be able to work to 0.005" with a hammer and chisel.

Removing metal with a whetstone, (Diamond hone lubricated with water would be quicker) will not match a machine for speed, accuracy AND consistency.

Manual production will not be as consistently accurate as a machine.

Yes, a machine made item can be improved by manual "tuning"; but not quickly, or economically..

Edited By JasonB on 29/10/2021 07:47:51

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Smith 47 on 28/10/2021 23:12:28:

Posted by JasonB on 28/10/2021 21:02:01:

Water works just as well to keep the surface from clogging but best not used dry particularly on softer metals and even more so when using the finer grades

Opinions seem to vary on that one. The Trend lapping fluid that I use does seems to get very good reviews overall, with a number of users saying that it actually improves cutting performance through lubrication and also avoids any theoretically possible risk of rust.

[…]

.

I have neither used, nor perceived the need to use, Trend Lapping Fluid … So I cannot comment on its performance.

I have, however, just found its Safety Data Sheet, and would advise due caution:

**LINK**

https://dccf75d8gej24.cloudfront.net/documents/051131101.pdf

MichaelG.

.

Edit: __ also found this version from 2010: 

http://www.trend-storage.online/productdocuments/osha_da_lapping_fluid.pdf

Edited By Michael Gilligan on 29/10/2021 09:05:47

[Howard LewisParticipant @howardlewis46836]

Be wary of using terms like "Absolutely flat"

You might well be asked to define the primary and secondary surface finish, in terms of micro inch Centre Line Average!

Or have you figures for these in mind?

Howard

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Howard Lewis on 29/10/2021 16:06:36:

Be wary of using terms like "Absolutely flat"

[…]

.

Very wise words, Howard

… especially, perhaps, if one has a patent specification in mind.

MichaelG.

[John Smith 47Participant @johnsmith47]

Posted by Michael Gilligan on 29/10/2021 16:32:05:

Posted by Howard Lewis on 29/10/2021 16:06:36:

Be wary of using terms like "Absolutely flat"

[…]

.

Very wise words, Howard

… especially, perhaps, if one has a patent specification in mind.

MichaelG.

Yes, fair cop.

Try "I need it to be as flat as I can get it as within a reasonable period of time and at a reasonable cost."

The point being that in the early stages of developing a novel concept, it's often not remotely clear what the tolerances will prove to be.

e.g. When I recently outsourced some work the engineers quite rightly asked what tolerances I needed it made to. So I asked "What tolerances do you normally work to without breaking sweat?"  
The answer came back as "0.2mm"
So I said "OK, do that".
 

Edited By John Smith 47 on 30/10/2021 00:50:54

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