Journeyman | 12/06/2021 15:03:19 |
![]() 1257 forum posts 264 photos | I think I would just go to the local stationers or visit Amazon and buy a really useful A4 box John |
John Smith 47 | 14/06/2021 13:20:27 |
393 forum posts 12 photos | @Bill Phinn Yes, I have already had a few samples from JPP about 3 weeks ago - thank you so much for the suggestion. Having spoken to them (James), they thought that their "JPP ARCHIVAL FOLDING BOXBOARD" (as per your link) would be too soft, as it is specifically designed to be folded and will not have the rigidity that I seek. JPP suggested their Heritage Conservation Board 1380micron, and sent me a sample of it, but it is way too soft and is for example very easily bent beyond it's elastic limit (i.e. creased!) between 2 finders and a thumb. However much more to the point is their "Gemini Mill Board" - which is fantastic stuff! To get clear 1.0mm is too thin to have much strength and 1.5mm is too thick for my requirements. [Part of the problem with the 1.5mm thick Gemini Mill Board is that it is unlined, and in order to make it durable and give it attractive, cleanable, moisture-resistant finish, I will need to bond some kind of paper, plastic film or book cloth onto both the sides of it once it is bonded into the 2 layers I need. And that will make it quite a lot thicker than my overall thickness (of the 2 layers) of being 3.0mm. For example most of the protective papers & films that one can obtain from the likes of Winter & Company are between 0.15mm and 0.20mm thick. So assuming 2 layers of film - one on the inside of the box one on the outside of the box (especially allowing for a little adhesive) the total thickness in mm would be something like: 0.15 - Protective film (minimum) ==> nearly 3.5mm (i.e. 3.45mm), which is a LONG way past my target of maximum of 3.00mm. @SillyOldDuffer - all true. However I am trying to make something that a high volume, mass production licensee company would be interested in making, is low in cost, can easily be recycled as well as having a reasonably good strength-weight ratio.
So still I need a strong Mill Board that is about 1250 to 1400 microns thick. J |
JasonB | 14/06/2021 13:25:55 |
![]() 25215 forum posts 3105 photos 1 articles | Can you make the core from one layer each of 1.0mm and 1.5mm which with the other items would give the total you desire. Or if you want to make sure the structure is balanced then two of the 1.0mm with something 0.5mm in the middle of the sandwich. |
Michael Gilligan | 14/06/2021 13:26:57 |
![]() 23121 forum posts 1360 photos | Posted by John Smith 47 on 14/06/2021 13:20:27:
[…]
. NO … I posted a link to the specific document, especially for your benefit. MichaelG. . Clause 4 is particularly relevant to ‘virginity’ Edited By Michael Gilligan on 14/06/2021 13:28:31 |
John Smith 47 | 14/06/2021 14:21:42 |
393 forum posts 12 photos | Posted by Michael Gilligan on 04/06/2021 09:53:40:
Well at least we now know what’s special about Millboard: MichaelG. . Edit: This may be more cost-effective than buying the current [2003] version of the standard: Edited By Michael Gilligan on 04/06/2021 10:00:41 My browser (Brave) can't open this link. |
John Smith 47 | 14/06/2021 14:33:48 |
393 forum posts 12 photos | Posted by JasonB on 14/06/2021 13:25:55:
Can you make the core from one layer each of 1.0mm and 1.5mm which with the other items would give the total you desire. Or if you want to make sure the structure is balanced then two of the 1.0mm with something 0.5mm in the middle of the sandwich. Hmm... 1.0 +1.5mm isn't completely impossible, but it would mean fundamental changes to other parts of the design. Moreover if the product went into production the unwanted added complexity would add unwelcome cost. J |
Michael Gilligan | 14/06/2021 14:38:59 |
![]() 23121 forum posts 1360 photos | Posted by John Smith 47 on 14/06/2021 14:21:42:
Posted by Michael Gilligan on 04/06/2021 09:53:40: Edit: This may be more cost-effective than buying the current [2003] version of the standard: Edited By Michael Gilligan on 04/06/2021 10:00:41 My browser (Brave) can't open this link. . Then [if you want it] you will need to choose between using another browser, finding another source, or buying the 2003 version. MichaelG. . . Edited By Michael Gilligan on 14/06/2021 14:46:33 |
Stuart Smith 5 | 14/06/2021 15:28:12 |
349 forum posts 61 photos | John Smith 47 It seems to me that all your posts are of a business rather than hobby nature. i.e. you seem to be asking everyone else to do your homework so that you can make commercial gain from their advice. I understood that this forum was for hobbyists.
Edited By Stuart Smith 5 on 14/06/2021 15:28:42 |
John Smith 47 | 14/06/2021 17:11:35 |
393 forum posts 12 photos | Posted by Michael Gilligan on 14/06/2021 14:38:59:
Posted by John Smith 47 on 14/06/2021 14:21:42:
Posted by Michael Gilligan on 04/06/2021 09:53:40: Edit: This may be more cost-effective than buying the current [2003] version of the standard: Edited By Michael Gilligan on 04/06/2021 10:00:41 My browser (Brave) can't open this link. . Then [if you want it] you will need to choose between using another browser, finding another source, or buying the 2003 version. MichaelG. . . Edited By Michael Gilligan on 14/06/2021 14:46:33 I am doing my best here but...
EDIT: Okay I have finally managed to get a new app "SumatraPDF" to open the PDF. and But got almost no results.... Edited By John Smith 47 on 14/06/2021 17:24:52 |
SillyOldDuffer | 14/06/2021 18:49:17 |
10668 forum posts 2415 photos | Posted by John Smith 47 on 14/06/2021 17:11:35:
Posted by Michael Gilligan on 14/06/2021 14:38:59:
Posted by John Smith 47 on 14/06/2021 14:21:42:
...Posted by Michael Gilligan on 04/06/2021 09:53:40: ......
Revisiting the design is a common engineering tactic. When a 'simple question' about the material needed to satisfy a design results in unsatisfactory answers it may be worth changing the design. Always done when materials turn out to be Unobtainium, Unaffordium or illegal. Or the manufacturing process is too awkward, or has a high failure rate. Don't dismiss anything. Another tactic is to defer the problem. When items are put into production manufacturers can resource almost anything, stuff can be specially made if necessary. In the meantime, build and test the prototype with something ordinary : who knows - the wrong thickness or a home-made laminate as suggested by Jason may be good enough. All a prototype has to do is provide proof of concept - it doesn't have to be perfect. I suspect most products are developed after initial design, and Production Engineering is another game again. Only then dies it gets to the customer, who won't like the colour! Don't be discouraged by suggestions. As you are finding, original design is the hardest stage in engineering. By comparison making articles from proven plans is a doddle, despite all the evidence to the contrary in my gigantic junk box. Dave
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John Smith 47 | 14/06/2021 19:11:05 |
393 forum posts 12 photos | Posted by SillyOldDuffer on 14/06/2021 18:49:17:
Posted by John Smith 47 on 14/06/2021 17:11:35:
Posted by Michael Gilligan on 14/06/2021 14:38:59:
Posted by John Smith 47 on 14/06/2021 14:21:42:
...Posted by Michael Gilligan on 04/06/2021 09:53:40: ......
Revisiting the design is a common engineering tactic. When a 'simple question' about the material needed to satisfy a design results in unsatisfactory answers it may be worth changing the design. Always done when materials turn out to be Unobtainium, Unaffordium or illegal. Or the manufacturing process is too awkward, or has a high failure rate. Don't dismiss anything. Another tactic is to defer the problem. When items are put into production manufacturers can resource almost anything, stuff can be specially made if necessary. In the meantime, build and test the prototype with something ordinary : who knows - the wrong thickness or a home-made laminate as suggested by Jason may be good enough. All a prototype has to do is provide proof of concept - it doesn't have to be perfect. I suspect most products are developed after initial design, and Production Engineering is another game again. Only then dies it gets to the customer, who won't like the colour! Don't be discouraged by suggestions. As you are finding, original design is the hardest stage in engineering. By comparison making articles from proven plans is a doddle, despite all the evidence to the contrary in my gigantic junk box. Dave Yes, all good points. However where find myself to be conflicted though, is that I don't want to waste everyone's time analysing the full specifications & design constraints of the proposed product itself, which needless to say is rabbit-hole of quite a complicated balance of competing criteria... J
Edited By John Smith 47 on 14/06/2021 19:12:07 |
Dave S | 14/06/2021 21:25:52 |
433 forum posts 95 photos | Posted by John Smith 47 on 14/06/2021 14:33:48:
Posted by JasonB on 14/06/2021 13:25:55:
Can you make the core from one layer each of 1.0mm and 1.5mm which with the other items would give the total you desire. Or if you want to make sure the structure is balanced then two of the 1.0mm with something 0.5mm in the middle of the sandwich. Hmm... 1.0 +1.5mm isn't completely impossible, but it would mean fundamental changes to other parts of the design. Moreover if the product went into production the unwanted added complexity would add unwelcome cost. J Can you enlighten us about the fundamental changes that having an unbalanced 1+1.5 laminate would cause? In your stack up: 0.15 - Protective film (minimum) You make no mention of anything “in the middle”, and by your numbers it would add up to 2.9, just inside your sweet spot for thickness. If you make it to production then presumably you’ll make an order for the right thickness of custom board, so no complexity there. Dave
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John Smith 47 | 15/06/2021 00:37:14 |
393 forum posts 12 photos | Posted by Dave S on 14/06/2021 21:25:52:
Posted by John Smith 47 on 14/06/2021 14:33:48:
Posted by JasonB on 14/06/2021 13:25:55:
Can you make the core from one layer each of 1.0mm and 1.5mm which with the other items would give the total you desire. Or if you want to make sure the structure is balanced then two of the 1.0mm with something 0.5mm in the middle of the sandwich. Hmm... 1.0 +1.5mm isn't completely impossible, but it would mean fundamental changes to other parts of the design. Moreover if the product went into production the unwanted added complexity would add unwelcome cost. J Can you enlighten us about the fundamental changes that having an unbalanced 1+1.5 laminate would cause? In your stack up: 0.15 - Protective film (minimum) You make no mention of anything “in the middle”, and by your numbers it would add up to 2.9, just inside your sweet spot for thickness. If you make it to production then presumably you’ll make an order for the right thickness of custom board, so no complexity there. Dave
OK, yes if one of the layers was 1.0 instead of 1.5, then my stack would now become 2.95mm thick instead of 3.45mm thick... and yes, that would be an ideal thickness. A) To keep the number of different part designs down, the embedded plastic parts have to have rotational symmetry (i.e. the same design of part needs to work upside down) B) Thinning the plastic connector down to 1mm from 1.5mm may weaken it too much and permit too much flexing - I'm not sure yet. C) I would have to change my CAD models... and my problem is that my freebie license of my CAD software (SolidWorks) has now expired and so making the change would be expensive & time-consuming.
J
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JasonB | 15/06/2021 07:04:48 |
![]() 25215 forum posts 3105 photos 1 articles | If you put the thicker of the two sheets towards the inside edges then you will not loose any strength as the "leaves" of the hinge will still be 1.5mm. Infact they will be stronger than if they had been 1.3mm. Edited By JasonB on 15/06/2021 07:05:47 |
Michael Gilligan | 15/06/2021 07:39:41 |
![]() 23121 forum posts 1360 photos | I don’t wish to interfere, John … but this may be of interest: Many years ago I worked for a company which was an ‘early adopter’ of integral hinges: They found that flexing a polypropylene hinge immediately after moulding blessed it with a much longer service life. Non-flexed hinges were prone to cracking. I have no real grasp of how the manufacturing technology might have changed since then, but [unless you are already familiar with such matters] this is probably worth a look: **LINK** https://www.creativemechanisms.com/blog/everything-you-need-to-know-about-living-hinges MichaelG. |
John Smith 47 | 15/06/2021 09:46:59 |
393 forum posts 12 photos | Posted by JasonB on 15/06/2021 07:04:48:
If you put the thicker of the two sheets towards the inside edges then you will not loose any strength as the "leaves" of the hinge will still be 1.5mm. Infact they will be stronger than if they had been 1.3mm. Edited By JasonB on 15/06/2021 07:05:47 How do you work that out? |
John Smith 47 | 15/06/2021 09:50:49 |
393 forum posts 12 photos | Posted by Michael Gilligan on 15/06/2021 07:39:41:
I don’t wish to interfere, John … but this may be of interest: Many years ago I worked for a company which was an ‘early adopter’ of integral hinges: They found that flexing a polypropylene hinge immediately after moulding blessed it with a much longer service life. Non-flexed hinges were prone to cracking. I have no real grasp of how the manufacturing technology might have changed since then, but [unless you are already familiar with such matters] this is probably worth a look: **LINK** https://www.creativemechanisms.com/blog/everything-you-need-to-know-about-living-hinges MichaelG. We are trying to avoid living hinges because they always seem to have a positional memory if left too long in one position. |
Neil Wyatt | 15/06/2021 10:57:09 |
![]() 19226 forum posts 749 photos 86 articles | Posted by Stuart Smith 5 on 14/06/2021 15:28:12:
John Smith 47 It seems to me that all your posts are of a business rather than hobby nature. i.e. you seem to be asking everyone else to do your homework so that you can make commercial gain from their advice. I understood that this forum was for hobbyists. While it's wrong to use the forum to 'advertise' there's no ban on discussing professional work, certainly asking for advice on interesting problems or sharing unusual jobs is welcome. Otherwise, we would not benefit from the input of many jobbing engineers, toolmakers, vehicle restorers, CAD and CAM experts and even on member who discusses his trackers and drones for keeping tabs on wild lion populations! |
Michael Gilligan | 15/06/2021 11:46:33 |
![]() 23121 forum posts 1360 photos | Posted by John Smith 47 on 15/06/2021 09:50:49:
Posted by Michael Gilligan on 15/06/2021 07:39:41:
I don’t wish to interfere, John … but […] We are trying to avoid living hinges because they always seem to have a positional memory if left too long in one position. . Sorry … I obviously misinterpreted your ‘Design Schematic’ MichaelG. |
Dave S | 15/06/2021 12:14:25 |
433 forum posts 95 photos | So there is an implicit symmetry in the stack up. Thinking production you presumably will cut the parts from a larger sheet, so an additional op to thin the edges first saves a glue stack up op. Dave |
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