Screw decisions for assembly

[DrHAX]

Triwing sounds good, and would be kind of amusing.

yeah also I'm sure they'd be easy to source. Also I thought I read about Nintendo using them so they wouldn't strip, also it prevents the unwilling to open up the device. You can buy triwing screw drivers for about 4 USD with shipping included . They're very cheap. And I'be disassembled ( and resembled) nine game
boys with no triwings stripping. Only the plastic on the Grey dmgs broke. I wouldn't mind triwing. If it worked for Nintendo for twenty years. Surely it can work for us. The only issue I could see is assembly line tool change
Since idk how the devices are assembled.

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[fusion_power]

In case anyone is still confused:

Philips, torx, slot, Pozi, hex, in that order, left-->right, top-->bottom

Or why not inventing a brand new Screw, the Dragonbox Pyra-Screw!

 

[rygD]

Triwing sounds good, and would be kind of amusing.

yeah also I'm sure they'd be easy to source. Also I thought I read about Nintendo using them so they wouldn't strip, also it prevents the unwilling to open up the device. You can buy triwing screw drivers for about 4 USD with shipping included . They're very cheap. And I'be disassembled ( and resembled) nine game
boys with no triwings stripping. Only the plastic on the Grey dmgs broke. I wouldn't mind growing. If it worked for Nintendo for twenty years. Surely it can work for us. The only issue I could see is assembly line tool change


Since idk how the devices are assembled.


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Yeah, I have opened many DMGs, usually many times, and don't recall having any issues with the triwing screws.  I know I have lost far more of those screws than I destroyed the head of.  I'm a bit surprised you had the grey cases break.  I have had some very minor problems with aftermarket cases due to not knowing how tight was tight enough, but the originals are made of some really tough plastic.  I did melt one, but that is another story.

 

[DrHAX]

Triwing sounds good, and would be kind of amusing.

yeah also I'm sure they'd be easy to source. Also I thought I read about Nintendo using them so they wouldn't strip, also it prevents the unwilling to open up the device. You can buy triwing screw drivers for about 4 USD with shipping included . They're very cheap. And I'be disassembled ( and resembled) nine game
boys with no triwings stripping. Only the plastic on the Grey dmgs broke. I wouldn't mind growing. If it worked for Nintendo for twenty years. Surely it can work for us. The only issue I could see is assembly line tool change
Since idk how the devices are assembled.

Sent from my Z665C using Tapatalk

Yeah, I have opened many DMGs, usually many times, and don't recall having any issues with the triwing screws. I know I have lost far more of those screws than I destroyed the head of. I'm a bit surprised you had the grey cases break. I have had some very minor problems with aftermarket cases due to not knowing how tight was tight enough, but the originals are made of some really tough plastic. I did melt one, but that is another story.

it was a dmg -3 Philips screws the case shattered and crumbled. Those screws were total s#@t they stripped at the drop of a hat.

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[rygD]

To support the case of everyone proposing not using Phillips, I had one DMG that had Phillips screws and chewed up a couple of those heads since I had grown lazy due to not having issues with the triwings (or maybe it wasn't me).  I wish I had knocked those screws on the floor instead.

 

[God Ginrai]

Through holes with nuts and bolts was and still is a bad idea.

You have not given any good reason to prove it a bad idea. On the contrary, the only viable con anyone has suggested with regards to the nut and bolt idea is the one that spud42 pointed out about the different bolt lengths. Although, I am not entirely sure that we wouldn't have different screw lengths even if we went with any of the suggested screw types.

-God Ginrai

 

[Binky]

Pozi has the advantage that most people have a set of "cross head" screwdrivers somewhere, which is not the case for tri-wing.

 

[levi]

Heh, I have a dedicated tri-wing screwdriver, for a bit of old-school hardware hacking. I don't own any dedicated torx drivers, fwiw, and only security torx 1/4in bits, but I'm sure I could source some if the Pyra goes down that route.

 

[rygD]

Pozi has the advantage that most people have a set of "cross head" screwdrivers somewhere, which is not the case for tri-wing.

While this may be an advantage for some people I would think the results of using the wrong tool would have similar, possibly worse, results to using Phillips.  I don't know for sure, though.  I would try to make sure I was using the right tool.  It should be mentioned in the manual that they are Pozi since they can easily be mistaken, and Pozi isn't well known in some places.  Down the road, when the decision has been made, it would be a good idea to mention it on the site when describing hardware.

 

[WizardStan]

While this may be an advantage for some people I would think the results of using the wrong tool would have similar, possibly worse, results to using Phillips

It wouldn't. Pozidriv is "Phillips plus an extra cross that doesn't slip". It was specifically designed so that you could use Phillips if you really needed to. Phillips is still a right tool, just not the best tool, certainly no worse than just using regular Phillips screws.

 

[rygD]

That's interesting, thanks for setting me straight.  I just looked at some pictures of drivers and close ups of heads.  I was under the mistaken impression that the outer edges were more vertical, like Torx instead of like Phillips.

 

[WizardStan]

This is a Phillips and a Pozidriv side by side

The Pozidriv is effectively identical to the Phillips with extra notches.

 

[thatgui]

This thread already accomplished at least one thing: I know a lot more about screws/screwheads then before

 

[DrHAX]

This threads a bit screwy

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[levi]

This is a Phillips and a Pozidriv side by side


The Pozidriv is effectively identical to the Phillips with extra notches.

Not exactly - note how the top vane of the Phillips driver head there flanges out, wheras the pozi top vane is straight up and down - I think that's the mechanism that allows it to cam out if over-torqued. However, the pozi screw head has a void in that are, partially filled by the diagnoal vanes of the pozi driver, but not entirely. Hence a Phillips screwdriver can be used in a Pozi screw and it should be no more or less likely to cam out, but a Pozi driver in a Pozi screw head shouldn't easily do so. On trying to use a Pozi driver in a philips head, those diagonal vanes will interfere with the screw head, stopping you fully engaging the driver.


Hence:


Philips driver in Phillips screw = +


Philips driver in Pozi screw = +


Pozi driver in a Pozi screw = ++


Pozi driver in a Phillips screw = -

 

[Grench]

Through holes with nuts and bolts was and still is a bad idea.

You have not given any good reason to prove it a bad idea. On the contrary, the only viable con anyone has suggested with regards to the nut and bolt idea is the one that spud42 pointed out about the different bolt lengths. Although, I am not entirely sure that we wouldn't have different screw lengths even if we went with any of the suggested screw types.

-God Ginrai

It feels like you're just trolling at this point since your last few ideas failed.  Anyway...

1.  Frankendora.  Exposed 1/2" diameter nut wells on one side or the other.  They will wind up exposed.  See #4.

2.  Nut wells would require clearance around the nut to put on the socket.

3.  Your suggestion of using rubber baby buggy bumpers to plug the socket/screw wells adds part count.

4.  The rubber baby buggy bumpers will be prone to falling off - see the rubber baby buggy bumpers used to cover the screen bezel screws on the Pandora for reference.

5.  Higher expense - screw + nut +engineered wells.

6.  Space for the larger nut wells would impinge on the keyboard or conversely on the speaker, battery and stylus spaces.

7.  Case edge/shoulder rounding become MUCH harder to do if it has to be restricted to not impinge on the 1/2" diameter nut wells.

8.  End users cracking and destroying cases by over-tightening the screw/nut combinations to keep them from loosening and falling out.  In order for a metal nut and a metal screw to interface and -not- fall out requires that the threads be 'stretched' under a significant amount of torque.

9.  Ugly as hell.  Whether considering shiny screws/nuts or rubber baby buggy bumpers, they won't match the case color or texture.  They will always look like an afterthought.

10.  Ineffective.  In order to prevent cracking the case, they will likely be under-torqued.  Under-torqued metal to metal fasteners WILL come loose as there is inadequate thread seating/stretching.

Do I really need to go on?  You're likely to just ignore it anyway.

 

[comradekingu]

I did some thinking just now to improve on http://boards.openpandora.org/topic/16355-example-from-japan-better-hinge-and-screen-integration/page-2#entry336994

It is very elegant and easy, but it does have its flaws.

Having a round shoulder-post as it is now coming from the bottom half going upwards, with the shoulder ring around it, only with a slot to push a round jagged nut into it.

A screw from above screws down into that.  The problem is though, is that strong enough to hold the case together?  If one is a total idiot and screw way to hard i think either the screwhead gets stripped, or the nut starts revolving, or ejects, which isnt a terrible thing, considering the options.

The L and R's cant be hotswapped, unless they clip on around the pillar, but thats not worth it. The microphone/lightpipe humps are gone, replaced by real hinges..

Slot nuts are easier to do than thermoinjected nuts, and its easier still than making the whole bottom half in one piece.

 

[God Ginrai]

It feels like you're just trolling at this point since your last few ideas failed.  Anyway...

 It's funny that you made that comment, because honestly, it has been feeling to me for a while now that you are specifically targetting me, which would make you the troll.

On to your reasons:

1.  Frankendora.  Exposed 1/2" diameter nut wells on one side or the other.  They will wind up exposed.  See #4.

4.  The rubber baby buggy bumpers will be prone to falling off - see the rubber baby buggy bumpers used to cover the screen bezel screws on the Pandora for reference.

We have exposed screw wells on the Pandora. It's not like that makes much of a difference. Also, there are plenty of products where the well covers do not fall out. The trick is to make them fit tightly and leave a notch to pick it out with something thin like a needle.

2.  Nut wells would require clearance around the nut to put on the socket.

Yes, they do. This isn't exactly a con, (screws have wells, too. Just smaller ones) but it certainly is something that needs to be considered if we went through with the design.

3.  Your suggestion of using rubber baby buggy bumpers to plug the socket/screw wells adds part count.

This is a viable con. However, how impacting is this?

5.  Higher expense - screw + nut +engineered wells.

The wells do not need to be "engineered" any more than a screw well needs to be. The only added expense would be the nut.

I do not know how much expense the nut would add, but you must also consider that there would not be any need to design a correct threading on the case for the screw to screw into. This saved expense may end up cancelling out the expense of the nuts.

6.  Space for the larger nut wells would impinge on the keyboard or conversely on the speaker, battery and stylus spaces.

This is your best reason yet. However, it may be possible there are places to put these wells that will not interfere with these areas.

7.  Case edge/shoulder rounding become MUCH harder to do if it has to be restricted to not impinge on the 1/2" diameter nut wells.

This sounds suspect. It is entirely possible to have one edge of the well curve down.

8.  End users cracking and destroying cases by over-tightening the screw/nut combinations to keep them from loosening and falling out.  In order for a metal nut and a metal screw to interface and -not- fall out requires that the threads be 'stretched' under a significant amount of torque.

They can already do this by over-tightening the screws that are currently in their Pandoras.

9.  Ugly as hell.  Whether considering shiny screws/nuts or rubber baby buggy bumpers, they won't match the case color or texture.  They will always look like an afterthought.

I beg to differ, I've seen many products where you don't even notice the rubber coverings over the screws. Also, I can tell you right now that a screw wouldn't look any better, which is what we would have if we didn't use my suggestion.

10.  Ineffective.  In order to prevent cracking the case, they will likely be under-torqued.  Under-torqued metal to metal fasteners WILL come loose as there is inadequate thread seating/stretching.

I don't know enough about this to make a comment on it. I would like to hear others' opinions on if this is true or not.

-God Ginrai

 

[comradekingu]

inserts into screw wells isnt good. Since we are trying to make fool proof a system of screwing together the case, for case of argument all of them will be lost on disassembly. And possibly other times.

The option is inserts that have a saferope, but that will snap if pulled hard, and its more complex.

Also there isnt any leeway to put insets in. A V-sunken screw, possibly, if you are going with a hole to set the insert in, why not just make the screw flush?

Inserts dont add much but trying to keep the user away from screws by needless complexion. Screws arent ugly. Not being able to see the screws at all isnt best case (heh), its a usability error.

If its a hacker device, make it easy to unscrew.

 

[spud42]

may i say that from my own experience of servicing different equipment, from all over the world ,for the last 30 years that posidrive is not common. i could count on one hand, and have several missing fingers, the number of times i have come across posidrive.

Also apart from HP servers that used torx screws everything else used philips screws. some may have had a hex head with Philips as well but the reason that Philips is used is that they work, are cost effective and simple to use...

A nut and bolt complicate both design and assembly. My computer,mouse,keyboard,camera,printer,two way radio,guitar,headphones,remotes,DVD player HDD enclosure,multimeter  and kids toy helicopter ; which is what i can see from my desk ; ALL are held together by Philips screws.

Why is in thought necessary to use something else?

It doesent matter what the head is if the plastic it screws into is too brittle or too thin to take the thread.  just my 2c .....