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Clam Shells

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I haven't seen any surplus sources of the clamshells, but it would probably be relatively easy to make some out of a metal ceiling tile. You would just have to form it into two halves of a nesting box, put screw holes at the appropriate locations and use nylon standoffs inside to get the boards porperly positioned, and cut a proper sized opening in the base for the card edge.

 

Foundation and Atronic both did something similar with a lot of their boards.

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Come here for the tech fix, get the jokes for free! 😃

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6 hours ago, InsaneMultitasker said:

Just need to get yourself down to the coast ;)

Short Razor Clam Shell of the Solecurtidae Family | Mexico – Fish, Birds,  Crabs, Marine Life, Shells and Terrestrial Life

 

With the right size clam shell, you could actually mount a pcb in it.

Imagine a FG99 or raspberry pi mounted in a real clam shell.

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How many clamshells can stack up to get a monitor off of a ti console...

just wondering

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1 hour ago, GDMike said:

How many clamshells can stack up to get a monitor off of a ti console...

just wondering

I'd say 5 high, on each end.....
😅

 

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In a more serious answer; 

 

Is there a need for a 3D printable model?  I have some PEB card in clamshells.  While the originals are metal, a plastic clamshell would likely work just fine.

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TI's were metal, would substitute for tank armor. The RS232 card in my backup PEbox is third-party with a black plastic shell. Seemed to me a good quality shell. I don't recall the card's maker off hand.

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3 hours ago, Ed in SoDak said:

TI's were metal, would substitute for tank armor. The RS232 card in my backup PEbox is third-party with a black plastic shell. Seemed to me a good quality shell. I don't recall the card's maker off hand.

Yup. I know that the original TI ones are metal.  Short of milling some out of short stock on a manual mill, you probably wont be getting new shells of that kind of construction, at least not in an affordable manner.

 

I went ahead an ordered some cream colored PVC filament (for a different project).  I have been wanting to try it regardless, and this seems a good excuse (to play with it when I get it).  At least in theory, I should be able to mix some PVC adhesive with some PVA glue, and use that on my metal bed to get good adhesion on the print. (Or rather, spray PVA glue, let dry, then spray PVC adhesive, and let dry.  The PVC adhesive contains dissolved PVC in a volatile solvent, so there will be 'same material' adhesion at the contact surface, with the PVA as a releasable interface underneath.) At some time I will pull a clamshell off one of my PEB cards, and put the micrometers on, then do some test prints.

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Myarc probably had the best clamshell design (screwless) I don't know if a printed plastic could handle the range of motions that happen, when they are opened and closed.

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Posted (edited)

Again, the filament ordered is PVC.  (as in, what your kitchen pipes are made from).  Assuming it lives up to expectations (HAH!), it should be quite durable. (If you dont mind it ending up purple, I can always slather it with PVC glue after printing and just let it dry. That would solvent weld all the print layers.)

 

Also, looking at the inside of the clamshell-- the screw hole location looks like I could embed an M3 standoff, like I did for the screwdown locations for the speech synth enclosure.

Edited by wierd_w
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True...  I don't have a proper solution for that with plastic, unless you want to get fancy with heat pipes. (which I don't).

 

I suppose it might be possible to install some ducted fans but that would make the voltage rail noisy. (and you would need a way to get power to the fan)

 

 

I am assuming (maybe wrongly), that these shells will be for very modern boards that are more energy efficient, such as TIPI interface, modern SAMS, and pals.

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Note that the plastic Myarc clamshells are from the same molds as the later plastic clam shells from TI. Myarc just ordered them from the OEM, just like most of the third-party cartridge manufacturers got their shells--they just used the TI molds with blank ID plates.

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My primary interest was as a case for geneve's/hfdc as they always seem to have plenty o floaty jumper wires.

Tim has of course came up with an excellent solution for heat dissipation... But, there are plenty of other boards that can benefit.

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A case also keeps the card secured in the PEB for those cards designed to use them.  Without its case, a card can partially shift and lift out of the bus socket even with the PEB cover in place.  Cards like the HFDC and Geneve with connectors at the rear of the card are highly susceptible to this, more so if the PEB cover is removed. 

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Those metal clamshells add weight to the PEB. Proper weight should be maintained at 580 lbs. Give or take a clam.

Make sure you follow those guidelines.

Well DHE. I've got a couple metal shells. 

They belong to a 32K ram card and a TI disk controller card.

If it's possible you could get my 32K card working, would be nice or the ti disk card(which might be easier).

I dunno...

But I suppose I could forfit the shells.

But I'd like to keep one shell for one of the 2 fixed cards???? Or....buy me the upgrade for geneve that shifty has with the latest memory I'll trade the two clamshells out??

 

 

 

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7 hours ago, dhe said:

My primary interest was as a case for geneve's/hfdc as they always seem to have plenty o floaty jumper wires.

Tim has of course came up with an excellent solution for heat dissipation... But, there are plenty of other boards that can benefit.

You know, with the size of miniature fans now, placing one could be a possibility in a clamshell.???

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Fair warning--the metal TI clamshells need some careful internal modifications if you plan to use them with any non-TI cards that weren't designed to use them (most Myarc cards fit in this category). There are some studs in there that will short out parts of the cards, so you have to file them off before using them.

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Didn't the Myarc "plastic" shells have some metallic content to them? That is, they were actually a composite plastic/metal shell.

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Posted (edited)

I dunno?

 

I only have metal TI shells inside my PEB.  The card I grabbed at random was the 32k card.  I am about 45% done with the initial modelling of the clamshell. (90% done with one side.)

 

I have taken the liberty to .... beef up... the studs and screw posts, so that a 3D print would actually be serviceable.  I still need to cut the vent holes, and make the recesses into which the wire pull tabs go. (also needs the M3 standoff holes put into the studs)

 

2108497691_PebcardsideAinside.thumb.png.e771750c70de03893468939e59ba5427.png2106954106_PebcardsideAoutside.thumb.png.7fd47b5fd4101c0a0212f6e2caf09235.png

 

 

 

to keep it easy to print, I have made the sticker area not be recessed. I just made a groove in the outer surface of the case to indicate its location. It is recessed in the original PEB card shell.

 

I will continue working on it.  I am unsure if my printer can make this though. If so, it will take up the entire allowed Y axis.

 

 

The metal ones I have come to suspect, were cast.  There is a 2 degree draft angle all over everything.  Incidentally, this means it should be possible to make resin shells. (use silicone mold builder to make a negative of the shell using an original, then pour some resin.)

Edited by wierd_w
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Look at the places where studs intersect with the holes in the 32K card (the ones near the card edge, not the ones in the corners). These are your problem studs, as third-party cards almost never have holes at these points, and some will even have components in one or more of those areas.

 

Definitely a good start on a printable file though! Be careful how much you beef up the bottom two corner studs as well--those screw holes often go through voltage regulators/heat sinks.

 

 

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2 hours ago, GDMike said:

Those metal clamshells add weight to the PEB. Proper weight should be maintained at 580 lbs. Give or take a clam.

Make sure you follow those guidelines.

Well DHE. I've got a couple metal shells. 

They belong to a 32K ram card and a TI disk controller card.

If it's possible you could get my 32K card working, would be nice or the ti disk card(which might be easier).

I dunno...

But I suppose I could forfit the shells.

But I'd like to keep one shell for one of the 2 fixed cards???? Or....buy me the upgrade for geneve that shifty has with the latest memory I'll trade the two clamshells out??

 

 

 

But then, shoot maybe I should just get these cards up and running

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