RAM SIMM storage
- Thread starter pff000
- Start date
I think the forum software removed my STL attachment. I tried to edit the post and upload again, but it disapears when I post.
Here is a shared dropbox folder with the STL and OpenSCAD files. There is one box to hold 30 pin SIMMs, and one box that holds other types of sticky memory things (ROM, VRAM, 72-pin RAM).
www.dropbox.com
Here is a shared dropbox folder with the STL and OpenSCAD files. There is one box to hold 30 pin SIMMs, and one box that holds other types of sticky memory things (ROM, VRAM, 72-pin RAM).
Dropbox
www.dropbox.com
oh sorry about that, we should add some more 3d extensions to the allowed upload. For now here's a zip in case that drop box ever disappears. Thanks!I think the forum software removed my STL attachment. I tried to edit the post and upload again, but it disapears when I post.
Here is a shared dropbox folder with the STL and OpenSCAD files. There is one box to hold 30 pin SIMMs, and one box that holds other types of sticky memory things (ROM, VRAM, 72-pin RAM).
Dropbox
Thank you! I didn't realize zip was allowed
Or I could stuff it, then binhex encode and paste the ASCII here ?? hehe
Btw, if zip is ok, why prohibit anything? one can always zip the file..
XenForo by default has these limits and we just add to them when we find a case - not sure if it can just be disabled, can take a look later.
Just found this thread today because I was Googling for anti-static bags sized for 30pin RAM SIMMs and ROM SIMMs but couldn't find anything the right size. I then thought about 3D printing and found a few designs on Printables, but then I asked ChatGPT to search more, and it amusingly found this very thread!
Because the case has no text on it at all, you'd need to use either a permanent marker or slap a sticker on it to know what's inside. Marking it would be extremely important because when you have more than one of those closed boxes, it means opening each one until you find what's inside. A bit fiddly.
A better solution might be to print the 2 box types in TRANSPARENT RESIN. JLC offers that, although it might be impossibly expensive now in the US now due to Tariff insanity, but here are the prices I am seeing (note that I live in Japan):
That's 15 smackers is for 2pcs of the 30pin RAM SIMM case, which is needed if you want top & bottom.
I also have ROM SIMMs and some VRAM for my Color Classic Mystic, so I will also need the bigger size too, which is more expensive (note the QTY for each below is only for 1pc, not 2)...
A whopping 32 smackers if you want two. Yikes! But putting it in perspective, there's nothing else like it out there, and certainly not something perfectly transparent. I've printed perfectly transparent speaker mounts for my Apple IIc, and I can attest to it looking truly transparent, like a MacEffects Clear Case for the SE/30.
Still, 32 bucks is pricey, even without tariff insanity. But if you go opaque with the big case, here are the prices...
TPU is probably too rubbery (i've never had anything printed in it so I don't know), but they do offer TPU in TRANSLUCENT (like frosted glass) for the same price as PLA above...
The cheapest price is WHITE Resin, but that color would get gunkied up with grime REAL fast:
What do you gentlemen think?
Because the case has no text on it at all, you'd need to use either a permanent marker or slap a sticker on it to know what's inside. Marking it would be extremely important because when you have more than one of those closed boxes, it means opening each one until you find what's inside. A bit fiddly.
A better solution might be to print the 2 box types in TRANSPARENT RESIN. JLC offers that, although it might be impossibly expensive now in the US now due to Tariff insanity, but here are the prices I am seeing (note that I live in Japan):
That's 15 smackers is for 2pcs of the 30pin RAM SIMM case, which is needed if you want top & bottom.
I also have ROM SIMMs and some VRAM for my Color Classic Mystic, so I will also need the bigger size too, which is more expensive (note the QTY for each below is only for 1pc, not 2)...
A whopping 32 smackers if you want two. Yikes! But putting it in perspective, there's nothing else like it out there, and certainly not something perfectly transparent. I've printed perfectly transparent speaker mounts for my Apple IIc, and I can attest to it looking truly transparent, like a MacEffects Clear Case for the SE/30.
Still, 32 bucks is pricey, even without tariff insanity. But if you go opaque with the big case, here are the prices...
TPU is probably too rubbery (i've never had anything printed in it so I don't know), but they do offer TPU in TRANSLUCENT (like frosted glass) for the same price as PLA above...
The cheapest price is WHITE Resin, but that color would get gunkied up with grime REAL fast:
What do you gentlemen think?
Yes I was wondering the same thing!
Looks like you can get ‘antistatic’ pla from protopasta:
proto-pasta.com
For ESD safe 3D prints! Designed for static dissipation Higher Ω than Conductive PLA Surface resistance 10⁴-10⁶ Ω
Looks like you can get ‘antistatic’ pla from protopasta:
ESD-safe Carbon Fiber PLA | Dissipative | Anti-static | ESD Filament
For ESD safe 3D prints! Designed for static dissipation Like Carbon Fiber PLA, but ESD Surface resistance 10^4-10^6 Ω Low warp + stiff carbon fiber Wear resistant nozzle recommend From Nov 2024 Endless Exploration USA made Protopasta exclusive Subscribe to Endless Exploration for new materials...
proto-pasta.com
For ESD safe 3D prints! Designed for static dissipation Higher Ω than Conductive PLA Surface resistance 10⁴-10⁶ Ω
Most of the bags sold as being "anti-static" are mostly made of polyethylene or polypropylene, but they also have other ingredients that contribute to their being anti-static, thereby protecting sensitive electronics inside. Those kind of bags are special in that they won't hold a charge. For example, if you rub your hand or your hair on a balloon and then touch something, you'll feel a zap of static discharge, but rubbing your hand on an anti-static bag won't do the same.
But here's the crux. Many people don't realize that the thru-hole components (with needle sharp spikes on the solder side) often penetrate the bags, creating tiny holes, thereby reducing or eliminating the protection of the bag itself. That is why I personally put a sheet of very thin cardboard under my motherboards or cards, on the solder side, to better ensure nothing will penetrate.
Also note that there are the pink kind of anti-static bags, and you also have the semi-transparent kind with black markings, which don't have any silver tone to them. Those don't offer any shielding from EM fields. So if you want protection from static and EM, you need the silver bags. The silver ones are SHIELDED.
If you have any kind of electronics sensitive to static discharge, and if you really want to protect that from static damage, then of course having a "box" or similar enclosure with anti-static properties will be important.
More specifically, in regards to my previous post, I was talking about 100% transparent 8001 Resin (mainly so you'd know what's inside). Transparent Resin obviously has no EM shielding capability at all. It is an "insulator," not something that "dissipates" a static charge. And while there are some 3D printable filaments which have SPECIAL INGREDIENTS to be anti-static (such as what @pff000 mentions), the clear Resin I spoke is no designed to dissipate a static charge.
So what would happen to an 8001 Transparent RAM SIMM box filled with SIMMs inside when you hold the box and then walk around on a carpeted floor while rubbing a balloon on your hair (a pretty worst case scenario)? The static charge likely wouldn't be able to make its way through the walls of the transparent box, although there will be a seam in the middle where top and bottom meet each other. That seam is an unknown. But the greater potential problem is that because the box is an insulator, it won't dissipate a charge, and so a charge might build on the outside of the box when you are talking it across that carpeted floor; and if you arrive at your workbench and then immediately open it and touch the RAM SIMMs without a grounded wrist strap, you have the potential to zap the SIMMs.
So does this mean it would be prudent to 3D-print a SIMM box in a dissipative plastic such as what @pff000 mentions? Sure! If and only if you have a printer, which I personally do not. I have to rely on JLC, which does NOT offer anti-static plastics. :-(
What I really need are slotted anti-static bags. I have a few but not enough. Each "slot" can accept a single SIMM, and they are nice and compact as a result. The only bags sold on Amazon are much larger than the SIMM itself and to save space you are inclined to put more than one SIMM inside. But when doing that, you risk the PCBs rubbing against each other and potentially causing damage, especially if you move the bags around a lot. That's why slotted bags made for SIMMs (which used to be easy to find back in the day, but currently no longer) are really ideal. But because I can't find the slotted bags, I eventually was led to this thread where my brain began to ponder slotted SIMM "boxes" instead.
The ability to dissipate charge without sending it through the electronics. i.e. slightly conductive, but not the point that it could carry any real current.
Not sure about the answer to this one, specifically, but one could always print using filament that is slightly conductive. There's multiple brands that sell CF-filled filament as ESD-safe, where the CF should be just conductive enough to dissipate the charge without accidentally shorting something out. Or use an ESD coating if you don't want to use CF-filled filaments. For those in NA, MG Chemicals has a few different products for applying a coating to plastic part to metalize the surface for ESD protection, grounding or RF shielding. Neat stuff.
EDIT: I meant to post this yesterday, whoops.
But here’s the crux…
Not all of us have around 3-D printer, and therefore our filament choices are limited to whatever 3-D printing service we need to use. In my case, that is JLCPCB.
Not all of us have around 3-D printer, and therefore our filament choices are limited to whatever 3-D printing service we need to use. In my case, that is JLCPCB.
I do mention details that are useful specifically for people in your situation. It's why I posted despite failing to post it yesterday when I intended to, and having others post similar information, because there's useful information when you either can't use CF filament, or don't have an officially labeled "ESD-Safe" filament available to you. Emphasis mine:
For example, JLC3DP offers up PA12-CF as an option for FDM, which will have a little conductivity from the CF embedded in it. That's really all ESD-Safe filament is.
For example, JLC3DP offers up PA12-CF as an option for FDM, which will have a little conductivity from the CF embedded in it. That's really all ESD-Safe filament is.
Oh, of course. I was simply taking an educated guess (based on my own observations over time) that a majority of vintage computing hobbyists probably don't have 3D printers of their own, hence my previous posts were not merely in consideration of myself alone, but those folks as well. And while our talk here is extremely important and has merit, especially what you have written thus far (which I certainly do NOT seek to undermine), there are "practical realities" that I wished to set forth in regards to what the majority of people may or may not have access too. But the good news is that the 2nd half of your last post addresses that...
Thank you very much for having made time to investigate and then post that info!
I see that PA12-CF is defined as a "carbon fiber reinforced PA12 filament." So basically its Carbon Fiber is adding just enough conductivity to bring down the inherent resistivity of the base filament to make it better able to dissipate static discharges. Saying that another way, PA12-CF should, at least in theory, bleed off the static charge on a SIMM box made with that filament, rather than allowing static to build on the box.
The only thing it lacks is EMI/RF shielding, which you get when you put your SIMMs into one of those silvery anti-static bags (which are shielded). But I suspect most hobbyists would be most concerned with anti-static, so the lack of shielding is not too significant a loss.
But there are 2 downsides to JLC's PA12-CF that should be considered.
First is Cost. Just under fifty bucks for both case types, top & bottom of each, not including shipping (or tariffs)....
The 2nd downside is that PA12-CF is not transparent. Without any markings on the outside of the box itself, you will ultimately forget what is inside, or you otherwise won't be able to know at a glance which of your SIMMs are in which box (assuming you have multiple).
Not deal-breakers necessarily, but things to consider before buying it at JLC.
Again, none of this dialog is to diminish the importance of anything that has been said in this thread. It's merely FYI — knowledge to ponder. And if better solutions come along, fabulous!
For now, my own SIMMs sit in a mix of silver shielded anti-static bags. They are protected, but I basically have to sift through them all to find particular SIMMs I am searching for, which is my personal reason to investigate other options line a SIMM tray or box.
Thanks to @Nycturne and everyone else who has kindly contributed important thoughts to this thread!
My one correction here is that ESD bags aren’t RF shielded, at least not intentionally. Circuits generally aren’t vulnerable to RF in the sense of getting damaged, outside of an EMP or similarly strong field. They are vulnerable to an early death if exposed to the couple-thousand volts in a discharge and it degrades the material in a transistor or diode.
I wouldn’t worry about RF, just static discharge.
I’ve only got a couple spares, so I use the ESD bags I got when buying upgrades off eBay. If I had more, I’d print this out. I stumbled into the thread because it did look like it might be useful a bit later for me.
Since I do have a printer though, I can use some PETG-CF I have, or order some MG 844AR to play with to coat a print in PETG. Would have to test compatibility with the solvents 844AR uses.
Since I do have a printer though, I can use some PETG-CF I have, or order some MG 844AR to play with to coat a print in PETG. Would have to test compatibility with the solvents 844AR uses.