0x0029.3 - 1/2 yr Update on HP-86 3D Printed Key Stems

[@craigleemehan]

Whoa, some old memories came flooding back. When I was a young engineer, the company I worked for used HP-85s with the IEEE-488 interface to control test equipment racks for auto test of production equipment. Imagine writing huge test programs in Basic.

[@TechTangents]

I definitely can imagine it! kzbin.info/www/bejne/qGPWdHWoerSYbpY

[@moofasa6953]

Your my favorite retro tech channel Akbkuku! I love how in depth you go as well the repairs. Please keep up the beyond amazing content!!!

[@skonkfactory]

If you give me the STL files I can print these on a FormLabs SLA printer with glass-filled plastic for you.

[@HamburgerExplosion]

they're in the description

[@rhfweb]

I would too be curious to see if these prints fair better. Also, post a vid of the print process ;)

[@skonkfactory]

@@rhfweb Well, I printed the first thirty or so last night. They look pretty nice; they're postcuring in my UV light box right now.

[@skonkfactory]

@@HamburgerExplosion I see that now. I made a plate of thirty of these last night. Printed at 50 µm resolution in glass-filled epoxy.

[@materialsguy2002]

Thanks for the video. I printed a full set of these for an HP86B and they are working well so far.

[@GolfhausYT]

9:29 I'm digging the use of Pretty Hate Machine as a measurement of time. Perhaps the switch to Downward Spiral will be as momentous an occasion as the switch from Julian to Gregorian calendars.

[@paulstaf]

I saw a YT video where a guy had to print a bunch of items so he wrote some GCODE that would knock the part off the bed after each print with the extruder. Worked great.

[@asagoodfriend]

Very nicely done 😎. You're truly appreciated! 👏👏👏👏👏👏👏

[@EnvAdam]

12:24 - I had a really nasty joke in my head which is rare but here it is Good job, you are now playing chinese factory worker simulator 2018

[@RetroBerner]

If you made those with only 3 of the top edges protruding could you print them on their sides? I don't know if that makes sense, but I thought making the 'grain' go in the direction of movement would make for smoother travel

[@TechTangents]

It would probably for three of the sides, but there are two problems with doing it that way. The side on the top would then have to bridge the whole way across empty space, and with how thin the walls are I don't think it would be possible to make it strong enough. Also, printing them with the the "grain" in this direction makes it the strongest against the key cap cracking the corners again.

[@RetroBerner]

@@TechTangents That makes sense, thanks!

[@idahofur]

As you probably know. Putting another processor in a machine to run other operating systems is common. I remember running into some type of Epson computer that used cpm and had a (optional) dos card with a intel processor on it. Even when I started into computers I remember the apple macintosh pds slot run a few different options. Dos card, power pc 601 process upgrade card, and even an apple IIE card. But as you say. That is a different story.

[@IanC14]

Didn't the Commodore 128 have another processor or am I making that up?

[@idahofur]

From my understanding the c128 had a z80 processor in it to run cpm. Along side of whatever process it would use.

[@skonkfactory]

The BBC Micro had at least four different second processors- from memory, there was a "turbo 6502", a 65C102, a Z80 you could use to run CP/M, an 80186 you could use to run DOS, a NatSemi 32016 you could use to run PANOS, and the ARM development kit.

[@obsidiangrimoire]

Hey, if I recall correctly there's shit you can do in the 3D print settings to make it so the print head doesn't move between parts during a batch print, instead finishing one before moving on to the next. Should look into that, as that would likely fix the main part of your issues with printing these.

[@thegoods1r694]

isn't it possible to specify in the printing software to finish each piece one at a time? Instead of doing everything all at once? I know you said this yourself, but is it possible to, when you're configuring the print job, make every stem an individual task on the same print job to force the printer to finish each stem before continuing to the next one?

[@hanro50]

He can't. His print bed is to small for that.

[@brandonupchurch7628]

Seems like the problem is mostly at the corners is is possible to redesign them and make the corners rounded inwards or make the whole piece round instead of square, as long as you can put clips on the bottom where they latch to the keyset and there's enough space for the spring and the levers the piece don't necessarily need to be square do they?

[@intel386DX]

fantastic restoration! now it is time for retro bright :)

[@olik136]

I don't know how tall or wide you can go with your prints but maybe you could print the stems as a continuous piece (like a pipe)and then cut them apart?

[@thedungeondelver]

Sir, where did you get your fine files? Who makes those? I do tabletop miniatures, and have similar files (and have for 30+ years) but the fine tips have broken off over years of use and if I could get replacements just like them - which yours is! - I would be so grateful. Mine were made by The Armory, a company sadly no longer in business.

[@TechTangents]

The files I have are very low quality, I suspect that while they may look the same they must not be the same as yours if they are still in use 30yrs later. But to answer your question, mine are just a $2 file set from Harbor Freight.

[@thedungeondelver]

@@TechTangents Ah, thank you very much. Yeah, I'll keep looking...heck, in my tiny little hobby I might even find new old stock!

[@SyphistPrime]

That kind of problem makes me think, is there some kind of way to print one completely without jumping then move to the next one? I can see the batch size being smaller so it doesn't bump into the already printed ones, but they might make it tolerable.

[@techn1fire]

Why don’t you angle the corners and make an octagonal shape to compensate for the over extrusion?

[@hotplatelabs]

If you put the dimensions of your hot end in to Cura you can do “print one at a time”. You’d probably need more plates to get them all, but less sanding.

[@kaitlyn__L]

Now that resin printers are getting super cheap, would you consider getting one of them and remaking these? They’re notorious for being good at making multiple small parts, and needing little to no filing. The density is super high because they use tiny 4k screens now.

[@oliverwalsh9614]

Could you have queued up a series of jobs, each containing a single key stem in a different location to get them printed correctly?

[@StevenOBrien]

Gonna retrobright it?

[@HarrisonFrazier]

I think my vt100 has the same (or similar) keystems... I’ve always been wondering if replacements are available!

[@owenmcglone5275]

I know there would be limitations but I'd love to see either AkBKukU or someone 3-D print a custom Cherry MX style key stem. If I had a 3-D printer I'd try it

[@one_b]

That is exactly what I would like to try for my Amiga 500 keyboard. Converting to a modern cherry keycap would make replacements a breeze.

[@owenmcglone5275]

@@one_b That would be badass, but also practical since Keycaps for those rare and older systems are becoming more scarce.

[@rhfweb]

Would a resin 3D printer be more accurate+strong? (ie, order some prints from a co. that uses laser-resin process)

[@UnreasonableSteve]

Generally the resins used in hobbyist printers are less strong than the plastic used in hobbyist extrusion printers, but you're able to get much finer detail.

[@rhfweb]

Yes, which is why I'm suggesting that as an idea @@@UnreasonableSteve

[@UnreasonableSteve]

I think you misread. I said *less* strong...

[@smallmoneysalvia]

Cura allows you to print one part at a time separately if you space them far enough to allow the print head to navigate, you could probably do 8-10 at a time, and maybe drop to 150 or 100 micron layers. That would take a long time, but get you an acceptable result.

[@branchonequal]

Never heard of OpenSCAD before, looks interesting! Until now I only worked with FreeCAD. Good job on the stems but that filing must've been a huge pain in the bottom. My printed parts are usually SLS nylon but I don't print them myself. ;)

[@douro20]

OpenSCAD is good but it has a steep learning curve. It is script based and everything is defined as mathematical functions. It helps to have a background in computer programming or engineering.

[@Dekkia_]

An automatic way to print them one at a time would make a cool video!

[@Space_Reptile]

hang on, since the CP/M cart has a Z8 computer in it , could you do some shinanigans w/ the ZX81 to "emulate" a CP/M cart?

[@NaokisRC]

Like DOS, CP/M requires not just a hardware standard such as a Z80 but the BIOS needs to be CP/M compatible as well since CP/M uses BIOS calls for doing hardware functions like writing to disk and keyboard control. Although that said, if HP made a 8086 or 8088 cart then they could use DOS and CP/M-86 even though the later was rediculously expensive compared to DOS. Theoretically if the computer is close to the specification, you only need to write a BIOS or handling code and yes, CP/M would work. You can also compile your own version of CP/M as well.

[@D.r0j]

you're a patient man!

[@Megabobster]

I hate to be the guy who tells you you're doing it wrong but...I think you might be doing it wrong. That kind of finishing work is really better suited to a belt sander or bench grinder. It's a lot to be done by hand with a file. And I'm 99% sure slicers have an option to randomize layer start points to mitigate this exact issue.

[@daviddavidsonn3578]

I'll grab popcorn and watch it a bit later.

[@vladimir7838]

Whats that os that you are using on your main PC?? (fedora??)

[@armanelgtron4533]

Kubuntu

[@vladimir7838]

how good is it?

[@tedmahsun]

Would it have taken more time if you printed the stems one by one? I imagine it'll be tedious either way anyway.

[@DoRC]

Thats tough to answer. Technically the total actual print time would be less as the nozzle wouldnt have to move between parts throughout the print. The thing is that would be way more than offset by the amount of time it would take to reset the cycle 99 times. Not to mention the massive increase in work to do it that way. One of the best things about a 3d printer is being able to let it run a job while you are doing other things. Having to babysit the printer ever 10 minutes kind of negates that advantage.

[@tedmahsun]

@@DoRC Thanks for taking the time to answer! Looks like filing one by one is the way to go then. (yeesh)

[@LeftoverBeefcake]

The CP/M cartridge isn't all that weird, because Commodore made a similar cartridge for the C64 that has a Z80 inside it, and the C128 has a Z80 inside it from the start. :)

[@eduardoavila646]

If you have a micro rectfyier (is that the right name for the drill-like rotary tool?) that could speed up quite a bit the process, and use less force fo file down the parts.

[@abhimaanmayadam5713]

Didn't you stream making these? Because it felt like yesterday when you did that.

[@TechTangents]

I did, six months ago.

[@abhimaanmayadam5713]

AkBKukU wow. That doesn't feel that long.

[@The_Keeper]

Could you make a program that makes the printer print them one at a time..?

[@succuvamp_anna]

I think there's something up with the extruder retraction, may wanna look in to a new hot end or maybe a new extruder nozzle. As for the computer. I just want one more and more each time I see it lol.

[@pesho9971]

get yourself a cnc mill and make an injection mold

[@potatoking8481]

Looks like a job for AVE's new mill

[@PeppercornVR]

You can just order an injection mould from a company :p

[@Wyatt_James]

Couldn't you change the bites to not have a greater height, but instead shift the peaks of them further upward? This would give them a more gradual slope when inserting for lower resistance as well as making them less prone to just popping out, as the upper slope would be higher. In theory they should be almost as easy to remove that way.

[@Handskemager]

You need one of those belt table printers, should be able to single print mass produce these on something like that

[@SkyCharger001]

what about negative printing them? if you did that, then you'd only need to file down the 3D-printed mold segments.

[@BackForwardPunch]

Well, youve already finished, but you could print one and then use a mold to duplicate it with fast set epoxy.

[@Agamemnon2]

You'd have the devil's own time casting pieces that thin reliably and without warpage.

[@cheater00]

are those of the self-sealing kind?

[@deaxes]

This may be a stupid question, but why not do it one at a time, it'll be much much more time consuming but then you don't need to manually file them.

[@station240]

Explained in the video, he's have to go back every 7 minutes to scrape the part off so the next one could be made. Making 100 would involve baby sitting the 3D printer for 12 hours.

[@AerinRavage]

@@station240 True, and the belt-bed or plow ideas would solve a lot of it. But if I were going down this path without those options, I'd choose "print one at a time, as many as will safely fit on the bed" and wait for the printer to beep. At least that way, I could be doing other things and only have to be interrupted briefly for bed-clearing, every x minutes... That filing looks brutal and MESSY!

[@DavidScheiber]

theres no way in slicer to have it print one after the other in bulk?

[@aveaoz]

Yeah, but he covered it on the video at 17:24, tl;dr the extruder is too big to be able to fit too many of them when printing each of them individually.

[@thegameroom4433]

I still like your Windows 98 video! 😊

[@bjh1971]

A job well done.

[@dvdbytes4348]

Am I the only one who would like to see those apps and CP\M running on that machine ?

[@PeppercornVR]

There seems to be a slight issue with your layers, the lines should be more consistent and the blobs should be smaller. Print these in ABS or nylon if you're not as PLA isn't suitable for this task. I print with a bowden so I can print a large batch one item at a time, improves quality and jobs finish much faster because of travel time.

[@StellaFoxxie]

a conveyor belt printer would be amazing

[@ChongMcBong]

if you still have an original intact stem, i could vacuum cast a set for you in resin if needed

[@heyarno]

You might want to cool your stepper drivers to avoid lost steps.

[@DoRC]

I think petg would be a better material for this job. Its a much tougher material and wouldnt wear so quickly. Its also more flexible by a little.

[@UnreasonableSteve]

I'm a huge fan of PETG too, but when he's already having some stringing issues, it's a hard sell. PETG tends to be 1000% stringier than PLA.

[@DoRC]

@@UnreasonableSteve true but stringing is almost always a setting issue (assuming the filament is good). As long as time is taken to tune everything properly petg stringing really shouldn't be an issue.

[@TheDecguy]

I've got an HP 85 and an HP 86. I also had my hands on an HP 87 for a short period of time but I let it slip away from me.

[@SilverX95]

why not have the parts spaced out more so they can be made one at a time and not all at once that would fix having to sand the part down one by one sure you will be printing a bit less but its better then sanding them down one by one for hours or print them one at a time. The plow thing is a good idea it just pushes the parts off in to a small tub and then starts on the next batch.

[@station240]

Now I find out they make key top pullers, after having pulled apart 7 entire keyboards to clean 30 years of muck from the keytops.

[@paulwratt]

2019: You could try and pick up one of those cheap new resin printers, check there reviews for overall product improvement

[@olik136]

You know your shit about 3D printers- and it still kind of sucks...that really puts me off of buying one..that and the money of course.... It doesn't help that I would want to use the printer for work stuff- but all things I would have to make for that would be straight and narrow- soo I guess I just keep thinking about getting a 3D printer until they are really good and usable by an idiot like I am

[@TechTangents]

It's more that this is a really edge case for a 3D printed part. The wall thickness of the stems really leaves almost no clearance to either side and basically every single surface of these touches something. So the margin of error is extremely small for something 3D printed. This is by far the most difficult 3D printed project I've done and I have a feeling most people wouldn't be up to it. Almost all other use cases for 3D printers I've encountered are much easier. I would say that in general for mechanical parts like this, if you can't handle a 0.1mm deviance from the design file then 3D printing may not be the best solution. But if you can then it could be a great solution or at least a great way to test your final solution.

[@DoRC]

Honestly modern printers like the ender 3 are pretty inexpensive and work well with only minor mods (i was a complete noob a couple months ago and get great prints in pla). Hes really pushing the limits of the material with a very small single wall design that has extremely tight tolerances. I hesitated for a long time getting a printer. Im glad i waited for the tech to mature but im really glad i have one now. I really use it a lot more than i thought i would.

[@ionstorm66]

@@TechTangents why not print fewer, and make it print each sequentially instead of by layer. I've done this a few times with mine, to stop stringing. I would also use the largest nozzle you can still get your wall thickness with, and do spiral single wall for as much of the part as you can. I built some extra storage containers for an parts organizer with a .8 nozzle, I could print 4 sequentially on the bed single wall spiral and they are ridiculously strong. Big nozzle, and spiral print give you the best layer adhesion you can get.

[@techn1fire]

The Prusa Mk3 probably wouldn’t have that problem on the corners, or at least I haven’t experienced that with my prints yet. I’d have to test your model.

[@DoRC]

@@techn1fire mine wouldn't either. Though he did say he was still tuning after making some mods.

[@BEdmonson85]

Why not just use a dremel?

[@UnreasonableSteve]

Powered abrasion methods tend to melt the plastic and leave large flaws because of that

[@rivards1]

But can it run Zork?

[@fnjesusfreak]

At least through the CP/M module it ought to be possible...

[@asejfgasuofghjsuih4013]

When will the Linux video be...

[@DolanDuckLuLz]

why not use a dremmel man. filing is a pain

[@dimscrawl4910]

you sound like Clint from LGR in this video

[@benshannon9386]

Is AkBkukU is druaga1's brother?

[@thechillhacker]

~3:33: anyone else thinking Qbert?

[@Fingelmeister]

Man that looked liked it took hours just to put in new keys

[@jangelelcangry]

[cracking sounds as the parts release]

[@captainmorgan9066]

Make a studio guide

[@cattharsis]

I vote for 3D Plowing Machine

[@Markokk888]

Holy shit..

[@Eo_Tunun]

Your PLA filament seems to be beyond its best-before date. It might have taken in air moisture which often is the reason for stringy prints despite proven-to- work slicer settings. It might also be one of the expensive "premium filaments" that actually are rubbish. I buy the cheapo Kaisertech stuff, and it works beautifully. When I once tried twice as expensive "premium brand" stuff, that ruined a hotend on my Anet A8. It also looks to me like you printed with something like 0.3mm layer heigth. If that was the case, try 0.1. It's slower but much neater and cleaner, usually. I found Uhu Allplast to be the perfect glue for PLA, by the way. My wall hanger for my guitar basically fell apart after printing, when I squeezed and pulled its arms to test their strength. I reattached the lose layers with the Uhu gunk, and it holds my beloved Strat wonderfully securely now. Skip the awkwardly handling Epoxy and Cyano-Acrylic stinky venom… Epoxy is fine for bridging gaps and really highly loaded big glued surfaces, but mixing and applying it is a lossy process a small repair simply doesn't justify. What with Cyano-Acrylic, that stuff only produces ephemeral joints that won't even outlast celebrity mariages. No good. And it stinks! Bluergh, Phooey!!1! That top bit that came off that one key stem is a perfect case for the Allplast sticky gunk.

[@Altoclarinets]

use the dildo* trick: print one, file it as desired, and use THAT to make a couple of molds... the process may take longer but it's less tedious manual labor and that's what counts *it is a very bad idea to 3d print a dildo because of the rough and sometimes porous surface created by the 3d printing process, but using a print to make a mold as described is more or less fine

[@dragonpjb]

I have access to a form1 resin printer. Send me files I'll send you keys.

[@TechTangents]

I have the design files up on github: github.com/AkBKukU/series80-ti99-keystemreplacement/blob/master/keystem.stl I would be very curious to see how resin printed examples would work. I would like to take you up on your offer! You can email me at [e-mail] for the PO Box or other information.

[@srfrg9707]

You can smooth PCB 3d printed parts with acetone vapor.

[@UnreasonableSteve]

Acetone vapor smoothing works with ABS, not PLA which is what he's printing with. Switching to ABS would likely cause more problems in the print than vapor smoothing would help with

[@UnreasonableSteve]

Acetone vapor smoothing works with ABS, not PLA which is what he's printing with. Switching to ABS would likely cause more problems in the print than vapor smoothing would help with

[@pancracio3188]

Try to clean it next time ;)

[@stogie28]

ay pretty hate machine

[@Mewtwoisabeast]

the errors seem to be from such a huge print if you did them 20 at a time the errors should be minimalized

[@罗梦宇-i6p]

Use sla printer!=

[@chupathingy5862]

>one pretty hate machine later I knew I liked you for a reason.