Yessss! So glad it worked!

To explain the confusion: I actually pulled the entire lead tube out before separating the collet from the lead tube, (the main body/grip of the pencil is a separate piece of plastic!) so I had plenty of room to grab the collet with tools. However your way might be better, since as I recall it took a fair amount of force to pull the lead tube out the back, and after doing it a few times the two halves no longer seem to click together and stay very well.

yeah that’s definitely the toughest part… the collet needs to come out the front of the pencil, it can’t fit out the back. It is barbed (visible in this pic if you zoom way in) so it digs into the plastic pretty damn well, but it can be pulled straight out.

I basically just used brute force. it should be pretty safe to pull straight outwards on the collet by the ring part (the part that moves freely) since that way there’s no bending, its all metal on metal, in tension, and the thin members of the collet are pulled snugly together and stressed evenly. you can use a small pliers but you don’t want to squeeze too much. either grab the ring head-on and squeeze enough to get a grip, or use a sufficiently tiny pliers to grab from the side between the spring and the collet ring, not squeezing basically at all and just hooking the jaws of the pliers under the ring and pulling out. Some wiggling/wobbling the collet (while still pulling outwards so nothing bends) as you go could help but will probably make the fit looser when you go to put it back in so don’t go overboard.

I don’t think there’s a great way to push it out from the rear either, since behind it there’s a narrowing of the hole in the plastic to about the same size as the one on the back of the collet. Maybe if you had just the perfect 1.5mm rod or something but it would probably just buckle.

yesss we’re back! I’m hyped, very interested in getting some boards made and soldering them up once its consolidated onto one board

seems like it’s particular to the person and their hair/skin but what I’ve gathered is that you take the machine and a tweezers, insert a fresh needle into the holder. lightly insert the needle at the root of the hair, parallel to the direction the hair is coming out. you basically just let it slide in until it reaches the root of the follicle, where it will meet some resistance. Then you trigger the pulse with the foot switch, and see if the hair will come out with the tweezers. if the follicle is properly destroyed, it should slide out with basically no resistance. if it does not come right out you can increase the power and try again, dont pluck it ofc.

Doing it to yourself is gonna be pretty damn challenging or impossible on many parts of the body but you could maybe find a partner willing to help. Seems like there are training videos online that might help learn proper technique as well but I cant vouch for any specific ones

should be fine, I feel like kitchen backsplashes are the single most common use for those lol And they mostly mean dont use it in a bathroom, IMO. cant go wrong with thinset but its a lot more work

yo congrats! Hope it all goes smoothly, that’s gonna be a crazy month :rat-salute:

The yasutomo is also available from amazon/probably elsewhere btw, I just tried to link the manufacturer because they do sell it directly unlike pentel seemingly

about the jack… yeah, perhaps 2.5 mm is not the way. The nice thing about this project is that it’s a single small wire to deal, so it probably won’t actually end up being very important for it be able to rotate freely like an audio jack. The easy/janky fix might be lever nuts. They provide a really solid tool-less connection. But they are kinda bulky and would have to either be attached to the pencil somehow or just hanging loose at the end of the probe…

Maybe a bullet connector? They are widely available, at least in the US, might fit inside the body of the pencil with a bit of effort, or if it doesn’t fit, at worst you could still have the plug side of one permanently attached to the pencil and the socket side on the wire coming from the board. They won’t spin freely but that almost certainly doesn’t much matter. I could try it out this week.

As far as tool requirements, what I’m doing with the pencil collets already uses a soldering iron, so the same iron could be used to do these connectors if someone doesn’t have a crimper (though many wire strippers have them built in).

If someone doesn’t have and can’t borrow a soldering iron idk. They could use a db9 crimp and a pliers and just glue it into the tip of any pencil or pen?

Here’s some photos of what I’ve got so far:

F Shank:

K Shank:

Agh! I started writing up an update comment in the old thread like an hour ago and didn’t check my notifications til now, so I put it in the wrong place! The needles and pencils I ordered have all come in now and I’ve done some testing!

from preliminary testing it seems like the idea of using the pencil lead collet as a holder will work! out of 6-7 pencil types tested I’ve come up with 2 that seem to work well for the 2 needle sizes (F and K shank)

For the larger F shank needles, I’m using this 1.1mm “Yasutomo Artist Pencil”

And for the smaller K shank needles, I’m using this 0.7mm Pentel Quicker Clicker

Both came apart reasonably easily and accommodated a small piece of wire running down the length of the pen and being soldered into the base of their brass collets, allowing for great electrical connection to the needles, and a reasonably strong physical grip. The pentel has an extremely grippy textured rubber grip, while the yasutomo is just plain plastic, but the pentel also required me to strip like 2.5 inches of insulation off the wire, since the insulation wouldn’t fit down the lead tube otherwise. Both are probably usable without any further modification, through trimming the end off of the yasutomo would probably be a good idea so that the needle can engage further into the collet without disappearing down in the pen tip.

Quick notes on other pencils I tried/what else could work:

The factors I was looking at were:

• collet material. You want the part gripping the lead to be metal, ideally brass (kind of a dull gold color). Often there is a little brass sleeve, but the actual collet is just 2 pieces of plastic, which won’t work. Unfortunately hard to tell this from a product listing.
• size:
  • the K shank is 0.8mm so a 0.8 or 0.7mm pencil is probably what you want (0.8mm doesn’t seem to even exist really)
  • the F shank is 1.25mm, so a 1.1mm (used in some antique and specialty pencils) or 1.3mm (I found one for construction use)
• ease of disassembly/reassembly/ general dimensional compatibility. If its too fiddly/fragile, or won’t fit a wire, has a long tip that’s integral to the mechanism somehow, etc. that’s ofc bad

I also looked at:

• staedtler 1.3mm jumbo construction pencil (crummy plastic collet)
• bic velocity “Side Clic” (crummy plastic collet)
• pentel Side FX 0.7 and twist-erase CLiCK 0.7 (plastic collet. hard to reassemble)
• Zebra M-301 (kinda crummy overall, removing the brass collet was tough and seemed to damage the plastic it clips into, plus the integral screw-on tip had to be cut down)

I will post pictures/instructions on how to modify the 2 I liked soon! I haven’t gotten to the point of attaching any plugs or anything yet, just a wire and a continuity test. But there may be enough space for a 2.5mm aux jack at least, if that’s the route we want to go.

Hello! The needles and pencils I ordered have all come in now!

from preliminary testing it seems like the idea of using the pencil lead collet as a holder will work! out of 6-7 pencil types tested I’ve come up with 2 that seem to work well for the 2 needle sizes (F and K shank)

For the larger F shank needles, I’m using this 1.1mm “Yasutomo Artist Pencil”

And for the smaller K shank needles, I’m using this 0.7mm Pentel Quicker Clicker

Both came apart reasonably easily and accommodated a small piece of wire running down the length of the pen and being soldered into the base of their brass collets, allowing for great electrical connection to the needles, and a reasonably strong physical grip. The pentel has an extremely grippy textured rubber grip, while the yasutomo is just plain plastic, but the pentel also required me to strip like 2.5 inches of insulation off the wire, since the insulation wouldn’t fit down the lead tube otherwise. Both are probably usable without any further modification, through trimming the end off of the yasutomo would probably be a good idea so that the needle can engage further into the collet without disappearing down in the pen tip.

Quick notes on other pencils I tried/what else could work:

The factors I was looking at were:

• collet material. You want the part gripping the lead to be metal, ideally brass (kind of a dull gold color). Often there is a little brass sleeve, but the actual collet is just 2 pieces of plastic, which won’t work. Unfortunately hard to tell this from a product listing.
• size:
  • the K shank is 0.8mm so a 0.8 or 0.7mm pencil is probably what you want (0.8mm doesn’t seem to even exist really)
  • the F shank is 1.25mm, so a 1.1mm (used in some antique and specialty pencils) or 1.3mm (I found one for construction use,
• ease of disassembly/reassembly/ general dimensional compatibility. If its too fiddly/fragile, or won’t fit a wire, has a long tip that’s integral to the mechanism somehow, etc. that’s ofc bad

I also looked at:

• staedtler 1.3mm jumbo construction pencil (crummy plastic collet)
• bic velocity “Side Clic” (crummy plastic collet)
• pentel Side FX 0.7 and twist-erase CLiCK 0.7 (plastic collet. hard to reassemble
• Zebra M-301 (kinda crummy overall, removing the brass collet was tough and seemed to damage the plastic it clips into, plus the integral screw-on tip had to be cut down)

I will post pictures/instructions on how to modify the 2 I liked soon! I haven’t gotten to the point of attaching any plugs or anything yet, just a wire and a continuity test. But there may be enough space for a 2.5mm aux jack at least, if that’s the route we want to go.

Oh hey I didn’t see this reply in my inbox for some reason (so maybe matrix is a good idea, though I don’t mind keeping the discussion out in the open here either for the most part)!

Thank YOU seriously, I wouldn’t have the knowledge or initiative to do the electronics side of this at all properly like you are (I could maybe pull off a DIY-as-fuck version like that reddit post but even then)

I was hoping to use the actual mechanical pencil collet that it uses to hold the lead (usually brass iirc so good enough electrically) but db9 pins is a pretty clever idea too and easier to crimp or solder a wire to them… Probably keeping that in mind as a fallback if the pencil collet thing proves too fiddly. I just looked and I think standard db9 pins are a 0.04" so a hair over 1mm, but there must be enough flex in the receptacle side to accommodate a 1.25mm F needle? probably adds a lot of needed friction to do it that way, pretty clever and easy. Modding the pencil to securely hold the contact might be tough but gotta start somewhere… I have a lot of ideas now actually… thanks for the link, I may pick up some of those pins locally too.

Also, does using a K needle require AC or different current or anything drastically different than F? I picked up some of those too, but then realized you seemed to be talking about primarily just the F needles. (side note if you or anyone else here needs needles, I will have an abundance when these show up lol)

I decided to just pull the trigger and buy some needles and a bunch of mechanical pencils. it’ll probably be a week before it’s all here but I’ll report back what I find in terms of making them fit and modding them for electrical connections (is soldering okay here? I guess that would raise the barrier to entry somewhat but it seems more reliable than just stuffing a wire in there… Maybe solid core wire the same diameter as the needle could be okay.)

Okay. more thoughts on the mechanical pencil side of things: Still no dice on the exact one being used but I still think its some knock-off of the pentel I linked, or an older version of it. There’s also the skilcraft slickerclicker, which again looks similar but not the same.

From what you linked, the F shank is 1.25mm and K shank is 0.8mm. you could probably snugly fit those into 1.1mm(or maybe 1.3) and 0.7mm pencils respectively, since there is some margin of error in the collet. But it will need some testing. finding a 1.1 or 1.3mm pencil with a side button might prove annoying, but a 0.7 should be no problem (I think the side button is important since it allows you to gut everything above that point, but maybe other styles could still work). I’ve been looking all around and I think the pentel SideFX could maybe be a good candidate, or the other two I mentioned above. I could probably buy a few and see which one is easiest to gut and add a wire/connector to, but I’ll need to acquire some needles then too. Another idea is looking for a pencil with a retractable sleeve, but I’m not sure you could get one long enough to cover up the needle anyhow so it might be best not to bother.

ALSO: I absolutely KNEW I would need this industrial foot switch I bought at the surplus store a couple months ago. It was just too satisfying not to buy but I thought I would never use it… WRONG

yo! I will probably comment more thoughts and or hype but i think that pencil is some sort of pentel? not this exact one maybe but same mechanism: https://www.pentel.com/products/quicker-clicker-mechanical-pencil-with-grip

yeah it can’t beat any of the overseas ones on price. But for the little projects I’ve used it for it’s been cheap enough that I didn’t care it wasn’t technically “a good deal”. For bigger PCBs that may be different. It was pretty fast (maybe I got lucky?) but not really better than jlc on that either even in the best case

idk why I have any loyalty to it… I mean I don’t really but I’ve only ordered pcbs a handful of times and I think the first one was one of those links you mention. someone on hackaday made a Pi Zero GPIO to VGA adapter board that I wanted to try (worked astonishingly well tbh even with “best I could find at the surplus store” through hole resistors)

I do like the purple and gold tho, and I’ve heard their quality is better in some ways that I almost certainly don’t need

add me to the ping! this is cool!

I’ve got enough knowledge to populate and likely troubleshoot a board like this but not enough to tell you anything you don’t already know! I’d totally build one and test it out or help manufacture it or whatever if that becomes necessary

oh also jlcpcb is probably a faster and more capable vendor esp if you might eventually want other services but I’ve also used OSHPark with decent results. honestly tho the big players may have the economies of scale to beat them on speed and price. and probably exotic board types too i just like the purple solder mask tbh lol

I tried to flip which side the hinges were on on my fridge once… I relate. I checked everything looked totally symmetrical, and yet one of the 3 bracket was… not at all. So it was totally untenable and I had to put it all back

mostly recovery codes. I have multiple yubikeys but that’s mostly for work

yeah, when sites support it, that’s definitely the best option, but many sites only barely do totp lol so I have to have to put the totp codes somewhere, and the yubikey handles it in a pretty nifty way