deep neck mechanical pencil? marking tool - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: June 05, 2024, 09:53:04 am
content: You can mark holes with graphite by extending a mechanical pencil, for even really small holes.The problem is for a deep bore, the graphite breaks.Mechanical pencils have say a 3-4mm steel tube on the bottom.I want a mechanical pencil that has say a 30mm steel tube on the bottom, that is a tight fit with the graphite, so you can stick it in a hole, and there is only a small amount of graphite that protrudes for making the marks.I Mean for like 0.7mm graphite.Does this exist?I thought it might be possibly to modify one combining it with a long needle of the correct size.It is possible to make this tool by gluing a lead into a long needle, but it has a short life.

author: tooki
author_rank: Super Contributor
timestamp: June 05, 2024, 10:31:59 am
content: I think the problem with this would be finding leads, since leads for thin mechanical pencils (0.9mm and thinner) are 6cm long, so with a full cm (at least) between the clutch and the beginning of the tube, and then your 3cm tube, and about 1cm inside the clutch itself, you’ve only got 1cm of lead to use before you have to replace it! (Never mind that any flex in the tube will break the lead prematurely.Could you use a 2mm drafting pencil, with their much longer leads?Otherwise, Edding sells special markers for marking inside holes.

author: jpanhalt
author_rank: Super Contributor
timestamp: June 05, 2024, 11:03:44 am
content: Use a layout ink, like Dykem, and a scribe.EDIT: Or hole center/transfer punch and ink. They come in many sizes to fit virtually any hole. (https://www.harborfreight.com/28-piece-transfer-punch-set-3577.html?utm_source=google&utm_medium=cpc&utm_campaign=12169518939&campaignid=12169518939&utm_content=114845717457&adsetid=114845717457&product=3577&store=221&gad_source=1&gclid=EAIaIQobChMI0ufzyqjEhgMVSTIIBR2SOgd8EAQYASABEgI-0fD_BwE)

author: coppercone2
author_rank: Super Contributor
timestamp: June 05, 2024, 09:47:06 pm
content: ehh i have most of those and transfer screw in punches but I like the graphite method alot. If your metal is fairly clean and polished you can make out the exact trace of the hole if you hold it to light at an angle and use a light thin punch to center it.Its really gentle, with the transfer punch you get a precise center but you can easily disturb what you are tracing and it requires fixturing. The long graphite is extremely gentle. I guess the benefit of using a bare graphite is that it will break instead of moving your work. I will try to glue some graphite rod into a syringe needle and see if I like it before looking more.It actually works pretty well, but in a set of graphite a few will be EXTREMELY fragile and a few will be strong enough to trace out fairly deep holes.You don't get that much strength even from a thick graphite (wood 'mechanical pencil' that uses a thick graphite core).But now I wonder if a sewing needle will mark a light hole on machinist blue..... that might be even better

author: jpanhalt
author_rank: Super Contributor
timestamp: June 05, 2024, 10:34:01 pm
content: So why did you supposedly ask for alternatives?Do you really think there is a market for the pencil of your dreams? Ask Pentel.There are also what are called "hole duplicators" that are used in aircraft repair (e.g., replacing a skin). In that example, you want to duplicate a hole position for a layer on top, not under the desired hole. You have so poorly described your current project, if there is one, that it's impossible to know what you want to do rather than your preconceived idea of how to do it.

author: coppercone2
author_rank: Super Contributor
timestamp: June 05, 2024, 10:50:04 pm
content: I told you it works you just go through alot of graphite with accidental breaks. its just a reinforcement. whats so complicated to understand here for you?its convenient, fast (no dry time, no need for acetone), clean and its very unlikely to disturb poorly setup parts, i.e. equipment modifications for fitting weird shaped things that don't clamp well. It also works for deep bores and it works better then 'spitting pens" and there is zero requirement for choosing the correct size (1 size fits all). It just needs to be fairly clean. Usually its enough to wipe it with alcohol after a light sandingA very long neck micro-sharpie type pen would work fine too. The problem with all of them is that the neck is no more then a few milimeters, making it not suitable for deep holes.And you can route out irregular things like for die grinding or drilling out a weird shape or slot, even if its deep.

author: tooki
author_rank: Super Contributor
timestamp: June 05, 2024, 10:54:31 pm
content: Quote from: jpanhalt on June 05, 2024, 10:34:01 pmWell, technically they didn’t, they just asked whether their dream concept exists. It doesn’t, and it’s fairly clear why, but clearly OP doesn’t want a proven solution, they just want confirmation of their idea.

author: coppercone2
author_rank: Super Contributor
timestamp: June 05, 2024, 10:56:31 pm
content: Quote from: tooki on June 05, 2024, 10:54:31 pmThere is a 100 year history of various pens and pencils, something might exist. could be a drafting tool or something for fitting. their usually hard to find because the industry of hand fitting mostly went away. There is a very large amount of unique scribes and such that became obsolete for anything but modding because parts improved and became more standardized.. just like watch making. CAD killed the general interest in all of this type of technology. Or lathe attachments, drill attachments , mold making tools, special clamps, slide rules, etc. I hear this stuff all the time when you are browsing something old and it shows up. Someone might have seen it.For instance it might feed graphite with a screw instead of a collet and got invented in 1950.I assume the people are getting mad because it will cut into some side business of someones selling or designing some kinda templates or stencils that these types tools threaten? or cad services? I seen this before, someone gets mad they don't get a assignment to work on some dumb template so they can delay a prototype design for 3 weeks before they can drill a switch hole lol

author: jpanhalt
author_rank: Super Contributor
timestamp: June 05, 2024, 11:25:37 pm
content: Quote from: tooki on June 05, 2024, 10:54:31 pmDo you want to divert this thread into a discussion of what words mean, as seems to be the case? The TS asked whether such a pencil existed. It does not to my knowledge. Do you know of one? If so, please share it with us and address the TS's question rather that drawing the discussion off into a tangent discussing those people who are actually trying to help. Talk about being off topic? Look in a mirror.Simply, if you need something, and it's not made, you have a limited number of choices:1) Make it yourself;2) Find an alternative way to do the same function; and/or3) Do it differently or do another project.I suggested alternative and well established ways to find the center of a hole. Using a pencil as described is not a very accurate way to find the center.

author: tooki
author_rank: Super Contributor
timestamp: June 05, 2024, 11:31:21 pm
content: Quote from: coppercone2 on June 05, 2024, 10:56:31 pmI know there have been many clever things made. But mechanical pencil leads certainly weren’t stronger in the past than now, and long, very thin leads are just going to be delicate, it’s the nature of the beast that is graphite pencil leads: the softness that lets them rub off onto the writing surface is the same softness that makes them fragile.Earlier you said this:Quote from: coppercone2 on June 05, 2024, 09:47:06 pmI don’t know what you mean by the “wood ‘mechanical pencil’” — a pencil is functionally either woodcase or mechanical, not both. The leads in woodcase pencils don’t need to be quite as strong as mechanical pencil leads — even of the same thickness — because the wood is there specifically to provide mechanical support, especially if the lead is fully glued in with a quality glue, as high quality pencil manufacturers do.What I can tell you is that going thicker most certainlydoesadd a ton of strength. I happen to like very soft pencil leads — 2B to 3B, depending on manufacturer — and 3B is absolutely no problem in 2mm mechanical leads (i.e. drafting pencil/lead holder leads), whereas 0.5mm and 0.7mm 3B requiresextremelyrigid, precise mechanical pencil mechanisms; most mechanical pencils have enough play in the clutch mechanism that 3B leads simply snap constantly. (And I do meanconstantly. Literally letting the pencil drop on its side, with the lead retracted, 6” onto the desk is enough to break a 3B lead in a typical mechanical pencil.) So far, I have found just one model (a Japan-only Staedtler model) that can handle 0.5mm 3B. But even with standard HB (~#2), a 2mm lead is way more robust than a 0.5mm or 0.7mm lead. There’s a reason they only sell the thin ones in 6cm lengths, whereas 2mm mechanical leads can be 13cm or more.

author: tooki
author_rank: Super Contributor
timestamp: June 05, 2024, 11:36:20 pm
content: Quote from: jpanhalt on June 05, 2024, 11:25:37 pmWTF man? I was actually agreeing with you…Where did you see me accuse anyone of going off topic? Or of discussing the meaning of words? Calm the fuck down, jesus…Stop putting words in my mouth. And others mouths: as I did point out, OP did not actually ask for alternatives (which is dumb, but they didn’t), yet you claimed they did.

author: aeberbach
author_rank: Regular Contributor
timestamp: June 06, 2024, 06:19:58 am
content: https://pica-marker.com/en/heroes/pica-dry-marker/It's a mechanical pencil but as you can see the tube is long and protects the exposed lead without adding much width at all. You can get graphite, chalk, crayon inserts as well as permanent marker versions.Maybe the "Pica Ink deep-hole marker" is best for what you describe.

author: jpanhalt
author_rank: Super Contributor
timestamp: June 06, 2024, 09:45:43 am
content: Quote from: coppercone2 on June 05, 2024, 10:56:31 pmThat was my favorite type of mechanical pencil until I was forced to change to the clicker variety.Quote from: coppercone2Your imagination is hard at work.Quote from: coppercone2Yes, a sewing needle will scratch the blue ink or any other color of layout ink. A scribe is easier to hold and control, can be very sharp, and is usually longer than a typical sewing needle. When you mention leaving heavy marks and disturbing the template, I wonder what you are using. When used properly, the base material is disturbed very little.There are calipers made for measuring hole center distance as well as adapters for doing that with ordinary calipers (attachment).Aside from wanting a 3-cm projection, you have not said what size holes and with what accuracy you are trying to transfer the center locations.