Breadboard Test Leads - Page 1
Forum section: electronics / projects

author: Pitron
author_rank: Contributor
timestamp: June 28, 2022, 10:36:22 pm
content: A couple of months ago, designed some custom test leads for a solderless breadboard. They are 4mm Banana plug tomale Dupont 2.45mmtest leads. They are perfect for connecting a multi-meter or power supply to a solderless breadboard.I am having the test leads custom manufactured and I’m reselling them on my project’s website.I would like some feedback on this idea before I invest too much money into it. ThanksProject Website:https://www.pitronllc.com___________________________________________________________________________________________________________________________________________________________________Update:I decided to turn Rev2 Banana Breadboard Test Leads into an Opensource Project.This project is licensed under Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).https://creativecommons.org/licenses/by-sa/4.0/Once the design is complete, I will register this project with Open-Source Hardware Association.https://www.oshwa.org/Also, I plan to upload the final design files to GitHub.https://github.com/PitronLLC/Pitron_Banana_Breadboard_Test_Leads

author: Ian.M
author_rank: Super Contributor
timestamp: June 28, 2022, 11:17:22 pm
content: Your design puts a lot of leverage on the duPont pin, which if its the crimp type isn't particularly robust, and on the breadboard contacts, which is why I and many others who have made something similar prefer to use much thinner and more flexible wire. Personally I use 3" extension adapter cables that fit over my ordinary DMM probe tips with duPont pins on the other end. If anyone is looking to DIY themselves, the female Molex 5 1/4" drive power contacts fit nicely over most meter probe tips. Discard the shell and use heatshrink to insulate.

author: Pitron
author_rank: Contributor
timestamp: June 29, 2022, 01:33:28 am
content: Hi Ian.M, thank you for your reply.The heads of the test leads are made of steel needles specially used for injection molding. They are more robust than the regular DuPont pins. DuPont pins are 0.65mm in diameter, the test leads areapproximately 0.8mm. They fit perfectly in a breadboard and I haven’t had any issues with them bending.I agree that I should use a thinner wire.I am planning on designing a second revision of the breadboard test leads. On the new design, I’m going to use a smaller wire gauge (20 or 22 AWG). I’m considering changing the wire material from PVC to silicon. Since silicon is more flexible and easier to work with.Also, do you think $17.98 is a reasonable price for a set of test leads?Thanks again for your feedback.

author: tggzzz
author_rank: Super Contributor
timestamp: June 29, 2022, 09:42:33 am
content: Quote from: Pitron on June 29, 2022, 01:33:28 amI have no comment on the general design, since I loathe solderless breadboards.However, there is a general point about pricing: what's the cost of achieving similar objectives by other means?In this case my first port of call would be a standard (i.e. cheap, multisourced, and maybe already available) lead with a banana plug on one end and a small croc clip on the other. I'd attach the croc clip to an offcut of wire or component lead.

author: Ian.M
author_rank: Super Contributor
timestamp: June 29, 2022, 12:28:28 pm
content: For price comparison, see what Walmart can do for your price-point:https://www.walmart.com/ip/Meterk-Multimeter-Test-Leads-Kit-21PCS-Digital-Electrical-Probes-Set-Alligator-Clips-Mini-Grabber-SMD-IC-Hook-Electronic-Lead-Kits/784565904If your customers are price-sensitive you've already lost.

author: RogerThat
author_rank: Regular Contributor
timestamp: June 29, 2022, 01:13:37 pm
content: For powering breadboards I have two of these cables, works perfect.edit: I think your cables are too bulky, if you put them in the holes next to each other they will probably not go in straight?I usually use the power rails on the breadboard, so no need to have the +- separate. When I want to measure something I use the multimeter tips directly on the components alternatively a small hook on a short jumper wire.

author: MikeK
author_rank: Super Contributor
timestamp: June 29, 2022, 01:24:41 pm
content: What RogerThat shows is exactly what I do too.

author: Pitron
author_rank: Contributor
timestamp: June 29, 2022, 04:25:53 pm
content: Thanks for all the replies.I’m going to work on lowering the price of the test leads. The reason the price is so high is because I put in a small order which caused the over all price per set to increase.Hopefully, on my next revision I’ll be able to put in a larger order which will bring the cost per set down to a more competitive rate.RogerThat, your cable is very similar to the cable I started out with. Ill test my cable to see how well it works when I put both of them in a hole next to one another.Also, does anyone have any preferences on the length of a test lead? The average length seems to be about 1 meter.Thanks again for all the feedback. I am still in the learning stages of this project and all your opinions are very valuable.

author: Pitron
author_rank: Contributor
timestamp: June 29, 2022, 05:21:12 pm
content: Hey RogerThat,I just tested the Test Leads, and they seem to both fit in the holes next to one another (it’s a snug fit). The molded strain relief is flexible, which helps out a lot.I’ll try to redesign the molded strain relief, to make in thinner and less bulky. The only issue is that ill have to order a new pressure mold. I’ll talk to my manufacture about it.Also, does anyone think 9-10 dollars is a good target price?Thanks again everyone.

author: viperidae
author_rank: Frequent Contributor
timestamp: June 29, 2022, 09:57:50 pm
content: Can't say I'm a fan of websites advertising a standard price as a "sale"In some countries, mine included, that is considered misleading advertising.I would be concerned about the weight of those probes bending the spring contacts in the breadboard

author: Pitron
author_rank: Contributor
timestamp: June 29, 2022, 10:14:19 pm
content: Hey ViperidaeWhen I originally launched the test leads the price was $21. I lowered the price do to lack of sales. I understand how that could be miss leading, so I removed the sales banner on the website.

author: tooki
author_rank: Super Contributor
timestamp: June 29, 2022, 11:58:23 pm
content: While I don’t revel in piling onto the criticism, and I absolutely do not want to discourage you, you did ask for feedback, so here goes:Quote from: Pitron on June 28, 2022, 10:36:22 pmSorry what?Do you mean 0.1” (2.54mm) pitch? Your cables do not allow for a 0.1” pitch, the grips are much too big. Pitch is the spacing between pin centers.Quote from: Pitron on June 29, 2022, 01:33:28 amNo. They are square, 0.025” (0.635mm) on each side.Quote from: Pitron on June 29, 2022, 01:33:28 amThe diagonal of a 0.635mm square pin is about 0.8mm, but when you insert those into a breadboard (which is already at the outer limits of what goes in them comfortably: on expensive breadboards they can be tough to insert, on cheap breadboards it stretches the contacts), you’re not doing it at a rotation where the diagonal is perpendicular to the contact axis.Upshot is, if you’re designing something expressly for breadboard use, I’d shoot for 0.5-0.6mm diameter, and it needs to have tapered points or you’ll never get them in. (I’ve encountered Chinese breadboard jumpers with 0.5mm round steel pins, which would be great if they were tapered, but they’re not, so they often just snag.)Quote from: Pitron on June 29, 2022, 01:33:28 amWhy so huge? Breadboards aren’t intended for huge currents. 24AWG is more than enough, comfortably.Quote from: Pitron on June 29, 2022, 01:33:28 amWell, silicon is a hard, brittle element. It’s not flexible in the slightest.You mean silicone, and indeed I do prefer using silicone wire for breadboards. But more important than the insulation material is the wire stranding: 24AWG stranded wire can have as few as 7 strands and as many as 128 (like Kabeltronik LiFY). This makes amassivedifference in how compliant and limp a cable is. Not all silicone wire is made for flexibility. Also bear in mind that silicone has inferior abrasion resistance than PVC, and the surface tends to hold onto dust. So a super fine stranded PVC may be superior in some respects. I’d take that over low-grade silicone wire any day. The good Chinese silicone 24AWG I mention later has somewhere around 40 strands.Quote from: Pitron on June 29, 2022, 01:33:28 amIf it’s a top-quality product in every respect then that is reasonable. (Top quality banana plugs cost $2-3 apiece, so that gives a sort of context. Hirschmann, a top-quality German manufacturer, sells a banana to female DuPont cable, made with ultra fine stranded 24AWG wire, for around $6-7 apiece. They don’t make one with male pins at all, alas.)Have you measured the contact resistance of your cables? Cheap banana plugs often do poorly here, so that’s one thing you wanna check yours for. (Another is longevity: do the lanterns weaken over time? Cheap ones do after a few hundred insertions, whereas a Stäubli or Hirschmann lantern plugs remain as good as new even after decades of use. I have some that are likely 30+ years old and still work like new.)I’ve attached some photos of a few cables I’ve made for breadboard use: the one with the banana plug is a 0.8mm pin intended for high-density D-sub connectors (like the HD-15 used for VGA). Even with the lovely torpedo-shaped point, they are quite difficult to insert into a 3M breadboard. Those pins aren’t intended for individual use, so I wrapped it in numerous layers of heat shrink to make a grip. It’s just baaarely within the 0.1” envelope. The plug is a Stäubli (top quality Swiss brand) stackable plug. The wire is French-made 24AWG test lead wire from Cal-Test, but honestly I don’t like the wire: it “takes a set” too much, so it’s always creased, and the surface is super rubbery (not slick like good test lead silicone). I don’t use those much, either, because of the insertion force required.Next are two bundles of jumper wires made with delightful 24AWG silicone wire from China (from a specific supplier, they’re not all this nice). The male pins are good quality Chinese “DuPont” contacts, but the female ones are made with genuine ultra-high-force Mini-PV contacts from Amphenol. Chinese DuPont female contacts are looser to begin with and loosen a lot more after a few insertions, whereas the genuine Mini-PV are specified at 1000 cycles, and the ultra-high-force versions are expressly designed for use as single connectors. Despite the Mini-PV contacts costing upwards of 10x as much as Chinese contacts, their vastly longer longevity and the aggravation they prevent makes them well worth it.The thinner red jumper on its own is one made with 28AWG Chinese silicone. Absolutely lovely for breadboard use.Last but not least, I’d be remiss if I didn’t mention that Pomona sells its model 4691 banana to pin adapters. They come in a few sizes, the smallest being this, the 0.8mm. They have rounded points (more or less hemispherical), and they’re significantly tougher to insert than the aforementioned torpedo-shaped HD pins. The 4691’s shaft is bendy, so you don’t have to have your fat banana cable’s weight dangling from the breadboard. But honestly, I never use them.I much prefer my homemade leads made with Chinese silicone with crimped male DuPont pins on one end and a soldered Stäubli or Hirschmann banana plug (for permanent installation) or a screw-mount Pomona 1825 or spring-loaded WAGO 215 banana plug (for temporary cables) on the other end.I’ve also experimented with making jumpers with TE MQS contacts. The housings are 0.1” pitch multi-pin automotive monsters, but using heat shrink does work. The pins are 0.025” square just like DuPont. As automotive connectors, they’re very robust: the male contacts are actually a solid pin (like a PCB header) welded onto the crimp terminal. The female ones are luxurious to insert onto a pin. The downside is that they’re a bit fatter than DuPont contacts, so by the time you’ve put heat shrink onto them, you’re just a bit above 0.1”, so you can’t line them up on adjacent rows. 2 or 3 will work, but beyond that it gets tight real fast.Quote from: Pitron on June 29, 2022, 05:21:12 pmThe real problem begins when you need more than 2, or when other components or plugs are adjacent. (It’s not uncommon for me to have 4 or more DuPont pin cables going off the breadboard: 2 or 3 for power supply, then 2 for a voltage or current measurement, sometimes more to a second or third meter.) DuPont pins in DuPont housings are designed to fit within the 0.1” pitch and can be lined up in any number.As you can probably tell, I’m quite the connector junkie, and put a lot of thought and care into my test leads, so I absolutely understand your motivation for wanting to make these leads. But I do think a bit more thought needs to go into the design, because I don’t feel your design quite yells “I really understand the use cases and constraints”.

author: Pitron
author_rank: Contributor
timestamp: June 30, 2022, 12:47:06 am
content: Hey Tooki,Thank you for taking the time to write down all this information. I appreciate constructive criticism.I’m going to have to read over your post a couple of time to take it all in.I am working on a new design for the test leads and I’m definitely going to use all your feedback in this revision.Thanks again

author: Berni
author_rank: Super Contributor
timestamp: June 30, 2022, 05:28:17 am
content: Yep i agree with others, this is way too bulky on the probe end.You simply want a normal 1 pin header soldered onto the end of a thin wire and covered with heatshrink. That way the connector does not stick out a long way (potential for being snagged and bent) while the heatshrink lets it gradually bend coming out of it, providing strain relief to the wire so that it does not break under repeated bending.I was actually considering making oscilloscope probes in this style (along with the option of plugging a micrograbber on the end) but those are a lot more complicated to make for a 10x probe that is properly compensated and works into the MHz

author: Ian.M
author_rank: Super Contributor
timestamp: June 30, 2022, 07:03:21 am
content: Yes. That's exactly how I built the probe to pin lead extensions I posted back in 2020, which I have been using for a decade or so:The clip adapters should have been built the same way - with a short flexible lead between the socket for the ordinary meter probe and the clip.

author: tooki
author_rank: Super Contributor
timestamp: June 30, 2022, 10:57:38 am
content: It’s funny how different people’s taste in test leads is. I know adapters that slip onto probe tips are very popular, so people must like them. Me, I hate that, I don’t want anything on my probe, I want a dedicated lead. I’m sure others hate having a bunch of different leads taking up space. I guess that’s why the market has them all.

author: Pitron
author_rank: Contributor
timestamp: June 30, 2022, 09:39:41 pm
content: Thanks for all the feedback.I’ve been speaking to my manufacturer today and I would like to give everyone an update on the progress.We’ve been working on sourcing new components for the Rev2 breadboard test leads. We were able to find square 0.5mm x 0.5mm tampered steel needles, to use as the heads. Does anyone have a preference between square or rounded heads?We are going to completely redesign the molded strain relief for the needle heads. The new design is going to be minimalist and discreet. This design is going to be similar in appearance to the net tail of apple’s charging cable. (I attached a picture for reference.) The molded strain relief is going to be made out of TPE (a soft elastic material). We are still working on the design and dimensions; I will post a picture of it in a future update.The wire is going to be 1 meter long and the insulation material will be silicone. The wire gauge will be 24AWG. Hopefully, we will be able to find some wire with around 40 strands.We are also looking for a new banana plug with a low contact resistance.I am not an expert in cable designs. However, this is a project I’ve been wanting to do for several years.Thanks again for all the feedback. I plan to keep all of you updated on the new design.

author: tooki
author_rank: Super Contributor
timestamp: June 30, 2022, 10:18:08 pm
content: Quote from: Pitron on June 30, 2022, 09:39:41 pmBecause of the shape of breadboard contacts, I’d recommend round. But either would be absolutely fine, provided it’s got a tapered point.FWIW, this is the wire that I like:https://www.aliexpress.com/item/32788107178.htmlThat’s the 24AWG, but they have every size. See the attached stranding and dimensions table. The only bad thing I have to say about them is that they do not have a true purple; their “purple” is maroon-ish brown. In my picture above, the “purple” is the one in the center, next to blue and gray, the one whose plug has a strong reflection on it.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 30, 2022, 10:37:14 pm
content: Already quite a long time ago I made my own.I made them from hardened steel sowing needles. (They are cheap and you can buy them in all kind of lengths and thicknesses). On the back side I soldered a single contact broken off from a single row (high quality) 2.54 pitch header. Then I put some hot glue on the needle and added shrink tube, and repeated that for a total of 3 layers to give the probe some thickness. Because it has no wire dangling from the back end, they can't get entangled either and you can stow a few of them in a small area box or drawer. The female plug at the back end accepts regular "dupont" wires which you have of course always available when working with breadboards.Even if your probes are made from good quality supple wire with silicone isolation they are still much too thick and heavy to work with breadboards.I also never iked any of the normal DMM probes. I made my own from simple "loudspeaker cable". On one side I split the two wires apart for about 5cm and added 4mm banana jacks. On the other side I split the wires apart for about 20cm and I added 2mm Hirschman banana jacks, but I drilled a concentric hole in them of about 0.8mm thick and (again) soldered tips of sowing needles in them. The 12+cm handles of normal probes are much too big to work with almost any electronic circuits, and the 3cm long 2mm banana plugs work quite nice. The 2mm barrel of course also accepts the 2mm crocodile clamps.I have also cut a section out of an inner bicycle tube and I put that on the under side of my DMM between the meter itself and it's rubber holster, so it's a loose hanging flap, and I put the crocodile clamps on them when I don't need them.

author: sleemanj
author_rank: Super Contributor
timestamp: July 01, 2022, 12:22:53 am
content: This could be a Dragon's Den "I've sunk my life savings into this bad idea" moment. Don't fall into the trap of losing sight of what is useful and desirable instead of just a fun challenge to get fabricated.Simple flying leads to standard crimped dupont connector with an inline banana socket or plug is better in all regards, cheaper, more convenient, more versatile... sure it's not a "sexy molded silicone test lead" but it doesn't have to be.Anyway, if you persist with the idea, I would suggest making them right-angle so the probes lie-flat, having the probes sticking up in the air like that is just awkward, a disaster waiting to happen.

author: rcjoy
author_rank: Regular Contributor
timestamp: July 01, 2022, 02:38:44 am
content: I use these banana-to-pin adapters from Pomona, part #4691:https://www.digikey.com/en/products/detail/pomona-electronics/4691-2/736931The ends are actually flexible, and work quite well.

author: tooki
author_rank: Super Contributor
timestamp: July 01, 2022, 05:15:47 am
content: I described (and showed a photo of) those a day ago.

author: bd139
author_rank: Super Contributor
timestamp: July 01, 2022, 05:54:23 am
content: I just use a cut off leg from a resistor poked into two holes to make a loop. Then connect that to Pomona minigrabbersAdvantage being you can use the same methodology for dead bug prototypes.

author: Pitron
author_rank: Contributor
timestamp: July 01, 2022, 10:03:14 pm
content: Thanks again for all the feedback.I think one of the drawbacks of the original design is the price. It seems most people would rather use cheap mini grabbers, alligator cable or build the cable themselves than to pay $18 for a cable specially made for breadboarding. Because of this, I am going to aim for a price of $9 USD for Rev2. I would appreciate some feedback on this.I attached a picture of the current design for the molded strain relief (grip). This is my first attempt at the design of Rev2, so the dimensions and overall layout can still be changed.I am still looking for 0.5mm rounded tampered steel pins. If I can’t find any, I’ll stick with the 0.5mm x 0.5mm square steel pins.The wire we found is 24AWG and has exactly 40 strands.The manufacture told me that the banana plugs I’m currently using is made from copper and has a low contact resistance. I’m going to take apart some the cables to do some additional testing. I’ll post the results in another update.Thanks again everyone.

author: bd139
author_rank: Super Contributor
timestamp: July 01, 2022, 10:07:53 pm
content: I would rather use expensive mini grabbers.The problem with this approach is that the cables and the connectors are huge compared to the breadboard pin. That means you effectively are putting a lot of leverage on breadboard headers and are likely to damage them or snap the pin off the connector. I know because I did that a couple of times.You can see roughly what I do here. I use the binding posts on the board for power and clip anything else on component leadsBut I don't even do that now. It's all FR4 sheets because the infernal breadboards are so unreliable, particularly after you've poked leads into them.

author: Pitron
author_rank: Contributor
timestamp: July 01, 2022, 10:56:31 pm
content: Hey bd139,Thank you for your feedback.Do you think the design I attached below would put less leverage on the breadboard pin?One of the issues I see is that the grip will block some of the other pin holes around the header.Thanks,

author: tooki
author_rank: Super Contributor
timestamp: July 02, 2022, 12:06:18 am
content: With 24AWG silicone and a small overmold like your latest (non-right-angle) design, weight will not be a problem: it doesn’t look much different from the ones I made (the red and white cable), and force on the pins is not even remotely a problem. I wouldn’t do the right angle version for precisely the reason you mention: blocking things. It’s not uncommon to realize after the fact that you need to measure something, and the available hole in a row may not be at the edge.

author: tooki
author_rank: Super Contributor
timestamp: July 02, 2022, 12:09:40 am
content: Quote from: Pitron on July 01, 2022, 10:03:14 pmI like this design. Maybe reduce the 20mm dimension if you can, perhaps to 12-16mm, but no biggie if there are sound reasons for keeping it at 20mm (like longevity). If it’s possible to mold some ribbing into it for grip, that’d certainly be welcome. (If you don’t have a 3M breadboard, get one so that you can feel the insertion force needed, and whether ribbing would really be helpful or not.)

author: tooki
author_rank: Super Contributor
timestamp: July 02, 2022, 12:17:36 am
content: Quote from: Pitron on July 01, 2022, 10:03:14 pmMaybe some folks here who are knowledgeable in failure testing, metalworking and metallurgy can chime in on how best to test a banana plug. What I know from other discussions here is that many people have had bad experiences with common AliExpress banana plugs, where the lantern (the spinny spring part) didn’t make great contact with the plug shaft, so they soldered them together. Not sure if it’s poor tolerances, or bad plating (bad plating makes cheap multimeter probes have surprisingly high contact resistance, which sanding down fixes), or both. I’ve also had some cheap banana plugs of various styles whose spring contacts were not springy enough and would not bounce back after a few insertions, so they’d then just fall out…

author: bd139
author_rank: Super Contributor
timestamp: July 02, 2022, 07:29:34 am
content: Quote from: Pitron on July 01, 2022, 10:56:31 pmThat might work better actually. Although on dense boards it might be an issue. Definitely one to experiment with.

author: Pitron
author_rank: Contributor
timestamp: July 04, 2022, 08:02:37 pm
content: Thanks for all the replies.I am still doing testing on the banana plugs.I am considering using a solid-state banana plugs on Rev2 (I am not sure of the proper name for this style). I attached a picture below for reference.Does anyone have any preferences between solid-state and rotating ring banana plugs?

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2022, 12:02:46 pm
content: The cool thing about the rolled sheet metal ones is that a) they’re compact and light, and b) you can mate them male-to-male, which is super handy on occasion!

author: Pitron
author_rank: Contributor
timestamp: July 07, 2022, 08:13:28 pm
content: I was able to find rounded 0.5mm steel pins and tampered.However, I have received feedback saying that 0.5mm (24 AWG) might be too small for a breadboard. They suggested using a needle closer to 0.644mm (22 AWG).Thanks again for all the feedback.

author: free_electron
author_rank: Super Contributor
timestamp: July 07, 2022, 08:24:52 pm
content: at that price you should be using Staubli-Multicontact pins : 1mm series 22.2070-xi picked the wrong part from the catalog. they look the samecorrect part number is SLS0.76-S , order code 22.2600-x and it is a 0.76mm pin which is perfectly compatible with breadboards.page 10 :https://www.staubli.com/content/dam/spot/TM-Main-11014124-en.pdfthey are specifically made for breadboard.https://www.newark.com/staubli/22-2070-23-24-25-26-27-22-1007/plug-1mm-5-colour-pk5/dp/05M2632?st=22.20703.78$ for 5. avaialble in 6 colors so yu can make all combinations.other side :https://www.newark.com/staubli/22-1028-22-2160-21/4mm-banana-plug-stackable-32a/dp/47AC2396?st=staubli%204mmplease don't do those isolated safety plugs. that is immediate disqualification in my eyes. they don't fit anything. take any bench power supply and it doesn't work.

author: tooki
author_rank: Super Contributor
timestamp: July 07, 2022, 11:10:14 pm
content: Quote from: Pitron on July 07, 2022, 08:13:28 pmI would suggest not taking too much advice from people who don’t know what the hell they’re talking about. A standard high-quality resistor or capacitor lead is 0.5mm (I just measured with calipers to make sure), and they certainly go in and hold just fine. The Chinese (non-DuPont) breadboard jumper leads use 0.6mm, but being untapered, they’re often difficult to insert, especially into high quality breadboards (which have high contact force) or super low quality breadboards (whose contacts aren’t funnel-shaped enough to guide the pin in).Speaking of bad advice:Quote from: free_electron on July 07, 2022, 08:24:52 pmThis is categorically untrue. 1mm is far too large for a breadboard and will cause permanent damage to the breadboard if forced in.Stäubli sells sockets for 1mm pins, they’re not for breadboarding.Quote from: free_electron on July 07, 2022, 08:24:52 pmWhere have you seen even the slightest suggestion that safety banana plugs would be used?

author: free_electron
author_rank: Super Contributor
timestamp: July 08, 2022, 05:44:42 am
content: Quote from: tooki on July 07, 2022, 11:10:14 pmThis is categorically untrue. 1mm is far too large for a breadboard and will cause permanent damage to the breadboard if forced in.Stäubli sells sockets for 1mm pins, they’re not for breadboarding.i've been using them for years in breadboards. long before those cheapo chinese bendy pins came along. Multicontact used to sell ready made wires in various colors and lengths. I had those already in 1986.They go in without problems and do not damage the breadboard ( provided you use good quality 3M or elenco breadboards )The plastic part spins around the pin and they used silicone leads.seem to be gone . i need to find my old paper catalog. Those and the premade LK410 cables. I had hundreds in the lab. never a bad contact.

author: tooki
author_rank: Super Contributor
timestamp: July 08, 2022, 06:02:33 am
content: The 3M breadboard specifications state a maximum diameter of 0.032” (0.813mm), but if you actually take a new 3M breadboard and insert a 0.8mm pin, you’ll see that the contact has been permanently deformed. Yes, to an extent it’s acceptable, but it’s better to stick to 0.6mm or less so that thinner component leads are still gripped firmly. 1mm certainly far exceeds the maximum allowed, and it’s decidedly untrue that the 1mm pins are “designed for breadboard” use. (I’ll gladly retract that statement if you actually find an old Multicontact catalog saying that’s what they’re designed for.)

author: free_electron
author_rank: Super Contributor
timestamp: July 08, 2022, 12:52:54 pm
content: found the catalogue on the wayback machine.correct part number is SLS0.76-S , order code 22.2600-x and it is a 0.76mm pin which is perfectly compatible with the maximum of 32mils in a breadboard (0.82mm)http://web.archive.org/web/20061117153033/http://www.multi-contact.com/AcroFiles/Kataloge/TM/Test&Measure_hi.pdfpage 11i only found the 1mm version in the latest catalog and assumed that was the one (they look identical but the pin is , of course, smaller on the 0.76)We used those in the lab all the time. had the crimp tool and all. they also sold ready made cables.so i stand corrected. it is not a 1mm pin but a 0.7mm pin. hard gold , crimp with sleeve.assembly document :https://www.staubli.com/content/dam/spot/TM_MA143-en.pdf

author: tooki
author_rank: Super Contributor
timestamp: July 08, 2022, 04:32:55 pm
content: Thanks, much appreciated!Those certainly look nifty. (For anyone who wants to try them, Bürklin, a reseller in Germany, has hundreds of them in stock, apparently!)I do still doubt they were actually made with breadboards in mind (they’d be thinner if that was their intended purpose), but rather made to go with the matching receptacles and inline sockets shown elsewhere in the catalog.For all the world, they look like a machined #22 contact in a cool little grip. It’d certainly be possible to make something similar using #22 contacts (like military contacts or D-sub HD contacts). See the photo of my example of that in my post above.Alas, most machined contacts you can buy now are brass (not copper alloy like the SLS0,76-S) which means that one unfortunate mistake and you’ve bent the pin over, and it being brass, bending it back will almost certainly cause it to break right off.The stamped D-sub HD contacts I used in the lead I made seem to be OK.)

author: Pitron
author_rank: Contributor
timestamp: July 08, 2022, 05:07:29 pm
content: I attached a photo of the current design for the Rev2 Breadboard Test Leads.I decided to use the Traditional (vertical) design in the first model. I think the right-angle design still has potential and I’m going to continue to experiment with it.Unfortunately, we had issues sourcing rolled sheet metal banana plugs. We are going to use gold-plated rotating ring banana plugs, instead.I ordered some samples of the components that will be used in Rev2. They will arrive in about 1-2 weeks.The current price point for Rev2 is around $9-$10. (Fingers crossed)With the current timeline, Rev2 could be in production around mid-August or early-September. I plan to use the rest of this month to prefect the new design.If anyone has any suggestions for Rev2, please let me know. I still have plenty of time to make changes.

author: tooki
author_rank: Super Contributor
timestamp: July 08, 2022, 05:13:15 pm
content: Consider a stackable banana plug, at least as an option. I find I very often use stackability.P.S. the word for something decreasing in thickness is “tapered”, as in “tapers to a point”. “Tampered” is the past tense of “tamper” (to illicitly modify something).

author: Pitron
author_rank: Contributor
timestamp: July 08, 2022, 07:36:05 pm
content: I attached a photo of a design I just completed, for a stackable banana plug.I haven’t shown this design to my manufacture yet. So, I not certain about the feasibility. I might have to make changes to the desgin, in the future.Thanks again for all the feedback.

author: Berni
author_rank: Super Contributor
timestamp: July 11, 2022, 06:17:46 am
content: Stackable banana plugs are definitely a pretty standard thing. Tho most off the shelf ones have a cable that is too thick and heavy to be suitable for this application.As for the breadboard side i think the connection should be made 90 degrees much like how multimeter test leads plug into the meter. This lets the cables lay flat against the table to avoid putting strain on the pin while also making it more difficult to snag. With a round pin the pin can freely rotate in the breadboard hole so the connection can swivel along with the cable too.

author: Pitron
author_rank: Contributor
timestamp: July 11, 2022, 11:25:21 am
content: Thanks for the feedback.One of the issues I had with the right-angled design is that the grip and cable could block some of the other pin holes around the header.I created a hybrid design, by combining the traditional and right-angled layout. This new design is similar to the right-angled design, except it has a 17mm clearance below the cable.

author: tooki
author_rank: Super Contributor
timestamp: July 11, 2022, 11:49:56 am
content: That’s the worst of both worlds. Think about the forces involved.A right-angle breadboard pin is stupid since it covers other holes. The reason people gave for wanting right angle is to reduce forces on the pin. An elevated right angle plug makes thatworse, and to solve a problem I know for a fact to not be a problem to begin with. (Remember, I’ve built 24AWG silicone breadboard leads before, and knowfor a factthat it doesn’t place worrisome forces on the pin (not even close). The wire sits there limply and the pin is perfectly happy.)

author: Pitron
author_rank: Contributor
timestamp: July 11, 2022, 03:47:25 pm
content: I decided to stick with the Traditional (Vertical) design. I doubt this design will put much strain on the breadboard contacts. I will, however, continue to keep this in mind during the design process.I attached a picture of the full layout for Rev2. I’m going to send this file to the manufacturer tomorrow. I’ll let you all know if any changes must be made.Also, we were able to find gold plated 0.5mm rounded and tapered steel pins. I am going to use these on Rev2.Thanks again for all the feedback.

author: Pitron
author_rank: Contributor
timestamp: July 13, 2022, 07:17:01 pm
content: I spoke with the manufacture yesterday and everything is setup begin production on Rev2 at the beginning of August.I attached a picture of an updated graphical design, using the correct dimensions for each component.If you have any ideas, feedback, or suggestions for Rev2, please let me know. I still have plenty of time to make changes.

author: tooki
author_rank: Super Contributor
timestamp: July 13, 2022, 07:56:59 pm
content: Looks nice. If possible I’d reduce the length of the grip. (For reference, a standard rectangular DuPont housing is 14mm long.) If 10-12mm is possible, that would be my target. What do others think?

author: Pitron
author_rank: Contributor
timestamp: July 13, 2022, 09:10:58 pm
content: Thanks for the feedback.I decided to use 20mm, because that is the average width of a small/medium size thumb. I also thought about 15mm, since that the width of a key on a MacBook.I could definitely, make the grip smaller, if others agree.

author: Pitron
author_rank: Contributor
timestamp: July 14, 2022, 03:31:11 pm
content: After looking over the design, I decided to reduce the size of the grip to 15mm. I would like to make the grip as small as possible while also being comfortable to pick-up.Also, I added a small 3mm Net Tail to the design. This should prevent the wire from ripping at the seam, increasing the longevity of the cable.I attached a photo of the updated design.Thanks,

author: Pitron
author_rank: Contributor
timestamp: July 14, 2022, 07:47:59 pm
content: I decided to turn Rev2 Banana Breadboard Test Leads into an Opensource Project.This project is licensed under Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).https://creativecommons.org/licenses/by-sa/4.0/Once the design is complete, I will register this project with Open-Source Hardware Association.https://www.oshwa.org/Also, I plan to upload the final design files to GitHub.https://github.com/PitronLLC/Pitron_Banana_Breadboard_Test_Leads

author: Pitron
author_rank: Contributor
timestamp: July 15, 2022, 03:41:06 pm
content: I received some feedback today saying that we should offer two cable lengths one 1 meter another .5 meter long. Does anyone else have any opinions on the length of the cable?Thanks again everyone.

author: tooki
author_rank: Super Contributor
timestamp: July 16, 2022, 11:30:04 am
content: Among my homemade ones, I have some that are 30cm long, some 50 or 60cm, some 1m. They all get used regularly because test setups vary.

author: tooki
author_rank: Super Contributor
timestamp: February 26, 2023, 12:16:01 pm
content: Quote from: Pitron on July 14, 2022, 07:47:59 pmHave you considered maybe doing a group order? I bet there would be interest, especially since you’ve done the legwork of finding and working with a contract manufacturer who could actually build these.

author: jonpaul
author_rank: Super Contributor
timestamp: February 26, 2023, 12:42:44 pm
content: Bonjour à tous !juste found this interesting old thread now.Seems like killing flies with an A bomb.In my over half century of analog, RF, power design, we used prototype with perf ( Vero) board, pad per hole, and the pictured 0.1" socket type bread boards.I used pin headers, or bare solid bus wire in the breadboard. Wire lead, Pomona EZ hook, or soldered to pin or bus.Alternative use stranded #24..28, wire or ribbon cable, separate, strip, tin ends. Insert direct into board.The cleverest solution is the simplist.Bon SoiréeJon

author: tooki
author_rank: Super Contributor
timestamp: February 26, 2023, 01:39:07 pm
content: Quote from: jonpaul on February 26, 2023, 12:42:44 pmWe aren't talking about the jumpers usedwithinthe breadboard.We are talking about leads to off-board devices like power supplies and multimeters, hence the banana plugs.Quote from: jonpaul on February 26, 2023, 12:42:44 pmUnless it doesn't solve the problem.Me, I use my homemade banana-to-breadboard cables all the time. I made a set for the new apprentice at work, for his breadboard lessons, and he uses them all the time now. The fact that someone on the forums periodically asks about such things means thereisa need for them.Genuine questions, not intended to be sarcastic at all:Is it actually yourintentto sound condescending? Or is that just by accident? Is there a language barrier that causes you to respond in so many threads with answers that show that you clearly have not understood the question being asked? Do you not understand other people's needs or preferences?

author: jonpaul
author_rank: Super Contributor
timestamp: March 03, 2023, 04:26:04 am
content: Incredibly long and complex thread for a,very old and simple,problem....Probing, leads, power to breadboards eg with 0.100 "spaced pin sockets.unsure the intention of " dupont" connectors, are these the old Molex/ Berg /'AMP 025" sq pins ?we used 0.025 sq headers from Samtech, soldered stranded wire or flat ribbon cable as needed.Far end was terminated in bannana, pin, or EZ hooks.cost was zero.Finally we would use a 24..28 AWG stranded wire, strip and twist, then tin to make a,pin end.In many 100s of proto and breadboards since 1970s, never any problems......Happy to send photos if I can unearth some.Jon