High-Precision Needle PCB Probing System - Quick Magnetic Holders, Low-Profile - Page 1
Forum section: electronics / general

author: Cortex
author_rank: Contributor
timestamp: January 19, 2018, 09:17:22 pm
content: Hi to all e-hobbysits, technicians and engineers,I have just completed the design of a new probing system for electronic circuits.It can handle the tiniest IC's on the market, thanks to the extremely sharp needles.It is a DIY to build KIT that gives a 10-piece probing system.It is sold for $60CAD+shipping*.See my eBay listing:https://www.ebay.ca/itm/Precision-Needle-PCB-Probing-System-Quick-Magnetic-Holders-KIT-TO-ASSEMBLE/263462899775*Shipping is flat rate for international shipping fees (except Canada):$12.00 CAD - Small Packet - International Air - 6 to 12 business daysI also accept requests to buy directly from me via Paypal, to save $5 CAD on eBay fees ($55 CAD then).Description:- Two different type of holders are provided, to be used in combination to maintain the PCB pinned down and steady.- The pawn-style holder has a fine thread screw that allows the knob to be adjusted to the desired height. It can pinch the PCB or wedge it as desired.- Three convenient thumb screws for easy and quick manipulation- The boom has two axis of micrometric adjustments: up-down and left-right- The boom also has a vertical swivel from its base for "coarse" adjustment of needle height- Two different lengths of booms. Kit includes two of each- Super low profile PCB holders at 5mm from base plate, for maximum ergonomy when using a soldering iron or other tools- Tin coated copper wire 18 gauge allows a stable yet flexible positioning- Copper wire allows bending and tilting of probes sideways to reach extremely tights spots, even on two adjacent 0.5mm IC pins- Copper wire can easily be swapped for different lengths, with only two solders- Can also be used to inject low power signals- Magnetic base on all parts and anti-slip rubber for perfect stability- Can hold virtually any size PCB- Compatible with classic rotating PCB vises- Easy to sharpen the needles' point with a fine sandpaper- Designed for super fast setup time- Each component is 3D printed from resilient PETG plasticKit contains:- Four 2-axis micrometric booms, 2 long and 2 short- Four pawn-style PCB holders- Two corner-style PCB holders- Screws, washers and nylons thumb screws- Magnets- Needles- 18 and 22 gauge wires- Rubber padsNotes:- Parts are pre-threaded- Some soldering is required- A small Phillips screwdriver is required to assemble- Steel plates shown in photos are NOT included- Any thin steel plate can be used, like an old PC cover (1 mm is ok)- An insulator is recommended to cover the steel plate. A thin self-adhesive vinyl gives best results- This is not for high speed signals above a few MHz. It has no coax or impedance controlLeverage the full potential of your 4 channel scope daily !NormCortex R&D Inc.Canada

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: January 20, 2018, 12:54:54 am
content: Nice. But why did you have to make it magnetic? I detest magnets on my workspace. Giving the feet some weight would be more sensible.

author: Cortex
author_rank: Contributor
timestamp: January 20, 2018, 03:41:59 am
content: I agree that magnets can be annoying when your tools and parts keep snapping against them all the time. But the advantages of this system far outweigh the inconveniences.Now, to get the force I needed, nothing even comes close to the performance of N52 magnets. The ring magnet I use gives 8.58 pounds of pull force on a steel plate. And I needed to add silicone rubber pads at the bottom of the pegs to prevent the PCBs from sliding around as I wedged the PCB. Can you imagine the huge chunk of iron I'd need on each peg to get the equivalent result?!When you get used to the routine of keeping things away, it's not that bad. And it helps to have the magnetic field confined into a tight loop when it's on a steel plate. So, when not in use, I store them in a bin, on a shelf away from metallic tools.On the other hand, you can always remove the ring magnet and replace it by a stack of washers, and finish with a strip of 3M VHB double-sided tape to stick it to a heavy weight of your choice and shape. The micrometric probes are even simpler, just push on the 3 magnet rods to remove them and use VHB again and a slab of iron.

author: exe
author_rank: Unknown
timestamp: January 21, 2018, 10:41:09 am
content: Interesting, it does not show up in search on ebay.co.uk . Does this mean if I want to buy something I have to check ebay.com, ebay.de, ebay.co.uk, ebay.ac, ebay.it, etc ?

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 21, 2018, 10:59:52 am
content: Quote from: exe on January 21, 2018, 10:41:09 amIt depends, but some products are only visible from certain countries.

author: alm
author_rank: Super Contributor
timestamp: January 21, 2018, 11:45:38 am
content: Quote from: exe on January 21, 2018, 10:41:09 amI'm guessing it does not show up on eBay UK because the item only ships to Canada.

author: Berni
author_rank: Super Contributor
timestamp: January 21, 2018, 12:02:30 pm
content: On Ebay you need to set your shipping address to other places to see things that only ship there. Quite annoying.Im not as much concerned about magnets as i am with using a large metal surface as the work area that has the potential to short things.I tend to put one of these clamps(attachment) on my scope probe to create a sort of "tripod" out of it where one leg is the probe tip and the other two legs are the clamps handles. But for when i know im going to be probing something for a while i just solder a tiny wire to it and clip the probe to that.

author: exe
author_rank: Unknown
timestamp: January 21, 2018, 09:00:51 pm
content: Quote from: alm on January 21, 2018, 11:45:38 amThanks, totally missed that. Although, delivery to EU would double the price, so economically unreasonable... Nice idea anyway!Are 3d models available?

author: Cortex
author_rank: Contributor
timestamp: January 21, 2018, 10:54:04 pm
content: I modified the listing. It was written that international shipping was offered, but it was at the bottom of page. Now it's quite clear - right at the top!!!eBay is really f#$! up on this shipping calculator. I can specify options for Canada and either "USA-or-International", but not the three of them. Everybody is complaining about that, but they do nothing about it. So I have to put some text in there manually, or create a duplicate listing just for international buyers. Grrr!And no, the fees are not ridiculous IMHO. Actually, I make no money on shipping.About the 3D models... sorry, they're not available.

author: Cortex
author_rank: Contributor
timestamp: January 21, 2018, 10:59:45 pm
content: Quote from: Berni on January 21, 2018, 12:02:30 pmTo be honest, I took the photos with a bare metal slab to highlight the ferromagnetic requirement. But when I use the probe in real life, they're sticking to a steel plate under my microscope, that is covered with a white, self-adhesive vinyl. This provides a very thin but robust insulator against shorts and mishaps.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 23, 2018, 08:29:27 am
content: You probably should mention that the 'probes' are just needles soldered into bits of bare wire. No coax or controlled impedance anything.So these will be for low frequency measurements only.

author: Pinkus
author_rank: Frequent Contributor
timestamp: January 23, 2018, 09:02:30 am
content: FYI: By entering your item number (263447821265) in the German Ebay.de or if I enter your headline (High-Precision Needle PCB Probing System) in the German Ebay, your listing will not appear.

author: Berni
author_rank: Super Contributor
timestamp: January 23, 2018, 09:29:49 am
content: Quote from: TerraHertz on January 23, 2018, 08:29:27 amTrue that.Tho even if it was coax all the way, still the ground loop would likely be too long for fast stuff. They are always a pain in probing (Well unless you got active probes).

author: Cortex
author_rank: Contributor
timestamp: January 24, 2018, 07:13:14 pm
content: Quote from: Pinkus on January 23, 2018, 09:02:30 amI don't understand why. Here when I try ebay.de it works both with the number and the search text. Are you sure you have the International option selected?

author: Cortex
author_rank: Contributor
timestamp: January 24, 2018, 07:39:43 pm
content: Quote from: TerraHertz on January 23, 2018, 08:29:27 amYes I agree. I was planning to mention that, but first, I needed to make a setup and come up with some actual scope captures of square waves for 3 different high frequencies (ex: 1MHz, 10Mhz, 50Mhz) so the user can decide wether or not this is acceptable. In the meantime, I just added generic warning to the notes.My next design would include an optional boom with a probe clip holder at the end, so you can use any probe you like, even expensive active ones. If you have a few models to recommend, I'd like to see them, or get the part number/manuf.

author: Cortex
author_rank: Contributor
timestamp: January 24, 2018, 07:45:29 pm
content: Quote from: alm on January 21, 2018, 10:45:38 PMTry again, I just changed the listing again so it is Canada+International instead of Canada+USA only. I really don't understand why eBay is limiting me to 2 out of 3 options!I also reduced the shipping fees to $12CAD.Come on guys!!! Encourage me! I worked so hard on this

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: January 24, 2018, 08:54:20 pm
content: That's a really cool idea, I like it very much! Sadly my budget is more or less nonexistant so I can't afford a kit right now. But I hope you will keep up thinking about great ideas like this

author: exe
author_rank: Unknown
timestamp: January 24, 2018, 09:13:52 pm
content: Quote from: Cortex on January 24, 2018, 07:45:29 pmOkay, okay, I bought one set.But I'm afraid I'll have to pay hell a lot of money for VAT and "processing"((.PS where to get a metal plate?

author: Berni
author_rank: Super Contributor
timestamp: January 25, 2018, 06:12:18 am
content: Quote from: Cortex on January 24, 2018, 07:39:43 pmI wouldn't really design it for any specific probe model since there are so many out there. Rather make it some sort of spring loaded clip like a giant clothes pin that can grip around round things between 5mm to 20mm in diameter.My favorite active probe is the HP 1152A (2.5GHz single ended) but this old probe is particularly bulky with a quite stiff cable. Would need a pretty strong grip on it to hold it so id just design it around standard passive probes that tend to come with scopes and just design it so that its capable of gripping slightly thicker probes than that.

author: Cortex
author_rank: Contributor
timestamp: January 31, 2018, 02:32:05 pm
content: Quote from: exe on January 25, 2018, 08:13:52 AMThanks for the purchase! Let me know if I can improve something.About the metal plate, it doesn't need to be as thick as the one in the photos. It can be just 1mm thick and it will be just as good.Here are a few examples:Side covers from old PCs. As a bonus, the hardened powder paint makes an excellent insulator against shorts. Same with old tape decks, amps, etc.Covers from dead CD or DVD drives. Good for small circuits. Easy to move around under the microscopeMost hardware stores have a stock metal section. Check there. I like to walk around through the aisles, and watch for any kind of parts that could have a secondary use. I'm always surprised to find something unexpectedLet us know what you found, with photos if possible.

author: blundar
author_rank: Contributor
timestamp: February 02, 2018, 12:58:52 am
content: Very interested. Ebay fees suck. Sent you PMs to get a paypal invoice and bypass fees.

author: Cortex
author_rank: Contributor
timestamp: February 02, 2018, 03:09:54 pm
content: Quote from: blundar on February 02, 2018, 12:58:52 amSure no problem. I will get back to you in private.

author: Cortex
author_rank: Contributor
timestamp: February 08, 2018, 04:28:49 pm
content: I have improved the design to include an extra thumb screw on the coarse vertical offset of boom.Also got rid of the annoying Torx screws. Now all standard Phillips.