Soldering a LEMO connector clone - Page 1
Forum section: electronics / repair

author: Ogitek
author_rank: Regular Contributor
timestamp: January 10, 2024, 01:04:46 am
content: First of all. For those with experience using LEMO or ODU clones from China. What is your comment about them? Are they identical to LEMO or are the pins not aligned or the keying not in exact angles, etc.?Also for size OB with housing diameter of 9.5mm (0.374") and pin size of 0.7mm (0.2756"). Let's say there are 4 pins. How easy it is to solder them? Should you match the wires size to the pins? What happens if the wire is bigger or smaller? And if a pin made contact with the metal and shorts the housing? What would happen? How easy it is to do the accidental shorting for those average users?Also in the China clones. What sizes of wires are the pins designed for?Lastly. What kind of soldering iron must you use? Without any experience, how successful would connecting one be especially if they are LEMO clones. Would the clones make it easier or harder?Thank you.

author: itkruglak
author_rank: Newbie
timestamp: January 10, 2024, 04:23:41 am
content: Hi, I have lots of experience soldering Lemo & Fischer connectors-but not clones. You must match wire size to the pin ID. 26 ga. should be OK with your 4 pin. You can always clip off a few strands if needed. I recommend using Teflon (PTFE stranded wire if possible as ordinary PVC insulation will melt. Any 40W to 75W iron is ok, but the tip has to be small & long enough to solder one contact at a time. It is a bit tricky, but I highly recommend using shrink tubing over each contact.It you are using shielded cable, use a sharp dentist's pick to separate the strands, cut off enough of the strands to fit in the contact and slide a piece of shrink over the braid before soldering, leaving just enough unsoldered braid to fit in the contact. If your connector has crimp contacts this makes life much easier. I don't necessarily like crimping the contacts unless you have the right tool & wire, but it is much easier to solder the wire to the contact, slip a piece of shrink over the joint and then insert the wire/pin into the connector.Hope this helps!

author: Smokey
author_rank: Super Contributor
timestamp: January 10, 2024, 04:23:53 am
content: please resize that image... edit the post with something like thisCode:[attachimg=1 width=400]https://www.eevblog.com/forum/news/(how-to)-testing-inline-image-attachments/?all

author: darkspr1te
author_rank: Frequent Contributor
timestamp: January 10, 2024, 08:52:09 am
content: Always use plenty of flux on both surfaces, that will always help doing a good join.darkspr1te

author: Ogitek
author_rank: Regular Contributor
timestamp: January 10, 2024, 11:02:33 am
content: Quote from: itkruglak on January 10, 2024, 04:23:41 amWhat do you mean by "You can always clip off a few strands if needed"? Did you mean crimp? What's the meaning "clip"?It's the solder type of pin inside the LEMO, not one with crimping.Do you know a USB pigtail with Teflon or PTFE stranded wire?Or do you know any USB to 4 pin LEMO connectors of any keys of size FXX.0B.304? The keying I need is the FGC with 90 degrees angle between the keys. But Lemo said it was already obsolete. But I can still find used empty FGC shell (see below). Let me ask you. If you can find a USB to any 4 pin solder type internal for other shells of any kind (like FGG). Can you just use the internal parts on any shell? Because there is now only one source of genuine LEMO FGC (even used) in the entire internet. And it is these:https://www.ebay.com/itm/265516899616?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3D261c424851c44c6cbf063f393e68088d%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D265516899616%26pmt%3D0%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DLEMO&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3Af2ff7ed618c0ac1cc86bbf99fffeae9e%7Cpageci%3A2feb5e25-afa6-11ee-acdb-caed037f3ddd%7Ciid%3A1%7Cvlpname%3Avlp_homepageSo I plan to get a ready made USB to 4 pin LEMO (and just replace the shell to FGC for right keying).Quote

author: Ogitek
author_rank: Regular Contributor
timestamp: January 10, 2024, 01:05:48 pm
content: To continue above.If I buy this.https://www.ebay.com/itm/334527237402?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3D4815c7ee372542a9bf5ce6f3bb6a57a0%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D334527237402%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DLEMO&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3Af35af58018c0ab8e43eef709fffe29b4%7Cpageci%3A24ab3c7c-afb4-11ee-b931-5a09ac647ec7%7Ciid%3A1%7Cvlpname%3Avlp_homepageCan I replace the empty shell of the following (FGC) to the above?https://www.ebay.com/itm/265516899616?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3D315bde06c9ff4e5fb7d3cf8f46a08849%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D265516899616%26pmt%3D0%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DLEMO&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3Af3766f1e18c0a8cdcc7900bcfffad894%7Cpageci%3A55e63f2a-afb8-11ee-a806-6e7d998a4094%7Ciid%3A1%7Cvlpname%3Avlp_homepageIf someone decides to buy the latter (16 shells in a pack). Please give me 1 piece

author: Echo88
author_rank: Frequent Contributor
timestamp: January 10, 2024, 01:13:42 pm
content: He means cutting off a few strands of the wire, if the wire diameter is to big for the solder cup contacts.A standard thin usb cable should fit a generic 0B connector.Teflon cabling isnt exactly necessary, but allows for longer soldering time which helps when youre inexperienced at soldering such connectors.Yes, it should be possible to just replace the standard shell of a FGG connector with the linked FGC shell.You can also just file off the key/keys on the standard shell to fit your existic LEMO jack, just gotta watch out for the correct orientation when plugging the connector it into the jack.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 10, 2024, 01:53:42 pm
content: Quote from: Echo88 on January 10, 2024, 01:13:42 pmCrimping it is just easier, isn't it. You don't have to use solder and crimping is neater. So why don't most just do crimping?

author: Stray Electron
author_rank: Super Contributor
timestamp: January 10, 2024, 02:21:03 pm
content: Quote from: Ogitek on January 10, 2024, 01:53:42 pmBecause a good commercial quality crimping tool used to cost from $80 to $200 and the crimp dies were often sold separately. That's too expensive for someone that just needs to make a few cables. That was the price 30 years or more ago when I was having to buy them. I don't know what the price of the Chinese made crimpers is today.uAlso a soldered connection can be unsoldered and reused but a crimped one can't. And when it comes to repairing or modifying the connectors unless your crimped connector has removable pins,and replacement pins are available, then you're going to have to cut off all of the wires and throw the connector away and replace the entire connector. In a lot of cases that I've run into shortening the cable was simply impossible so we HAD TO use soldered connectors.Soldering a connector is no more difficult than crimping one. In both cases if your wire is larger than the hole in the pin then you're going to have to cut out a few strands (although you're supposed to use pins that match the wire size) . And placing heat shrink over each individual pin/wire joint is just good practice, for both soldered or crimped connections.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 10, 2024, 02:34:43 pm
content: Ok. I just bought the 13 pcs of FGC shells at Ebay.Does someone have a original LEMO crimping tool. I'll order this and send this to you then you ship it back to New York with the USB cable (I'll pay you of course).https://www.ebay.com/itm/334527237402?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230811123856%26meid%3D4815c7ee372542a9bf5ce6f3bb6a57a0%26pid%3D101770%26rk%3D1%26rkt%3D1%26itm%3D334527237402%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2%26brand%3DLEMO&_trksid=p4375194.c101770.m146925&_trkparms=parentrq%3Af35af58018c0ab8e43eef709fffe29b4%7Cpageci%3A24ab3c7c-afb4-11ee-b931-5a09ac647ec7%7Ciid%3A1%7Cvlpname%3Avlp_homepageIf you prefer solder. It is also possible (see below). I'll pm you the connection details. I just don't have the confidence to try to solder LEMO at first time because I don't want to short the USB. Now where to buy the USB pigtail that is compatible with both?https://www.ebay.com/itm/134452459167?hash=item1f4dfdb69f:g:Xy8AAOSwpeVj7UAV&amdata=enc%3AAQAIAAAA4K1g%2BWaboiEMR%2BmnrSFEfuxJuMGSYTWLlgq9HSnp8p4EYa%2FdALqWnH41z3jorkIasftKp17OnctXZzGISKtObjUTHgzl0Bs4KZ2PyQudVuRZeVyqtXxTgzC7RnsELi04tNwrqCr6VgE%2BdTmZH4kB5WEIt0kHdexhOY2GbB3OwNUFoipzdklYUqMoFS8uindvYK9r4I00TbKlfEyMrvFRKgV6g90WBaXQLhXYpD2fZw%2BqBEY80QKyXGfXLwe2h4lUYjMIPH0%2FY2D%2Bt2ssHj9Fq22RLd9WCvvDV6yVJ7Qbf9yi%7Ctkp%3ABk9SR-rHo7yeYw

author: Ogitek
author_rank: Regular Contributor
timestamp: January 11, 2024, 12:00:35 am
content: Quote from: Stray Electron on January 10, 2024, 02:21:03 pmWhat happens if you just use pliers (with long nose) to climp the LEMO connectors. You can crimp at different positions and this may cause them to permanently be in contact, won't they?And if no one wants to solder my connector for me here. Is there any service center that can specifically do that? Solder a USB cable to the 4-pin Lemo connector?And do USB cables have different gauges. I need one between 22 and 30 AWG.

author: Ogitek
author_rank: Regular Contributor
timestamp: January 11, 2024, 02:48:57 am
content: [ Specified attachment is not available ]Notice the wings of the pins (they looked like sidewinders). If they are not properly situated in the connector and you push against the socket pin in the equipment and the pin got push out backward, what would happen? But then isn't it the connector housing has retention screw at the back that can prevent the pins from moving backwards? This is my primary concern about the crimp connectors besides how to crimp it using long nose pliers (see last message for my question).

author: tooki
author_rank: Super Contributor
timestamp: January 13, 2024, 05:02:57 pm
content: Quote from: Stray Electron on January 10, 2024, 02:21:03 pmLemo connectors use machined contacts intended to be crimped with military-style indent crimpers. About $500 for the tool and another $100-200 for the locator. Far, far less on the used market, though!