toolboard connector crimping
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@nick9one1 said in toolboard connector crimping:
Does anyone else finds the new JST terminals on the toolboard 1.1 fiddly and difficult?
The screw terminals were so much better on the 1.0! I cant understand why there is a change. Cost maybe?
Any tips on crimping them?I'd not even try it.
My boards were V1.0 luckily, with screw connectors or pre-wired pigtail connectors.
If I need to use any newer type ones, I'd get pre-crimped wires to suit and extend them as needed..
eg. Digikey sell JST-manufactured assembled inserts + wires:
https://www.digikey.co.uk/en/products/detail/jst-sales-america-inc./ASHFSHF22K51/9954373?utm_adgroup=Jumper Wires%2C Pre-Crimped Leads&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Cable Assemblies_NEW&utm_term=&productid=9954373&gclid=Cj0KCQiA3fiPBhCCARIsAFQ8QzWWqyZ83L9B0zCkUV6-3ctHdai3FajGpS1pltoxD-ndAXW6DOkkHeoaAq8-EALw_wcB(I'm not sure which it is for each connector, offhand).
I know I'll get flamed again no matter how much independent evidence I provide each time I say this - but no generic tool, especially a non-compound plier style, can create a 100% reliable, true (gastight, cold weld) crimp on small fold-crimp inserts such as JST or Molex.
You need the makers specific tooling for that, which typically costs £300 - £600 per type.
Bigger ones (2.5mm pitch and up) can be carefully soldered after using a generic tool, to ensure a permanent connection - but that's not possible with the smaller ones without solder flowing all the way through and wrecking them.
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@nick9one1 I happily crimp all the sizes on the toolboard, generic printer boards and duet printer boards (except the molex VH connectors which I have a separate tool) with a set of engineers PA-09 that @oozeBot linked to. Not had a crimp fail on me yet (and I have crimped a lot of connections).
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@jay_s_uk
It's not a short term problem, it's long term reliability - corrosion/tarnish over possibly years, if the crimp is not gastight (no significant internal gaps that can allow oxygen or moisture in to degrade it over time).It's a fundamental requirement in crimp joints or plugs & sockets, for reliability, though not many people outside the electronics manufacturing industries have heard of it.
https://blog.samtec.com/post/gas-tight-testing-for-connectors/
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@rjenkinsgb I've had stuff I crimped 4 or 5 years ago that gets used every day. Again, never had a failure. I believe it's a mute issue
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@nick9one1 I bought one of thse kits: https://www.amazon.com/gp/product/B096QG96J4
Don't have to crimp those tiny connectors that like to go poof into another demension. -
@stephen6309 said in toolboard connector crimping:
I bought one of thse kits: https://www.amazon.com/gp/product/B096QG96J4
Nice! that will save a lot of messing about and hassle - and far cheaper than Digikey etc.
Edit - Amazon UK don't appear to sell any version of that kit.
These may be the nearest alternative?
https://www.amazon.co.uk/XLX-Connection-Single-Battery-Compatible/dp/B0811GVDBH/ref=sr_1_10?crid=QZVLG4FUJQJ4 -
@arnold_r_clark said in toolboard connector crimping:
We need to remember that history proves there were smaller groups of specialized people (people who were artisans of their craft) who were 100% producing quality crimped (and soldered) termination of wires long before there was a need for mass production which heralded the requirement for a larger amount of averagely competent people to do the job to the same level as the skilled specialists were in smaller numbers, which is why very specialized equipment came about.
As for soldering that discussion has been flogged to death before and it is generally agreed that soldering after a crimp has taken place is nothing more than a bodge to rectify the mistake created by the incompetent crimper.Wrong and wrong, but I'm not interested in an argument - just providing information for others to make up their own minds. There are enough online articles giving the facts.
(And note I'm only referring to miniature maker-specific crimp types, not crimps in general - many larger types can be done properly with generic tooling.
Any part large enough to fit heatshrink sleeve entirely over the crimp section is not exactly miniature).Another reference, for general info, giving a timeline of electrical crimp connectors - and a section on judging quality.
https://wiki2.org/en/Crimp_(electrical)
End.Robert J.
Printers: Overlord pro, Kossel XL+ with Duet 6HC and "Frankentron", TronXY X5SA Pro converted to E3D toolchange with Duet 6HC and 1LC toolboards.
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One day I'll get around to buying one of those Engineer PA crimpers but it's low on my shopping list. When I first started with 3D printing way back whenever, I bought a RepRap Mendel kit from Adrian Bowyer's company RepRap Pro. Some time later, I bought the 3 colour upgrade kit but had all sorts of problems. After much head scratching I traced the problems down to poor crimp connectors on most of the supplied leads. RepRap pro held their hands up and admitted that the problem was due to them using a new crimping tool and offered to supply replacement leads ( @droftarts arts was that you?).
In the event, I was too impatient and fixed the crimps using a pair of bent nose pliers. When I later built my CoreXYUVAB with 6 extruders (13 motors), I did all the crimps using those same bent nose pliers and later still, when I upgraded it to Duet 3 (1 main board and 3 expansion boards), I used those same bent nose pliers to do all the crimps. And I've never had a single failure due to a bad crimp.
With all that practice, I have become quite proficient but I wouldn't recommend that technique for everyone (unless you are trying to live on a meagre pension and need to save cash). I suppose the moral of the story is that whilst the correct tool will undoubtedly make life easier, it doesn't guarantee a better outcome.
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( @droftarts was that you?).
Probably; I worked there! The first 500 Ormerods had hand crimped looms, everything after that including Mendel Tricolours had firstly bought-in looms (heaps of problems) then we bought our own crimping machine. That generally worked well, but quality depended on who was operating it! And the dies wore out quite quickly, making crimps loose. Occasionally operators forgot to wire strip (had an automatic machine for that, too, but not part of the crimper unfortunately), but the crimper was so powerful it would happily crimp insulation! I think we ended up building a loom tester, but some looms didn’t fit on the tester, so were either tested by hand… or not tested. I expect your wiring loom fell into one of these groups.
Glad you got it going in the end! The Tricolours were buggers to set up. I built three of them; one demo machine, one for documentation, and one a customer returned because they couldn’t work out how to get it to work (lots of building mistakes, eventually became a production machine as the customer didn’t want it back after we showed where they had gone wrong). All worked well enough… for the time (2012)!
Ian
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@droftarts Good Lord, was it really 10 years ago? As an aside, I converted my tri-colour Mendel to use a Diamond 3 colour because I never did like trying to get 3 nozzles to exactly the same height (to say nothing of the amount of X travel that was lost). That was the start of my journey.............
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Now where did I stash my popcorn ....
Oh, to stir the pot a bit, I use the PA 09 tool for small crimps and although I get occasional failures, they are all on me and easily corrected.
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@arnold_r_clark said in toolboard connector crimping:
This tool, the MS3191-1, was for military applications, they defined the tooling and its accessories. So yes there 100% were small groups of specialized people carrying out crimping before automation took over.
How is that relevant?
1: That was done using the correct manufacturers tooling, which of course is made specifically for that terminal and should form the best possible connection.
2: That standard relates to turned-pin terminals, not stamped / "folded" ones like JST or KK etc., as I originally referred to.Reliability problems arise from using non-specific or low quality tooling, which is my point of concern and something I've seen many times over several decades of experience in faultfinding industrial electronics.
These are examples of one common defect from incorrect tooling with this general style of terminal - the die does not properly contain the lower edges of the "U" that the wire end fits in to, and the legs are partially forced down the sides of the die, then scraped/crushed at those points as the die closes.
That results in sharp creases at one or both sides, drastically weakening the sides, so internal pressure is not maintained, as well as the amount of fold over the wire being reduced at the other side.
The correct die would contain the base / sides of the U rather better, to avoid kinking the metal.
Those are 2.54mm pitch inserts; the tool is a decent quality compound action one that visually appears to be a perfect match - but is obviously not quite correct for those, as they regularly mis-form.
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@rjenkinsgb said in toolboard connector crimping:
sharp creases at one or both sides,
to understand, you mean those two are wrong?
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@joergs5 yes, looks like the die has pinched the crimp. Probably the wrong die shape for the crimp. Can happen as the die wears, too.
Ian
