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Posts from — August 2015

Crimping Adventures

Crimp Pins (L->R: Picoblade, Sherlock, Micro-Fit, Mini-Fit, HD Dsub, Dsub, UMNL)

Crimp Pins (L->R: Picoblade, Sherlock, Micro-Fit, Mini-Fit, HD Dsub, Dsub, UMNL)

Making cables from connectors is often an adventure; today’s tale is about crimp connectors.  I prefer crimp connectors over solder, especially trying to solder high density connectors like HD D-Sub or MDR.  Crimp connectors are typically very affordable, and are often less fussy than IDC connectors.

Avoiding Expensive Crimpers

However, you have to have a crimper to make a good crimp connection (duh!), and crimpers from the manufacturers can be very pricey.  For example, a while ago we used some IMS MDrives with JST crimp connectors; the official JST hand crimper was ~$1000, so we decided to use an existing crimper (which worked OK but occasionally wasn’t good enough), and just planned on redoing a significant number of crimp pins.

Sometimes crimping is impossible without the correct tool.  I have a few cute Haydon Kerk NEMA 8 stepper motors with US Digital E4P encoders – and no encoder cables.  The E4P uses a Molex Picoblade connector; since 100 Picoblade pins costs less than one pre-wired cable from US Digital, I decided to make my own: I bought the connector shells and 100 pins, and expected a high failure rate.

I didn’t expect a 100% failure rate – even with our smallest crimper and the help of our assembly technician, I could not get an acceptable crimp using those tiny Picoblades.  I was defeated, but I still wasn’t going to spend my hard earned cash on a crimper that I was only going to use a couple times.

Instead, I went Excess Solutions, and looked for prewired cables with Picoblades.  I was in luck – I found some short cables.  Then I cut open the housing with a knife, and inserted the crimped wires into my E4P Picoblade housings.  Success!

But since then I’ve found an even better solution: pre-crimped wires from Molex, such as the 06-66-0015 (red wire) or 79758-0006 (black wire). One disadvantage: the wires are all the same color.

picoblades

Picoblades (from top: #1 cable from Excess, #2 E4P cable made from #1, #3 cable with pre-crimped black, #4 cable with pre-crimped red)

I have an Elmo servo drive with Molex Sherlock connectors, which look just slightly less devilish than Picoblades, and I’d like to use the same solution, but unfortunately I can’t find any distributors that stock the appropriate Molex parts (68801-4044 or 68801-4045).

Molex Micro-Fits and Mini-Fits

Crimpers

Crimpers (L->R: Molex 64016-0201, 63819-0000, 63819-0900, Hansen Hobbies)

For Molex Micro-Fit and Mini-Fit Jr, we started with the Molex 64016-0201 crimper which can affordably crimp a variety of pins including Micro-Fit, Mini-Fit, KK, and CGrid.  However, we had a noticeable failure rate, and it was a little awkward,  so we bought the dedicated crimpers for Micro-Fit (63819-0000) and Mini-Fit Jr (63819-0900).  These crimpers are truly wonderful; it’s easy to make a good crimp with them (especially since the crimp pin is held in the correct position and orientation), and the price is reasonable considering they are made in Sweden.

My New Crimper- Hansen Hobbies Deluxe Crimper

I decided I wanted my own crimper that could handle Mini-Fits and such, and settled on the Hansen Hobbies Deluxe Crimper.  Some of the RC guys use the one from Servo City, which is substantially cheaper, but I felt more comfortable that the Hansen model would meet my needs.  Later, I noticed a cheaper but similar looking model on Amazon.

I’m pretty happy with Hansen crimper; it was definitely worth the money.  So far my results are:

  • It works well for Mini-Fit Jr crimp pins.
  • It works well for standard DSub crimp pins.
  • It can do Mini-Fit Jr pins, with some failures and extra checking
  • It can do High Density DSub with some failures and extra checking
  • It can do Universal Mate N Lok (UMNL) pins, but they’re a little large

I don’t have any plans for more crimpers now, but I have to say since I do a lot of HD DSubs, the Paladin 8029 looks sweet.  I also might get a ratcheting ferrule crimper some day.

Inserting the Crimped Pins

Some crimp pins can be inserted any way, for example, round pins such as Dsub, HD DSub, and UMNL.  However, many pins such as Molex Mini-Fit Jr and Micro-Fit must be inserted in the correct orientation (top towards the tab I believe) — but when everything is done right, they go in with an easy but satisfying click!  Sometimes all of the pins need a little push – for that I typically use a very small flat screwdriver.

Removing Unwanted Pins

HD Dsub, Dsub, and Mini-Fit pin removers

HD Dsub, Dsub, and Mini-Fit pin removers

Sometimes you screw up, and often you screw up worse trying to remove that pin you put in the wrong spot.

UMNL pins are easy to remove if you have the correct TE/AMP pin remover.

However, I consider DSub pin removers to be disposable items — it’s hard to use them more than a few times.  Sometimes they work great, often they’re a challenge.  Micro-Fit and Mini-Fit pin removers are similar, and if the wire breaks, it’s even harder.  Plus the Micro-Fit/Mini-Fit pin removers are only slightly more robust than DSubs, but a lot more expensive (>$15 versus ~$5).

 

August 24, 2015   No Comments