I just received my Preciva and used it on some Iwiss Dupont connectors. I need experience.
Which you’ll get. Buy a strip of 1000 terminals on AliExpress for a couple of bucks. Spend a meditative half hour at a time bending them off the strip (or cutting the strip into little bits to give you something to grip, as some people like to do). Then you have cheap material to practice with. I recommend 24AWG wire: inexpensive crimpers often don’t crimp tight enough for 26AWG or thinner wire, and 22AWG or thicker usually has insulation so thick that insertion becomes difficult. (Luxury option: get 22AWG or 24AWG wire with thin mPPE insulation, which is easier to insert.)
Get a feel for the right length of insulation to strip, which is about 4mm. The exact optimal length varies slightly by contact manufacturer, but whatever it is, you only have a tolerance of 0.5-1mm, so you need to strip accurately.
Crimping these is not as easy as crimping 14g wire! It is fussy.
Definitely! The smaller, the fussier. The tiniest I’ve crimped so far is a 1.2mm pitch Hirose DF57H, which supports only AWG 28-30 for hand crimping. Now those are fussy little bastards… (And that’s fussy with the $$
$$ original tool. I can’t even imagine trying to do those on a Chinese tool…)
After about 6 terminals, I am getting close. My main issue is that the insulation ears of the connectors are too wide to fit into the die, I have the partially close them.
Yeah, not only do the dies of practically all tools except the originals lack the wide “ramps”* to feed wide insulation wings into the die, but it’s common for the insulation wings to get splayed even wider than they’re supposed to when vendors roll up lengths of contact strips.
*see attached photo I nicked from Matt Millman’s site, showing the dies of an original DuPont tool. You can see how the jaws begin with a very shallow angle at the bottom, and then make a sharp transition to nearly vertical, almost parallel jaw shape with the half-circle at the top. Genuine Mini-PV contacts have extremely wide insulation wings, much wider than Chinese DuPont, so this shape is essential for them.
… I have the partially close them. This does make it easier to hold the assembly in the crimper. The connectors do fit into the housing at least.
If you get your wire stripping length well-controlled, with some practice you should be able to hold the contact in the tool with one ratchet click, then insert the wire to the right depth.
FYI, in your last photo, the wire was inserted too far. The insulation should not touch the conductor wings — there must be a gap. Otherwise you cannot tell if insulation has become entrapped in the conductor crimp itself.