A new budget “DuPont” crimp tool is bought to my attention

Preciva PR-3254 crimp tool

Back in 2015 when I first wrote up my crimp connectors page. I pointed out that there was no cheaply available tool which could crimp “DuPont” contacts properly (cheap Chinese connectors which resemble DuPont’s Mini-PV connector).

Crimped Mini-PV Terminals
Crimped Mini-PV look-alike contacts

At the time pretty much all tools in the $30 or less price bracket got you a result like on the left, because the insulation crimp die was a ‘B’ shape when it needed to be an ‘O’ shape.

Comparison of the DuPont Mini-PV crimp tool, and the die of a typical budget tool

Anyway… onto the tool in question. This was bought to my attention by a reader, and it’s actually sold in a kit (Amazon UK / US). It’s very affordable and it’s got a die specifically designed for “DuPont” contacts. My first reaction: Wow. The bounty for such a tool has been out for 5 years now. Could this be the one?

First impressions unfortunately weren’t particularly good.

PR-3254 “DuPont” die compared to DuPont HT-208 (AWG 24) die

When the die is fully closed, it ends up with an uncomfortable “oval” shape, rather than the circular shape all DuPont original tools have. You cannot partially close it either because the wire part wouldn’t be crimped at all.

Top: AWG 24 wire crimped with PR-3254. Bottom: AWG 28 wire crimped with PR-3254

Results aren’t too bad. It’s doing the right thing, wrapping the insulation crimp instead of making a mess of it. For AWG 24 wire, there’s far too much force on the insulation, crushing and damaging it, but the wire part is reasonable.

For AWG 28 wire, force is about right on the insulation, but there’s not enough force on the wire part. In the long term, moisture may get into that and cause troubles. You could double it over to mitigate this to an extent.

Conclusion

It’s very encouraging to see a budget tool specifically designed for these contacts.

It does so-so job of AWG 28 on “DuPont” contacts. Its other dies are fairly standard and ones like it are found in other tools, for example the IWISS SN-28B. Don’t go rushing to buy it. I’ve since looked at another tool which gets slightly better results than this one.

This tool is probably OK for people who are building temporary/non critical things, however ultimately this particular effort appears to have stopped for a cigarette just short of the finish line.

3 thoughts on “A new budget “DuPont” crimp tool is bought to my attention

  1. Best “affordable” tool I have found that does mini-PV style contacts is the Hozan P-706. The conductor crimp die is the correct size for 22-28 AWG wire, just bear down on it and it’ll crimp it good enough that the strands will break before they come out. It even makes a bellmouth at the side where the strands enter the crimp barrel. The correct way to crimp the conductor is to line the far end of the conductor crimp with the face of the tool so that the strand side hangs over the edge by about 0.5mm. The insulation crimp requires a bit more finesse, you have to squeeze it enough to make the crimp snug but not enough to over crimp but because you crimp each separately this is no problem. The results aren’t quite as nice as the HT-95 but pretty close. I’ve actually taken to using this tool to lightly precrimp the insulation and then finishing them in the HT-96. You can give the insulation a light squeeze so that it can still be moved inside the crimp barrel then give it a firmer squeeze to set it in position. This method is slower but I crimp a lot of three conductor ribbon wire leads (servo leads for R/C hobby stuff) using these and it’s important that all three contacts are lined up with each other so that the end of the lead is nice and neat.

    1. I have a P-706 on order, and am going to look at it shortly. I was recently reading a thread you contributed to on another website where you mentioned the Harwin Z20-320, I’ve now got one of those too. More write-ups coming.

    2. Pre-crimping, also, an interesting consideration. I find this to be a real bother with the HT-2xx and HT-95 i.e. it’s hard to position the cable correctly, this is much less of an issue with the Harwin Z20-320 as you can easily see into both ends, but this is quite a hard tool to find second hand, so will make a mention of this in the context of the P706 too.

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