China MIL spec crimpers?? (AF8, AFM8 etc) - Page 1
Forum section: electronics / general

author: RogerThat
author_rank: Regular Contributor
timestamp: November 04, 2019, 07:34:41 am
content: Hi,Anyone have any experience with the china made stuff? Searching for AF8 crimper comes upp with producers JR ready, Precisetools etc. Half price compared to DMC and they look very much like it's the same stuff.

author: ender4171
author_rank: Contributor
timestamp: November 04, 2019, 06:07:30 pm
content: I don't have experience with the MIL spec crimpers, but I do have a litany of Chinese-ium crimpers for other terminals. They seem to be very hit or miss. Most work adequately, some as-good-as-name-brand, and some (though very few) are garbage. Overall, I would say they are just fine for low volume work, with the occasional dud (which is usually obvious even in pictures, as they just scream "I am junk"). Based on the complexity of the MIL crimpers and the visual "quality" I see in the pictures, I would say that even the clones are going to have much more care and labor put into them than your run of the mill die-based crimps. I hope someone who has used one chimes in, as I have been debating picking up a set (even though I currently have no use for them, lol).

author: reboots
author_rank: Regular Contributor
timestamp: November 04, 2019, 08:20:04 pm
content: This is the first time I've seen these clones. I would note that they're still significantly more expensive than used, good condition DMC/Astro crimpers on eBay (and there are occasionally new ones around the same price point).Gotta love 10USD positioners on Amazon.com!https://www.amazon.com/dp/B0746GJTD4

author: coppercone2
author_rank: Super Contributor
timestamp: November 04, 2019, 11:41:44 pm
content: just don't sell it to the military because they might not do things by the book if it fucks up

author: RogerThat
author_rank: Regular Contributor
timestamp: November 05, 2019, 10:01:08 am
content: After a lot of scratching my head I went for a nice used AF8 DMC tool. It's one thing to copy dimensions/design but to also get the right high-quality steel/material, it's another thing. I'm fearing(just speculation, I have no proof or the like) the china copy might have inferior steel in the yaws which will bring it out of calibration quicker. I'm just using it for a short project so second hand value plays a role also. Not military btwThe positioner I see no worries with, not much that can go wrong. Or what you think?

author: ender4171
author_rank: Contributor
timestamp: November 05, 2019, 05:25:09 pm
content: Getting inferior quality components/materials in a Shenzhen clone is always a concern. However, I have found that many times when you are dealing with a relatively niche item, and when the China price is still fairly high, you are often times not buying a "clone", but actually the same part as the real-deal. When someone contracts a Chinese manufacturer to make something, they will sometimes do things like do an extra production run to sell themselves, "file" the logo/serial off extra units, or sell the "not quite to spec"/blemished cast-offs. It's a crap shoot, but sometimes you can get essentially the exact same part, from the same factory, and the same quality as the original, for quite a bit less. As mentioned, this is a LOT more likely when you are dealing with an uncommon item. Things that they sell a bajillion of are usually just low-end clones made from "appropriated" design files, or copied by some guy with a set of calipers. No idea which category these crimpers fall into, but I would lean towards these probably being just fine, if not quite perfect.

author: RogerThat
author_rank: Regular Contributor
timestamp: November 15, 2019, 03:25:31 pm
content: Here is a JRready (on the right) compared to a DMC turret positioner.My feeling is that they are extremely similar, but not the same. Stuff like radiuses on edges and details like the machined, extra clearance, for the fastening screws. The DMC have some more engineering gone in to it. Does it matter for the crimping quality? Not sure.I noted there was different material in the pin seat. I do have a TP45 positioner (DMC) also which uses a material which looks the same to the JRready. Maybe there is no standard what to use as long as it doesn't corrode?

author: coppercone2
author_rank: Super Contributor
timestamp: November 15, 2019, 11:10:32 pm
content: Quote from: RogerThat on November 05, 2019, 10:01:08 amif you got used (or regardless really if you are serious ), you might want to invest in all the different tools required for crimp calibration in terms of wear, there are guides on how to measure the dies with different types of micrometers to verify the dimensions. (and how to check the actual crimped connections). You probably want to get the different micrometers and a micrometer stand for verifying the crimps. Luckily you can use some of the tools required for crimp inspection for other electronics purposes to ensure quality. For inspecting the dies you might need to follow the blue print and check dimensions + do microscope inspection.Also, do read about crimp plating, dies are sometimes coated in ceramics and there is a question of friction.. I believe it results in sheer force (may be called differently, not a crimp expert) that deforms the crimp in unexpected ways that may not be measured if only the standard crimp height verification test is performed (unique early failure mode). Like it drags because the contact area being used to perform the deformation operation is wrong. I believe they are built to be reliable based on the metric of pressure and overall deformation but it may not be optimal. I am not sure how much it matters before bulk deformation leading to 'full contact' occurs. I guess it depends on how much metal is pulled into the plastic region and residual stresses.http://www.visioneng.com/wp-content/uploads/2017/11/Crimp-Connector-Inspection-and-Quality-Control.15SEP16.pdfI think you should cut some samples open and do a cut/lap microscope inspection too in addition to just measuring with micrometer since its used.It makes me wonder if crimp quality can be improved by changing temperature prior to forming..

author: reboots
author_rank: Regular Contributor
timestamp: November 18, 2019, 07:08:25 pm
content: Quote from: coppercone2 on November 15, 2019, 11:10:32 pmFor production, these crimpers are typically checked with a "go/no go" gauge which verifies that the closed dies are within a certain tolerance. I've performed this test using wire drills of the appropriate diameter. Of course that tests basic operation, but not other types of wear nor the quality of the resulting crimp.

author: coppercone2
author_rank: Super Contributor
timestamp: November 19, 2019, 01:46:14 am
content: I have a feeling that's implemented once a director starts playing with assembly line allowances to reduce cost/maintain uptimenot sure if I would trust that on a old tool at first (more like something you add once confidence in process is high, meaning smooth operation for a long time).maybe just to figure out if labor should be reallocated in the morning before bad measurements start coming in