To diagnose your crimping issues, we need to see pictures of the crimp. We can see if you're going to have problems with the housing if you provide clearly focused pictures of the connector after crimping.

View attachment 274774
Are you re-using housings that have previously failed one of your pull tests? Are you still damaging the prongs that hold the male connectors in the housing?

If you're using the end of your wire strippers to pull the male connector into the housing; you shouldn't need to do that and it looks like you're damaging the pin.

I apologize for playing catch up ball. Yes I have reused the housings occasionally but normally load fresh ones (500 pieces for less than 5 dollars). If I need to invest in a tool to make the wire creation more reliable I would be interested in knowing that as well, assuming we don't fix me here..

If you're using the end of your wire strippers to pull the male connector into the housing; you shouldn't need to do that and it looks like you're damaging the pin.

That's exactly what I am doing. I'm getting 100% connectivity when testing the samples but it may not stay that way. But if not done correctly, than its not 100% right.

I've attached some photos

 

If I need to invest in a tool to make the wire creation more reliable I would be interested in knowing that as well, assuming we don't fix me here..

If the problem is that the connectors are pulling out of the black housings, it's because you're crushing the prongs that the housings used to retain the connector.

In the marked up picture of your crimp below, the green areas are where you're supposed to crimp. The red area is where you're not supposed to crimp, but did. The orange area is where the conductor brush should be and you don't have one. It looks like you also crushed the part of the connector to the right of the damaged prongs. A picture of my crimp is shown above yours:

Your conductor crimp doesn't look very good either.

 

If the problem is that the connectors are pulling out of the black housings, it's because you're crushing the prongs that the housings used to retain the connector.

In the marked up picture of your crimp below, the green areas are where you're supposed to crimp. The red area is where you're not supposed to crimp, but did. The orange area is where the conductor brush should be and you don't have one. It looks like you also crushed the part of the connector to the right of the damaged prongs. A picture of my crimp is shown above yours:
View attachment 274854
Your conductor crimp doesn't look very good either.

Thx for your reply. Given the problems with my crimping what do you suggest. I've got time to practice.

 

Given the problems with my crimping what do you suggest. I've got time to practice.

Work on positioning the connector in the crimping tool correctly. There's an area for the insulation crimp and another for the wire crimp. Make sure that the retaining prongs aren't in the jaws. Adjust the wire stripping length so you'll have a good conductor brush. Make sure you position the wire properly in the connector.

Are you using pliers to make the tabs for the insulation crimp parallel? That will help it seat better in the jaws.

Are you closing the jaws enough to hold the connector before inserting the wire?

Did you mangle that connector with pliers after crimping? If not, you may need to adjust the crimper. My tool (from Ali Express) was adjusted correctly.

 

Are you using pliers to make the tabs for the insulation crimp parallel? That will help it seat better in the jaws.

No, and please explain.

Also, what is the word for wire that comes in pairs...for example a stranded wire that's joined together in parallel (not electrically parallel but the wires are oriented along side of each other) that way they (the 2) stay together.

 

retaining prongs aren't in the jaws. Adjust the wire stripping length so you'll have a good conductor brush. Make sure you position the wire properly in the connector.

I've been using approximately 2mm = stripping length. Should I increase the length?

 

No, and please explain.

The tabs that grip the wire insulation on most connectors don't form a 'U' when they're manufactured. Using pliers to make them form a U will encourage them enter the jaws more evenly and be less likely to twist in the jaws.

Also, what is the word for wire that comes in pairs...for example a stranded wire that's joined together in parallel (not electrically parallel but the wires are oriented along side of each other) that way they (the 2) stay together.

I'm not aware of any official name. Ribbon cable has multiple wires joined in that fashion and it can be torn off as pairs of wires. The pre-made DuPont jumpers I buy from Ali Express are made using 40 conductor rainbow ribbon cable and you almost always separate them into smaller cables. Sometimes singles, but I try to avoid that. If I need a single, I'll make one from regular stranded wire.

I've been using approximately 2mm = stripping length. Should I increase the length?

The stripping length depends on the connector. It needs to span the length of the conductor crimp area and extend past the end to make a conductor brush. It wasn't until a few months ago that I learned about conductor brush. Before that, I tried to have the wire end at the end of the conductor crimp area because I didn't want to interfere with the mating connector. Apparently having a sufficient conductor brush improves the crimp.

This is from the document previously referenced:

 

Work on positioning the connector in the crimping tool correctly. There's an area for the insulation crimp and another for the wire crimp. Make sure that the retaining prongs aren't in the jaws. Adjust the wire stripping length so you'll have a good conductor brush. Make sure you position the wire properly in the connector.

Are you using pliers to make the tabs for the insulation crimp parallel? That will help it seat better in the jaws.

Are you closing the jaws enough to hold the connector before inserting the wire?

Did you mangle that connector with pliers after crimping? If not, you may need to adjust the crimper. My tool (from Ali Express) was adjusted correctly.

Most of the tutorials and forums suggest 2m-4mm on the stripped exposed stranded wire. Can a tool type be recommended for cutting at a particular stripped length? Have been approximating it so far.

 

Most of the tutorials and forums suggest 2m-4mm on the stripped exposed stranded wire.

If these tutorials are on YouTube, they're probably being made by people who act like some sort of expert but, in reality, are clueless. As I said, strip length depends on the connector.

EDIT: On the DuPont connectors, I'd use 2.5mm. 2mm is too short, 4mm is way too long.

Can a tool type be recommended for cutting at a particular stripped length? Have been approximating it so far.

You can measure and mark the wire, you can eyeball, etc. I bought one of these and find that it works pretty well:

I tried others that didn't work:

 

Have you read the Molex publication I recommended earlier? It is quite specific and detailed. It is also effectively authoritative on reliable crimping.

You might find this publication from Molex helpful. It targets QC professionals but it is extremely informative concerning howe to successfully use crimped connectors.

 

Have you read the Molex publication I recommended earlier? It is quite specific and detailed. It is also effectively authoritative on reliable crimping.

I'm sorry I digressed. I will put it on for ASAP

 

If these tutorials are on YouTube, they're probably being made by people who act like some sort of expert but, in reality, are clueless. As I said, strip length depends on the connector.

EDIT: On the DuPont connectors, I'd use 2.5mm. 2mm is too short, 4mm is way too long.
You can measure and mark the wire, you can eyeball, etc. I bought one of these and find that it works pretty well:
View attachment 275263
I tried others that didn't work:
View attachment 275264

Thanks for the reply - I guess to be more accurate I need something to reliably cut 22 gauge stranded to 2mm or to 5mm -- what happens is the strands come apart at 2mm when I cut it and sometimes 5mm making it near difficult to estimate or approximate what the strip length should be. The wires get smashed and only a few get cut. I can't reliably cut at this low

 

Thanks for the reply - I guess to be more accurate I need something to reliably cut 22 gauge stranded to 2mm or to 5mm -- what happens is the strands come apart at 2mm when I cut it and sometimes 5mm making it near difficult to estimate or approximate what the strip length should be. The wires get smashed and only a few get cut. I can't reliably cut at this low

What do you currently use to cut?

 

I guess to be more accurate I need something to reliably cut 22 gauge stranded to 2mm or to 5mm

Why are you trying to cut the wire that short?

 

Why are you trying to cut the wire that short?

A lot of crimping videos (DuPont on YouTube) and internet postings recommended 2mm - 4mm. It seemed they were credible sources. Of course 5mm would be a lot handier b/c 5mm is easier cut than 2mm.

 

A lot of crimping videos (DuPont on YouTube) and internet postings recommended 2mm - 4mm. It seemed they were credible sources.

2mm is too short and 4mm is too long. I don't care how credible the sources seemed to you. Measure the length of the conductor crimp and add length for the conductor brush. That's going to be closer to 2.5mm.

Of course 5mm would be a lot handier b/c 5mm is easier cut than 2mm.

How are you cutting that makes it so difficult to strip 2.5mm or strip more (which is a waste) and cut it down to the correct length?

 

2mm is too short and 4mm is too long. I don't care how credible the sources seemed to you. Measure the length of the conductor crimp and add length for the conductor brush. That's going to be closer to 2.5mm.
How are you cutting that makes it so difficult to strip 2.5mm or strip more (which is a waste) and cut it down to the correct length?

I am using a wire cutting/ striping tool. There are different slots for different gauge wire. Once I have stripped it in the respective slot, I then use the jaws of the cutting tool to cut the just stripped wire in a scissors-like fashion. My trouble starts here: I mistakenly shred and tear the wire when there doesn't seem to be enough to grab onto. This usually happens around 5mm and below. So what ever method to cut the wire I adopt I've got to b able to not just strip the wire but cut it. How can I fix this?

 

Once I have stripped it in the respective slot, I then use the jaws of the cutting tool to cut the just stripped wire in a scissors-like fashion. My trouble starts here: I mistakenly shred and tear the wire when there doesn't seem to be enough to grab onto.

You only need to trim the stripped wire if you stripped too much. If you strip the correct amount, there's no need to trim. If you don't strip enough, you can remove more insulation to have more wire exposed.

If you're shredding or tearing wire, your tool isn't sharp enough. You can twist the strands together if they get separated when cutting after stripping.

If you're nicking or cutting strands, you need to improve your stripping technique.

If you're removing too much insulation or too little, you need to measure more carefully before you strip the insulation.