Wiring/Connecting/Terminating Materials Thread.

[auraslip]

Perhaps I was being unfair - the connection that came undone a few times was getting tugged on a bit. These connections aren't designed to be heavily stressed like that.

In any case, I redid it, and filled the back of the connect with super glue.

We'll see how that works.

 

[auraslip]

After talking to the Molex tech advisors, they admitted this: "Hand crimpers are a necessary evil. We don't like them, and wish we didn't have to sell them. They can provide inconsistent crimps, with the possibility of human error. And they can make our highly engineered products fail when they should not fail, if machine installed." So keep that in mind when hand crimping!

Sums up my feelings.

 

[Alan B]

The Molex crimpers I have are the worst of any crimper I've ever had. I've also had more trouble with Molex connectors than any other. This was a long time ago, perhaps they're better now. However using the same piece of metal for the spring, conductor and contact together with extreme cost minimization produces some compromises.

 

[liveforphysics]

The Molex crimpers I have are the worst of any crimper I've ever had. I've also had more trouble with Molex connectors than any other. This was a long time ago, perhaps they're better now. However using the same piece of metal for the spring, conductor and contact together with extreme cost minimization produces some compromises.

Yes, I agree with all of that as well. When your spring is your conductor, you introduce a positive feedback loop into your failure mode. Molex is kinda the last resort for me, but it does work when everything is OK.

 

[amberwolf]

Not that I've had too many crimpers to compare, but so far the Molex-branded one I have is the best of them, and turns out to work very well on the Anderson PP 15/30/45 so far, although since I don't have a strong enough grip to squeeze it fully, I have to squeeze with both hands, then set one edge on the floor, and lean on it with both hands and as much body weight as I can get into it.

Then I get a crimp that doesn't let me pull the wire out of it.

I can also do the JST-SM pins with it, though those don't require the second part of the crimping process, as they're much thinner and smaller.

 

[auraslip]

Isn't the molex one a couple hundred buck a roos?

I've been looking for some good, cheap, reliable connects for low power applications. Can't stand the idea of spending $5 in andersons to plug my CA in.

 

[rscamp]

Reliability is king.

Having worked on military equipment including sonar arrays with thousands of crimp connections I can't bring myself to crimp anything without good tooling. I have seen too many failures caused by improperly crimped connections even with tooling much better than hobbyists normally purchase. I have also seen failures in crimped connections due to abnormal impulse loads that would not affect a soldered joint. Unfortunately, the proper crimp tool for just about anything usually costs $300 and up.

The Amp Microfit connectors are a pretty good replacement for most ebike signal connections and can almost replace all of the signal level connectors in ebike kits. To reduce tooling costs, I standardize on these and the few other connectors whose pins can be crimped with the Molex "Service Grade" (i.e. reasonably good, relatively cheap) Hand Crimp Tool for C-Grid SLTM, SPOXTM, Micro Fit TM, and 0.100” KKTM Terminals. This crimp tool isn't the same quality as production crimpers and is a bit of a pain to use but at least it is versatile and not a toy.

This covers almost all wiring up to 20AWG.

Everything else gets soldered. Period.

For lighting circuits I use Deans Micro as these handle higher currents.

All connections get some form of strain relief. No exceptions.

Any connections exposed to the elements are sleeved and/or sealed and/or the contacts are coated with high dielectric grease.

 

[auraslip]

Rscamp,
Great post. I always find it fascinating how the military engineers their equipment, and how it compares to our ebikes. A lot of us rely on our bikes every day, yet we use failure prone connections

Here is a link to the crimping tool on mouser. That's pretty cheap compared to other professional crimpers, but more than the aftermarket anderson power pole crimpers. About how much do you think it cost to make standard 5 pin male/female connections with the micro fits? At low volumes it would cost about $.50 per anderson x 10, or $5, which is a lot more than I think is worth.

I just ordered some of the MPX connectors from HK, they look a pain with out a third hand, but at least I won't have to crimp.

 

[neptronix]

I personally solder everything i can get my hands on, then add extra long shrinkwrap..
Also; silicone is added for stress /vibration relief.
I think this will work well, as the flexing part of the wire will not have solder on it. I use copper wiring everywhere so i am not worried about fraying wires.

It is an expensive and time consuming way to do things but i want stuff to last forever and never give me trouble.

And it is 4mm bullet connectors for me, and JST. I like using stock connectors all the way. For the hub motor, HK sells a 3-bullet 4mm connector block, i may use that too.

I have heard of andersons slipping out and doing all sorts of bad stuff, i don't know why they are so popular.

Although the one thing i won't have stock is a set of these for balancing, to avoid accidentally reversing the leads:

http://www.arcade-electronics.com/detail.aspx?ID=28065

We'll see how those go!

 

[amberwolf]

Isn't the molex one a couple hundred buck a roos?

I dunno, I inherited mine when my dad moved out of state, he left behind his toolcase (and lots of other stuff) that had one in it, along with various other crimpers, mostly just there for the small-gauge strippers in them, I think, and the automotive-style crimper on one of them.

I have heard of andersons slipping out and doing all sorts of bad stuff, i don't know why they are so popular.

Because they can easily be setup to prevent this:

Although the one thing i won't have stock is a set of these for balancing, to avoid accidentally reversing the leads:

among other things. Ease of connect/disconnect for frequent reconfiguration (or disassembly for charging, etc.) is likely another.

The main reasons andersons slip out is probably because there is no real strain relief on them, and either weight of cable or vibration ends up pulling htem out. It happens to me on various types of connectors that are low-insertion-force, that don't have a clip on teh housing to physically force engagement and lock them together, not just on ebike stuff but even stationary equipment.

Also, andersons have (at least) two versions of each contact size, one for low insertion/retention force and one for higher, and I suspect that all or almost all of the ones in Powerpole 15/30/45s used on ebikes are the former, but I can't tell for sure from the information avaiable. I don't think any of what I have is the high force version, except in my Multipole (SB50+) connectors, some of which are the low but most of which are the high force version, based on how hard they are to pull apart (regardless of which housing I have them in, or how much they've been cycled).


There are unfortunately no perfect connectors, as each has advantages for a particular use, and disadvantages for others.

 

[rscamp]

For those soldering Anderson Powerpoles, it is important to know that it is possible to remove the temper in the contact beam with excessive heat. You'll know when this happens because the contact beam becomes much easier to bend by hand. Therefore, it is important to pre-tin the wire and use an appropriately massive tip to make the soldering operation quick and effective. You want to do this quickly anyways to reduce solder wicking up the wire. I mention this because it was previously noted that some are having issues with these connectors pulling out and this can be one cause...

This is not to say I am a fan of crimping Powerpoles. I have been soldering them since the early 90's and bought the insertion/removal tool from Mr. Sermos himself at KRC. Long time e-fliers will understand this reference.

I view crimping like using adhesive as a structural member. Yes, it can be good, but it absolutely has to be done right and you never really know how good it is until you do a destructive test. A soldered connection is more inspectable for quality - sort of like using bolts to hold something together rather than glue...

 

[Spacey]

I crimp Andersons then lightly solder over the top of the crimp. Best of both worlds.

 

[mclark999]

I like the EC5 connectors. Stops the chance of inadvertent shorts and keeps positive and negative where they belong.

http://www.ebay.com/itm/5-Pack-5-Male-EC5-Losi-Style-Bullet-Connector-Plugs-FREE-US-Shipping-/230822727274?pt=Radio_Control_Parts_Accessories&hash=item35be1b4e6a#ht_610wt_1032

http://www.hobbyking.com/hobbyking/store/__9194__EC5_5mm_Connector_Pair_.html?strSearch=ec5

You can get them in 10 or 12 awg