Tips for Strain Relief on PCB Solder Joints.. my wires keep breaking!

[cdo221]

I'm pretty sure this is due to bad technique or just general miscalculation of wire length but in any case, I'm building my first saber using the Prizm 3.5 sound board. I wire everything up and it fires up perfect! Everything works great, accent leds flashing all pretty-like... but the problem comes when I take my chassis in / out of the hilt. After a few go's, my wires start to break at the solder joint connection to the sound board. To clarify, the solder joint itself is fine, it's the wire that breaks right at the solder joint, leaving a bit of the wire stilled soldered on. I'm pretty sure it's due to the way the wires are curled and the length of the wires themselves... however, I did some quick google and saw that hot glue is sometimes used directly on that point, even in factory electronics, to help relieve the strain on the bare wires. Is this a good practice to use hot glue directly on the Plecter lab soundboards? Any other tips for relieving strain on the wires at the solder joints?

I am going to try to adjust the length of my wiring and making it curl in such a way that it doesn't pull quite as much when sliding my chassis in and out for now... thoughts/tips?

[Greenie]

If the wire is breaking not the solder joint, you maybe a little 'heavy handed' when stripping the insulation.

[darth_chasm]

You may also be stripping your leads too long. You only need around 1/16. You can use hot glue but you have to keep in mind 1) how messy it is and 2) that it will make repairs and re-wiring a pain.

More impotantly though. Why are you removing and reinserting your chassis?

[Darth Vislir]

As darth_chasm already pointed out your chassis, once in, should stay in place. if you made the mistake I made, then I can see why you would be removing the chassis. I got the wrong speaker holder which doesn't allow me to unscrew the main body of my hilt and slide it off in a reveal fashion. so I opted to leave the chassis unmounted so I can take it out and access the SD card. I use solid copper wires and I haven't had one issue with breakage.

what gauge and type of wires are you using?

all my upcoming sabers have the chassis mounted at some point so I can access the entire board if need be and there isn't any stress on wires at all.

[snilam]

what gauge and type of wires are you using?



Are you using mulit stranded or solid core wire? You should be using multistranded. but yes hot glue helps.

[Sloda Foade]

Coming from a Military Spec soldering position (many years ago) it helps if you put a strain relief in the cable just before the joint, one loop of a coil in the wire is usually enough. Wind the wire around a nail to get a nice tight loop. Mil spec then specifies that the whole joint should be potted, but hot glue would do, or silicon sealant which can be pulled off if need be later.

[hapki]

Probably not typical good practice, but I cut the leads very short, stick them in the hole on the board, and solder it. The quality of wire makes a huge difference, too. Flexible wire seems to work best for me.

[cdo221]

Thanks for all the tips guys! I'm using 26 gauge wire, multistranded (bought from TCSS).. I built the chassis using speaker mount v5 (locks in place between the pommel and main body). I built it such that it could be slid out of the main hilt body to gain access to the recharge port + SD card. After looking at some of the chassis build threads and your tips, I think I've realized my problems...

I've been exposing too much of the wire, also going to loop all the wires kinda like a J hook to help relieve the stress.. right now it's a straight line from the solder joint to the LED, switch, or where ever the wire is going. I think having the lines loop down, secured somehow (like looped around something or zip tied down), then back up to the solder joint, will prevent the pulling on the joints as the chassis slides in and out.