Heat shrink solder connectors

JRA

Well-Known Member
First of all although I know how to solder and have the right tools but the hardest technique I have run into on my eBikes is shortening the controller to display cable that has many small wires. You really need the right size of strippers first of all and soldering isn't too bad but getting them covered is where I have had problems in the past and usually end up using a liquid tape but it is not very precise and then covering with heat shrink tubing. Basically it is a fussy affair especially it you only solder infrequently.

I had put together a bike for my son that had one of my "jobs" on it and it lost all power. Checking the connections we found a separation in the battery tray under the cover of the pos wire. After soldering it back together and still no power I thought it had shorted out the controller as there is no fuse in between and no readings on the voltmeter to be had. I had a spare controller so we put that on and still no love.

Then I saw the splice I had done which still looked good on the outside but upon cutting the heat shrink off there was a good amount of corrosion in there and one of the wires had parted. I wasn't in much of a soldering mood and so I whipped out my little box of heat shrink solder connectors that I got on impulse but only used a few time previously. It had connectors for the small wires so we cut apart the old "job" and re-stripped the wires and put it all back together with them. It was fast and easy but did end up with a bigger "bulge" however it seems very solid.

So I would have to put my stamp of approval on them in general and they are far better than butt connectors for sure. This is the type of product I have:

 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Bought these on an impulse myself but have yet had the need to use them on an ebike.
The few that I have used seem to work well.
I like that they are much more flexible than a butt crimp connector when done.
All depends on location and wire slack... But if you can stagger connections you can usually end up with a thinner longer bulge that is more manageable/better looking.
 

fooferdoggie

Well-Known Member
I have sometimes its hard to get them to melt before the plastic gives away. but that could be a bad source of heat. a hot air gun would be better then a lighter.
 

PedalUma

Well-Known Member
Region
USA
City
Petaluma, CA
I need to solder today. I have a step through going out today that is getting through frame to the display, so I had to chop the connector to feed it through the down tube. Soldering is like putting the legs of two spiders together. The wires are very small. There are six colors in this case. What I do is slip a larger tube of heat shrink over one end. Then I solder and heat shrink the little wires. I press every other back and forward. So three wires are back an three forward. Then slip down the larger tube and shrink it. This joint is then hidden inside a hidden compartment behind the chainring.
 

fooferdoggie

Well-Known Member
I need to solder today. I have a step through going out today that is getting through frame to the display, so I had to chop the connector to feed it through the down tube. Soldering is like putting the legs of two spiders together. The wires are very small. There are six colors in this case. What I do is slip a larger tube of heat shrink over one end. Then I solder and heat shrink the little wires. I press every other back and forward. So three wires are back an three forward. Then slip down the larger tube and shrink it. This joint is then hidden inside a hidden compartment behind the chainring.
ya you need one of these extra hand devices. I had to solder some fine control box wires on the ground had to buy it just for that job.
 

m@Robertson

Well-Known Member
Region
USA
I have yet to have a crimp fail on me, but I also use marine adhesive connectors, with marine adhesive heatshrink over that. The adhesive versions that seal to the wiring are light years better than the connectors that you only crimp.

Not too long ago I supplemented my 9.5" commercial crimper with a Klein semi-auto crimper and yup its a step up in terms of a perfect crimp that you don't have to think about ensuring you don't tear the outer adhesive material.

Tried the solder connectors. Too fine of a line between 'success' and 'melted'.
 

fooferdoggie

Well-Known Member
I have yet to have a crimp fail on me, but I also use marine adhesive connectors, with marine adhesive heatshrink over that. The adhesive versions that seal to the wiring are light years better than the connectors that you only crimp.

Not too long ago I supplemented my 9.5" commercial crimper with a Klein semi-auto crimper and yup its a step up in terms of a perfect crimp that you don't have to think about ensuring you don't tear the outer adhesive material.

Tried the solder connectors. Too fine of a line between 'success' and 'melted'.
man I try just using basic crimps and they never stay on. but I dont do it very often and I usually have odd sized wires.
 

m@Robertson

Well-Known Member
Region
USA

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
it was all I had at home. I had a butane torch like crack smokers use and that worked well. I dont have soldering irons everywhere.
I only have the one and don't see the need to have one everywhere...
That said I've never tried to cook up some base with it.... Interesting proposal 🤩
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Just an FYI that might be interesting here. I used to work on older aircraft, which occasionally would lead you into the wiring. It was there I learned solder connections are NOT allowed by the FAA due to the potential failure rate under vibration. Crimp on connectors, good ones that support the wire outside the crimp, are the preferred connection/splice.....
 

kevinmccune

Member
Region
USA
Just an FYI that might be interesting here. I used to work on older aircraft, which occasionally would lead you into the wiring. It was there I learned solder connections are NOT allowed by the FAA due to the potential failure rate under vibration. Crimp on connectors, good ones that support the wire outside the crimp, are the preferred connection/splice.....
"OCD-FAA",keeps you in the air, there is another problem with solder joints no one seems to address, the potential for corrosion with the junctures of two different metals at the joint When the "EMV" is different there is always the potential for corrosion,case in point I have seen stacked galvanized steel sheets get full of pinholes when a little moisture was present. I would always give the nod to any thing "Maritime' or FAA approved.The zinc coating on the steel is supposed to act as a sacrificial anode, in some cases it functions as a battery of sorts.