Soldering flex cable

[tanasit]

FYI, my last drive hardware I joined the flex and drive shaft with the LT 603 and let it sit for only about 6 hours, no problems. The room temperature was however around 80 degree.

[Stinger9D9]

FYI, my last drive hardware I joined the flex and drive shaft with the LT 603 and let it sit for only about 6 hours, no problems. The room temperature was however around 80 degree.

Oh, I believe the Loctite works. I put a couple of shafts together with it a few years back and they work great (the bottle of Loctite I have is now past its due date though so I'd need to buy a new one).

I've also used silver solder to braze a whole bicycle frame together. A bike that I rode myself (and I'm not a small guy). I know how strong that stuff can be - it's so strong it's overkill, but that's fine. That combined with longballlumber's recommendation, the price and availability and I was sold.

[Jeff Wohlt]

I braze mine as well that I sell. Not all of them...just the ones listed Takes some skill and you have to waste plenty of them until it works well.

[JIM MARCUM]

Stinger9D9's link is excellent. When soldering it's all about prep, flux type & heat. When soldering 1/4" flex cable/shafts I wire wheel brush the last 1" of the flex cable, put the last 6" flex drive into a 1 Gallon can of acetone and slosh it around. Clean the prop shaft the same way. I use a 3 oz. jar or Rectorseal flux paste from Home Depot on the end of the flex shaft & work it into the shaft. I use silver solder 60/40 (60% silver 40% lead) & lay the assembeled shaft/cable flat on an a piece of old asbestos heater vent pipe (asbestos is not dangerous in solid form, just when inhaled in power form). If asbestos scares you lay a thick piece of fiberglass cloth on a piece of sheetmetal or other fireproof surface. Heat the prop shaft end with a micro torch (Harbor Frieght cheep) & add solder to the flex cable. It will flow will flow easily into the prop shaft. Keep adding solder until no gap remains. If it's a little off axis just heat it up again till you have everything straight. It works great for me. I've tried brazing them with ox/acetlyene torch but the heat destroys the flex cable. JIM

[Stinger9D9]

So that's what I'm supposed to do with all that asbestos cement (transite) pipe I keep coming across. I do have a couple nice thin flat pieces of the stuff handy as well...hmm. Fun fact, just look for an old house with this type of siding - it's asbestos cement, grab a piece of it and you're good to go.

asbestos_2.jpg

It (asbestos cement) is not a material that people could easily find though, maybe a brick or piece of terra cotta (flower pot material) may work. Just don't heat one small area too much or the stuff (brick, tile, etc.) can blow up a bit - if you overheat one area of the material, and it expands too much while material around it stays the same size and it goes BANG (or is that POW...or BLAMO?).

The heating up of the stub shaft is right on the money - capillary action is your friend here and will (almost unbelievably) draw the solder from the cooler part (the flex shaft in this case) even against gravity to the warmer part (the inside of the stub shaft). That's some basic stuff they teach in welding class. It still takes practice though.

Everything has got to be SUPER clean before you start - that's the key to everything.

[JIM MARCUM]

I almost added that capillary attraction was why the silver solder flows to the hot spot when you heat up the prop shaft, but I thought my post was a bit long as it is. Thanks for adding that little physics fact. JIM

[bigwaveohs]

I just bought a couple from this Ebay seller listing:

http://cgi.ebay.com/150-x-17-Flex-Shaft-Hughey-Boats-/220804121099?pt=Radio_Control_Vehicles&hash=item3368f3820b

I contacted them and they are willing to ship to Canada for a little extra shipping so 2 new flex shafts are on the way.

That's a good price too...just noticed it's really Zipp kits.

[Stinger9D9]

Ok, I'm through with trying to braze flex shafts after seeing this beauty. I met up with Ray Schrauwen this afternoon and picked up a brazed flex shaft from JE Products. If they aren't Hughey cables, they are just as nicely done. I could never dream of doing such a good job.

I then made a brass version of the original, chamfered drive dog (once I realized didn't have any spares) and now my MC is ready for the water.

Thanks Ray!

flex.jpg

[ray schrauwen]

You silly, I would have gave you a drive dog too If I had known...

Just ask, you saw all my crap, lol.

[brushlessfreak]

I struggled with this for a while and then i figured it out and its so easy.first clean the end of the cable about an inch or so down with 91%rubbing alcohol.next take your dremel with a small wire cleaning bit and use it to clean and scuff the end of the flex cable,make sure to do this thoroughly till the cable is very clean and scuffed dont worry you wont hurt cable.now clean the cable again with alcohol.now time to solder i use metal work acid core solder and standard paste flux.dip the cable in flux and coat it liberally you want a good amount of flux on there.next fire upp your propane torch and get about 3-4in of solder ready and heat the cable in the flame till the flux liqufies 6-8seconds now keep it in flame and start spreading on the solder till it melts and coats the flex,then remove from flame and carefully wipe it and your done.good luck

[brushlessfreak]

Take your dremel with a wire wheel and thoroughly clean the cable end,then clean with 91%alcohol.i use a propane torch,metal work "acid core"solder readily available at lowes-etc and regular paste flux not rosin core elec flux.once the cable end is cleaned and shiny from the wire wheel apply a very liberal amount of flux to the end,dont be skimpy,and fire up the torch.pull out a 3in line of solder and heat the cable for few seconds till flux melts and keep in flame and start to sort of brush the solder on while slowly spinning the cable. Once the solder melts and has covered the end of the cable i wipe it carefully with a rag to smooth out the solder while its still hot and melted.thats all there is to it,the solder gives the motor coupler something to bite on when you tighten it.keep trying you will get it.remember clean surface and plenty of flux..good luck

[crispyspa]

I know this is an old thread, but I wanted to share my method of soldering flex cable. The crucible method. I've been just buying brazed cable, but I use this method to close up the loose ends after cutting the cable to length.

[ashcroft3]

https://www.youtube.com/watch?v=17hVYS12Q-o

[danielplace1962]

First you cut it nice and true. https://youtu.be/jW-VSCDe-_E

Then tig weld up the end to keep the center core locked in place and regrind the end.

[crispyspa]

Beautiful. Not real practical for the average joe, but beautiful nonetheless.