Which is the best solder to use for flex shaft to drive shafts?

[raytam]

I know it part of our wonderful hobby, but it still sucks to lose a prop.

Ok, my story... I bought an unassembled octura 0.15 flex shaft, drive shaft, drive dog and bullet nut.

First I initially used solder from the plumbing section at the hardware store to connect the flex shaft to drive shaft. This resulted in the drive shaft loosening up causing my boat to rev but move like the remote control boats at Disneyland. I luckily did not lose anything.

So I cleaned both drive shaft and flex removing any dirt and oil. I bought some solder with 2% silver (since I've read that silver solder works good) and used an acid flux (translucent hot pink in color) to connect the two.

Last week, I went out to the pond and it held very well. What ended my session prematurely is a burnt out steering servo. I replaced the servo.

Today, I went out and for the first couple of 5 minute runs, it was fine with each run better than the last. On the third run, it started out sweet. My new boat FF18 with os tz18 was screaming. I'd say at least 45mph(no gps on board) on the straight. I took a sharp turn and as it was about to accelerate, the engine started to rev but not accelerate so I shut down...I had a feeling I wasn't so lucky this time and I was right. I Lost a great prop x640 and the shaft and a bullet nut.

I know I could always buy something that is preassembled, but I want to learn how to do this on my own, but knowing which materials and technique to use is something only experienced boaters would know.

I tried to search but only found that tinning both the flex shaft and driveshaft is one key in making a good connection. Can someone recommend what would be the best solder (percentages would help), flux and solder iron temp is optimal?

Thanks

Ron G

 

[Kez]

I know it part of our wonderful hobby, but it still sucks to lose a prop. Ok, my story... I bought an unassembled octura 0.15 flex shaft, drive shaft, drive dog and bullet nut.

First I initially used solder from the plumbing section at the hardware store to connect the flex shaft to drive shaft. This resulted in the drive shaft loosening up causing my boat to rev but move like the remote control boats at Disneyland. I luckily did not lose anything.

So I cleaned both drive shaft and flex removing any dirt and oil. I bought some solder with 2% silver (since I've read that silver solder works good) and used an acid flux (translucent hot pink in color) to connect the two.

Last week, I went out to the pond and it held very well. What ended my session prematurely is a burnt out steering servo. I replaced the servo.

Today, I went out and for the first couple of 5 minute runs, it was fine with each run better than the last. On the third run, it started out sweet. My new boat FF18 with os tz18 was screaming. I'd say at least 45mph(no gps on board) on the straight. I took a sharp turn and as it was about to accelerate, the engine started to rev but not accelerate so I shut down...I had a feeling I wasn't so lucky this time and I was right. I Lost a great prop x640 and the shaft and a bullet nut.

I know I could always buy something that is preassembled, but I want to learn how to do this on my own, but knowing which materials and technique to use is something only experienced boaters would know.

I tried to search but only found that tinning both the flex shaft and driveshaft is one key in making a good connection. Can someone recommend what would be the best solder (percentages would help), flux and solder iron temp is optimal?

Thanks

Ron G

I use only Ste-Brite silver solder. Make sure you clean the cable and the stub shaft real well and use the supplied flux.

kez

 

[raytam]

I know it part of our wonderful hobby, but it still sucks to lose a prop. Ok, my story... I bought an unassembled octura 0.15 flex shaft, drive shaft, drive dog and bullet nut.

First I initially used solder from the plumbing section at the hardware store to connect the flex shaft to drive shaft. This resulted in the drive shaft loosening up causing my boat to rev but move like the remote control boats at Disneyland. I luckily did not lose anything.

So I cleaned both drive shaft and flex removing any dirt and oil. I bought some solder with 2% silver (since I've read that silver solder works good) and used an acid flux (translucent hot pink in color) to connect the two.

Last week, I went out to the pond and it held very well. What ended my session prematurely is a burnt out steering servo. I replaced the servo.

Today, I went out and for the first couple of 5 minute runs, it was fine with each run better than the last. On the third run, it started out sweet. My new boat FF18 with os tz18 was screaming. I'd say at least 45mph(no gps on board) on the straight. I took a sharp turn and as it was about to accelerate, the engine started to rev but not accelerate so I shut down...I had a feeling I wasn't so lucky this time and I was right. I Lost a great prop x640 and the shaft and a bullet nut.

I know I could always buy something that is preassembled, but I want to learn how to do this on my own, but knowing which materials and technique to use is something only experienced boaters would know.

I tried to search but only found that tinning both the flex shaft and driveshaft is one key in making a good connection. Can someone recommend what would be the best solder (percentages would help), flux and solder iron temp is optimal?

Thanks

Ron G

I use only Ste-Brite silver solder. Make sure you clean the cable and the stub shaft real well and use the supplied flux.

kez

Thanks Kez. Is stay brite silver solder the same thing?

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFS75

 

[Terry Keeley]

Try 45% silver brazing solder, you'll need the flux too. I put a wheel collar on the shaft after the cable collet, has saved a coupla props for me...

 

[Brian Swejkoski]

I know it part of our wonderful hobby, but it still sucks to lose a prop. Ok, my story... I bought an unassembled octura 0.15 flex shaft, drive shaft, drive dog and bullet nut.

First I initially used solder from the plumbing section at the hardware store to connect the flex shaft to drive shaft. This resulted in the drive shaft loosening up causing my boat to rev but move like the remote control boats at Disneyland. I luckily did not lose anything.

So I cleaned both drive shaft and flex removing any dirt and oil. I bought some solder with 2% silver (since I've read that silver solder works good) and used an acid flux (translucent hot pink in color) to connect the two.

Last week, I went out to the pond and it held very well. What ended my session prematurely is a burnt out steering servo. I replaced the servo.

Today, I went out and for the first couple of 5 minute runs, it was fine with each run better than the last. On the third run, it started out sweet. My new boat FF18 with os tz18 was screaming. I'd say at least 45mph(no gps on board) on the straight. I took a sharp turn and as it was about to accelerate, the engine started to rev but not accelerate so I shut down...I had a feeling I wasn't so lucky this time and I was right. I Lost a great prop x640 and the shaft and a bullet nut.

I know I could always buy something that is preassembled, but I want to learn how to do this on my own, but knowing which materials and technique to use is something only experienced boaters would know.

I tried to search but only found that tinning both the flex shaft and driveshaft is one key in making a good connection. Can someone recommend what would be the best solder (percentages would help), flux and solder iron temp is optimal?

Thanks

Ron G

I use only Ste-Brite silver solder. Make sure you clean the cable and the stub shaft real well and use the supplied flux.

kez

Thanks Kez. Is stay brite silver solder the same thing?

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFS75

yes,that is the stuff

 

[Kez]

Raytam, yes it is the same thing.

Terry, I have tried 45% hard silver brazing with a Borox flux but the problem is that the heat would anneal both the stub shaft and the cable. I have not been able to restore the temper by heat treatment. If you have a process that works I would like to know. I have found that using Stay Brite silver solder if done correctly, the cable will last many seasons.

Thanks,

kez

 

[Terry Keeley]

Raytam, yes it is the same thing.
Terry, I have tried 45% hard silver brazing with a Borox flux but the problem is that the heat would anneal both the stub shaft and the cable. I have not been able to restore the temper by heat treatment. If you have a process that works I would like to know. I have found that using Stay Brite silver solder if done correctly, the cable will last many seasons.

Thanks,

kez

Not sure if you're soldering the stub shaft or not too, I'm talking about just soldering the tip of the flex cable to keep the inner & outer windings attached.

I think what happens is they separate, the inner winds up, the outter gets smaller then the collet slips making a mess.

Stay brite didn't always hold for me... :blink:

I solder just 1/4" on the tip and let it cool on it's own, works for me.

 

[raytam]

Raytam, yes it is the same thing.
Terry, I have tried 45% hard silver brazing with a Borox flux but the problem is that the heat would anneal both the stub shaft and the cable. I have not been able to restore the temper by heat treatment. If you have a process that works I would like to know. I have found that using Stay Brite silver solder if done correctly, the cable will last many seasons.

Thanks,

kez

Not sure if you're soldering the stub shaft or not too, I'm talking about just soldering the tip of the flex cable to keep the inner & outer windings attached.

I think what happens is they separate, the inner winds up, the outter gets smaller then the collet slips making a mess.

Stay brite didn't always hold for me... :blink:

I solder just 1/4" on the tip and let it cool on it's own, works for me.

I believe it is the stub shaft (if that is the shaft that you attach the prop to, then yes). I bought more prop/stub shafts today. So what I should do is to clean the flex shaft of all oils and dirt. Now there is still some solder left-over from before. Should I remove that or reuse that? Also, is it neccessary to scuff the inside of the stub prior to tinning?

Thanks

Ron

 

[Chris Thomas]

I would have scrapped the other shaft before you ran it again (lost it). The previous compound you used to solder the shaft to the stub still had the solder from the initial bond still present. I believe this would have been a contaminant even if you used a good silver solder the second time through. It would have been weaker than a clean silver solder joint. I try to use only silver solder on anything I need to bond permanantly. This eliminates the questions of what was used should a repair have to be made. Chalk one up for experience, sorry about the prop. The collar in front of the strut should help too. I also use a small chunk of silicon tube between the prop and the prop nut. It helps absorb changes in prop RPM without loosening the prop nut. I also use the crimped type nuts or nylocks. A good prop is painful to lose. Especially one tailored for the specific boat. Hope this helps. Chris

 

[Terry Keeley]

Raytam, yes it is the same thing.
Terry, I have tried 45% hard silver brazing with a Borox flux but the problem is that the heat would anneal both the stub shaft and the cable. I have not been able to restore the temper by heat treatment. If you have a process that works I would like to know. I have found that using Stay Brite silver solder if done correctly, the cable will last many seasons.

Thanks,

kez

Not sure if you're soldering the stub shaft or not too, I'm talking about just soldering the tip of the flex cable to keep the inner & outer windings attached.

I think what happens is they separate, the inner winds up, the outter gets smaller then the collet slips making a mess.

Stay brite didn't always hold for me... :blink:

I solder just 1/4" on the tip and let it cool on it's own, works for me.

I believe it is the stub shaft (if that is the shaft that you attach the prop to, then yes). I bought more prop/stub shafts today. So what I should do is to clean the flex shaft of all oils and dirt. Now there is still some solder left-over from before. Should I remove that or reuse that? Also, is it neccessary to scuff the inside of the stub prior to tinning?

Thanks

Ron

Why not just buy them already soldered from Hughey, CMDI, Speedmaster etc.?

Of is this for one of those square drive units? :blink:

 

[raytam]

Chris-Thanks for the tips. Will buy a new shaft.

Terry K-It's not a square drive. I just like to learn how to do stuff on my own. It's part of the hobby, right?

 

[Terry Keeley]

Chris-Thanks for the tips. Will buy a new shaft.
Terry K-It's not a square drive. I just like to learn how to do stuff on my own. It's part of the hobby, right?

Kewl!