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Building Tips and technical articles. => Building techniques => Topic started by: James Holford on November 13, 2016, 12:39:36 PM
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For the love of all that is modeling.
Can someone please show or explain to me the easiest way to Solder a pushrod and the sleeve for my Ringmaster ARF?
I went out and got a cheap soldering Iron (harbor frieght) and flux for it( harbor frieght again) and all it does is puddle up on the tip...
Help?
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For the love of all that is modeling.
Can someone please show or explain to me the easiest way to Solder a pushrod and the sleeve for my Ringmaster ARF?
Pushrod and sleeve? What is that for? Pushrods *should not have solder joints in them*.
However, in this case you might have to use a more aggressive flux than the usual rosin-core. I would start with the "safe" plumbing type, and if that didn't work, then resort to Sta-Brite. Clean everything with sandpaper until it is completely bare metal, then apply the flux everywhere, then heat the parts and apply the solder when the components are hot enough to melt it. You might have to apply just a little to the iron tip just to get it to conduct heat, but you cannot attempt to apply the solder directly to the iron and then move it to the parts. Once the solder has flowed everywhere, then remove the heat without moving the parts, otherwise, the solder will be very weak.
If you do it right the solder should flow everywhere and make nice shiny fillets at every edge. If it's rough, or lumpy, you didn't get it quite right.
Brett
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(http://uploads.tapatalk-cdn.com/20161113/ab3dd4ae6f720fa8bed32a10fe210e29.jpg)
I assure ya I'm not too thrilled with having to solder this... but perhaps it's the Flux itself.. just isn't the right stuff.
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Key to soldering is tinning every contact point, and by that I mean the soldering iron tip as well.
It must be thoroughly coated with bright solder before attempting any work.
I always tin every surface BEFORE joining and clean with both mechanical and chemical means, and then sweat parts together using as little added solder as possible.
One point often skipped when pre-tinning is wiping the scale or 'grunge' off the parts. And dark coloured dross left on a joining part is a part that resists joining.
A wet cloth is your best friend here for removing dross from HOT just tinned parts, and especially the tip of the iron.
Pre-tinned parts ensure that the 'glue' or solder has already reached every contact point possible and all there is left to do is add the minimum of heat to sweat and a guilt relieving amount of solder to finish - indeed sometimes no more is needed.
As Brett says, joint movement during cool down is to be avoided like the plague, both with mechanical bumps and jolts and too rapid a cool down by say blowing on the area or (shudder) dipping in water because it will propagate micro cracking and advanced joint failure.
Good luck!
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You'd think Brodak could have made a simpler attached than this lmao.
Thanks for the info guys
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I assure ya I'm not too thrilled with having to solder this... but perhaps it's the Flux itself.. just isn't the right stuff.
That looks like a roll pin with a black-oxide finish. You will not be able to solder to black oxide without removing it first. In this case it needs to be removed on the *inside* of the hole. Maybe if you roll up a bit of 220 wet/dry sandpaper you can get in there. You need to solder to shiny silver metal, not an oxide finish.
Obviously, disassemble this, clean it up and get ready do so something different - even if it seems connected now, the joint you have is not very good at all.
Sta-Brite might take that off, but I will have to look around to see if I have anything similar to experiment on.
This is a very bad idea overall. I have seen these arrangements fail over and over again. I would even feel safer with a copper-wrapped lap joint than this. Give me a while to see if I can experiment.
Brett
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Better by far is to tin the rod (this makes sure that the metal will accept the solder in the first place) overlap the two ends of the rods, bind with fuse wire and then sweat the whole thing together.
An exposed joint is far easier to see Q.C. and an oncoming failure with and an overlap will be far stronger.
Done with say a 50mm overlap and bind in a mid size model I highly doubt that failure is an option.
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That looks like a roll pin with a black-oxide finish. You will not be able to solder to black oxide without removing it first. In this case it needs to be removed on the *inside* of the hole. Maybe if you roll up a bit of 220 wet/dry sandpaper you can get in there. You need to solder to shiny silver metal, not an oxide finish.
Obviously, disassemble this, clean it up and get ready do so something different - even if it seems connected now, the joint you have is not very good at all.
Sta-Brite might take that off, but I will have to look around to see if I have anything similar to experiment on.
This is a very bad idea overall. I have seen these arrangements fail over and over again. I would even feel safer with a copper-wrapped lap joint than this. Give me a while to see if I can experiment.
Brett
If I can avoid soldering it all together I'd be happy.
They could have at least had the end of the rod coming out wing threaded on end. Screw on an insert on a carbon rod.and bam done... but nooooooo
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Replaced that black sleeve with a bare metal sleeve that comes with the Twister kit and things are going ALOT better than it was. Didn't take long for the heat to spread and the Flux started flowing.(http://uploads.tapatalk-cdn.com/20161113/c5cbceb9faf55fcefe695c5b5bcfde04.jpg)
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(http://uploads.tapatalk-cdn.com/20161113/d17839ee53cda58a5d5c95a5728a6b2a.jpg)
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Go back to where you bought the solder and get a small tube of soldering flux, soldering paste, or whatever other name may be on the tube. Also get a small stainless steel brush. Clean up the joint that you have with the brush and whatever fluid will dissolve the existing flux - sometimes water or try lacquer or dope thinner. Smear your new flux over the whole joint and reheat it, maybe needing some more solder in there. It appears to me that the joint in the photo wasn't quite hot enough. The solder has to flow like water, not just melt and creep around like epoxy. Of course, too hot is also bad but you most likely won't have that problem unless you use a torch. It's really pretty easy but it does take practice. Good luck.
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That last picture still doesn't look good. Solder must form smooth "fillets" all around the edges. Solder blobs indicate the joint isn't getting hot enough.
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I'm about to just epoxy the damn thing lol!!
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James, did you get the 30 watt, $3.99 iron from Harbor Freight? If so, I don't believe it is possible to solder that pushrod. That iron would be for small electrical connections.
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James, did you get the 30 watt, $3.99 iron from Harbor Freight? If so, I don't believe it is possible to solder that pushrod. That iron would be for small electrical connections.
Lol it surely is... need a hotter iron.
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I sent you an email James...
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Just received. Thanks
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You definitely need more power to solder those with. 30 watt is plenty for most circuitry and connectors though. First clean the tip, use the hot iron on wet paper towel and apply solder to the tip until the entire business end is tinned and not peeling when wiped. There are tip cleaners made from brass turnings that work much better though.
https://www.sparkfun.com/products/8964
Now for soldering pushrods I have a Craftsman soldering gun, which is made by Weller. The HF version is supposed to be pretty good too, but I think it is a 1-stage instead of a 2-stage. These tend to get TOO hot sometimes so you need to work with it a little. Use a small fan blowing away from your work area to keep the fumes down.
http://www.harborfreight.com/180-watt-industrial-soldering-gun-61170.html
Same deal with cleaning and tinning the tip before use.
Phil
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OK, I experimented a bit this afternoon. The black oxide will be removed by the Sta-Brite flux and you can solder to it. However, as you found, it will take much more heat that 30W pencil iron can supply. I only had an oversized example but my 280 watt Weller gun didn't come close to being enough. I have an ancient American Beauty 200 watt industrial iron and that was pretty good, but I ended up using my propane torch - very carefully and at a good distance to avoid overheating the joint - to get good flow. I would guess a very heavy gun or ancient industrial iron would be sufficient for 3/32 wire and the proper sized roll pin. How you would ever convince yourself you got good joint in the places you can't see, I have no idea, and I also have no idea how you could get all the very corrosive flux out of the joint. With this much surface area, there would be no issue with the strength of the solder itself, as long as it didn't later corrode.
Sorry, but your second try with the bare roll pin isn't really good enough. The solder has to flow like water into the joint, and this is just sort of blobbed on there.
*If it was me*, I would forget about soldering it and use a carbon pushrod assembly with the stub pushrod coming out of the wing. I assume you don't have that at hand, so a second choice would be a lap joint with maybe 1 1/2" overlap. Clean everything, apply flux everywhere, wrap the ends of the lap joint to hold it together but leave the middle section open. Solder the music wire parts together using a much hotter iron until the joint is solid. Then remove the wrapping wire, clean some heavy bare copper wire (like you would wrap leadouts with), clean the soldered pushrods with a wire brush and solder, flux all over the outside, close-wrap the joint from end to end, then solder that until every bit of the wire is flowed cleanly with water-thin solder on all sides. Clean the finished joint with first water, then polish it with the tiny Dremel wire brush from end to end. Remove anything that looks like a black spot (which is probably corrosion).
This should be good enough. For the future use a single-piece music wire pushrod, or a graphite arrowshaft pushrod assembly.
Brett
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OK, I experimented a bit this afternoon. The black oxide will be removed by the Sta-Brite flux and you can solder to it. However, as you found, it will take much more heat that 30W pencil iron can supply. I only had an oversized example but my 280 watt Weller gun didn't come close to being enough. I have an ancient American Beauty 200 watt industrial iron and that was pretty good, but I ended up using my propane torch - very carefully and at a good distance to avoid overheating the joint - to get good flow. I would guess a very heavy gun or ancient industrial iron would be sufficient for 3/32 wire and the proper sized roll pin. How you would ever convince yourself you got good joint in the places you can't see, I have no idea, and I also have no idea how you could get all the very corrosive flux out of the joint. With this much surface area, there would be no issue with the strength of the solder itself, as long as it didn't later corrode.
Sorry, but your second try with the bare roll pin isn't really good enough. The solder has to flow like water into the joint, and this is just sort of blobbed on there.
*If it was me*, I would forget about soldering it and use a carbon pushrod assembly with the stub pushrod coming out of the wing. I assume you don't have that at hand, so a second choice would be a lap joint with maybe 1 1/2" overlap. Clean everything, apply flux everywhere, wrap the ends of the lap joint to hold it together but leave the middle section open. Solder the music wire parts together using a much hotter iron until the joint is solid. Then remove the wrapping wire, clean some heavy bare copper wire (like you would wrap leadouts with), clean the soldered pushrods with a wire brush and solder, flux all over the outside, close-wrap the joint from end to end, then solder that until every bit of the wire is flowed cleanly with water-thin solder on all sides. Clean the finished joint with first water, then polish it with the tiny Dremel wire brush from end to end. Remove anything that looks like a black spot (which is probably corrosion).
This should be good enough. For the future use a single-piece music wire pushrod, or a graphite arrowshaft pushrod assembly.
Brett
Brett
Oh believe me.. I rather a single rod or even Carbon.... this is what Brodak gives you with this ARF.... a short piece of wire already attached to bell crank lol..
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As already mentioned, clean that old stuff and sleeve off, make a rear pushrod that overlaps at least an inch or so. Tightly wrap the overlap joint with as fine copper wire that you can find, unvarnished. Use solder that is .030" in diameter. This will probably be rosin core electrical solder, but will work. Hard to find acid core that small. I only keep rosin core on hand so I don't get mixed up. Most guys problems arrise from using solder that is too large. You can even strip down insulated wire and unwrap a strand about 10 inches long. Tightly wrap the joint from one end to the other. It should get tight, but you can still move it one way or the other to set neutral. When you are happy with the elevator setting, apply soldering paste and apply the iron to the joint. Tin the tip as best you can, even if you have to touch the tip in flux. Then apply the tip to the joint. Let it heat the joint, it won't do it instantly, may take 30 to 40 seconds. Apply the solder near the tip. If things are hot enough, it will flow. Observe ho it is going, and dab more solder in as you go. As mentioned it should look smooth and not lumpy or what is referred to as a cold solder joint. If it looks good, clean the joint well with water and baking soda to kill the flux. A 40 to 80 watt iron with a broad chisel type tip will help also, more area to transfer heat. That is all I use to solder everything. You have to be patient and let things work. Get things as CLEAN as possible. Practice on some scrap pieces first. Practice makes perfect.
Good luck and have fun,
Dan McEntee
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I have an oxy-acetelyne outfit. Bring it over and I'll take care of it for you.
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When I built my Brodak ARF, I tried to solder that piece of garbage and couldn't get a good joint. I ended up just throwing it away. Go to your local hobby shop and buy a pre-tinned solder sleeve made just for this application. They come in different sizes. I think they're made by DuBro, but I'm not sure. Being pre-tinned, your solder flows well and you get a good joint.
Mark
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I had a Twister with nylon horns and wanted to use washers for retainers. I didn't dare try solder. What I did was to use JB Weld. I did rough up the end of the pushrod a bit and used a heat gun to help the JBW to flow to form a fillet.
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I had a Twister with nylon horns and wanted to use washers for retainers. I didn't dare try solder. What I did was to use JB Weld. I did rough up the end of the pushrod a bit and used a heat gun to help the JBW to flow to form a fillet.
I agree with the JB Weld. I have used it in many control system applications and never had a failure. I also use it to attach wheel retaining washers to the landing gear. The secret is to prepare the surfaces correctly. It requires a little "texture" to the surface so I use sandpaper and/or a fine ridged file. You also have to do this to the inside surfaces such as the sleeve in the above posts. Then clean with your favorite solvent and never touch the surface again with your fingers. Let it set for at least 24 hours.
Paul
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Big Ron and I about to tackle this S.O.B.(http://uploads.tapatalk-cdn.com/20161119/d6702ec7f6d4e56689c1411e805dc99c.jpg)
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Got it... now I can continue with the build!
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