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Old Mar 14, 2007, 09:28 AM
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Controlled Fall's Avatar
Chantilly, VA
Joined Dec 2006
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Soldering Question

Had a quick thought. I found a video in the Beginners section on "How to solder." I have a better idea of how its supposed to work, but was hoping to avoid a trip to the store if what I have is sufficient.

1. Could the heat shrink tubing provided with the Dandy be used to cover the battery/JST joint after soldering?

2. Is "silver bearing solder," 0.022 diameter, 62/36/2 (don't know what that means) suitable for this application?

I don't mind going to the store to get the right stuff, but if I can avoid it I'd like to These may be dumb, basic questions, but I actually have minimal background in electronics.
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Old Mar 14, 2007, 10:42 AM
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Bailey, CO
Joined Apr 2006
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Dear Controlled,

Looks like you are making great progress. I am stalled out on my MiniFlash due to family activities, and I ran out of dark blue So-Lite. My LHS is quite a distance from my house. Here are some of my opinions regarding your questions.

Quote:
Originally Posted by Controlled Fall
OK, I finally got a picture of my defective wing section and would welcome any advice on:
Its identity
Can it be reshaped?
Should it be replaced?
Even the absolute best covering jobs have flaws. Sometimes only the builder can see the flaws. Although hard to tell from your photo, the wrinkles look to be in the first panel between flat wing section and the angled tip. I suspect that as you applied covering to the wing there was quite a bit of slack in the covering at this joint. As you sealed the wing parameter the adhesive activated at this joint with the wrinkles in place. You would find it near impossible to take these wrinkles out with a sealing iron. Air is trapped under some of these winkles (bubbles). As long as the bubble is over solid structure you can poke a small hole in the bubble and carefully iron the air out. DO NOT poke holes in covering over open areas.

The way I would approach this problem is to use my handy heat gun to heat the wrinkled area which would debond the adhesive, and at the same time, shrink the covering. However, this method takes a lot of practice because the heat required is on the ragged edge of burning a hole in the covering!

You can (1) live with it. The wrinkles will not affect the flying character of your plane to any great degree, or (2) carefully poke holes in the bubbles and iron it down which will likely result is a few minor surface wrinkles. (3) You can cut the panel out leaving about 1/8" to 1/4" of covering hanging out over the ribs and spar. Iron this covering over the edge of the spar and ribs. Then cut a patch 1/4" larger than the hole on each side. Iron the patch in place making sure you stretch it as much as possible. This third method is also haw you repair crash damage that tears the wing covering.


Quote:
Originally Posted by Controlled Fall
During motor installation, I began to wonder about attaching the prop. There were no instructions at all included with my motor and figured that this was another case of tribal knowledge where it is assumed everyone knows how to attach a prop. There were two nuts and a washer on my prop shaft. I assumed that the prop went between the two nuts. The washer did not fit since the mating surface on the prop was hexagonal like the nuts...so I removed it.
I have attached the tribal knowledge of how a GWS slow-fly propeller is attached. The exploded view is from the GWS web site, and is also on the back of the motor package. The sequence is (1) nut, (2)prop, (3)washer,(4) nut. The first nut fits into the hex on back of the prop.

Thanks, Bruce
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Old Mar 14, 2007, 11:21 AM
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Bailey, CO
Joined Apr 2006
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Quote:
Originally Posted by Controlled Fall
Had a quick thought. I found a video in the Beginners section on "How to solder." I have a better idea of how its supposed to work, but was hoping to avoid a trip to the store if what I have is sufficient.

1. Could the heat shrink tubing provided with the Dandy be used to cover the battery/JST joint after soldering?

2. Is "silver bearing solder," 0.022 diameter, 62/36/2 (don't know what that means) suitable for this application?

I don't mind going to the store to get the right stuff, but if I can avoid it I'd like to These may be dumb, basic questions, but I actually have minimal background in electronics.
Dear CF,

The questions you ask are really challenging. Solder is a complex technology. Here is what your numbers mean:

62% Tin (Sn)
36% Lead (Pb)
2% Silver (Ag)

This formulation of solder is for bonding plated surfaces, not wire. The melting point is fairly high, and the resulting bond lacks ductility, which means it is pretty brittle. You could use the stuff and it would likely work, but it would be less than optimal.

Standard electrical solder is 60/40, or 60% tin, and 40% lead. You want Rosin core 60/40 electrical solder with a diameter of about 0.040" (1mm) to 0.060.

You will also need some heat shrink tubing. I find that 3/32" diameter heat shrink tubing to be the most useful for small electrics. In the Du-Bro product line 3/32" is green. Slide the heat shrink tubing on the wires to be soldered. Get the tubing as far from the joint as possible. After you solder the joint, let the solder cool a bit then slide the tubing over the joint and shrink.

Thanks, Bruce
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Old Mar 14, 2007, 01:02 PM
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Canada, BC, Victoria
Joined Mar 2004
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A couple of notes:
1) I would suggest getting some clear heat shrink tubing from your local electronics supplier. That way you can check the status of your solder joints. In my case, the battery wires have broken just behind the solder joint to the connector. Twice!

2) Prop saver. Saves props, drive shafts, etc. Attach a servo arm as you would attach a prop. Rubber band the prop on, leaving enough give so the prop bends back on a "bumpy" landing. Searching will turn up a ton of info, or PM me if interested.

3) JST connectors, I hear, are suited only for low amp applications. My GWS 350 can pull 10+ amps depending on prop/battery. I hear that this can cause JST connectors to melt. You may want to look at something like deans micro (~10 amp rating?) or Deans ultra/Anderson powerpoles/similar (~25 amp ++?).

The Deans ultra have worked for me, but they really can be a pain to pull apart. They are easy to solder the wires to, and I'm a newbie at soldering too. (40 watt iron.)

Hope this helps.
Colin
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Old Mar 14, 2007, 02:20 PM
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Bailey, CO
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Quote:
Originally Posted by ColinB
A couple of notes:
1) I would suggest getting some clear heat shrink tubing from your local electronics supplier. That way you can check the status of your solder joints. In my case, the battery wires have broken just behind the solder joint to the connector. Twice!

2) Prop saver. Saves props, drive shafts, etc. Attach a servo arm as you would attach a prop. Rubber band the prop on, leaving enough give so the prop bends back on a "bumpy" landing. Searching will turn up a ton of info, or PM me if interested.

3) JST connectors, I hear, are suited only for low amp applications. My GWS 350 can pull 10+ amps depending on prop/battery. I hear that this can cause JST connectors to melt. You may want to look at something like deans micro (~10 amp rating?) or Deans ultra/Anderson powerpoles/similar (~25 amp ++?).

The Deans ultra have worked for me, but they really can be a pain to pull apart. They are easy to solder the wires to, and I'm a newbie at soldering too. (40 watt iron.)

Hope this helps.
Colin
Dear Collin and CF,

A GWS EPS-100 will at best pull about 5 Amps. I have pulled as much as 15 Amps through JST connectors without any problems. The JST connectors seem to be good for applications up to and including geared 400s.

Thanks, Bruce
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Old Mar 14, 2007, 03:07 PM
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Frederick Maryland USA
Joined Jul 2004
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While it is true that the JST connectors won't melt at 5-10 amps, you are losing power because of their higher resistance.
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Old Mar 14, 2007, 09:44 PM
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Chantilly, VA
Joined Dec 2006
213 Posts
Holy Cow! Great info guys! Thanks for the diagrams Bruce. Still got my washer!
Colin, you've piqued my interest about prop saver. I'm not sure what you mean, but things that extend service life do interest me!
Duetto, I assume Deans have lower resistance...I have had read great things about these connecters but don't have any yet.
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Old Mar 14, 2007, 09:52 PM
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Chantilly, VA
Joined Dec 2006
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DONE! Sort of...

Except for scavenging up a receiver to test my controls and soldering up my power plant, the airframe is done!

Thanks to everyone who has participated in this thread--I have learned an awful lot in six weeks of building, and I realize its just the tip of an iceberg.
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Old Mar 15, 2007, 12:56 AM
The Evil Twin
Garden City, GA
Joined Feb 2004
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CF, this has been fun. Thanks for bringing your experiences public. Following all of this brings back many great memories.

Your plane looks great. Double check your CG and the washout as my brother Doug mentioned and go fly. Seems that you have everything under control but I'll suggest that if you have an experienced flyer locally to check everything out it wouldn't hurt. Some of the the best times at MM were when local flyers would come by the shop for advice. That's the beauty of this community, there are so many who wish to share.

Waiting to hear of the maiden.

Matthew
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Old Mar 15, 2007, 10:31 AM
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brucea's Avatar
Bailey, CO
Joined Apr 2006
1,540 Posts
Congatulations!

Quote:
Originally Posted by Controlled Fall
Except for scavenging up a receiver to test my controls and soldering up my power plant, the airframe is done!

Thanks to everyone who has participated in this thread--I have learned an awful lot in six weeks of building, and I realize its just the tip of an iceberg.
Dear Controlled,

The Dandy looks great! I have looked forward to your posts. You have taught yourself how to build an airplane. Congratulations!

What is your next project?

After the MiniFlash, my next project is a MM Switchback. I need to build some plane storage racks. Then I will whip together some Foamies. And throw together another IFO.

I learn something new every time I build a kit. Keep us posted on your maiden flight, and other experiences you may have. When I maiden a plane, my heart is pounding, my palms are sweaty, and my knees are shaking!

One last bit of advice. When you are installing and testing your in-flight electronics, please REMOVE THE PROPELLER.

Thanks, Bruce
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Old Mar 16, 2007, 07:10 AM
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Chantilly, VA
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Matthew and Bruce,
Thanks for the kind words! Both of you were instrumental in helping me put this together.

Luckily, there are a few RCGroup members in the area so hopefully I can get some QA "in real life." Whereas I think I have some washout, I don't think its as much as Doug suggested.

As far the next step, I'll probably take a break for a week or so. My normal building time was actually between 5-7AM, but the accumulated fatigue of being a new father has really caught up with me and the wife the last couple of weeks. I'd like to reorganize my basement. Its still hasn't been fully unpacked from the move last summer, and I need to find places for all my new toys, covering rolls, etc.

I do have an EVA bipe on the shelf just waiting for me to glue myself to it

And as far as a maiden goes, I live in pretty overdeveloped part of Northern VA (20 miles west of DC), but I do have lots of small parks. Before our daughter was born, I'd slip over to the largest one and fly in the cold morning air before other folks showed up. However since her birth, I've been oversleeping on weekends.

So the day before yesterday, I made a concerted effort to schedule my lunch after an off-site meeting that just happened to be within a mile of this park. My EZ* is in the car so I can park, charge, and fly.

I get there in the middle of a work day, and the park is full of grown men playing soccer. Don't these people have jobs???!!!!

Hopefully I will find a solution to sneak in some flying!
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Old Mar 16, 2007, 10:29 PM
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Bailey, CO
Joined Apr 2006
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Quote:
Originally Posted by Controlled Fall
Matthew and Bruce,
Thanks for the kind words! Both of you were instrumental in helping me put this together. Luckily, there are a few RCGroup members in the area so hopefully I can get some QA "in real life." Whereas I think I have some washout, I don't think its as much as Doug suggested.

As far the next step, I'll probably take a break for a week or so. My normal building time was actually between 5-7AM, but the accumulated fatigue of being a new father has really caught up with me and the wife the last couple of weeks. I'd like to reorganize my basement. Its still hasn't been fully unpacked from the move last summer, and I need to find places for all my new toys, covering rolls, etc.

I do have an EVA bipe on the shelf just waiting for me to glue myself to it

And as far as a maiden goes, I live in pretty overdeveloped part of Northern VA (20 miles west of DC), but I do have lots of small parks. Before our daughter was born, I'd slip over to the largest one and fly in the cold morning air before other folks showed up. However since her birth, I've been oversleeping on weekends.

So the day before yesterday, I made a concerted effort to schedule my lunch after an off-site meeting that just happened to be within a mile of this park. My EZ* is in the car so I can park, charge, and fly.

I get there in the middle of a work day, and the park is full of grown men playing soccer. Don't these people have jobs???!!!!

Hopefully I will find a solution to sneak in some flying!
Dear CF,

I have been frustrated that I have not been able to go flying for a couple of weeks. The weather has been terrible here. I work at home so I can often sneak out and get some flying done during the workday. It has been too windy. Besides, I want better performing planes. I have the Switchback on deck. I have a BMJR Fast Freddie III that is on my shelf. This is a very small wing and boom plane.

BMJR Fast Fredddie

BMJR sells some quirky kits. My wife gave me a StevenAero G480 V2 Re-Groove for Christmas. This is a cool plane.

SA G480 Re-Groove

I have two Great Planes kits, A Tutor Trainer and RV-4. These are not easy kits to build and were designed for geared brushed motors. The quality of the balsa is not as good as Mountain Models. The parts do not interlock. These are very old school kits that have to be pinned to the plans. On the plus side the kits build into very light and good flying planes.

Great Planes RV-4 Kit

Tutor Trainer

I have a 200 Watt Himax outrunner looking for a home. I wonder if the Flashback or Tantrum would be a good place for this motor. I like the Mountian Models kits.

Take some time off and rest. This weekend, I have to do the brakes on my wife's car and take one of my sons back to college. I am making very slow progress on the MiniFlash. I hate it when life intrudes on my hobbies. I gotta figure out a way to get more building time.

Thanks, Bruce
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Old Mar 20, 2007, 10:47 PM
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Chantilly, VA
Joined Dec 2006
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Not Quite Done Yet: Solder! Ouch!

If you could have been a fly on the wall the past half hour. Come with me wise modelers down memory lane...welcome to Newbyville...

Yep, I finished the airframe but still had the formality of joining my JST connections with the battery pack. I had a soldering iron I bought as a kid for some long forgotten (failed) project, and taking Bruce's shopping list, I went looking for the appropriate solder.

Last weekend I went to Home Depot to pick up solder, some weed and feed for the yard, as well as some organizing gear for the shop. The fertilizer was easy, but I could not find the right stuff for the workshop. The organizing gear was either a "tacklebox" or some monstrosity that was far too big for what I needed. The solder there was huge diameter so I left with only a big bag of seed. That's not any fun

This afternoon I go to the mall as I know there is a Radio Shack. Certainly Radio Shack would come through. I walk in confidently but am slowly reduced to dumbfounded gawking as I realize that is a glorified cell phone shop.

"Can I help you?"
"Uh, yeah, do you all carry solder?"
"Sorry, you need to go to a bigger Radio Shack..."


I drop by the LHS, they're out too, but lo and behold, they're next door to an electronics store, and I'm in luck.

So I set up shop after getting the kids to bed. I refreshed myself on this link which showed me what effective soldering looked like. I am confident.

I trim my leads, insert my heat shrink, clamp my lead, and prepare to weld.
As I touch the iron to the solder I wait and wait, and then smoke! The metal gets shiny and liquid, and I've put too much on. It hardens as a big nasty blob. The fumes are choking. I reheat the clot and push it off onto my work table. Finally, after lots of coughing and manipulating I get it looking so so. Its not going to win a beauty contest.

I place my soldering iron down to move on to the second wire, but the tightly coiled power cord almost latches on to the hot tip! As I "rescue" the iron from itself, my grip is lousy, and it flips over landing on the back of my middle finger I immediately flip it off (literally not figuratively but I am thinking about screaming the word ), but it lands on a plastic bag holding my terry cloth on the far side of the table--melting the bag while I reach for the sink trying to cool my hand.

I regain my composure and restart the job. One wire down, one to go.

As I flawlessly join the two leads I begin to sit back and enjoy my handiwork. That's when I realize I forgot to put the heat shrink on first

OK, I'm abusing the out of the emoticons

By the time I'm done it doesn't look nearly as good as the original bond, but its done. I am reminded that metal conducts heat as well. Even with the insulation and even though its over an inch away, my finger gets uncomfortably warm in the latter stages of trying to get wires rejoined.

I'm less than confident that this will charge and power my plane properly, but I've got to learn this skill somehow. Photos are attached!
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Last edited by Controlled Fall; Mar 20, 2007 at 10:58 PM. Reason: Typos...too tired to type....too tired to solder...
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Old Mar 21, 2007, 10:10 PM
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Chantilly, VA
Joined Dec 2006
213 Posts
Rather anti-climatic test run.

After charging up my NiMH, I plug it into the speed controller, and...

nothing.

I'm still pulling about 10V when I check with a multimeter so how would I troubleshoot a speed controller?
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Old Mar 22, 2007, 11:10 AM
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Canada, BC, Victoria
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CF,
Can you explain in more detail? How do you know it is the speed controller?

- Check your solder joints.
- Polarity correct?
- Is speed controller plugged into correct channel? (Don't ask me about this one.)
- Motor connected?
- Throttle off, and trim down, to allow controller to "arm?"
- Any lights on the controller, movement, or servo action?
- Does receiver work?
Colin
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