Building a Flite-Test Flyer Airplane from Speed-Build Kit and from Scratch - Page 2 - RC Groups
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Apr 12, 2018, 10:59 AM
Nu2RC
BSquared18's Avatar
Quote:
A good visual indicator of which connector to use is : if an ESC has thicker gauge wires ( garden hose ) , use a connector ( and battery ) that has the same gauge wires connected to it . If an ESC has thinner gauge wires ( drinking straw ) , use a connector ( and battery ) that has the same gauge wires connected to it .
The leads from the battery are definitely thinner than the leads coming from the ESC. Is there a danger from the battery leads overheating because of the thinner wires?

Bill
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Apr 12, 2018, 11:42 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by BSquared18
The leads from the battery are definitely thinner than the leads coming from the ESC. Is there a danger from the battery leads overheating because of the thinner wires?

Bill
That depends on the amp draw of your motor/prop . If the amp draw is greater than what the battery can deliver , yes there may be overheating of the wires and possibly battery overheating/damage .

Simplified rule of thumb ( as I understand it ) :

If your motor/prop's max amp draw rating is 20A , then you want to use an ESC and battery capable of delivering AT LEAST 20 amps . A battery's ability to deliver is determined by two things : mAh ( capacity ) and C rating ( discharge rate ) , so :

For a motor/prop with a max amp draw of 20A , you want a battery that is :
250mAh ( .250Ah ) with a C rating of 80 ..... .250 x 80 = 20
or
500mAh ( .500Ah ) with a C rating of 40 ..... .500 x 40 = 20
or
1000mAh ( 1Ah ) with a C rating of 20 ..... 1 x 20 = 20
or
2000mAh ( 2Ah ) with a C rating of 10 ..... 2 x 10 = 20

I'm sure someone will come along with a better explanation , but bottom line : it's always best to UNDER prop ..... and OVER ESC & battery .
Last edited by balsa or carbon; Apr 12, 2018 at 01:10 PM.
Apr 12, 2018, 11:54 AM
treefinder
springer's Avatar
Bsquared, I agree with BoC, There's nothing "wrong" with using the xt60s on a smaller 2s pack, the only downside is a small increase in weight (not typically the worst weight gain that you can have - probably less than the "swappable pod" which, considering the low cost of gear nowadays, is a waste of time weight and complexity - my opinion) and space crowding inside the fuse if you do a full fuse. It is by far a more robust connector than the JST.

The little red JST connectors that came on your lipo are generally good for up to 10 amps. I have many of them, and have not had a problem with them. I use a lot of 850 mah 2s packs with JST on my onesheeters that have 1700kv 24gm "blue wonder" style motors and a 7x6 prop. great speed range, runs forever, etc.

The xt60 are good for 60 amps (BIG safety factor for you). I use the XT60s for everything else (1000mah 3s to 2200mah 3s).

Amazon isn't the best place for a first time builder to get gear IMHO, I continue to get most everything from either HobbyKing or Banggood. For the smaller ones, I've settled on zippy compact 850mah packs (25C) with JST. I have several over 4 yrs old, still not puffed, and full capacity. I also use 1000mah 3s Zippy compacts with XT60s from HK. I have found 1500mah 3s pack (ZOP brand) on banggood for about the same prices. The 1500ZOP are same physical size as 1300mah zippys and have been good batteries so far. You will note that all these are available with the connectors that I need, so no soldering.

I should add, Welcome to the scratchbuilding adventure! And congrats on getting your wife to join you!
Apr 12, 2018, 02:08 PM
Nu2RC
BSquared18's Avatar
Below is some info on my battery and motor:

For the swappable power pack I will be building, the Flite-Test store recommends the Turnigy 500mAh 2S 20C or 500mAh 3S 20C battery.

The four batteries I bought are Turnigy 1000mAh 2S 20-30C. Because they are so light (1.9 oz) I thought I could get longer flights with 1000mAh as opposed to 500mAh.

The motor that's part of Flite Test's power pack for the swappable planes is the Emax 2213-935kv. It lists a maximum current of 12 amps.

Given those specs, does it appear that the battery leads can handle the current without overheating?

The table on the package the motor came in mentions stats for only 3S and 4S batteries. If I use 2S batteries, will that be a problem? I realize performance will be less with 2S vs. 3 or 4S, but that's okay. I'm looking for something that can be easily flown.

Bill
Apr 12, 2018, 03:22 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by BSquared18
Below is some info on my battery and motor:

For the swappable power pack I will be building, the Flite-Test store recommends the Turnigy 500mAh 2S 20C or 500mAh 3S 20C battery.

The four batteries I bought are Turnigy 1000mAh 2S 20-30C. Because they are so light (1.9 oz) I thought I could get longer flights with 1000mAh as opposed to 500mAh.

The motor that's part of Flite Test's power pack for the swappable planes is the Emax 2213-935kv. It lists a maximum current of 12 amps.

Given those specs, does it appear that the battery leads can handle the current without overheating?

The table on the package the motor came in mentions stats for only 3S and 4S batteries. If I use 2S batteries, will that be a problem? I realize performance will be less with 2S vs. 3 or 4S, but that's okay. I'm looking for something that can be easily flown.

Bill
The 1000mAh ( 1Ah ) 20C batteries should be good for delivering up to 20 amps ( 1 x 20 ) , so hopefully the wires and connector that the manufacturer put on those batteries are able to handle up to 20 amps . A lot depends on if you trust the accuracy of the manufacturer's stated mAh , C rating and wire/connector choice . If you are curious what the actual amp draw & watts are for a particular motor/prop , many people use a wattmeter .

The kv number of a motor is roughly RPM's per volt , so you'll get higher revs from a 3S battery ( 12.6v fully charged ) .... than a 2S battery ( 8.4v fully charged ) . For example : 935kv with a 10v battery = roughly 9,350 RPM's . There are other factors involved , but that's the gist of it .

The Emax 2213-935kv is a multi-rotor motor with a threaded shaft ( the prop & cap nut may unscrew if spinning in the wrong direction ) . It's totally useable for a fixed wing aircraft , but for future fixed wing aircraft builds .... I recommend getting airplane motors that can use a prop saver or collet prop adapter . HobbyKing , Banggood , Heads Up RC and others have a good selection of airplane motors . Heads Up RC has fast flat rate ( $2.50 ) shipping , and many of their motors & ESC's come with the connectors already soldered on .
Apr 12, 2018, 03:52 PM
Nu2RC
BSquared18's Avatar
Sounds good, BoC. Thanks for the info. I'll keep it in mind.

springer, I'm sort of an Amazon addict because of the free shipping (Prime) and quick (usually one or two days) delivery. I also like the fact that I can read reviews and ask questions of other buyers and see what other questions have been asked/answered. I realize, however, that online stores that specialize in RC stuff have a larger selection to choose from.

Bill
Apr 13, 2018, 10:42 AM
treefinder
springer's Avatar
heh heh, I have a couple of friends just like you. It's ok, but my limited experience with it is that most amazon sellers specialize in a few motor/battery/esc, etc that they like or use, so at each site you get their view of the world. Whereas with HK, Banggood, and Headsup, you can browse the whole gamut of stuff and compare prices, capacity, weights, connectors, etc. Heads up probably has the best analysis of motor prop combos on the web. very useful and if you can't wait for the container boat from China, they have the quick shipping. I tend to use them when I have forgotten something and need it "right now". With all the sites, it is still Caveat emptor, though as we aren't dealing with ASTM certified stuff! On the other hand we aren't using it in $15,000 planes either!

It's funny, that many times if I just do a search for a certain item (like your motor, for instance) that it takes me to one of the sites I use, and is often easier search than if I use the site search. Google is sometimes scary (maybe most times...).
Apr 13, 2018, 11:05 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by springer
It's funny, that many times if I just do a search for a certain item (like your motor, for instance) that it takes me to one of the sites I use, and is often easier search than if I use the site search. Google is sometimes scary (maybe most times...).
Yes : for a specific search , most of the time it's easier/better to use Google than the site search feature . I use Google to find specific items at the HobbyKing site , and I also use Google to find specific information here on RC Groups . Google is all seeing .... all knowing ....
Apr 13, 2018, 12:54 PM
Nu2RC
BSquared18's Avatar
Quote:
Google is all seeing .... all knowing ....
Yes, even with Amazon, sometimes when I haven't been able to find what I want by using Amazon's search feature, I have found it on Amazon by using Google. (Sorry, Springer, for mentioning Amazon again. Can't teach an old dog new tricks, I suppose.)

Bill
Apr 13, 2018, 10:16 PM
treefinder
springer's Avatar
No worries, we have two kindles, so amazon gets used here too.
Apr 14, 2018, 07:38 PM
Registered User
Quote:
Originally Posted by balsa or carbon
Yes : for a specific search , most of the time it's easier/better to use Google than the site search feature . I use Google to find specific items at the HobbyKing site , and I also use Google to find specific information here on RC Groups . Google is all seeing .... all knowing ....
Hobbyking is a special case. They seriously screwed up the site. Search hasnt been the same for years. It gives the weirdest results. Google? Straight to what u want
Apr 14, 2018, 08:12 PM
treefinder
springer's Avatar
Pretty amazing how they could have made a slightly quirky, but consistent and easily learned site into a setup that most everyone loves to hate! That was one of the things that pushed me more to Banggood as they were growing their business. The generally free shipping and way they handle multiple warehouses is excellent.

Hobby King anecdote: I ordered two things from them and one was only available at global warehouse, the other at both global and US. I specifically selected global for both items as total was under 100 grams and got the $3.99 shipping. As I went through the ordering the site asked what address I wanted for the US warehouse. My address was the default, so I clicked it without thinking. Finlshed the order and found that they had shipped one item from global for $3.99, and the other from US for $7.99. Back on the old site, they would not let me order from two warehouses, so I learned to place a separate order from each. I now realize that I still must!
Apr 14, 2018, 08:20 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by bazsound
Hobbyking is a special case. They seriously screwed up the site. Search hasnt been the same for years. It gives the weirdest results. Google? Straight to what u want
HobbyKing is slightly better now .... compared to when they first screwed up the site . They've added lots of filters ( on the left side ) to help you narrow things down a bit .... but it's still a hassle .
But I still use HobbyKing because I like their products ( like hexTronik motors & Turnigy batteries ) and their prices . And I happen to live in the city where the HK USA warehouse is located .... so I just pick up my orders at the warehouse .
Apr 15, 2018, 09:21 AM
treefinder
springer's Avatar
Agree, they are the only source for certain good and useful things.

Same town, some folks have all the luck!
Apr 22, 2018, 01:03 PM
Nu2RC
BSquared18's Avatar

Basic Training


Hi,
Because I’m using tools and techniques for these builds that I’ve never tried before, I wanted to test them out before applying them to the models. The process provided some valuable lessons.

My goals were to practice…
… printing decals and applying them to foam.
… using an Exacto-type knife to cut through and partially cut through (score) foam.
… gluing pieces of foam together using a hot-glue gun.
… painting onto foam without causing damage to the foam.
… cutting foam with a soldering iron equipped with a copper wire.

Decals
One of the most interesting experiences was the application of DIY waterslide decals to foam. While researching this topic, I came across a fascinating method, which I describe and is discussed in the thread: Applying DIY Waterslide Decals to Depron Foam.

In short, it involves spraying adhesive on the face of a decal, placing the decal face down on the foam, dampening the decal’s paper backing, and peeling off the backing so that the decal shows.

My steps in using that decal-application method are that I …

… trimmed and taped to create a paper sheet with A4 dimensions (the size of the sheets I’m using). This paper sheet is used to print a proof copy before committing to printing a decal sheet. Later, used an easier method: Took a piece of legal-sized paper and trimmed it to A4 size.
… checked to make sure there is sufficient printer ink of all colors for the print run.
… set up the printer’s tray for A4-sized sheets.
… determined the dimensions I wanted for each decal.
… created in Photoshop a new .psd canvas with a white background and the dimensions of A4 paper, because that is the size of the decal paper/film I’m using; i.e., 8.27 × 11.69 inches. (Hayes Paper Co., Water-slide Transparent Decal Paper for inkjet printers)
… set the grid view to primary size 1-inch squares and secondary size 1/10-inch squares (so that decimal dimensions can be estimated).
… in Photoshop imported, drew, and/or typed the artwork for the decals.
… resized each image as necessary.
… for non-symmetrical images, used Edit --> Transform --> Flip Horizontal to make a mirror image. For example, USAF became a mirror image. The US Air Force roundel did not need to be flipped because it is symmetrical. (These directions are for Photoshop 6—yes I still use that version—and may differ for other versions of Photoshop or other programs.)
… created a .png version of the finished Photoshop .psd file (fig. 1)
… opened the .png image.
… opened the Print window. In the print menu, I set Glossy Photo Paper and High Quality.
… printed a proof copy of the page on plain paper.
… on the proof copy, checked to see that the dimensions of the images on the page are correct.
… emptied the printer’s tray and inserted one sheet of Hayes transparent inkjet decal paper, with the shiny side oriented to be printed on.
… once the decal sheet was printed, allowed 30 minutes to dry.
… then used sharp scissors to cut out each decal, allowing about 2-3mm (~ 0.10 inches) of border around the decal. Any 90-degree right angles were rounded to minimize peeling (fig. 2).
... Used Painter's Mate painter's tape on the foam board as guides to assist in positioning the decals. To avoid smearing when water is added later, used a pencil to write notes on the tape.
… sprayed thin coats of 3M Super 77 Multipurpose Adhesive onto a decal. Three passes from about a foot away did the job.
… allowed 30 seconds for the adhesive to become tacky.
… carefully positioned the decal face down onto the foam. Once positioned, it can’t be moved (fig. 3—shows one decal completed and another with the backing still on).
… using a damp cloth or sponge, dampened the decal’s paper backing so that the decal can be seen through the paper backing (fig. 4).
… waited 30 seconds.
… using a hobby (Exacto, etc.) knife, carefully lifted one edge of the paper backing and then peeled the backing off.
… dried the decal, using a hair dryer set on low.

The decals look great and are firmly attached. RCAV8R13 says, “I have used 3M-77 for this next step for years but it eventually fails and the decals peal and shrink. I've had better luck with glue stick.” Because I’m using “Super 77,” I decided to stick with it (no pun intended) to see if it does a better job of holding up over time.

Scoring
In my research, I wasn’t able to find a hobby knife with a built-in way to limit the depth of a cut when scoring instead of cutting all the way through is desired. So, I used an idea mentioned by Granted. He shows a picture of the clip from a mechanical pencil attached to the hobby knife. In that same thread are several other solutions. To hold the clip in place, I added a small hose clamp I happened to have on hand (fig. 5).

Hot-Glue Gun
I purchased the Ad tech 2 Temperature corded hot-glue gun (fig. 6). I also bought a package of four-inch long, large-size glue sticks. I pushed a glue stick all the way into the gun. As instructed, I let the gun heat for 10 minutes on the low setting. Then I pressed the trigger, but nothing happened. I then remembered a video I had seen where a second glue stick was stacked behind the first one. When I did that (the second stick can be seen protruding from the gun) the trigger had something to grab a hold of, and the gun worked.

I realize there is some controversy concerning the weight of the glue-gun glue. One thing I like about this glue gun is that the bead is very narrow, minimizing glue weight. I confirmed that even with the narrow bead, the pieces of foam are firmly attached to each other.

Paint and Masking Tape
I was interested in finding out if the green Painter's Mate painter’s tape and the spray paint that I chose will work with foam.

As you probably know, there are a lot of cautionary comments in these forums about paint “eating” foam. So, it’s important to select the right kind of paint. Concerning aerosol cans, my understanding is that the propellant can be the culprit. One solution is to hold the can a good distance from the foam and use several very light coats instead of fewer heavy coats.

While I’ll be using decals for most of the colored areas on the models, for larger areas I’ll probably be using paint. The paint I chose is Tamia Color for Plastics with the prefix TS. The hobby-store guy said the TS version doesn’t eat foam but the PS version does. (EDIT: Later, I decided to use decals instead of paint because the decals are much brighter.)

After cutting some masking tape to create a circular open area on the foam, I placed the foam board in a spray box and applied several very thin coats of paint with some time to dry in between coats (fig. 7). The result was a well-defined, green circle with no bleed under the tape and no damage to the foam (fig. 8).

One thing I learned is that they aren’t kidding when, on the can, they say “Avoid breathing mist and vapors.” I made the mistake of trying to use the paint indoors. Bad idea! I quickly changed to painting outdoors. (Fortunately, our weather had just gotten warm enough to do that.)

Cutting Foam with Heat
Although I won’t be doing heat-cutting on the kit pieces of foam, and I may not be using it for the scratch-built version, I wanted to see how my soldering-iron setup would work on the piece of scrap foam I was using.

I have a second soldering iron that I’ve modified with a piece of 18-gauge copper wire (fig. 9). As you see, the copper is wrapped around the iron’s tip, with a single, straight piece of wire sticking out for cutting. Also, a rubber band was added to hold the trigger down, making it easier to handle the iron while cutting.

For this soldering iron, the low setting works fine. The copper wire tends to bend a bit during cutting, so I might want to change to a slightly thicker wire at some point. Fig. 10 shows the result of cutting with the soldering iron.

That does it for now. Next step will be to actually start building the kit model. Stay tuned.

Bill
Last edited by BSquared18; May 01, 2018 at 07:51 AM. Reason: Added information to my decal-making/applying steps.


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