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Mar 26, 2018, 02:14 AM
Registered User
PaulB's Avatar
IMHO it looks about right.........

IF your C of G is where B o C has posted (and not, for example, 27% away from the REAR of the wing, had that one before) you should be good to go.

As you are not, something else must be happening that is not apparent on the ground or in the air.

Are you wings REALLY secure???? I cannot see how they are attached but if you are using rubber band you need 6 fitted from front to back (LE to TE). Is your elevator secure and stiff enough, sometimes a floppy rear stab can twist if flight.

Now for my 'Hummmmm' one. That engine mount, good idea but I don't like it .

COULD be prone to 'pulling away' from the bulkhead and then it could tilt in any direction..... In theory a 'break away' engine mount may seem to be a good idea but in practice i have not come across one that is firm enough to fly but will still 'give' when it needs to without some form of sacrificial plate or whatever.

Now for the 'Dad' bit...... My STRONG advice would be to LISTEN to what C o B says and build a known design first to learn to fly!!!! Great respect for 'doing it your way' but cannot say that that is the right way. Build an EZ Fly for a couple of beer tokens and learn to crash fly that first to give yourself the best chance then go back to your Baby.

Paul
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Mar 26, 2018, 02:24 AM
flyin' fool
goldguy's Avatar
Your design is too 'shortly coupled' to be a good stable platform to start with .............. meaning that the nose and tail are far too short.

If you want to be successful, find a proved design and build it as the designer intended or follow the basic rules of design.

Once you've mastered building and flying, then you can experiment with making your own rules and try to 're-invent the wheel.
Last edited by goldguy; Mar 26, 2018 at 02:37 AM.
Mar 26, 2018, 07:44 AM
I Look, Listen, and Learn
Timbo383's Avatar
It's a good attempt at your first build and flight (alot better then my first time).
Now in addition to what the others have said, it looks heavy just sitting there to me. Now the breakaway designs you used for the motor and landing gear seems like a good idea but they just add alot of unnecessary weight. Just glue them on, foam is easily repaired or replaced and it will cushion and collapse in a crash and the damage to the hard parts are minimum. The duck tape you used, while very strong is very heavy, try to use packaging tape if you can. It's almost as strong but it's one quarter of the weight.
All of this weight reduction is for a reason....you are using the foam because it's light after all...like the others have said "a lighter plane gives you more time to correct mistakes in the air.
Also, in my unprofessional opinion, I think the dihedral of the wings could be a little less, but that's just what I think.
Keep trying and making adjustments as you go, it is not an easy hobby to start on but it is very satisfying when you do get it all together and the plane that you built with your own hands is up there flying. I've been doing this for four years now and am still learning and still enjoying it even after all the crashes...many... and rebuilds.
Mar 26, 2018, 11:35 AM
Scratch building addict
rotagen's Avatar
I'm sticking to my original assessment of the problem (wing incidence issue) since I have run into it many times with my designs, so often .... with an added observation.

It's kinda hard to tell with the tape on the wing, but from the side view it looks like the rear of your wing might have some reflex ( pointing upward.)
This would be great for a flying wing design, but decidedly not great for a tailed model.
And it would cause the plane to nose up.

In one of the side view pics it does look like you have a pretty steep wing incidence but I've seen worse.

I've done this a few times, line up a long ruler perfectly with hor. stab holding it vertically and actually marke the side of fuse with pen.

Then put it vertically on the lower surface of the wing and compare, should be only slight angle difference.

As noted, some models just have weird airflow, your wing might be real efficient and it's above the tail so it could be pusing lots of air downwards... But I don't see any major flaws in design.
Last edited by rotagen; Mar 26, 2018 at 11:54 AM.
Mar 26, 2018, 12:46 PM
Registered User
Quote:
Originally Posted by balsa or carbon
jawsqb , here's the info for building an EzFly . Do you have access to flat foam sheets ?

For determining how large to build your EzFly , what is the size/weight of your battery ? To keep wing loading light , you may have to build an EzFly airframe sized 110% or 120% .... depending on the weight of your battery .

Here are the plans ( PDF file ) : https://www.rcgroups.com/forums/show...6&d=1334660760
You'll need a computer connected to a printer . Open the file on Adobe Reader , then scale up to the size needed ( 100% , 110% , 120% , etc ) at the top of the page . Then on your printer's set up page , select "poster" , "cut marks" & "labels" . The printer will then print out tiles that can be assembled into one large poster-sized set of plans .


Here ↓ are what the foam pieces should look like before assembly , and assembly instructions .

Thank you for the build details!

I am confused on a couple things:

- What is the weight of the craft supposed to be at 100% size? I have a range of lipo's that I can use for the craft

- Do I have to get a special pushing prop for this place? Or do I just reverse the motor ?

- For the spar can I use a carbon fiber tube? I have a preety small diamter carbon fiber tube laying around

- I'm unsure exactly where the spar goes

- Would it be possible to add ailerons to this design? For the purposes of a school project


Sorry if these are super beginner questions

I really appreciate your help!
Mar 26, 2018, 01:09 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
Thank you for the build details!

I am confused on a couple things:
1 ) What is the weight of the craft supposed to be at 100% size? I have a range of lipo's that I can use for the craft
2 ) Do I have to get a special pushing prop for this place? Or do I just reverse the motor ?
3 ) For the spar can I use a carbon fiber tube? I have a preety small diamter carbon fiber tube laying around
4 ) I'm unsure exactly where the spar goes
5 ) Would it be possible to add ailerons to this design? For the purposes of a school project

Sorry if these are super beginner questions

I really appreciate your help!
1 ) I'm going to try to help you make a slow flying EzFly . To achieve slow flight ( light wing loading ) , you want to make the plane as light as possible . For a 100% sized EzFly , I've made it as light as 135 grams flying weight .... using a 10 gram motor , 3.7 gram servos , 350mah 2S battery , etc . Please list ALL the electronics you have ( motors , ESCs , servos , batteries , etc ) , so I can make a recommendation for what size EzFly to make .
Also , do you have access to flat foam sheets ? If you live in the USA or Canada , you can get $1 foam board at a Dollar Tree Store .

2 ) You do not need a pusher prop . The MOTOR will be on backwards , but you put the prop on facing forwards ( letters/numbers facing the front ) .

3 ) Yes , you can use a carbon fiber tube . If it bends easily you can add anything else .... wooden stick , bamboo stick , arrow shaft , etc .

4 ) you can put the spar anywhere on the wing ( to keep the wing from folding ) , I put mine right behind the KFm step on top of the wing .

5 ) For "learning to fly" practice , I recommend building your EzFly as designed ..... then building another plane with ailerons later . The rudder on the EzFly controls yaw AND roll , so I recommend plugging the rudder servo into the ROLL ( aileron ) channel .


A very good AILERON plane you can make ( later ) is LeadFeather's Yak 55 . Here's one made and flown by RCG member boa2110 :





Y42 (2 min 28 sec)
Mar 26, 2018, 01:43 PM
flyin' fool
goldguy's Avatar
Or..............

Here's a good trainer that started hundreds upon hundreds of new RC pilots off on the path to success.

https://www.rcgroups.com/forums/show...&highlight=Blu
Mar 26, 2018, 02:14 PM
serial scratchbuilder
Granted's Avatar
You should really buy some glue. I know duct-tape is a "Real-Man"s tool, it really has little place as a primary adhesive in this hobby. Glue your empennage and control horns on and you might have some control, tape flexes too much for this. Fix that wiring too, that is well on its way to being tragic.
Rotagen is right about the shape of your wing, the profile looks like a bisected fish. Lose the tail.
Mar 26, 2018, 03:44 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
The OP jawsqb has asked me ( in a PM ) to help him build an EzFly , so that's the path we're on now . Due to the fact that he's broken a few props , he likes the EzFly because it has a protected motor/PROP . I'm not sure if he has completely abandoned trying to get his current plane to fly .
Mar 26, 2018, 07:32 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
jawsqb , have you practiced on an RC simulator ? RC sims are good for developing a little muscle memory in preparation for real world RC flight .
If you have a cable to connect your transmitter to a PC , there are free downloadable sims available ..... such as FMS & RC Desk Pilot .
http://modelsimulator.com
http://rcdeskpilot.com

There are also free RC sim apps for touchscreen devices ..... Apple or Android .

Mar 27, 2018, 07:19 AM
Registered User
davereap's Avatar
Give up on the first model, strip the gear out and go with an EZfly... its a good one to start with..
Keep it light...
Mar 27, 2018, 12:03 PM
Registered User
Quote:
Originally Posted by balsa or carbon
1 ) I'm going to try to help you make a slow flying EzFly . To achieve slow flight ( light wing loading ) , you want to make the plane as light as possible . For a 100% sized EzFly , I've made it as light as 135 grams flying weight .... using a 10 gram motor , 3.7 gram servos , 350mah 2S battery , etc . Please list ALL the electronics you have ( motors , ESCs , servos , batteries , etc ) , so I can make a recommendation for what size EzFly to make .
Also , do you have access to flat foam sheets ? If you live in the USA or Canada , you can get $1 foam board at a Dollar Tree Store .

2 ) You do not need a pusher prop . The MOTOR will be on backwards , but you put the prop on facing forwards ( letters/numbers facing the front ) .

3 ) Yes , you can use a carbon fiber tube . If it bends easily you can add anything else .... wooden stick , bamboo stick , arrow shaft , etc .

4 ) you can put the spar anywhere on the wing ( to keep the wing from folding ) , I put mine right behind the KFm step on top of the wing .

5 ) For "learning to fly" practice , I recommend building your EzFly as designed ..... then building another plane with ailerons later . The rudder on the EzFly controls yaw AND roll , so I recommend plugging the rudder servo into the ROLL ( aileron ) channel .


A very good AILERON plane you can make ( later ) is LeadFeather's Yak 55 . Here's one made and flown by RCG member boa2110 :



https://www.youtube.com/watch?v=8mw4...ature=youtu.be




Okay, I will definitely put my first design I put earlier on hold, and go for the EZ Fly Design.

I have gotten the dollar tree foam board for the build.

I will weigh out all the components I have later today. However Its looking like my build would be around 250 - 350 grams, ill get a more specific weight asap.

I tried printing out the design using the poster print method on adobe however I'm getting some white space on the edges of the paper that make it a bit hard to line up the drawings to get it all together. Is there a better way to go about printing out the template for the ez flyer?

Do you think it would be better if I start off with the yak -55 rather than the ezflyer? I have about a week and half time to get a well functioning plane.

Ill definitely check out those simulators, not sure what cable I would need to connect it however. I have a flysky transmitter

I plan to then add in an arduino with acclerometer/gyroscope to measure angle of the plane (Pitch and roll angle) and the arduino with actuate the servos (that control the controlsurfaces) to try and level the plane . This is for a feedback control class
Last edited by jawsqb; Mar 27, 2018 at 12:10 PM.
Mar 27, 2018, 01:22 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
Okay, I will definitely put my first design I put earlier on hold, and go for the EZ Fly Design.

1 ) I have gotten the dollar tree foam board for the build.

2 ) I will weigh out all the components I have later today. However Its looking like my build would be around 250 - 350 grams, ill get a more specific weight asap.

3 ) I tried printing out the design using the poster print method on adobe however I'm getting some white space on the edges of the paper that make it a bit hard to line up the drawings to get it all together. Is there a better way to go about printing out the template for the ez flyer?

4 ) Do you think it would be better if I start off with the yak -55 rather than the ezflyer? I have about a week and half time to get a well functioning plane.

5 ) Ill definitely check out those simulators, not sure what cable I would need to connect it however. I have a flysky transmitter

6 ) I plan to then add in an arduino with acclerometer/gyroscope to measure angle of the plane (Pitch and roll angle) and the arduino with actuate the servos (that control the controlsurfaces) to try and level the plane . This is for a feedback control class


1 ) Great ! DTFB ( Dollar Tree Foam Board ) will work well for building your EzFly , but you can not let it get wet ... so don't fly where your plane will land on wet grass . Also , use a low temp hot glue gun to assemble the EzFly ..... less than $3 at Walmart .

2 ) Until I know how light-or-heavy your components are , I can't make an airframe size recommendation . Do you have smaller/lighter components than the ones I can see in your photos ? If you will be using the components I can see on your plane in the photos , my guesstimate is that you should make a 120% airframe .

3 ) Did you select "cut marks" & "labels" on your printer's set up page ? The cut marks are to help you align the tiles , and the white space on the edges are overlap .... you can cut them off at the cut marks on the left side and top side of each tile .
Or you can print out the EzFly R3 Drawing on one sheet of printer paper ; then take that print to a FedEx Office where they can scan it , enlarge it to 120% ( using the inch scale on the R3 drawing ) , then print it out on their large format printer .

4 ) The Yak 55 is NOT a good plane for an unassisted first time flyer ..... it has no inherent airframe stability , and you'll be right back to breaking props all the time .

5 ) if you have a touchscreen device ( tablet/iPad , smartphone , etc ) , try a free RC sim app . Or a local RC hobby shop may have a demo PC sim in their shop .

6 ) Electronic flight stabilization is great .... IF .... it's properly set up on a plane that's been properly designed/constructed & set up ( CG , control surface direction , control surface throws/high-low-rates , expo , etc ) . The reason I recommended the EzFly is that the airframe is inherently stable , so electronic flight stabilization isn't needed .

Let's get you flying successfully FIRST ....... then deal with ailerons/etc LATER .

If the EzFly plans/printing-tiles/assembling-tiles/etc are too much to deal with right now , I know of two MUCH simpler planes that can be built without plans ..... let me know .
Last edited by balsa or carbon; Mar 27, 2018 at 01:46 PM.
Mar 27, 2018, 05:43 PM
Registered User
Quote:
Originally Posted by balsa or carbon
1 ) Great ! DTFB ( Dollar Tree Foam Board ) will work well for building your EzFly , but you can not let it get wet ... so don't fly where your plane will land on wet grass . Also , use a low temp hot glue gun to assemble the EzFly ..... less than $3 at Walmart .

2 ) Until I know how light-or-heavy your components are , I can't make an airframe size recommendation . Do you have smaller/lighter components than the ones I can see in your photos ? If you will be using the components I can see on your plane in the photos , my guesstimate is that you should make a 120% airframe .

3 ) Did you select "cut marks" & "labels" on your printer's set up page ? The cut marks are to help you align the tiles , and the white space on the edges are overlap .... you can cut them off at the cut marks on the left side and top side of each tile .
Or you can print out the EzFly R3 Drawing on one sheet of printer paper ; then take that print to a FedEx Office where they can scan it , enlarge it to 120% ( using the inch scale on the R3 drawing ) , then print it out on their large format printer .

4 ) The Yak 55 is NOT a good plane for an unassisted first time flyer ..... it has no inherent airframe stability , and you'll be right back to breaking props all the time .

5 ) if you have a touchscreen device ( tablet/iPad , smartphone , etc ) , try a free RC sim app . Or a local RC hobby shop may have a demo PC sim in their shop .

6 ) Electronic flight stabilization is great .... IF .... it's properly set up on a plane that's been properly designed/constructed & set up ( CG , control surface direction , control surface throws/high-low-rates , expo , etc ) . The reason I recommended the EzFly is that the airframe is inherently stable , so electronic flight stabilization isn't needed .

Let's get you flying successfully FIRST ....... then deal with ailerons/etc LATER .

If the EzFly plans/printing-tiles/assembling-tiles/etc are too much to deal with right now , I know of two MUCH simpler planes that can be built without plans ..... let me know .


Here is the weight of my components, I have already started cutting the foam at 100% size. Is it still fine?

I should have most of the construction done by tomorrow.

Thanks!
Mar 27, 2018, 06:02 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
Here is the weight of my components, I have already started cutting the foam at 100% size. Is it still fine?

I should have most of the construction done by tomorrow.

Thanks!
Those components should be OK for a 100% EzFly . Is that the only ESC you have ? ...... it seems big/heavy for that quadcopter motor .

If possible , post photos of your build progress so I can spot potential problems ( before it's too late to correct them ) .

If it's not too late , you can still get more wing area ( for lighter wing loading ) by extending the SPAN of each wing-half at the root .... like in the drawing below ↓ . Adding 3" or 4" to the root of each wing-half will increase the total wingspan to 37" or 39" .


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