Thread Tools
Mar 27, 2018, 06:22 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
If I haven't mentioned this earlier , build your EzFly ( and any other plane ) with FLYING IN MIND ........ NOT surviving crashes in mind . In this forum that's often called " build to fly , not to crash " .
So ONLY add what it needs to fly , do NOT add unnecessary weight such as : landing gear , decorations , "crash-proofing" reinforcements ( plywood , duct-tape/packing-tape , etc ) . The ONLY reinforcement an EzFly needs is a wing spar .

A light , slow-flying plane flies better ( and is therefore less LIKELY to crash ) ..... and if it DOES hit the ground , it does so with less speed/mass/momentum/energy ( than a faster flying heavier plane ) .
Sign up now
to remove ads between posts
Mar 27, 2018, 06:59 PM
Registered User
Quote:
Originally Posted by balsa or carbon
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" .
I'll definitely post some pictures tomorrow!

Its seems that I have to use 3 layers of the foam board to get it to fit flush in that reinforced section where the KF doubler goes, is this okay?

I'm still a bit confused on how the vertical stabilizer and the rudder is attached to the plane. Is it just hot glue'd on? Can I get some more detailed pics regarding that connection?

Also what is the best way to get those bends at the end of the wing?

What is the method that you suggest for hinging the control surfaces?

Just out of curiosity is this dollar tree foam suitable for a laser cutting machine? Have you ever tried using laser cutting machine on foam, how about a CNC on some thicker 2" thick Home Depot Pink foam?
Mar 27, 2018, 08:14 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
I'll definitely post some pictures tomorrow!

1 ) Its seems that I have to use 3 layers of the foam board to get it to fit flush in that reinforced section where the KF doubler goes, is this okay?

2 ) I'm still a bit confused on how the vertical stabilizer and the rudder is attached to the plane. Is it just hot glue'd on? Can I get some more detailed pics regarding that connection?

3 ) Also what is the best way to get those bends at the end of the wing?

4 ) What is the method that you suggest for hinging the control surfaces?

5 ) Just out of curiosity is this dollar tree foam suitable for a laser cutting machine? Have you ever tried using laser cutting machine on foam, how about a CNC on some thicker 2" thick Home Depot Pink foam?

1 ) Don't make the entire KFm doubler three layers ..... but where the wing fits into the fuselage : just fill in the gap with a piece of scrap foam .

2 ) Hinge the rudder to the vertical stabilizer ( only ) , then AFTER you insert/glue the horizontal pieces into the vertical pieces ..... hinge the rudder to the bottom/rear of the fuselage . After hinging the bottom of the rudder to the bottom/rear of the fuselage , then hot glue the vertical stabilizer to the TOP of the fuselage .... centered , straight , square and true . When inserting/gluing the horizontal pieces into the vertical pieces , be sure to keep everything true & square ( fuselage straight , & wing at 90 degree angle to the fuselage when viewed from the front ) .

3 ) Link to how I put in polyhedral angles on wing : https://www.rcgroups.com/forums/show...1&postcount=67

4 ) Link to how I hinge control surfaces : https://www.rcgroups.com/forums/show...0&postcount=71

5 ) I've never tried any type of laser/CNC cutter , I just use a VERY-sharp brand-new razor blade . But if you have that technology available to you , just try it on some scrap foam board .
Last edited by balsa or carbon; Mar 27, 2018 at 08:27 PM.
Mar 28, 2018, 08:28 AM
Registered User
Quote:
Originally Posted by balsa or carbon
1 ) Don't make the entire KFm doubler three layers ..... but where the wing fits into the fuselage : just fill in the gap with a piece of scrap foam .

2 ) Hinge the rudder to the vertical stabilizer ( only ) , then AFTER you insert/glue the horizontal pieces into the vertical pieces ..... hinge the rudder to the bottom/rear of the fuselage . After hinging the bottom of the rudder to the bottom/rear of the fuselage , then hot glue the vertical stabilizer to the TOP of the fuselage .... centered , straight , square and true . When inserting/gluing the horizontal pieces into the vertical pieces , be sure to keep everything true & square ( fuselage straight , & wing at 90 degree angle to the fuselage when viewed from the front ) .

3 ) Link to how I put in polyhedral angles on wing : https://www.rcgroups.com/forums/show...1&postcount=67

4 ) Link to how I hinge control surfaces : https://www.rcgroups.com/forums/show...0&postcount=71

5 ) I've never tried any type of laser/CNC cutter , I just use a VERY-sharp brand-new razor blade . But if you have that technology available to you , just try it on some scrap foam board .

Got it! Thanks again for for all this help!

Another question:

I read online that for rear facing motors the thrust angle has to be compensated up. Is this true for this design? Or should I disregard that for now.

I also seem to have cut the vertical section into two pieces instead of cutting it as one whole piece (I misinterpreted the drawings) would it be okay to connect the two pieces together just with some duct tape rather than doing the whole piece over?

Also I'm a bit skeptical on how strong the vertical stabilizer would be securely attached to the plane with just some glue on the bottom of the piece. I'm not seeing it in the diagrams given but is there and indent cut out of the horizontal section (section with with the elevator is attached) to allow for the vertical stabilizer to be secured in?


I will post pictures soon!
Mar 28, 2018, 10:00 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
Got it! Thanks again for for all this help!

Another question:

1 ) I read online that for rear facing motors the thrust angle has to be compensated up. Is this true for this design? Or should I disregard that for now.

2 ) I also seem to have cut the vertical section into two pieces instead of cutting it as one whole piece (I misinterpreted the drawings) would it be okay to connect the two pieces together just with some duct tape rather than doing the whole piece over?

3 ) Also I'm a bit skeptical on how strong the vertical stabilizer would be securely attached to the plane with just some glue on the bottom of the piece. I'm not seeing it in the diagrams given but is there and indent cut out of the horizontal section (section with with the elevator is attached) to allow for the vertical stabilizer to be secured in?


I will post pictures soon!

1 ) No need to adjust the thrust line . The motor/prop are mounted slightly above the pitch axis , giving it down thrust effect . Just mount the motor/prop so the prop is straight and centered in both the vertical & horizontal prop slots . Don't forget that the numbers/letters on the prop need to face to the front of the plane .

2 ) Can you show me in a photo what you mean ? And please do not use duct tape anywhere on this plane , it's too heavy . The only place you need tape is the hinges , and it's best to use lightweight packing tape .... or even just scotch tape .

3 ) I've built DOZENS of EzFlys ( for myself and other people ) , and I've never had the v-stab come loose . You can add a hot glue fillet to both sides if you want ↓ .
Last edited by balsa or carbon; Mar 28, 2018 at 10:12 AM.
Mar 28, 2018, 11:48 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Here's a video of my neighbor flying his EzFly ( that I made for him out of DTFB ) . He has a crazy flying style , at about 3:40 the EzFly takes a hard hit to the ground ..... then it just keeps on going ! ..... tough bird !

Bouncy Plane (4 min 58 sec)
Mar 28, 2018, 01:32 PM
Registered User
Dont question the designs. There proven to work. Follow the plans and dont change anything. Once you get a feel for what works then you can change things.

I built a yak 55 on thr heavy side. It flew but wasnt very good in slow flight. It usually broke in every crash.
Mar 28, 2018, 01:33 PM
Registered User
Quote:
Originally Posted by balsa or carbon
1 ) No need to adjust the thrust line . The motor/prop are mounted slightly above the pitch axis , giving it down thrust effect . Just mount the motor/prop so the prop is straight and centered in both the vertical & horizontal prop slots . Don't forget that the numbers/letters on the prop need to face to the front of the plane .

2 ) Can you show me in a photo what you mean ? And please do not use duct tape anywhere on this plane , it's too heavy . The only place you need tape is the hinges , and it's best to use lightweight packing tape .... or even just scotch tape .

3 ) I've built DOZENS of EzFlys ( for myself and other people ) , and I've never had the v-stab come loose . You can add a hot glue fillet to both sides if you want ↓ .
Here is a pic of my cutouts so far,

whats the best way to connect the tail end of the horizontal section with my wing?

also im supposed to peel the paper off the foamboard before hot glueing correct?

Let me know if theres anything else I need to fix!
Mar 28, 2018, 02:14 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
Here is a pic of my cutouts so far,

whats the best way to connect the tail end of the horizontal section with my wing?

also im supposed to peel the paper off the foamboard before hot glueing correct?

Let me know if theres anything else I need to fix!
No , do NOT remove the paper from the foam ..... the paper skins will give your EzFly a LOT of strength ! Just don't let it get wet ( landing on wet grass , etc ) !


In photo #1 below :
This is what all your vertical pieces should look like BEFORE assembly . Then :
1 ) glue nose doublers to nose , one on left side & one on right side .
2 ) Hinge rudder to vertical stabilizer ONLY ( for now ) .


In photo #2 below :
This is what all your horizontal pieces should look like BEFORE assembly . Then :
1 ) hinge elevator to horizontal stabilizer .
2 ) put polyhedral angles on wing .
3 ) glue ONE KFm doubler on wing .
4 ) glue spar on wing .
5 ) glue h-stab/elevator to rear of horizontal fuselage piece .
6 ) glue front of horizontal fuselage piece to rear of wing .

Then :
1 ) Insert and glue horizontal pieces into vertical pieces , making sure everything is straight , true and square . If there's a gap on top of wing , fill in the gap with a piece of scrap foam .
2 ) Hinge bottom of rudder to bottom of fuselage .
3 ) Glue vertical stabilizer to top of horizontal fuselage .... straight , true and square .
4 ) Glue TOP vertical fuselage piece in place .

Install electronics and FLY !!!!
Last edited by balsa or carbon; Mar 28, 2018 at 05:13 PM.
Mar 29, 2018, 03:19 AM
Registered User
man supe reasy assembly! i need to make me one of those
Mar 29, 2018, 09:53 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by bazsound
man supe reasy assembly! i need to make me one of those
Best scratch-built trainer , IMO !
Mar 29, 2018, 10:16 AM
Registered User
Quote:
Originally Posted by balsa or carbon
No , do NOT remove the paper from the foam ..... the paper skins will give your EzFly a LOT of strength ! Just don't let it get wet ( landing on wet grass , etc ) !


In photo #1 below :
This is what all your vertical pieces should look like BEFORE assembly . Then :
1 ) glue nose doublers to nose , one on left side & one on right side .
2 ) Hinge rudder to vertical stabilizer ONLY ( for now ) .


In photo #2 below :
This is what all your horizontal pieces should look like BEFORE assembly . Then :
1 ) hinge elevator to horizontal stabilizer .
2 ) put polyhedral angles on wing .
3 ) glue ONE KFm doubler on wing .
4 ) glue spar on wing .
5 ) glue h-stab/elevator to rear of horizontal fuselage piece .
6 ) glue front of horizontal fuselage piece to rear of wing .

Then :
1 ) Insert and glue horizontal pieces into vertical pieces , making sure everything is straight , true and square . If there's a gap on top of wing , fill in the gap with a piece of scrap foam .
2 ) Hinge bottom of rudder to bottom of fuselage .
3 ) Glue vertical stabilizer to top of horizontal fuselage .... straight , true and square .
4 ) Glue TOP vertical fuselage piece in place .

Install electronics and FLY !!!!


Okay so I have mostly finished assembly!

My weight with all the components is 400 grams however, is this okay?

Where is the CG supposed to be located from the wing tip?

Please let me know if I need to do any modifications before adding components!
Mar 29, 2018, 10:40 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by jawsqb
Okay so I have mostly finished assembly!

My weight with all the components is 400 grams however, is this okay?

Where is the CG supposed to be located from the wing tip?

Please let me know if I need to do any modifications before adding components!
I don't see a spar or polyhedral on the wing .....

And you forgot this ↓ piece that goes on top of the fuselage ( just in front of the vertical stabilizer ) .
Last edited by balsa or carbon; Mar 29, 2018 at 10:59 AM.
Mar 29, 2018, 11:54 AM
Registered User
I'm in the process of adding that right now, I just wanted to check with you first if the 400g weight was excessive for a 100% scale model or not

also how is the motor attached to the plane?

At what location do I measure cg on the wing?

Also is it okay if I use a tri blade prop?
Last edited by jawsqb; Mar 29, 2018 at 12:05 PM.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! APM Tricoper yaws left while in backwards flight. dynam Tricopter Drones 3 Sep 22, 2016 03:19 PM
Discussion US healthcare ranked lowest in developed world, despite being most expensive Tim Green Life, The Universe, and Politics 122 Sep 07, 2016 10:48 PM
Discussion Young voters in 2014 may be less Democrat-leaning Mr Mootsie Life, The Universe, and Politics 58 May 11, 2014 10:46 AM
Discussion Despite Being Careful Accidents Can Happen! Big Foot 48 Life, The Universe, and Politics 8 Apr 07, 2014 08:49 PM
Discussion T-Rex "leaning" front to back 40trainer Mini Helis 3 Feb 27, 2007 06:56 PM