Tron inspired canard type build - Page 2 - RC Groups
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Jan 12, 2018, 05:16 PM
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psychedvike's Avatar
Where do you think the CG will be? That will make or break your maden!
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Jan 12, 2018, 06:13 PM
I Look, Listen, and Learn
Timbo383's Avatar
Quote:
Originally Posted by psychedvike
Where do you think the CG will be? That will make or break your maden!
Based on my precise calculated 'guess' it should be 3/4 to 1 inch in front of the LE of the main wing using the chuck glider CG as reference. Going start at 1 inch and adjust as needed based on the test flight....flights, if I get lucky enough to have more than one.
Last edited by Timbo383; Jan 18, 2018 at 07:51 AM. Reason: Wrong number input
Jan 13, 2018, 05:47 PM
I Look, Listen, and Learn
Timbo383's Avatar
Well good news is it was a good enough day to maiden this plane....yep, bad news now, throttled up and tossed it, it went about 4-5 feet almost straight with a what appeared to be a little nose heavy fall to the ground before I gave the elevons some up elevator and it dove "pitched?" into the ground. Took some weight off the front and it went even faster into tera firma. Looks like Ninja was right, I may need to either make some working elevators in the canard or make the canard alot smaller.
Jan 17, 2018, 03:39 PM
I Look, Listen, and Learn
Timbo383's Avatar
Good news, I was reading and looking at some of the planes here on some site and noticed a plane that had a pusher mounted motor with a fuse higher than the wings that was angled down a little. Started thinking maybe my motor isn't properly inline with the cg and that could be causing the downward push into the ground. Did some adjustments and lo and behold up she went into the sky this time...yay. It still wanted to dive when I let go of the up elevons but it went almost straight with a little bit of climb while inverted. Now I need to do some reading and find out what causes that effect. Did not have enough time to do any more testing, I had to pick up my son from school and even tho it was a tough choice, him or the plane, he won....mainly because my wife said pick him up or else....
Jan 18, 2018, 12:50 AM
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ninjasword71's Avatar
Good job! Did you change anything else?
Jan 18, 2018, 07:48 AM
I Look, Listen, and Learn
Timbo383's Avatar
Quote:
Originally Posted by ninjasword71
Good job! Did you change anything else?
Not for that flight, but it is amazing how one little adjustment can make such a difference.
I did shrink the canard a little last night. It looked like....yeah, I just guess, Im not much of a number cruncher type of guy....it was about 35% to 38% of the main wing. I wanted to get it down closer to the suggested 30% so I took off 1/2 inch from the chord and 1 1/2 inch from total width. It still looks good and I'm hoping that will help with the diving problem. If not then I'll give it a degree or two more of up incedence next.
I will need to do some surgery to try to move the battery foward to improve the CG placement, need to fix the nose anyways from the previous lawn darting. I think that can be done and I can avoid using lead up front.
Jan 18, 2018, 01:13 PM
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ninjasword71's Avatar
Was looking at the side angle pic. Does the canard have a 0 incidence? That can fight against you. The canard should be at least a couple degrees positive as in catching the wind idea. The motor shouldn't need any thrust angles in case there is.
Jan 18, 2018, 06:57 PM
I Look, Listen, and Learn
Timbo383's Avatar
Looking at it I think you are right. Well, gee, no wonder it dived. When I designed it I had put in about 3 degrees incedence in the cut of the fuse and also where the h-stabs mate to the main wings and canard but somehow I think I messed it up while cutting or gluing it...just went back and checked my plans and it is in there. I think I need to subtract a couple more mm to the height of the h-stab design, maybe it's pushing the canard up and I'm loosing the incedence. Ok, since I'm gonna do surgery to the front I'll redo the incedence and take some of the thrust angle out of the motor. Thanks for pointing that out Ninja.
Last edited by Timbo383; Jan 18, 2018 at 10:23 PM. Reason: Wrong adjustments direction
Jan 18, 2018, 08:36 PM
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elewon's Avatar
video?
Jan 18, 2018, 09:08 PM
I Look, Listen, and Learn
Timbo383's Avatar
Sorry elewon, the maiden was a failure so no vid then, and in the second attempt I only had a few minutes to test the adjustments before picking up my son so I didn't bother taking my hat cam at that time either. But once I get the proper adjustments to the incedence and readjusting the thrust angle of the motor I will take a video on that outing....it's suppose to be a decent weekend so hopefully I'll get it done and be able to retest it by Sunday.
Jan 18, 2018, 11:45 PM
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ninjasword71's Avatar
I really like the look. My latest canard plane has the canard higher up on the fuse as well but it has elevators. What is your wingspan? With any success of yours, I may try something similar.
Jan 19, 2018, 03:57 AM
Registered User
Someone wrote a very eloquent, clear and non-technical explanation about how a canard that's above and horizontally close to the main wing will likely have detrimental effects most of the AOA range (downwash, etc.)
Can't seem to find it right now...
Anyhoo, making the canard smaller will require moving CG back - but that reduces the moment arm of the elevons, making them less effective...
Jan 19, 2018, 07:19 AM
I Look, Listen, and Learn
Timbo383's Avatar
Quote:
Originally Posted by ninjasword71
I really like the look. My latest canard plane has the canard higher up on the fuse as well but it has elevators. What is your wingspan? With any success of yours, I may try something similar.
Haven't measured the ws but I think it's about 36 " I can get an accurate measurement when I get home tonight. I'll also post the plans here for you, they're simple and basic but you may be able to use some of it for your build.
Jan 19, 2018, 07:40 AM
I Look, Listen, and Learn
Timbo383's Avatar
Quote:
Originally Posted by nuteman
Anyhoo, making the canard smaller will require moving CG back - but that reduces the moment arm of the elevons, making them less effective...
Hey Nuteman, how you've been? Well, hopefully I didn't take off too much from the canard area, when I rolled it inverted it went without any effort, I do like an agile plane. I think the size of the elevons will still be enough to have fun with this plane. Also now that I've done some surgery to the nose area I think I can also add a servo up front and make some working elevators in the canard and change the elevons to ailerons if I want.
Jan 19, 2018, 07:14 PM
I Look, Listen, and Learn
Timbo383's Avatar
Got home early today from work...yay...checked the ws and it is 38 inches. Also had time to finish the nose and incidence and while I was looking at it I was thinking that the v-stabs were a little bit too big so I did some cutting and shrunk them a little.
Also did some calculations...ok, so I cheated and used an online one...and figured out the square areas of the wings and canard. The canard is now at 28.6 percent of the main wing, so it's just about what I wanted. I hoped I didn't make too many changes at one time and screwed up my chance to determine what works good and what doesn't.
Ninja, here's the pdf plans with the latest adjustments I made. I designed it to fit on one sheet of dtf, but maybe you can use it for some reference for your build. Heads up tho, they are not the best quality like some of the stuff I've seen guys do. I have an older program that I know how to use for doing plans, it gets the job done but it's not perfect. I'm still in the process of learning sketchup but all that 3d view stuff is still a little bit difficult for me to do. I do want to get to learn it because I know it would help me to do more accurate plans.
Last edited by Timbo383; Jan 19, 2018 at 07:30 PM.


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