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chaos Albatross - WORLDS FIRST - Resin printed RC plane WIP

chaos23

Senior Member
#1
Hi there, so some of you might know me as that guy that started designing the Draco RC or that fast looking chaos Long EZ. Both of which are on hold for a number of reasons. So I decided a few weeks ago to start working on YET ANOTHER PLANE....... however this one would be different, in that it would be designed around constraints that would allow me to actually get started and finished with the knowledge resources I have on hand. (no waiting for components that are on back order for indefinite amounts of time).

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So I have a big resin printer, and I have some insanely good resin from Siraya Tech, no its not brittle or weak, no its not heavy (its actually lighter than PLA and stronger). I would say im pretty good with CAD software and know my way around designing stuff, but I always like to challenge myself to go further.

If you would like to see more of the design process, CFD sims and the reasons behind the design Ive posted many videos on my YouTube channel in the chaos daily series starting at episode 025. Otherwise I also post very regularly on my twitter

Ok, lets go over some specs.

--Wingspan: 1570mm
--length (without spinner): 1111mm
--Estimated flying weight (based on CAD model properties and known component weights) : 1.1kg - 1.2kg
--Wing loading: 32g/dm^2 (ish... havent included the surface area of the Vtail... do you include Vtails in wing loading?)
--Airframe weight: 580grams ish (based on CAD data, whole plane not printed yet)
--Current Projected flying weight (based on weighed parts and components) : under 1.1kg
--Cost in printing materials: somewhere around $30 USD
--Motor: MultiStar 3525-650Kv 14Pole Outrunner
--ESC: modified MultiStar 20amp ESC
--Battery: 4s CNHL 3000mah 55c
--Servos: 4x TSS-10MG turnigy metal gear servos
--Prop: 12x4.5 inch carbon fiber

More technical detals on the CFD results can be found in the attached pictures, but generally it has great slow speed results and will be on rails above 16m/s with very sharp handling. The motor prop combo gives it well over 1:1 TWR.

I have held off on making this post until I had actual parts printed, since my other 2 projects are in limbo I didnt want to come off as that guy that does a lot of talking and has nothing to show for it. so here it is. As far as I can find online this is the first resin printed RC plane, and I hope to have it in the air by the end of the month. Taking the time to document everything for my YT channel means things progress a bit slower but I really enjoy putting in the effort to share my work with you all.

Let me know what you think, Please check out my YT videos since I go over loads of the the details there.
 

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quorneng

Well-known member
#3
chaos23
When I saw the design of the cockpit area my immediate concern was its likely lack of torsional rigidity even with that internal diagonal bracing given that it will have a motor driving a big prop on the front.
The flexibility of the resin you show in the video can only make the problem worse.
If you want such a large removable section I suspect you will have to make the whole cockpit area as a double skin structure with internal bracing.
 

chaos23

Senior Member
#4
chaos23
When I saw the design of the cockpit area my immediate concern was its likely lack of torsional rigidity even with that internal diagonal bracing given that it will have a motor driving a big prop on the front.
The flexibility of the resin you show in the video can only make the problem worse.
If you want such a large removable section I suspect you will have to make the whole cockpit area as a double skin structure with internal bracing.
Honestly torsional strength hasnt been an issue, Ive run up the motor and prop on the nose section with little twisting effect to the section. The big concern is the opening of the hatch flexing in or out which would cause the nose to flex up or down inducing adverse elevation. I have already done most of the re-working on the internal structure in CAD and ill be going over it in the next Daily.
 

chaos23

Senior Member
#6
V2 of the fuselage turned out perfect. Im using siraya tech's Fast white resin mixed with their Blu 3 to 1 ratio. The color is a gorgeous light peppermint color that is also UV fluorescent. so far the changes to the structure are night and day. Ill post again later with today's daily episode going over more of the details
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quorneng

Well-known member
#10
Looks good.
Difficult to tell in the video but is the receiver buried in the nose with the ESC and the V tail servos?
If so it could result in radio interference issues. The conventional advice is to keep the receiver, and its aerial(s), as far away as possible from other electromagnetic sources.
 
#11
Looks good.
Difficult to tell in the video but is the receiver buried in the nose with the ESC and the V tail servos?
If so it could result in radio interference issues. The conventional advice is to keep the receiver, and its aerial(s), as far away as possible from other electromagnetic sources.
nah, the black box up front above the ESC is the gyro, the reciever is tuched away in the belly under/infront of the battery tray. Im hoping this area has a low enough EMF, otherwise there arent too many places I can easily put the receiver.
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#12
The battery can act as a 'shield' and in that position it is very close to the receiver aerials. It should be ok as you would expect the plane to be above the transmitter most of the time.
To be sure when you do a ground range check see what happens when the plane is positioned so the battery is exactly between the receiver and transmitter.
If it does prove to be a problem a solution would be to add a 'satellite' receiver positioned a bit further down the fuselage.
 
#13
This is the servo im using, and I dont have the funds to source other hardware for this project. So I am glad that I was right on my hunch to put it near the bat. the batery tray is slightly raised from where the antenna will be, so I should get a fair amount of lateral radio line of sight.


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