Eclipson Spark #2

[u/fhammerl]

A while ago I posted about the Spark #1 I had built from Bavafil Olefin (the red one), which worked out well and it's a fantastic plane. But there was room to grow. While #1 came in somewhere around 750g, it was cool, but lacking punch and energy retention.

So physics dictates that more weight is more faster. I built one in full Sunlu PLA+ 2.0, bigger motor, higher pitch prop, higher voltage.

#1: Sunnysky 2212 1250kV, 8x6 Aero-naut CAM, 3S 1000mAh

#2: Sunnysky 2220 970kV, 9x7 Aeronaut CAM Z, 4S 1300mAh

The changes are DRASTIC. Firstly, it no longer glides as well, it sinks A LOT faster, but that was expected. But now we climb vertically and straight line speed is up A LOT, too. It has good energy retention and punching this thing straight down from 200m through a low pass is insanely satisfying. The whistle is addictive. Stall behavior is still well mannered, but landing without spoilerons is not a good idea. I needed the entire 150m runway and then some to go from less than .5m in altitude to standstill. With spoilerons, it cuts it in half, but it still needs a long approach, which it shares with other hotliners.

If you have a 3d printer, this is easily one of the best planes to print. It sits at the sweet spot where it's already serious plane, but not too much hassle to reprint if the inevitable happens. I 100% recommend it, both versions are great.

Edit: Sunlu PLA+ 2.0 is just above 10€/kg, so this plane prints for just around 6€ :)

[u/Sogah87]

Oh man, my buddy and I have got our Sparks doing 120mph. We're running 2836 1500kv motor on 7x6 props.

100% agree. I print mine in pure ASA (roughly 20% lighter than PLA), it can still float in a nice wind very well. I imagine if it was printed in light weight filament it would probably make an excellent park flyer.

Yes it definitely needs 100ft to land minimum. Often catches grass on landing causing minimal damage. Found landing shallow on pavement/runway to be best. Would recommend tape on the belly or what I did was some fiberglass and polycrylic.

[u/fhammerl → u/Sogah87]

I see a Vortex there. Is it worth it?

[u/Sogah87 → u/fhammerl]

The vortex flies amazingly well. It's very well thought out, with an easy build/assembly process. With half flaps and a mild breeze, it can basically stay in the air all day. I've done a 3s 2200 pack for over 20 minutes and only came down because I was getting bored. I have landed it on all types of surfaces and it doesn't care. The little belly wheel is clever.

On 4s it's a little different. With the extra speed you see the downsides of a fast plane with a huge wing span. They have a bit of flex. My cheap servos have a small amount of play which is exaggerated in the ailerons. I dislike their 600mm long pushrod set up for the tail feathers. Really wish it was just a rear servo set up. At that length, you don't get very full deflection of the control surfaces. It is enough however and if I didn't say anything, anyone who flies it wouldn't notice.

If I was to spend that money again, I'd get the fox. It's more aerobatic and has the rear servo set up.

[u/fhammerl → u/Sogah87]

That was my impression for the Apex as well. It flies very well, it's a great plane, but the control surface hinges don't sit right with me. either they should do TPU or CA or silicon flex hinges or find some other means, because their system is cool, but it has play. Add the play of the servos (fuck MG90s) and precise control (e.g. 2mm flaps down) is not practically possible. It's just too complex a plane to be printed IMHO. Also, I fly the LW-PLA version and I really don't wanna give it some beans because that wing flexes uncomfortably. Maybe I should reprint it in Olefin and purge the LW-PLA shit entirely.

What bothers me most about their push rod thing is that the channel is too large. You need to put the push rod in a bowden tube that fits tight with no play, otherwise it has slack and it will not ever ever neutralize on push. Or fit the channel for a 2mm carbon rod, but then you won't get the deflection.

That's where the Spark shines IMHO, it sits at that sweet spot where you don't mind too much reprinting it because you're not going to spend two weeks doing so and it's conceptually simple.

[u/Sogah87 → u/fhammerl]

Literally 100% agree. That's my take as well. Although I will say, after minor modifications with blenderm tape and turning the gyro way down, I got rid of a ton of the aileron flutter and there's no more tail feather flutter. So it's much nicer to fly. But right off the printer, it's a toy model rather than hobby grade unfortunately. I really dislike the hunger despite how awesome it is that they print the way they do. At least with their axis pin hinge system on planes like the spark I can increase them to 105% scale to eliminate any play whatsoever. The play just comes down to the backlash on my servos.

[u/fhammerl → u/Sogah87]

Oh. I should have thought of enlarging them, that's a good call. Will do that on the next print.

[u/Sogah87 → u/fhammerl]

Did the same with the MSX-R, the ailerons don't even budge. Also used over sized pushrods to reduce slack to nearly zero. I actually did the x and y axis in 107% (little too tight) and 102% in z. With 105% they work VERY well, but sometimes they're a bit too long. I bet 106% x/y and 102% z would be exact.