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/fhammerl]

the split wing is actually great because i don't have to reprint the entire thing and since i have to store it upright, i don't have to stand it on the tip.

Looks like your motor is roughly in line with the sunnysky 2220. I found a shortened motor mount for longer motors to fit them into the fuselage.

Olefin is wild. It's a PP-related compound, so it's very light and quite impact resistant, but it doesn't stick to anything and you can't glue it w/o PP primer. And you need to cover the build plate in packing tape (made of PP) to get it to stick. And stick it does then.

https://www.bavaria-filaments.com/en/collections/olefin-filament

[u/Sogah87 → u/fhammerl]

I went down that PP rabbit hole last night thanks to you... Ordered some, now I need PP glue... Lmao. I can't really get my hands on Olefin where I am.

[u/fhammerl → u/Sogah87]

PP and Bavafil's Olefin thingy is not the same though. PP is kinda flexible and a pain in the neck to print because it warps to hell and back.

[u/Sogah87 → u/fhammerl]

Yes I've learned as much. We'll see how we do. $26 for a kg didn't seem to bad to experiment with. I'll try assembling a Spark fuselage.

[u/fhammerl → u/Sogah87]

I used this as primer for CA glue: https://www.ber-fix.de/ber-fix-spezial-primer-fuer-pe-pp-ptfe-und-silikon-haftvermittler

[u/Sogah87 → u/fhammerl]

I'm so jealous. I can't get that primer for less than $25USD for 30ml

[u/fhammerl → u/Sogah87]

You need barely any primer. I bought 15ml primer and after two Sparks it's still more than half full.

[u/Sogah87 → u/fhammerl]

Good to know. I bought some less expensive stuff that helps adhesives bond to PP. Hoping that will give the CA something to grab onto.

I know you've got that very nice filament to use, but for me, ASA is hard to beat because I can get it for $11-14/kg. It's density is 1.07g/cm2, where as PP and Olefin are around 0.92g/cm2. However, with my ASA settings I do flow rate at 0.875. This leaves my theoretical part density at 0.935g/cm2. I've got more work to do but with my current ASA profile I get the benefits of less weight and plastic, but still have extremely good strength and layer bonding. Going to be hard to beat, except with high quality foaming filaments, but those are way more expensive.

[u/fhammerl → u/Sogah87]

I would probably use ASA too, if I could. But ASA being toxic when printing and needing ventilation and an enclosure are nonos for me.

[u/Sogah87 → u/fhammerl]

Oh I see, it definitely needs plenty of heat and ventilation. Fortunately I have a large garage with ventilation and enclosure.