I'll try and make my way out there for a few flights. Hoping to get my wings maybe.

I'm using the EDF from a Viper 70.  6S 3300mAh.  A thrust tube is securely taped to the EDF and the EDF is solidly mounted.
So many nice features from Planeprint.  The landing gear wheel wells also double as Air Intakes for a bit more takeoff power.
The Air Intakes are incorporated into a piece that also houses the wheels and is the EDF Cover.
This EDF Cover is secured in place with the rear 10mm Carbon Fiber tube.
I don't know how Rene thinks all this stuff up... it's very cool.

Looks fantastic Dave

Perhaps some fibreglass might stiffen it up a bit?

Unlike David's fabulously designed L-39, this GWS kit relies on old fashioned tech!

The elevators are joined by a wire. And having learned from making this mistake before, you have to feed the elevator joining wire through the gap in the fuselage for the horizontal stab, BEFORE you glue in the stab! Luckily, I did remember that today!

Now, this is a later EPO foam kit, not the EPS version, so it's a bit heavier. So I tried to beef up the way the elevator wire mounts to the elevators. I added a thin wooden plate on top of the wire joiner hoping it would stop any twist.  Unfortunately, despite being better, it's not eliminated elevator deflection difference side-to-side and I fear the heavier EPO foam model will exhibit this in flight.

I might see if I can get some wax paper down in the hinge line and add some extra epoxy.

One wing complete.  The Flap and Aileron Servos are back to back in one section.  Servo attachments are screwed onto the servo and then glued to the servo cover.
2 types of wingtips are provided... Reno Air Race and standard tanks.  Of course... the tanks look cooler.
Parts are included for quick wing connects using MPX connectors.  I was looking forward to this before I realized I'm never going to take the wing off.  I'll use the MPX connectors for the OV-10 Bronco that's up next.

Landing Gear on printed planes has always been the weak point.  With the L-39 it may just have a chance to survive the first landing.  100% infill PLA printed retract servo mount tied into 2 6mm Carbon Fiber tubes all glued into the fuselage.  And... a Planeprint version of trailing link gear.  1mm piano wire is used to give the gear some suspension.  I think it might actually work.  Since the tires are printed as well, I can adjust how soft or hard they'll be by changing the amount of infill.  Right now they're 15%.  I may try 10% for a softer tire.

Well @Frank v B , it has rained for 3 of the proverbial 40, so far...

I am planning to be at Rogo Field this coming Sunday from about 11 am to 2 pm....if the rain ever stops*.

If any new members need check flights, returning members need some help or if you need help with a maiden flight for a winter project...come join me.

I will post a final decision after dinner on Saturday.

Frank

* there is a song in here somewhere.  "Have you ever seen the rain" or "who'll stop the rain" by CCR

Quote from: bfeist on April 11, 2024, 03:33:56 PMThis really looks great. I've been following the 3d printed plane idea for a while but I haven't done it. I'm curious, being PLA, will you be glassing or otherwise sealing the surface somehow?

No, doing anything like that would add a lot of weight.  Some have done that, but it changes the characteristics of a well designed plane.  I'm not even one to paint, so I print in colours instead.  This isn't PLA, it's active LW-PLA so the texture and finish are really nice.  Not on this L-39 though.  This was a print experiment using PrusaSlicer and has a terrible finish to it.

LW-PLA with a gyroid infill has a very balsa-like feel and strength to it.

For the OV-10 Bronco I printed I used OrcaSlicer and BambuLabs LW-PLA settings with perfect results.  Same printer, Prusa MK4, but dialed in settings with OrcaSlicer.

The design is the most important part for a nice looking finish and Rene from PlanePrint thankfully understands this.  His designs produce really good results.