Thread Tools
This thread is privately moderated by jackheli, who may elect to delete unwanted replies.
Feb 19, 2020, 08:23 AM
Registered User
Thanks for all the input!
NX does all that (parametric, lofting through curves, exporting STL)
So what I heared from you gave me the confidence to stick with NX and gon on.
I don't think that the P-61 is thebest learning object since I thinkits shape is pretty complex, but for now the aircraft motivates me to keep going. I hope to provide you some pictures that are worth sharing and later on some STL to print.
Sign up now
to remove ads between posts
Feb 19, 2020, 09:18 AM
Registered User
Dirty Dee's Avatar
The P-61 shouldn't be too difficult, especially if you have plenty of cross section drawings and reference images.

Id be interested if you post a design/ build thread for this project
Feb 19, 2020, 12:50 PM
Registered User
Quote:
Originally Posted by Quorneng
rupert80
" to print something that is within the same weight ballpark as a traditional balsa or even foam build."
You will be fighting some basic physics laws to achieve that.
Balsa and even more so foam has a fine cellular structure with individual cell wall thicknesses that 3D printing cannot match or if it could it would take fore ever (literally) to print.
You do much better to use various materials that are appropriate for purpose.
3D plastic printing can accurately produce complex shapes that have to carry loads worthy of a 'solid' plastic but for a complete air frame the result will always be comparatively heavy.

My own guess is that some day it may be possible to print some sort of self foaming plastic then stiff really light structures may be possible.
If you have not done so already, you should check out the lightweight PLA made by the Colorfabb company in the Netherlands. This material is a 'foaming' plastic than can expand to nearly 3 times its original volume as it is being extruded (https://learn.colorfabb.com/print-lw-pla/). And by designing parts to be printed in 'vase mode' with this material, after many trials I was able to design, print, and fly a free-flight rubber powered airplane (https://www.thingiverse.com/thing:4127098). This airplane has a wingspan of 527 mm (20-3/4") and a total flying weight of 63g.
Feb 19, 2020, 01:13 PM
Registered User
rpstar's Avatar
My question on the lw-pla is are you able to print with the true 2 to 1 or more expansion without it getting too flimsy? Another guy here in this section just printed the mig in lw-pla but it appears to only have resulted in a 20% weight reduction. I don't know yet if that is on purpose or if he just did not realize he needed a higher temp to get it to "foam" more. Dunno. Have to wonder if it's due to it becoming structurally too weak when at it's max expansion so I'd like to know your experience.
Feb 19, 2020, 02:12 PM
Registered User
Thread OP
I am happy with my slicing templates which use a regular .40 nozzle and PLA. The walls are thinner than 3dlp and require closer supports to avoid warping, but the overall result is 30% reduction in weight.
Feb 19, 2020, 07:50 PM
Registered User
Quote:
Originally Posted by rpstar
My question on the lw-pla is are you able to print with the true 2 to 1 or more expansion without it getting too flimsy? Another guy here in this section just printed the mig in lw-pla but it appears to only have resulted in a 20% weight reduction. I don't know yet if that is on purpose or if he just did not realize he needed a higher temp to get it to "foam" more. Dunno. Have to wonder if it's due to it becoming structurally too weak when at it's max expansion so I'd like to know your experience.
Of course, the airplane that I printed out of LW-PLA was rubber powered, so it was not being maneuvered like an RC plane. My structure was mostly 'vase-mode' printed sections of LW-PLA printed with a 0.3 mm wall at a flow rate of 35%. The fuselage was reinforced with thin keels and stringers printed out of eSun PLA+, while the wings did not have (or need) this kind of reinforcement. The only stresses my airplane was subjected to were landings and crashes, and this structure proved tough enough to survive them. The video below is my airplane in action, which includes a couple of crashes into trees, and one into a chain link fence. (The chain-link fence crash broke off one of the wing supports and put a small crack in my rudder, but I was out flying again after making repairs about one hour later. I would suspect a balsa-and-tissue plane would also have suffered some damage as a result of such a crash.) Obviously, since I am flying under the very limited power of a rubber motor, my airplane needs to be very light. But I would think that a motorized RC plane could be printed with this material with enough strength to withstand the stresses of RC flying.

More 3D-Printed Rubber-Powered Airplane Adventures (12 min 34 sec)
Feb 20, 2020, 03:39 AM
Registered User
Breitlingwings's Avatar
Quote:
Originally Posted by billbo1958
Obviously, since I am flying under the very limited power of a rubber motor, my airplane needs to be very light. But I would think that a motorized RC plane could be printed with this material with enough strength to withstand the stresses of RC flying.
Of course it is possible. A whole thread about Eclipson Model V, specifically designed for LW-PLA, and it flies pretty well: https://www.rcgroups.com/forums/show...inted-airplane

This one printed at 45% flow, weight just 445 grams on a 140 cm wingspan aircraft.

Vuelo del Model V, versión LW-PLA, de Eclipson Airplanes (1 min 53 sec)
Feb 20, 2020, 09:57 AM
Registered User
rpstar's Avatar
Quote:
Originally Posted by Breitlingwings
Of course it is possible. A whole thread about Eclipson Model V, specifically designed for LW-PLA, and it flies pretty well: https://www.rcgroups.com/forums/show...inted-airplane

This one printed at 45% flow, weight just 445 grams on a 140 cm wingspan aircraft.

https://www.youtube.com/watch?v=C1lzLAoDTLU
The Eclipson V seems well suited to LW-pla but I'm not convinced that Jets are as said today in other thread.
Feb 20, 2020, 10:10 AM
Planes N' Trains
cale10's Avatar
so when you all are mentioning flow rates, im assuming thats the flow of the material through the extruder correct? If so, how can things be printed without holes everywhere? i had to up the extrusion on my A8 to 103% to get prints without missing layers here and there.
Feb 20, 2020, 11:07 AM
Registered User
Breitlingwings's Avatar
Quote:
Originally Posted by cale10
so when you all are mentioning flow rates, im assuming thats the flow of the material through the extruder correct? If so, how can things be printed without holes everywhere? i had to up the extrusion on my A8 to 103% to get prints without missing layers here and there.
Thst's the "miracle" of the foaming PLA. If you print at 100% flow with a 0.4 nozzle, the wall thickness is not 0.4 mm but probably 0.85 or more, depending on each printer. So you have to lower flow rate to get the desired wall thickness. The result is the same part or object using 45% material.
Feb 20, 2020, 11:57 AM
Planes N' Trains
cale10's Avatar
now that i have a caliper, and have a better idea of how my printer works, i will be tweaking these settings very soon! thanks.
Feb 20, 2020, 01:59 PM
Registered User
Quote:
Originally Posted by majeraz
The new version 2.82 of Blender is more friendly to begin, but it's still a hard work learn.
I am a professionnal photographer and designer and I make flight simulator addons since 15 years, and, as said Dirty Dee, after some years of work with design softwares, it's not more a problem. You can take a look at my we bsite http://www.llhinfo.com/home.html
I always prefer starting with Bézier curves, then convert to meshes. Many, many backup are needed because when done, there is no turning back.
I think that if you are not familiar with 3d modeling, it is easier to start with CAD softwares.
Your SIAI MARCHETTI SF260 design looks great.
Any estimated date to be released?

Regards
Feb 24, 2020, 04:50 PM
Registered User
Thread OP
Sorry if this is a bit out of the context of the thread, but I wanted to point out the importance and convenience of having a 3D pen to help on the prototyping and even fixing damage.

I've used it many times to quick fix a part so I could save a prototype print, and also it's amazing what I accomplished this weekend with it while repairing a landing gear that was ripped off the fuselage.
Feb 24, 2020, 07:13 PM
Build'em and Crash'em
Ken Lapointe's Avatar
Quote:
Originally Posted by jackheli
Sorry if this is a bit out of the context of the thread, but I wanted to point out the importance and convenience of having a 3D pen to help on the prototyping and even fixing damage.

I've used it many times to quick fix a part so I could save a prototype print, and also it's amazing what I accomplished this weekend with it while repairing a landing gear that was ripped off the fuselage.
Good idea, any recommendations for a particular pen?
Feb 24, 2020, 07:58 PM
Registered User
Thread OP
I got this one. Inexpensive and works well for our purpose.

Several vendors selling the same pen at different prices...

https://www.banggood.com/2nd-Generat...r_warehouse=CN

Hot Modelling Tools are useful too, such as these:
https://www.amazon.com/STAGE-Wood-Le...NsaWNrPXRydWU=

https://hobbyking.com/en_us/3d-print...r-ul-plug.html


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion DYI 3D Printed Planes/Design/Slicer settings AdrianM 3D Printing 14 Aug 07, 2018 03:07 AM
Help! Challenge to people with CAD skills! Design a gear cover for the Kyosho Lazer ZX-5 SoloProFan Car Talk 24 Aug 07, 2017 06:35 AM
Question Builder / Cad designer for hire ??? Aero12 Foamies (Scratchbuilt) 1 Jul 07, 2016 06:39 PM
Discussion Frame Design Tutorial - CAD v3r73x Scratchbuilt Multirotor Drones 0 Jun 05, 2016 07:05 AM
Discussion Let's all share our designs! CAD plans for you! soaringtuna Scale Kit/Scratch Built 0 Nov 26, 2015 08:36 PM