A Modular Plane Design - My Next Big Project

L Edge

Master member
I've seen some of your work. It's really great stuff. That's a big printer you're talking about to do it all at once in 15" sections. Probably about $300 at the cheapest. But you could also print in smaller sections (up to 10") which means that what you're describing could be done on the lowest end printers. Materials wise, one roll of PLA should be plenty and goes for about $15-20

Hey, I give you a lot of credit for one of the few building EDF planes out of PLA. ? for you, How do you determine the overall weight(components as well as electronics /EDF/battery) for where to put the wing saddle to get CG right?
 

telnar1236

Elite member
Hey, I give you a lot of credit for one of the few building EDF planes out of PLA. ? for you, How do you determine the overall weight(components as well as electronics /EDF/battery) for where to put the wing saddle to get CG right?
For off the shelf components, I just weigh them with a postage scale. For 3D printed components, Fusion 360 will give an estimate of weight and CG based on assigned materials, so I'll tend to make a material for solid PLA and then a couple materials for PLA at different infills. Then it's just a matter of taking the weighted average of the locations of the CGs of different components, or of making blocks that have the right mass in Fusion 360 for OTS parts and reading the CG location. The other thing I do is make a very big battery bay to give me as much room as possible to move the pack around. 3D printed planes are mostly empty space anyway, so it's pretty easy to make enough space that you can get the CG right. And, being perfectly honest, I sometimes mess up the way the plane balances (like with the prototype modular prop I posted about) and need to stick a ton of weight in the nose to get it to work.

1695687060326.png

The CG of just the 3D printed parts of the F-104
 

L Edge

Master member
For off the shelf components, I just weigh them with a postage scale. For 3D printed components, Fusion 360 will give an estimate of weight and CG based on assigned materials, so I'll tend to make a material for solid PLA and then a couple materials for PLA at different infills. Then it's just a matter of taking the weighted average of the locations of the CGs of different components, or of making blocks that have the right mass in Fusion 360 for OTS parts and reading the CG location. The other thing I do is make a very big battery bay to give me as much room as possible to move the pack around. 3D printed planes are mostly empty space anyway, so it's pretty easy to make enough space that you can get the CG right. And, being perfectly honest, I sometimes mess up the way the plane balances (like with the prototype modular prop I posted about) and need to stick a ton of weight in the nose to get it to work.

View attachment 240207
The CG of just the 3D printed parts of the F-104
Thanks, you presented a nice overall picture of 3D printing. Gone from balsa to foam to 3D PRINTING? Need to explore Fusion somewhat to decide if this is new route. Looking for stuff to print that is complicated design. Lot's of hours to learn their system commands. It's very tempting.
 

telnar1236

Elite member
Thanks, you presented a nice overall picture of 3D printing. Gone from balsa to foam to 3D PRINTING? Need to explore Fusion somewhat to decide if this is new route. Looking for stuff to print that is complicated design. Lot's of hours to learn their system commands. It's very tempting.
I look forward to seeing what you do
 

GH05T

New member
Yeah, after I recently learned modeling I think it's pretty good. Other than my mental issue with how to scale everything correctly it's a lot of fun.
Thanks, you presented a nice overall picture of 3D printing. Gone from balsa to foam to 3D PRINTING? Need to explore Fusion somewhat to decide if this is new route. Looking for stuff to print that is complicated design. Lot's of hours to learn their system commands. It's very tempting.
 

Arsenalfan1

New member
Telnar1236, I tried to download the open source files for Power Broker's HMD-1 on Thinkverse but got a 404 error.

Please could you kindly provide a copy of the HMD-1 files you downloaded, if your f104 is also open source, I would appreciate if you would kindly provide the files for it as well.
 

telnar1236

Elite member
Telnar1236, I tried to download the open source files for Power Broker's HMD-1 on Thinkverse but got a 404 error.

Please could you kindly provide a copy of the HMD-1 files you downloaded, if your f104 is also open source, I would appreciate if you would kindly provide the files for it as well.
I don't think it would really be appropriate for me to supply one of Power Broker's designs here. You will have to ask him about that issue. As far as the F-104, those files are already available in this thread a few posts back.
 

Arsenalfan1

New member
The files are open source so they can be freely distributed as long as the attribution to Power_Broker is maintained, I reached out to him on the HMD-1 topic but he has not made any posts in quite a while so I am not sure if he is still reading comments.

I am quite sure that it would be completely ethical for you to make it available as long as you clearly state that Power_Broker was the creator of the files (that is how open source licenses work). If you do not wish to post it openly on the forum for everyone, you can make it available to me in a one on one conversation (I will start one now).
 

telnar1236

Elite member
The files are open source so they can be freely distributed as long as the attribution to Power_Broker is maintained, I reached out to him on the HMD-1 topic but he has not made any posts in quite a while so I am not sure if he is still reading comments.

I am quite sure that it would be completely ethical for you to make it available as long as you clearly state that Power_Broker was the creator of the files (that is how open source licenses work). If you do not wish to post it openly on the forum for everyone, you can make it available to me in a one on one conversation (I will start one now).
I just tried the link as well but I'm getting the same error. I don't have a local copy of those files unfortunately. My model is similar in concept but pretty different in execution so I never downloaded them, sorry.

My concern was that @Power_Broker seems to have intentionally deleted those files and I didn't want to share something he had meant to take down.
 

Arsenalfan1

New member
He clearly stated that all files are open source and added the remark "feel free to download them" so it is quite clear he wanted to contribute it to the community, a problem on the thingiverse site is likely to be the reason for the 404 error.
 

telnar1236

Elite member
He clearly stated that all files are open source and added the remark "feel free to download them" so it is quite clear he wanted to contribute it to the community, a problem on the thingiverse site is likely to be the reason for the 404 error.
Again, I do not have the files and get precisely the same error you do. Regardless of my thoughts on if I should post them, I cannot.
 

telnar1236

Elite member
While I'm working on rebuilding my F-104 for the final (hopefully) time, I have been working on the next modular plane design. This time, it's designed for FPV and should be simple to assemble and easy to fly in comparison to the F-104. It's a pretty standard configuration for this type of aircraft, built for gentle flight characteristics and good efficiency. It also gives me the opportunity to use one of my favorite airfoils, the Wortmann FX 63-100. While not really suited to aerobatics, it feels great on aircraft meant for stability and range. Another thing I'm working on for this aircraft is an internal wing structure better optimized for assembly. The wing on my earlier test airframe for a modular prop design held up fine in the air, but wasn't really suited to the harder impacts that came with landing, so I've returned to a fully modeled internal structure.
Modular_FPV_Plane.png

Wing_Ribs.png
 

telnar1236

Elite member
As I'm rebuilding the F-104, I've made a couple minor improvements. First, I redesigned the flaps (again) so that they maintain a cleaner profile with the top of the wing as they deflect. I've tried to illustrate in paint.
1699117161877.png

The other change was to finish the wing tip tanks. In general on F-104s, tip tanks improve every characteristic except for top speed, so I'm hoping to see the same for this model.
1699117250915.png