Gentlemen,
I have decided to invest in a 3D printer, my first project would be to print the connections for the netting to the current thinner arms for the OpenPPG is there anyone who has the files?
I am learning the process and still in the process of finalizing the equipment, so any feedback or positive recommendations are appreciated.
Thanks,
Dax
The files at the bottom of this post work really well:
I’ve made several 3D printable improvements for OpenPPG and the files are available in this thread: Paul B & Braedin B (GliderPilot & Glydrfreak) Flights & Build Modifications
Thanks GliderPilot, do you know how soon the new arms might be available?
Paul said batch 4 would have the new arm design but as far as I know they haven’t shipped batch 4 yet and I doubt you could order them till they do. You shouldn’t need the new arms if you use my connector design and a set of 4 arms is quite pricey. However, if you want a modification that is as strong as the batch 4 arm I created yet another design. It requires the hoop pieces to be trimmed a little because the arms are trimmed a little shorter:
Here are the files:
Hoop Connector (Shortened Arm) - Right Tip.stl (317.7 KB)
Hoop Connector (Shortened Arm) - Right Center.stl (253.1 KB)
Hoop Connector (Shortened Arm) - Left Tip.stl (317.7 KB)
Hoop Connector (Shortened Arm) - Left Center.stl (253.0 KB)
wow, that’s cool Paul, as always.
I am probably going to go for this, once I receive my 3D printer as well (ordered the snapmaker 2 on kickstarter - they’ll ship it in december 2019 if everything goes well)
This is a really good idea for reinforcement, also because the current hoop is slightly larger than actually needed due to the size of the props.
Did you implement this already on your OpenPPG?
I’d love to see photos 
Glad you like it! Yes, I am using my new design. I fell onto my knees after a hard landing and hit the hoop on the ground which broke one of my connectors (old design). Again, the old ones are plenty strong as long as you don’t fall! 
Here are some pictures:
I printed an extra one to use as a guide for cutting the carbon. I used a dremal tool followed with sandpaper. This picture shows how much I had to cut away:
Woah that’s super nice! Thanks for sharing Paul. Hope your knees faired okay in the fall.
Paul,
Did you end up having to trim your hoop down again? or was the previous trim down still work? How do your connectors attach, do you use a standoff on the inside? Really nice design.
Thanks, I just lost my balance is all. The cage hit harder than my knees. I think the cage actually hangs below my knees so it’s not possible to kneel down without hitting the cage.
Same as before, two standoffs inside. I did trim the hoops a little more.
Hi Paul,
I sent the files to a 3D printer, they noticed the cavity inside the connections and were asking if there is a reason for this space and the parts would be stronger if the space was filled in.
Thanks for your recommendations.
Regards,
Dax
I designed the center pieces to be hollow to save weight and material. It was actually a lot of extra work to get it that way. Filling that cavity in wouldn’t make it stronger because the strength comes from the outer shell (similar to an I beam vs a solid beam). Plus, the area where the cavity is doesn’t need to be stronger.
Thanks Paul, I will let them know
Hi Paul, I got the 3D parts you were kind enough to share back. I was surprised to see that they were small pieces.
What is even more interesting is that I already have a similar set of pieces on my OpenPPG, as I bought my unit from Dario.
My question is, why not print one single part to connect to the arms and then allow the tubing to slide on to that?
I am sure there is a good reason, I am guessing that the strength of the 3D printed materials would not support a single piece?
I am working with a 3D printer that is able to put carbon fiber inlaid into the parts. It’s called Markforge I was hoping there was a design of a single part that can attach to the arm and then support the connection for the tubes.
Thanks
A 3D printer can’t print plastic in mid air. The strength of those parts come mostly from the standoffs that go through the middle and the bolts. If the printer is capable of dissolvable support material then I guess it could be printed in one piece but my design is printer friendly with no support material needed, aesthetically pleasing, and plenty strong.
If you want I could merge the parts as one piece and send you the file.
I understand now, yes I would really appreciate your help in merging the parts as one piece. After seeing the carbon fiber printed parts I am pretty sure it will be able to provide the required support.
Thanks for all your help Paul🙏
Sincerely
Dax
Actually… I just realized that if it was one piece you wouldn’t be able to put the standoffs inside of it. We could make it two pieces. Or make the center one piece with two tips.
Paul I am relying on your experience, the idea of 2 parts sounds more appealing. Are you familiar with Carbon Fiber 3D printing?
The weakest link in 3D prints is the layer lines. Even the strongest material will be weakest where the layer adhesion is. It’s a lot like wood grain how it breaks really easy in one direction. The parts I designed are plenty strong printed with PETG. Again, it’s the bolts that make it strong not the material it’s printed with. If you pry on it with the hoop the hoop will deform long before the printed part will.
Thanks Paul, I am actually understanding, so let’s do it the way you have it, I need to replace the top 2 connections completely, can you send me a picture of all the parts individually? I think I printed all the parts you sent the files for, but they do not seem to create the complete connection.
