3D printed C/L model

[Akihiro Danjo]

I am sorry if any topics about this has already posted here, because I had hospitalized over 100 days in '19 and just released from a hospital this week.

Has anyone in the world built and flown a 3D printed C/L model ??
A Japanese modeler has built and flown one in Japan (see the link). Is this the FIRST 3D printed C/L in the world?

http://www.ne.jp/asahi/thx-1195/book/gallery2.html

Aki

[Dave Hull]

Aki,

Sorry to hear of your illness, but I am glad that you are on the mend.

I have seen one 3-D printed fuselage for a small scale model. I would guess it was perhaps 29 inches (~74cm) long. It was done in sections due to size limits of the printer, and it was too heavy to easily be used as a flyable fuselage. They then planned to use it to make a mold to allow them to make an accurate composite fuselage for lighter weight and greater strength.

If your friend has successfully printed a competitive stunt fuselage, that is a significant accomplishment. The model you show in the link has obviously been designed to take advantage of printer's capabilities, and to avoid the limitations. The scale model that I saw was generated from a solid model database with limited effort (no effort?) to make it strong enough and light enough to fly.

He may be the first for control line.

Best wishes,

Dave Hull

[Dennis Leonhardi]

That is really amazing - Thanks for posting the link here!


Dennis

[Paul Walker]

Do you know how much that plane weighs?

I have seen an RC 3D printed plane, but it was heavy, even for an RC plane.

[Dave Hull]

One key is that the mechanical properties of the available plastics for printing have improved a lot over the last 10 years. But they are not isotropic, so that would have to be considered when designing the parts.

The other issue is the "terracing" due to the printer step size. Was the plane shown in the link manually smoothed? If so, how did that work out?

Dave

[Peter Grabenstein]

And YES it flys very well and fast.
3th Winner COX Mouse Race @ Lassogeier Comp. 2017 .

See pic. @ post # 94.

www.rc-network.de/forum/showthread.php/637885-Die-Hummel/page7

post # 107

http://www.rc-network.de/forum/showthread.php/637885-Die-Hummel/page8

post # 143

http://www.rc-network.de/forum/showthread.php/637885-Die-Hummel/page10

BTW, I am not the builder but eyewitness.
Cheers
Peter

 

[Akihiro Danjo]

>Do you know how much that plane weighs?

It weighs 937 grams (flyable). Wing area is 16 dm2 = 248 sqin, Span 888 mm. Yes, it's heavy.

>Was the plane shown in the link manually smoothed?

The surface is not smoothed.

Aki

[Dan McEntee]

   Like Ty said, looks kind of "Spitire-ish" with a little Cox TD-1 thrown in! It will be interesting to follow the progress of this venture.
    Type at you later,
   Dan McEntee

[TDM]

I think it can be ideal for scale modeling. However for aerobatics you might end up with smashed pieces all over the place as I do not believe you can do it and have it stay together. When you print something 3D you lay material layer by layer and the bond between layers is not perfect. The thing is the pieces I printed out at work were weak and as soon as I added a screw or the lightest pressure they delaminated in the grain direction in which it was applied. For level flight and low G it is just fine.

[Perry Rose]

How will this fit into the Builder of the Model rule?

[Dan Berry]

33oz and 2/3 the wing of a Ringmaster?
Huh.

[Mike Alimov]

 

How will this fit into the Builder of the Model rule?

Well, after reading control line forums to about 20 years now, I predict it goes something like this:
1) uproar in the general control line community: "this is the beginning of the end of stunt as we know it", "there goes the tradition of craftsmanship", etc.. along the lines of BOM and ARF discussions; this goes on until....
2) someone shows up at the NATS with a 3D-printed model and demonstrates a top-5 level performance, after which...
3) a BOM rule is amended on the spot, and now reads "POM - Printer of the Model", which requires the author to click the Print button...
4) a few years go by, the uproar subsides, and everything returns to its usual status quo. 
 

[Serge_Krauss]

The P-38 video is really fascinating and breathtaking - for a dinosaur "techie" like me. I love the video. 'like the little racer too. Concerning Mike's prognosis, which I liked, my most recent experience with peers and those older than I (dwindling, but most) at the field, I doubt there will be nearly as much passion left about this, considering all the suddenly more menacing things in the world to gripe about  I'll just enjoy this while it lasts.

[Jason Greer]

If only we had 4-6 pound/sq ft filament.

[Howard Rush]

Very cool. So far the only flight articles I’ve printed are spinners and vortex generators. Were I more original, I could do more. I might try fillets and motor mounts. The plastic isn’t strong, but the part buildup can be pretty fancy: my spinners have two shells with honeycomb between. Ridges are not a problem.  You can get paper coated with abrasive particles in many different sizes. Rubbing this on the plastic can make it plenty smooth.

[Dan Berry]

  You can get paper coated with abrasive particles in many different sizes. Rubbing this on the plastic can make it plenty smooth.

Most of us just use some shark skin.

[pat king]

How do you get the shark to cooperate and not bite?

[Dan Berry]

How do you get the shark to cooperate and not bite?

Well, it's wet sanding.

[Dave Hull]

"Uhh, Quint, I think we're gonna need a bigger shark..."

Mega-stunt-alodon



PS--So does the printed plastic actually sand ok, or does it fuzz up?

[Howard Rush]

PS--So does the printed plastic actually sand ok, or does it fuzz up?

I use ABS, which sands dandy.  I chuck up spinners in the drill press to sand.  My main problem is sanding through the outer shell.  Per Mark Scarborough's advice, I use an adhesion promoter, https://www.spraymax.com/en-us/products/product/surface-preparation/1k-plastic-adhesion-promoter/ , and DC 540 primer (the old stuff).  Then it's ready for color.

[Igor Burger]

Has anyone in the world built and flown a 3D printed C/L model ??

Hi Aki, I thought that it will be way for our kids, so I tried, but I gave up when I saw how fragile and heavy is the wing.

Our RC combat guys (from 3d lab mentioned upper) making semiscale models (their rules call for semiscale models) like visible on that link are using it, but what I saw is really not for aerobatics. May be for flying in level, but since our kids can fly figures after practive in gym, it is not usefull for them.

Regarding gluing, sandig etc. There are several materials for printing, all of them are getting soft in heat, so sanding is not easy. The other problem is that construction needs very thin "empty" construction, so sanding is really not easy. They have to be printed "nice" so that it does not need sanding. Gluing is not problem at all, CA glue is for all :- ))

Strength is questionable. PLA is hard but cracky. It is mostly used for printing those models. ABS will not crack, but is is soft and does not work well on wings. Many guys use PET (like used on bottles) that looks good, but limited number of colors. There is till one issue with those models - they will not survive in high temperature, I saw model on back seat of car nicely copying seat shape ... just because sun did its job :-P ... the same problem is with printed motor mounts. That is mostly problem of PLA.

However do not expect printing of such models is easy, it needs lot of expeciece to print so large structures of such thin walls.

I saw also combined technology of model printed very hnin, double surface with 3d honeycells  and then layer of CF or CF laminate. It was like rock, but yes, still heavy, good for RC but probably not for us.