True

[peabody]

I am the membership chair for the MCRC and often get inquiries via telephone regarding membership.

One such was from a guy that had built a laser printed P-38 from programs on the Interweb.

He was very enthusiastic and allowed that he had flown it successfully on the simulator.

He was hot to trot, and arrived at the field that morning, with P-38 and "all the fixings" (RC)

It had about a 5' wingspan and was very scale like....thin wings, etc.

He explained that his printer was 14" and allowed as to if he crashed it, he could just build another!

I picked the thing up, and imagine it weighed around 8 pounds. 

I pointed him to the club head pilot and suggested that the flight take place with an experienced flyer.....

They taxied it to the other end of the runway. I was figuring that it would be in the trees at about 10' IF it got off the ground. WRONG! It took off in about 30' and seemed to fly pretty well. An issue with not being able to trim the left aileron caused the wing to dip as it was landing and the left wing end broke off. The owner was delighted! He printed the repair parts and has flown it several times.

He reports that there are control line planes/programs available as well.

Kinda puts an even newer spin on the BOM?

 

[john e. holliday]

In some areas the BOM is a moot point.  If the winner was at least 20+ in the lead, why complain as long as they are flying.  If flyng for your own enjoyment keep having fun.  I've seen videos of those kits and there is still work to be done as well as trimming them.  If I was better off finacially I would have to entertain spectators.

[Brett Buck]

Kinda puts an even newer spin on the BOM?

  How so? There has never been any debate that if you build it yourself, you can use whatever means you choose. 3D printing can certainly be done at home, and seems to be no different in principle that using someone else's rib templates.

   Brett

[Mark wood]

Yup, what Brett said. Being able to use your tools, including 3D printer to make parts that you put together creates a model. Seems to me no different than using an exacto knife to cut parts to put together to create a model. Only difference is  the technology. That the technology simplifies the assembly doesn't change who built it. Besides plastic aint got nothin on good old balsa in terms of flyability.

[Serge_Krauss]

If it's all clear to you, then great; have at it.

[Paul Wescott]

  How so? There has never been any debate that if you build it yourself, you can use whatever means you choose. 3D printing can certainly be done at home, and seems to be no different in principle that using someone else's rib templates.

   Brett

Stop it Brett.  Stop stirring up trouble LOL (just kidding, go right ahead).

“There has never been any debate that if you build it yourself, you can use whatever means you choose.”  Just because there never has been a debate does not mean there should not be a debate.  I think there should be a debate.

“3D printing can certainly be done at home, and seems to be no different in principle that using someone else's rib templates.”  Oh really?

What if a “builder” has a very large 3D printer.  Now instead of creating the aircraft in sections and “building” (assembling) it, all one has to do is push the start button and a couple of days later remove the complete airframe with no assembly required?  Does this still count as “building” your own model?

What if I farm out the 3D printing to a vendor that has a very large 3D printer because I don’t have room for one or can’t afford one?  Is borrowing (or renting) someone else’s 3D printer the same as borrowing a friend’s X-Acto knife?  Is placing an order on a web page and clicking < SUBMIT > the same as pressing the start button on a 3D printer in my back bedroom, garage, workshop, workplace…?

I don’t like the idea of losing the spirit of the BOM rule.  To me there’s nothing more awe-inspiring than many of the airplanes hand built by folks who do it just for the love of doing it.  The late Kirk Mullinix’ Corsair.  Bob Harness’ Two-Bits.  Whatever the heck new airframes Warren Walker and Antone Kephart show up with at the next contest.  Intricate collections of HAND fitted parts, then HAND sanded, HAND painted, and sometimes HAND rubbed to gleaming perfection (or near perfection).

The Craftsmanship museum in Vista, Calif is filled with crafted pieces of art meticulously machined from aluminum, brass, and other shiny metals one piece at a time, and the museum is worth a visit.  Those cheap steam engine kits and Stirling engine kits available online are a distant second and a far cry.

I can’t imagine a 3D printed stunter in the front row after concourse judging.  I don’t think I’d have much interest in seeing a gaggle of 3D printed plastic airplanes at the next contest.

If 3D printing a stunter is ok, why don’t we have Igor or one of the other electronics geniuses cobble together an Arduino based control system, 64-bit flight controller, GPS module, 6-axis solid state gyro, LIDAR module, high-speed digital elevator servo, you know, all the parts that are already off-the-shelf in the dreaded multi-rotor (aka “drone”) arena.  With a couple of minor rule adjustments we can attach our single cable to the top of the pylon at center circle, position the aircraft, push the start button, sit down in a comfy chair OUTSIDE the circle, and watch our computer controlled 3D printed brushless motor powered stunter cruise through the entire pattern including takeoff and landing.  We’ll just basically turn the entire exercise into a computer programming competition.  Yeah let’s do that.  YAWN…

Maybe in the near future we won’t be using as much balsa, if any, but…
There should at least be a debate.
Folks who hand-build should be praised and rewarded.
We should hang on to the spirit of the BOM rule as long as we can and strive to be as good as the giants who have come before us in this unique endeavor.

Go ahead: Change my mind.

I gotta stop posting in the middle of the night.

Paul

[Mark wood]

Paul. I think your imagination has gone wild. A large format 3d printer may be able to print something resembling an airplane but it definitely wont create one which is viably competitive. These 3d printed airplanes must be printed is sections for several reason but primarily to be able insert CF spars and such. These thing are quite heavy and it may be that some day they will be the only thing around because we old hanger onners are gone. I think the worry over technology taking away the essence of stunt is mute. The young people with the savviness to do so aren’t interested in what we do. In my perspective, if a 3D printed model gets one youngster started, i say print away to your hearts content. Besides, you yourself most likely correctly doubt a 3D printed airplane will make the concourse and as such, similar to an ARF, wont likely have great appearance points. Its just not a debate worth the energy.

[Brett Buck]

Stop it Brett.  Stop stirring up trouble LOL (just kidding, go right ahead).

“There has never been any debate that if you build it yourself, you can use whatever means you choose.”  Just because there never has been a debate does not mean there should not be a debate.  I think there should be a debate.

“3D printing can certainly be done at home, and seems to be no different in principle that using someone else's rib templates.”  Oh really?

What if a “builder” has a very large 3D printer.  Now instead of creating the aircraft in sections and “building” (assembling) it, all one has to do is push the start button and a couple of days later remove the complete airframe with no assembly required?  Does this still count as “building” your own model?

What if I farm out the 3D printing to a vendor that has a very large 3D printer because I don’t have room for one or can’t afford one?  Is borrowing (or renting) someone else’s 3D printer the same as borrowing a friend’s X-Acto knife?  Is placing an order on a web page and clicking < SUBMIT > the same as pressing the start button on a 3D printer in my back bedroom, garage, workshop, workplace…?

I don’t like the idea of losing the spirit of the BOM rule.  To me there’s nothing more awe-inspiring than many of the airplanes hand built by folks who do it just for the love of doing it.  The late Kirk Mullinix’ Corsair.  Bob Harness’ Two-Bits.  Whatever the heck new airframes Warren Walker and Antone Kephart show up with at the next contest.  Intricate collections of HAND fitted parts, then HAND sanded, HAND painted, and sometimes HAND rubbed to gleaming perfection (or near perfection).

  OK, running with your premise - where would you draw the line? Everybody has to draw their own airplane in Solidworks, then print it?  Ban printing entirely?   What about regular 2D decals? They are printed, and many times from other people's art. What about laser-cutting flat balsa parts? What about die-cut parts?  Do we make it illegal to print your own wing skins - but allow people with a machine shop to build their own metal molds with which to lay up carbon fiber/epoxy parts. What if they use a CNC machine and someone elses CAD files to drive their Haas 5 DOF milling machine?

    I note that there is absolutely nothing stopping anyone from doing the same thing this afternoon with a solid block of balsa and a CNC router, except the will do to it. Is carving it out of balsa intrinsically different from building it up from plastic? Same thing with foam cores - there are certainly CNC foam cutting machines, grab someone's "Infinity" CAD file, you have the same thing I did with a bit of plywood and the sole of my shoe.

   To me, as long as you do the work yourself, you are good to go.  If you think otherwise, then you have to figure where the line is -  based on some underlying principle that is agnostic. Technology has radically changed the event over the years, we have managed to accommodate it before, I think we still should, without trying to come up with a never-ending "laundry list" of things that we, today, this instant, think are OK or not OK.   

     I really don't like the idea of banning anything outright, if we listened to people who want to ban things, we would have no carbon props, tuned pipe engines, electric, or a whole lot of other things we generally like.

   To me it is not that complicated, but what's your idea, what, exactly, would you write as a rule?

     Brett


  p.s. I add that, I can't have imagined that one day we would be questioning whether *building it yourself in your home workshop* would not be good enough to meet the BOM. Even if you 3D print all the parts, it certainly will require more than "a few minutes of unskilled effort" to put together. Although some people interpreted the (nonexistent) "gel-coat rule" to preclude *anything with the finish built in to the construction", whether you made it yourself or not.

[Brett Buck]

Paul. I think your imagination has gone wild. A large format 3d printer may be able to print something resembling an airplane but it definitely wont create one which is viably competitive. These 3d printed airplanes must be printed is sections for several reason but primarily to be able insert CF spars and such. These thing are quite heavy and it may be that some day they will be the only thing around because we old hanger onners are gone. I think the worry over technology taking away the essence of stunt is mute. The young people with the savviness to do so aren’t interested in what we do. In my perspective, if a 3D printed model gets one youngster started, i say print away to your hearts content. Besides, you yourself most likely correctly doubt a 3D printed airplane will make the concourse and as such, similar to an ARF, wont likely have great appearance points. Its just not a debate worth the energy.

   I think you are underestimating the possibilities of additive manufacturing. I have seen 3D printed metal parts that you could not distinguish from those hogged out of solid blocks with a CNC machine, aside from having no machining marks. They even have perfectly formed and sufficiently strong 8-32 threads printed into them, no tapped threads. Same with plastic, including some pretty high-strength polymers.

    You can't get the printers at home for any reasonable price - yet - but people are doing it already, to plenty high enough quality. If I had unlimited funds and access to some of my work resources, I could probably have .014* thick titanium wing skins, with all the stiffeners and spars necessary printed on, by the end of next week. Smooth enough to prime and paint with no other prep.

   I don't think it changes any of the arguments, but I would not base any arguments on "it's too crude" or "it will never work", because you could have said the same thing (correctly) about electric 30 years ago.

   Brett

*note that this is just a wild guess as to what might work - not that I have thought about it too much.

[Dan McEntee]

   This all proves the old saying, " The more things change the more they stay the same!"  There are probably very few people that view this website that have not built a Top Flite kit of some kind like the Nobler, Flight Streak and such. They were known for the use of machine balsa parts and preformed molded balsa assemblies. There were letters to the editors of most major model magazines back in the 50's and 60's on what an abomination that was and how does THAT meet the Builder of the Model Rule!! To fully met the rule for scale some guys believed it was necessary to  draw your own plans !! Lots of similar jokes , comments and cartoons like we see today! I could see a model with partial or full printed components being put down for appearance judging but I don't think the material for it has been invented yet for the average modeler to be able to take advantage of the technology.  The average modeler can't take advantage of the technology for the molded composite contractions we see today for that matter, but no need to ban or restrict the technology. Where would we be if they had done that to Top Flite years ago!!
   Type at you later,
  Dan McEntee

[Bruce Shipp]

I follow a few slot car forums and 3D printing of bodies and chassis is becoming very popular.  It allows creating unusual cars that are not available from the slot car or scale plastic model manufacturers.  The catch is that the quality of the piece off the printer is far from that of traditionally manufactured bodies.

If someone was to print an airplane or parts from the average home printer and turn that into a front row airplane with good flying qualities, that would be a feat. Not just another ARF.

[Brett Buck]

I could see a model with partial or full printed components being put down for appearance judging but I don't think the material for it has been invented yet for the average modeler to be able to take advantage of the technology. 

   An obvious use for the existing technology and limitations - making jigs and molds for use with conventional or advanced construction/materials. One of the holdups to making, say, carbon/epoxy wing skins is making a mold for it. Ideally, it would be something like steel, and not many people can hog out an acceptable female wing skin surface from a block of steel. It would, however, be entirely feasible to print it from plastic using existing consumer-grade tools (reallly big ones...) fill/it with Bondo, finish with 3/4 glass and epoxy to a mirror finish, perfectly usable mold.

   Are we going to try to ban that, too?

    Brett

[Scott Richlen]

I am already on the 3-D printed pathway!!

Here's my Chubby's Checker with its 3-D printed exhausts.

So, I figure that I am currently about .00002% of the way to a fully printed stunt ship!     

[Mark wood]

I'm doing a lot of very interesting things with my 3D printer using a carbon fiber impregnated nylon material. Some of those results will be showing up here in photos soon. This material has a tensile strength of 14,500 psi or about half that of aluminum. It could be used to make an airplane if you could glue it adequately which it doesn't glue very well. It also doesn't sand very nicely and I don't know how well it paints but I'm guessing not good.

Metal additive manufacturing is already beginning to be available to the small / home shop engineers. Today it is possible for a guy like me to purchase the filament, it's not cheap, make my part and send it off to be sintered in to a honest metal part. Sintered metal is not as strong as a machined part but handling that is simply an exercise in application engineering. My electronic stooges are shipping with the retention block made from the material and some parts I am making for the 4/4 arena are as well. My next model will have a lot of 3D FFM parts in it.

[Mark wood]

Found some CF impregnated ABS filament today and ordered some. The CF impregnated nylon I have been using is super tough but it doesn't glue well. I'm thinking this CF/ABS will be strong and glue well. That makes me thing of things like ribs and other things like supports for the log crank system I'm working on.