chris398mx
Master member
The only issue I had was on full throttle passes, it seamed to start to "wobble" like the ailerons were going back and forth. I was afraid I was going to lose control so I backed out if it. Any idea what might cause this?
36" Northern Pike - 3D Printed Cuda Clone (It Flies & STL's are Posted!)
- Thread starter localfiend
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chris398mx
Master member
She likes fashion and design, but she also seems to like math and science. She is learning a little 3D design (Autodesk Inventor) at school so I have been trying to get her to help me here and there. Mainly, just so I can spend some time with her.Dale - awesome new design! I'm drooling over here!
Chris - great build and love that you've got your daughter engaged in the hobby too!
Is your motor mount secure? Servos secure? Also, what did you print the motor mount out of? I know one guy on here who used PLA for the mount, and it got soft when he pushed it hard, which adds some weird thrust instability.
Usually the faster you go (Within reason) for most rc planes the more stable it is, so something may be loose.
Grifflyer
WWII fanatic
Could it be wing wobble? Or do forward swept wings not experience this?Is your motor mount secure? Servos secure? Also, what did you print the motor mount out of? I know one guy on here who used PLA for the mount, and it got soft when he pushed it hard, which adds some weird thrust instability.
Usually the faster you go (Within reason) for most rc planes the more stable it is, so something may be loose.
Normal flying wings do, but when you go slower, not when you go faster. Forward swept wings should do the same. CG can factor into wobble as well, but once again, that kind of thing is usually less noticeable at speed. The only other thing I can think of is wing flex, but at this smaller size, that should be less likely compared to the big one.
All the spars are now in place on the Ægir. The motor pods, V-Stab, Fuselage & hatch parts are all ready to be printed. Just waiting on some silver PETG filament. Hopefully that'l get here tomorrow.
The wing pieces still need to have lightening holes added to the spars however. Think I'll rest my brain for the rest of the evening. It's 8pm and I have work in the morning.
Keno
Well-known member
Dale this something I have been a great fan of, Bill Evans Simitar's RC Airplanes. I built and flew them back sometime ago, probably before a lot of are young folk were conceived. A lot of flyer had problems with this design or concept as it did not follow the normal thinking of (modern) aircraft design. The Simatar's are in fact flying DARTS with wings to provided lift and power to keep them in flight. As you note in landing they are smooth as an arrow or dart in flight and will descend as the wing design provides lift to keep their judicatory level. Hey this is only my opinion so I maybe wrong in my assumptions. I am willing to listen to all of our aeronautics genius to comment and educate me. Learning is a gift offered only by a higher authority. Thank you for your work and please continue.
PS: I going to print one but a good friend will be its pilot and that will be my reward.
Enjoy Ken
PS: I going to print one but a good friend will be its pilot and that will be my reward.
Enjoy Ken
chris398mx
Master member
I will check for loose components.firewall is Petg motor mount is PLA. do the mount and firewall both have to be PETG?Is your motor mount secure? Servos secure? Also, what did you print the motor mount out of? I know one guy on here who used PLA for the mount, and it got soft when he pushed it hard, which adds some weird thrust instability.
Usually the faster you go (Within reason) for most rc planes the more stable it is, so something may be loose.
I wouldn't think so, just the part that physically bolts to the motor. It's also possible to soften PETG parts as well, but only if you're pushing your motor hard enough to endanger the actual motor. If you're not drawing more amps than your motor can handle, it shouldn't be an issue.
Everything is done and ready for printing. Got filament in the drier now, once it's done I'll start printing the prototype.
PETG absorbs moisture from the air. The majority of the filament I buy ends up being slightly wet straight from the package. So I stick it in an oven for 12 hours minimum at 165f. Save me time in the long run.
In this case, the E-Sun Silver petg seems particularly bad. I really hope it'l recover, otherwise I'm sending it back.
chris398mx
Master member
I checked for loose parts, all seams to be in order. Everything is tight.
Grifflyer
WWII fanatic
Gotcha, at first I thought you were talking about a clothes dryer
Gotcha, at first I thought you were talking about a clothes dryer
I only take things to that level when I need to scare bears away from my house.
Got lucky, the dryer worked better than I hoped it would. Seems to have gotten rid of all the moisture and I'm getting really clean prints now.
Color isn't as silver as I would like, more like a slightly shiny grey. Oh well, should make a very good base for a light coat of metallic aluminum paint. I can leave some stuff unpainted to act as an accent. Also a good opportunity to see how much weight a bit of paint adds.
Ok, so the metallic aluminum takes almost nothing to adequately coat things, it's only a few percent added to the weight of the part.
Even more good news, is that sanding the part beforehand to knock down the layer lines actually seems to remove as much weight as you add back with paint. Seeing as how that's the case I'm using a bit of sand-able primer to fill in gaps. After things are sanded back down after one coat of primer, the part weight is back to the original. I'll probably do one more coat of primer, then hit it with the silver and see what happens.
If this goes as well as I'm hoping, this plane will be very shiny. Good news for carbon impregnated filaments as well. I may try and print one of these entirely out of polycarbonate cf filament. Should be lighter, stiffer, and still look good assuming it sands as easily as PETG does.
Even more good news, is that sanding the part beforehand to knock down the layer lines actually seems to remove as much weight as you add back with paint. Seeing as how that's the case I'm using a bit of sand-able primer to fill in gaps. After things are sanded back down after one coat of primer, the part weight is back to the original. I'll probably do one more coat of primer, then hit it with the silver and see what happens.
If this goes as well as I'm hoping, this plane will be very shiny. Good news for carbon impregnated filaments as well. I may try and print one of these entirely out of polycarbonate cf filament. Should be lighter, stiffer, and still look good assuming it sands as easily as PETG does.
Headbang
Master member
Looking forward to this!
I printed a new Pike and will build it this winter with a 2207 2400kv. Going to crank it up with as much prop as possible on 4s. The one Photo001 gave me met its end with a very hot landing that caught a wing tip and sent it rolling in an explosion of plastic. Turns out landing at about 65kph is a bad idea!
Flite Risk
Well-known member
what what a great thread, what a great plane.
At least the explosions on bad crashes are awesome to watch!
Getting closer to having everything ready to assemble. Have a few things to reprint. Been tweaking parts as I go to fix little errors and such.
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