3-Rotor head creation problem

CovertOne

New member
Hello all, I seem to be having trouble solving a problem with importing a model with a 3 rotor head on it. I am making a tilt-rotor model that has two 3 bladed heads on it, but when I build the model and link the mainhub flap 3 doesn't respond to any inputs at all. I've checked the blender model to see if its orientation and origin are in the right place and everything seems to line up as it should. This problem happens on both rotors, and after some troubleshooting I cannot figure out what the problem could be. One measure of troubleshooting I did was use an already existing 3 bladed heli as the flight model when importing and immediately linked the visuals to the left one on the tilt-rotor model and it appeared to work fine. Yet when I created another identical main rotor and linked it to the other, the problem persisted. Some screengrabs of both the blender model, hierarchy, and realflight imports are included to hopefully help anyone that could shed some light on what is going on. Thanks for any help.

Blender Model of Flap 3:
Flap_3_Left_blender.PNG

Blender Model of main hub:
mainhub_left_blender.PNG

Parenting hierarchy and naming:
left_pod_hierarchy.PNG

Realflight model with flap 3 facing camera, no collective:
Flap3_left_no_collective.png

Reakflight model with flap 3 facing cameral, full collective: Notice the lack of movement on flap 3.
Flap3_left_full_collective.png

Realflight model with flap 3 pointing left (away from main body) with full collective, along with parameters:
Flap3_left_full_collective_with_parameters.png
 
Import this model I created and let me know if all 3 blades react correctly on your PC
Try using this model as the "linked to" when importing your 3DS model.
 

Attachments

  • Two Rotor Helicopter_EA.RFX
    1.1 MB · Views: 1
All three blades appear to react correctly when this one is used as the flight model base. However, creating any new heli mechanics and rotors seem to have the same problem. The model I am building needs to have two separate heli mechanics and rotors as the two operate independently from one another.

I don't know if it makes a difference, but this model is one that is being updated from a 2 blade version to a 3 blade version. I was under the impression that the name of the mainhub was all that mattered for realflight to determine the functionality of things like the flaps.
 
Last edited:
You have to name the visual frame (Hub Graphical) in the editor.
Look to see if it shows 2blade or 3blade for the visual frame, it is easily changed by clicking on the 2blade name and selecting the other option.
 

Attachments

  • Visual frame.jpg
    Visual frame.jpg
    364 KB · Views: 8
@legoman Here is the EA as requested. Though it will not fly very well as it uses some custom control laws.

@asj5547 There is no 2 blade option as there is no 2 blade object in the model anymore. It was replaced with the 3 blade version.
 

Attachments

  • SD3 Micro 2 (1)_EA.RFX
    9.2 MB · Views: 3
I tried the EA model and as you noted in post #1 only flaps 1 & 2 (visual blades) works on the left and right rotors.
Could you post the FBX export file from Blender, so I can look at Hierarchy, pivots and naming in 3DSMax.
What model did you initially use for the helicopter (linked to) when you imported the Blender file into RF.
 
I dont see any issues in RF. I have a hunch that it may be a white space at the end the name of flap3. question did you convert the fbx from binary to ascii coming out of blender. or if there is an ascii setting in blender I would love to know about it.
 
@asj5547 The zip file includes the .tga and the fbx file exported from blender. For this model, I used the custom model of the 2 blade version of this that I made before. That one used the osprey as a base, but I deleted everything down to the airframe and built it from scratch. For the troubleshooting example I included in the first post, I used the Schweizer float heli to see if the 3 bladed hub there would function correctly when linked to one of my hubs.

@legoman Wonder why you don't see any issues. From looking at the blender model, there is no white space at the end of the name flap3. In regards to the conversion of the fbx, I don't really know whether blender does anything like that. It is pretty much as simple as clicking the export as .fbx in the file menu and it does everything else on its own. I haven't had issues like this before, so i don't know what could have changed. If you would like to go a bit more in depth, the documentation for exporting fbx's is in this link. https://docs.blender.org/manual/en/2.91/addons/import_export/scene_fbx.html
 

Attachments

  • SD3 Micro.zip
    8.6 MB · Views: 3
@CovertOne I downloaded the zip file and extracted the TGA and FBX files but unfortunately the FBX will not import into Blender or 3DSMax on my PC, however that may not be necessary, I just reread your post#1 and initially I read that both rotors were having flap3 not working concerns, I did not finish reading the sentence saying you imported with the Schweizer Float Heli and the rotor (left rotor) apparently worked okay, then you made another identical rotor for the right side, which did not work correctly (no flap3 action), okay I have seen that problem before, what you have to do is use the Schweizer as the import model, select the original Schweizer Heli Mechanics and rotor, move them to the left wing location, (rename them Heli Mechanics Left, Rotor left) test the "new left rotor" to make sure all flaps/Blades work normally, if they do then right click on the "Heli Mechanics left" and select "Copy", scroll down to the Right Wing and right click on that name and select "Paste", this will give you an exact replica of mechanics and rotor, now rename them as right side components and don't forget to click on the "Hub Graphical Name" and change that to your 3Blade name.
last year I remember banging my head against a brick wall for many days trying to fix this issue too, for some reason if you use the "Add" Heli mechanics and "Add" Main Rotor it only seems to load a two bladed rotor and there is no way I know of to add extra blades (I bet Legoman has a solution for that) he is amazing.
Let me know if this works,
 
Sorry for that late response, I wasn't able to try the solution until today. It would appear that copying the 3 bladed rotor from the float heli does indeed create another set of blades where all three function as intended. I believe this fixes the problem, but I'll be sure to update this thread if there are any other related problems, solutions, or root causes I run into. Thanks for the help.
 
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