Eskandare

[1.1.3] K.R.X Kerbal Rotor Expansion 0.31.1

Recommended Posts

8 minutes ago, V8jester said:

It's actually just a BD 20mm Vulcan on a custom gimbal made from RKE Kanadarm and IR Rework parts. Took several iterations before I figured the whole setup out. One AG to deploy the turret and FLIR ball, and another to retract everything. Once deployed I use "JKIL" to aim the turret and IR / Hull cam FLIR ball.

You are a master builder sir. I wish I could talk you into posting your stuff to KerbalX, but I can understand dealing with all the mod questions can be a pain.

Share this post


Link to post
Share on other sites

Please, i need help. Why the hell this thing flips? At 50% throttle is everything okay. At any higher throttle the nose goes uncontrollably up. The reaction wheels don't help. The centre of mass doesn't move from it's place. I don't understand. I had a similar problem with a helicopter with only one Sea Gull rotor.

PNV9msu.png

Share this post


Link to post
Share on other sites
1 hour ago, Salvator said:

Please, i need help. Why the hell this thing flips? At 50% throttle is everything okay. At any higher throttle the nose goes uncontrollably up. The reaction wheels don't help. The centre of mass doesn't move from it's place. I don't understand. I had a similar problem with a helicopter with only one Sea Gull rotor.

PNV9msu.png

Twin rotor helicopters are tricky. Use the COM / COT alignment as a guide but not a concrete rule. If it does a backflip. Try moving more the weight forward slightly. Another trick is tilt both rotors slightly forward say 15 degrees or less. An keep the COT through the COM. Now when it flips are the engines on the tail running? And how fast are you going straight up? Wind resistance will also figure in to an extent.

Share this post


Link to post
Share on other sites

@V8jester TY very much, i'll try. I was a bit puzzled, because i haven't ecountered such problems when building VTOLs with multiple jet engines, nor using the Huey rotor from K.A.X. in twin configuration. Maybe it has something to do with the excessive power of Sea Gull rotors...

Share this post


Link to post
Share on other sites
1 hour ago, Salvator said:

@V8jester TY very much, i'll try. I was a bit puzzled, because i haven't ecountered such problems when building VTOLs with multiple jet engines, nor using the Huey rotor from K.A.X. in twin configuration. Maybe it has something to do with the excessive power of Sea Gull rotors...

Sounds about right. When you have an excessive power to weight ratio. Strange things tend to happen. You might even want to decrease the power output in the SPH. Typically my rule of thumb is. 1/2 - 3/4 power to achieve liftoff. You want the heli to feel just a little heavy. If it's too powerful / maneuverable. It really won't be as controllable. VTOLs are a delicate balance to get just right.

Share this post


Link to post
Share on other sites
9 hours ago, V8jester said:

Sounds about right. When you have an excessive power to weight ratio. Strange things tend to happen. You might even want to decrease the power output in the SPH. Typically my rule of thumb is. 1/2 - 3/4 power to achieve liftoff. You want the heli to feel just a little heavy. If it's too powerful / maneuverable. It really won't be as controllable. VTOLs are a delicate balance to get just right.

Yeah, this is gonna be the problem, yesterday i tried to build an Osprey-like helicopter, and it flipped too, this time around the roll axis instead of pitch axis (although i had some pitch problems too). And the Osprey rotors seem very powerful too. Thanks very much, ill try to fine tune it.

Share this post


Link to post
Share on other sites
4 hours ago, Salvator said:

Yeah, this is gonna be the problem, yesterday i tried to build an Osprey-like helicopter, and it flipped too, this time around the roll axis instead of pitch axis (although i had some pitch problems too). And the Osprey rotors seem very powerful too. Thanks very much, ill try to fine tune it.

Yeah the osprey rotors were increased probably because of me. I built my osprey with over 200 parts. So it's pretty heavy (can't recall ATM how heavy it is) but I had recommended to Eskandare to increase the output. And a trick I used was surface attach a structural part with a node to the outside of the helicopter. Then stack 4-6 aditional SAS rings to that and offset the whole thing inside the helicopter. It's a cheat, but on some crafts it's almost necessary.

Share this post


Link to post
Share on other sites
7 hours ago, Salvator said:

Yeah, this is gonna be the problem, yesterday i tried to build an Osprey-like helicopter, and it flipped too, this time around the roll axis instead of pitch axis (although i had some pitch problems too). And the Osprey rotors seem very powerful too. Thanks very much, ill try to fine tune it.

Could be worse... You could be flying this.

EQrZy3P.png

oetzu4T.png

DKvEb4r.png

 

You may be wondering, what that thing is in the distance? Shhhhh... you'll know soon enough. :wink:

Share this post


Link to post
Share on other sites
On 8/24/2016 at 11:21 AM, Salvator said:

Please, i need help. Why the hell this thing flips? At 50% throttle is everything okay. At any higher throttle the nose goes uncontrollably up. The reaction wheels don't help. The centre of mass doesn't move from it's place. I don't understand. I had a similar problem with a helicopter with only one Sea Gull rotor.

PNV9msu.png

I usually hate that solutions to questions always wind up being "a mod," but I can't recommend Throttle Controlled Avionics enough for Helicopters and VTOLs. It's feature-rich, but at the very least the thrust balancing mode can keep a craft like that stable at hover or even booking along at high speed.

Edited by Beetlecat

Share this post


Link to post
Share on other sites
2 hours ago, Eskandare said:

Could be worse... You could be flying this.

Wow, what a monster! Nice job though.

 

45 minutes ago, Beetlecat said:

I usually hate the solutions to questions always wind up being a mod, but I can't recommend Throttle Controlled Avionics enough for Helicopters and VTOLs. It's feature-rich, but at the very least the thrust balancing mode can keep a craft like that stable at hover or even booking along at high speed.

Yeah, i've been playing with the idea of using TCA myself for some time now. I guess i'll give it a try.

Share this post


Link to post
Share on other sites
8 minutes ago, Salvator said:

Yeah, i've been playing with the idea of using TCA myself for some time now. I guess i'll give it a try.

Since you can dial it back or simply turn it off when you don't want or need it, no real reason *not* to. :wink:

Share this post


Link to post
Share on other sites
35 minutes ago, Salvator said:

Wow, what a monster! Nice job though.

 

Yeah, i've been playing with the idea of using TCA myself for some time now. I guess i'll give it a try.

Thank you, it takes some practice to fly.

TCA is a recommended mod which works great with KRX, however, by no means is it required. TCA does help make things hover and VTOLs easier to fly.

I do have a suggestion for you, try to put all your fuel at the lowest part of the fuselage. You want a low center of mass with your thrust at the top. 

 

I flew this helicopter without TCA, as a matter of fact I did not use TCA for any of KRX's example pictures.

b58f82C.png

 

 

Edited by Eskandare

Share this post


Link to post
Share on other sites
7 hours ago, Eskandare said:

Thank you, it takes some practice to fly.

TCA is a recommended mod which works great with KRX, however, by no means is it required. TCA does help make things hover and VTOLs easier to fly.

I do have a suggestion for you, try to put all your fuel at the lowest part of the fuselage. You want a low center of mass with your thrust at the top. 

 

I flew this helicopter without TCA, as a matter of fact I did not use TCA for any of KRX's example pictures.

b58f82C.png

 

 

See in that statement you can understand why it was such a pain building an Osprey :) my CG was just under the wings. Because in plane mode the thrust would push around the CG and set the craft into an unrecoverable nose dive. Aero forces and a high CG where the only way to get it flying with neutral trims on all axis. I swear I spend more time in the SPH building planes and helicopters now. Especially since you gave us KRX!

Share this post


Link to post
Share on other sites
1 hour ago, V8jester said:

See in that statement you can understand why it was such a pain building an Osprey :) my CG was just under the wings. Because in plane mode the thrust would push around the CG and set the craft into an unrecoverable nose dive. Aero forces and a high CG where the only way to get it flying with neutral trims on all axis. I swear I spend more time in the SPH building planes and helicopters now. Especially since you gave us KRX!

I had the same problem with my rendition of the Boeing V-322 Bigboy.  There is a transition point that causes the craft to pitch down. My solution is to throttle down once I'm at a good lift velocity, transition to full forward and then increase thrust.

Share this post


Link to post
Share on other sites
1 hour ago, Eskandare said:

I had the same problem with my rendition of the Boeing V-322 Bigboy.  There is a transition point that causes the craft to pitch down. My solution is to throttle down once I'm at a good lift velocity, transition to full forward and then increase thrust.

Yup same here. And yeah I have to do the same. As lift increases from the wings I decrease thrust at that tipping point. I am curious if the real v-22 does the same thing. I have a feeling the flaps on the main wing, on the real plane cancel a lot of this out. Coupled with the fact the props are actually rotors. I used an IR Rotatrons to spin an RKE arm section with B9 Proc control surfaces to achieve my 90 degree rotating flaps. And it helps but in some situations it provides a little too much lift / stopping power.

Share this post


Link to post
Share on other sites
1 hour ago, V8jester said:

I am curious if the real v-22 does the same thing. 

I don't know, but I do know that they had a lot of trouble with its stability and had to make many revisions to the tilt rotor.

Share this post


Link to post
Share on other sites
7 hours ago, Eskandare said:

I don't know, but I do know that they had a lot of trouble with its stability and had to make many revisions to the tilt rotor.

Yeah as cool as the Osprey is. It had a very horrific beginning.

Share this post


Link to post
Share on other sites
11 minutes ago, V8jester said:

Yeah as cool as the Osprey is. It had a very horrific beginning.

I think they had something like 7 crashes with a total 36 fatalities. DARPA is currently running a competition for the next VTOL aircraft. 

https://en.wikipedia.org/wiki/Bell_V-280_Valor

Edited by Eskandare

Share this post


Link to post
Share on other sites
1 hour ago, Eskandare said:

I think they had something like 7 crashes with a total 36 fatalities. DARPA is currently running a competition for the next VTOL aircraft. 

https://en.wikipedia.org/wiki/Bell_V-280_Valor

:) I already built one of those. Video was taken down when I got a copywrite strike from YouTube due to music used in my original videos. Been re dubing and re uploading them gradually. Maybe I'll redo that one now that you bring it up.

Share this post


Link to post
Share on other sites

I'll be making a few minor adjustments to KRX.

Edited by Eskandare

Share this post


Link to post
Share on other sites
14 hours ago, V8jester said:

:) I already built one of those. Video was taken down when I got a copywrite strike from YouTube due to music used in my original videos. Been re dubing and re uploading them gradually. Maybe I'll redo that one now that you bring it up.

I just built a V-22 Osprey, it was quite the effort to get it to fly. I had to put the center of lift just ahead of the CoM to balance the over wing thrust. Still, transition is tricky.

Share this post


Link to post
Share on other sites
On 25. August 2016 at 6:06 PM, Eskandare said:

Could be worse... You could be flying this.

EQrZy3P.png

oetzu4T.png

DKvEb4r.png

 

You may be wondering, what that thing is in the distance? Shhhhh... you'll know soon enough. :wink:

 

How did you gert the texture on the right rotor to load? Or do I have to download the newest update?

Share this post


Link to post
Share on other sites
6 minutes ago, DeepSlayLP said:

How did you gert the texture on the right rotor to load? Or do I have to download the newest update?

You should always update to the latest version, also all textures should be loading. Double check to make sure the installation is correct.

 

Share this post


Link to post
Share on other sites
5 hours ago, Eskandare said:

You should always update to the latest version, also all textures should be loading. Double check to make sure the installation is correct.

 

Actually I have the same problem. I'm still using the part folders from the old rotors modified to have more power. As the regular rotor won't load its texture for some reason. This only became an issue after they were modified to spin the proper direction.

Share this post


Link to post
Share on other sites
23 hours ago, V8jester said:

Actually I have the same problem. I'm still using the part folders from the old rotors modified to have more power. As the regular rotor won't load its texture for some reason. This only became an issue after they were modified to spin the proper direction.

I'll look into why that is happening.

 Meanwhile, my updated version of the V-322 Big Boy and V-22 Osprey.

PWWkQ0M.png

UopT24k.png

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.