Agathorn Posted January 23, 2014 Share Posted January 23, 2014 The nodes on the side of the Dragon capsule where the SuperDracos and ladder/parachute attach (seen here).Oh you mean the attachment nodes themselves, not the items, are causing is? Interesting. Link to comment Share on other sites More sharing options...
Agathorn Posted January 24, 2014 Share Posted January 24, 2014 I really think the problem is still with the engine cluster, and hope that single engines with gimbals will fix it.In RO I just built a rocket using no SpaceX except for the engines, and it was all over the place. The fact that six of the engines have no gimbal, and that the 3 with gimbal have a very limited range, means the whole thing just isn't very controllable without the reaction wheels. Link to comment Share on other sites More sharing options...
hieywiey Posted January 24, 2014 Share Posted January 24, 2014 Could you add a Falcon 1? Link to comment Share on other sites More sharing options...
LazarusLuan Posted January 24, 2014 Author Share Posted January 24, 2014 I really think the problem is still with the engine cluster, and hope that single engines with gimbals will fix it.In RO I just built a rocket using no SpaceX except for the engines, and it was all over the place. The fact that six of the engines have no gimbal, and that the 3 with gimbal have a very limited range, means the whole thing just isn't very controllable without the reaction wheels.I've rebuilt the Merlin 1D engines and the octaweb housing, fixing a few problems I discovered with the model and thrustTransform within the Merlin 1D. You can download the HD version here: LTSpaceXMerlinUpdate01.zip The engines are now designed to be attached separately and have a .5 gimbal. Each engine needs to be rotated to visually fit the graphics on the housing, but this obviously doesn't affect the mechanics. I've tested the new engine assembly on all of my Falcon configurations and have found no problems so far using no ASAS or reaction wheel. Additionally, I can easily perform controlled reentry with the new configuration, as it allows me to control the number of engines being relit at any time. Please test this setup to see if it fixes the issue. Link to comment Share on other sites More sharing options...
NathanKell Posted January 24, 2014 Share Posted January 24, 2014 That's wonderful! With an addon gimbal module that'll even give us excellent roll control. Link to comment Share on other sites More sharing options...
LazarusLuan Posted January 24, 2014 Author Share Posted January 24, 2014 My latest update to the Rescale config (now linked to in my sig) adds in ferram's code for both versions of the solar panel covers. He mentioned that it was the horizontal nodes causing the issue, which FAR sees as cylinders sticking out the side of the rocket, obviously very bad for aerodynamics and control. I wonder if maybe the nodes on the Dragon capsule, which are similar to that of the solar panels', might be causing a problem as well. I'll need to do more testing today. Also I would second Agathorn's request for the optional engine bottom part with the 9 connect points.Edit: Just tested a rocket with nodes on the Dragon and a rocket with nodes removed from the Dragon. They are definitely causing issues in the same manner that the solar panel covers nodes were. I'll message ferram and see if he knows of a fix. If not, I'm just going to remove them from my config.I originally set up the attachment points to solve a rolling problem I had when creating the Dragon 2 capsule. After testing today I discovered I no longer need these attachment points as long at I rotate the ship 45 degrees before installing the nacelles. I've rewritten the .cfgs for the Dragon 2 and SuperDraco nacelles to surface attach only, eliminating all attachment points and rebuilt the DragonChute and DragonSteps to surface attach as well. You can download these updates here: LTSpaceXDragonUpdate01.zipPlease let me know if this works better. Link to comment Share on other sites More sharing options...
LazarusLuan Posted January 24, 2014 Author Share Posted January 24, 2014 The nodes on the side of the Dragon capsule where the SuperDracos and ladder/parachute attach (seen here).I've also changed the solar panels and covers so that the cover attaches to and decouples from the solar panels themselves, removing the need for the nodes on the trunk, so there shouldn't be any nodes at all on the new updates. Link to comment Share on other sites More sharing options...
HoneyFox Posted January 24, 2014 Share Posted January 24, 2014 (edited) I really think the problem is still with the engine cluster, and hope that single engines with gimbals will fix it.In RO I just built a rocket using no SpaceX except for the engines, and it was all over the place. The fact that six of the engines have no gimbal, and that the 3 with gimbal have a very limited range, means the whole thing just isn't very controllable without the reaction wheels.I've just finished my tweaking of these two engines of the 1st stage and the roll control is pretty good.However the 4 small aux engines (well they might be used when landing the 2nd stage, but i use it as vernier thrusters too, donno if it is like that in RL or not) on the 2nd stage don't have gimbal animations so that i cannot accurately tweak the gimbal coefficients for roll channel control in VAB. I might need some more tests. Edited January 24, 2014 by HoneyFox Link to comment Share on other sites More sharing options...
Agathorn Posted January 24, 2014 Share Posted January 24, 2014 Laz very awesome updates! Not sure when next i'll get a chance to do some more testing but I will let you know how it goes.Thanks for all your work on this awesome mod! Link to comment Share on other sites More sharing options...
Agathorn Posted January 24, 2014 Share Posted January 24, 2014 I've just finished my tweaking of these two engines of the 1st stage and the roll control is pretty good.However the 4 small aux engines (well they might be used when landing the 2nd stage, but i use it as vernier thrusters too, donno if it is like that in RL or not) on the 2nd stage don't have gimbal animations so that i cannot accurately tweak the gimbal coefficients for roll channel control in VAB. I might need some more tests.Hey HoneyFox any tips? I'm having trouble with the 8 engines around the outside because they don't mount along the centerline. What I mean by that is if you point the camera directly at the front of the craft, such that yaw on the center engine is directly left and right, the next two outboard engines left and right of that are slightly fore and aft, not next to it. so when I then put those engines in, the yaw isn't directly left and right but at a small angle.How do I tweak the gimbal stuff to make them straight? Is this just a painstaking process of finding the right h and v values for each engine to make it straight? Link to comment Share on other sites More sharing options...
Agathorn Posted January 24, 2014 Share Posted January 24, 2014 Laz,I only had a few moments for a quick test of the first stage but I noticed a huge improvement in both initial craft stability and control authority.Once I got pitched over past about 15 degrees I started having control problems, but I think that's because of my gimbals so that is something I need to work on.Anyway, I only tested the first stage (so no second or capsule on the craft) but looks like a nice improvement! Link to comment Share on other sites More sharing options...
HoneyFox Posted January 24, 2014 Share Posted January 24, 2014 (edited) Hey HoneyFox any tips? I'm having trouble with the 8 engines around the outside because they don't mount along the centerline. What I mean by that is if you point the camera directly at the front of the craft, such that yaw on the center engine is directly left and right, the next two outboard engines left and right of that are slightly fore and aft, not next to it. so when I then put those engines in, the yaw isn't directly left and right but at a small angle.How do I tweak the gimbal stuff to make them straight? Is this just a painstaking process of finding the right h and v values for each engine to make it straight?That's right, there's an angle off. So you have three options:1. tweak both Roll Coeff H & V to a proper ratio.2. rotate that engine cluster base until the attach nodes are just right at the front direction. 3. rotate the outboard engines to proper orientation. (they used to face to the front instead of to the center of the cluster base)If you chose to tweak instead of rotating:To adjust that correctly, you get to the bottom of the rocket, point the camera towards the top of the rocket, and turn the camera so that your two outboard engines are right in front of the camera, now tweak that two coefficients ( & reverse if needed ). use Roll Test (set to 1.0) to see if the gimbal is shifting along the tangent direction (i.e. only horizontal shift from your viewpoint) & is shifting to the left side (otherwise the roll control is reversed).Note that the two outboard engines are not symmetric counterparts (you cannot install them by 2x mode, right?). So these two engines need individual tweakings and there might be some difference between their reverse controls. Edited January 24, 2014 by HoneyFox Link to comment Share on other sites More sharing options...
Scripto23 Posted January 24, 2014 Share Posted January 24, 2014 Laz, thanks for addressing so many issues and so quickly! I'm going to give things a test today and implement some more changes in my config then update it later on.HoneyFox, for those small aux engines, are you referring to the white SuperDraco engines that attach to the Dragon, or the spherical looking "SuperDraco single engines"? If it's the latter, that was a part I added based on what I saw in and just used the solid fuel "separation engine" model, so they weren't in the original mod. I wasn't aware they don't have gimbal animations so I can use a different model in its place, maybe a greatly scaled down Merlin 1D? Link to comment Share on other sites More sharing options...
LazarusLuan Posted January 24, 2014 Author Share Posted January 24, 2014 Could you add a Falcon 1?Yes - I have created 3D models of the entire historic SpaceX line, plus the proposed Falcon X super heavy lift design, and will put these out over the next couple of months. Link to comment Share on other sites More sharing options...
Agathorn Posted January 24, 2014 Share Posted January 24, 2014 That's right, there's an angle off. So you have three options:1. tweak both Roll Coeff H & V to a proper ratio.2. rotate that engine cluster base until the attach nodes are just right at the front direction. 3. rotate the outboard engines to proper orientation. (they used to face to the front instead of to the center of the cluster base)If you chose to tweak instead of rotating:To adjust that correctly, you get to the bottom of the rocket, point the camera towards the top of the rocket, and turn the camera so that your two outboard engines are right in front of the camera, now tweak that two coefficients ( & reverse if needed ). use Roll Test (set to 1.0) to see if the gimbal is shifting along the tangent direction (i.e. only horizontal shift from your viewpoint) & is shifting to the left side (otherwise the roll control is reversed).Note that the two outboard engines are not symmetric counterparts (you cannot install them by 2x mode, right?). So these two engines need individual tweakings and there might be some difference between their reverse controls.Thanks for this. With the new part, I actually have to tweak all 9 engines And yeah unfortunately I can't drop the outboard ring of 8 with symmetry for some reason. Link to comment Share on other sites More sharing options...
LazarusLuan Posted January 24, 2014 Author Share Posted January 24, 2014 Hey HoneyFox any tips? I'm having trouble with the 8 engines around the outside because they don't mount along the centerline. What I mean by that is if you point the camera directly at the front of the craft, such that yaw on the center engine is directly left and right, the next two outboard engines left and right of that are slightly fore and aft, not next to it. so when I then put those engines in, the yaw isn't directly left and right but at a small angle.How do I tweak the gimbal stuff to make them straight? Is this just a painstaking process of finding the right h and v values for each engine to make it straight?The engines are placed that way only because I am duplicating SpaceX's real life design exactly. If it is needed for stability, I can shift the engines to a symmetrical layout instead. Link to comment Share on other sites More sharing options...
Agathorn Posted January 24, 2014 Share Posted January 24, 2014 (edited) The engines are placed that way only because I am duplicating SpaceX's real life design exactly. If it is needed for stability, I can shift the engines to a symmetrical layout instead.Aren't the real ones symmetrical? I was under the impression that it was. An evenly spaced ring of 8 around the outside, and a center engine.Am I misunderstanding the real design?EDIT: Ah right I see what you are saying now. I wonder why they did it that way? I'd rather keep it real. Edited January 24, 2014 by Agathorn Link to comment Share on other sites More sharing options...
HoneyFox Posted January 25, 2014 Share Posted January 25, 2014 Laz, thanks for addressing so many issues and so quickly! I'm going to give things a test today and implement some more changes in my config then update it later on.HoneyFox, for those small aux engines, are you referring to the white SuperDraco engines that attach to the Dragon, or the spherical looking "SuperDraco single engines"? If it's the latter, that was a part I added based on what I saw in and just used the solid fuel "separation engine" model, so they weren't in the original mod. I wasn't aware they don't have gimbal animations so I can use a different model in its place, maybe a greatly scaled down Merlin 1D?I'm refering to the sphere looking one.Plus, from that video it seems like the nozzle of the uppers stage engine is extendable... which reminds me of one engine comes with KOSMOS pack...Plus 2: the SuperDracos attached on Dragon seem to induce roll moment quite a lot... is it because i didn't install them correctly? Link to comment Share on other sites More sharing options...
LazarusLuan Posted January 25, 2014 Author Share Posted January 25, 2014 I'm refering to the sphere looking one.Plus, from that video it seems like the nozzle of the uppers stage engine is extendable... which reminds me of one engine comes with KOSMOS pack...Plus 2: the SuperDracos attached on Dragon seem to induce roll moment quite a lot... is it because i didn't install them correctly?To eliminate roll, the best way I've found to install the SuperDracos is to rotate the capsule by 45 degrees (SHIFT+Q, 9 times), install them in a set of 4 and then rotate the capsule back 45 degrees. Link to comment Share on other sites More sharing options...
Scripto23 Posted January 25, 2014 Share Posted January 25, 2014 I'm refering to the sphere looking one.Plus, from that video it seems like the nozzle of the uppers stage engine is extendable... which reminds me of one engine comes with KOSMOS pack...Plus 2: the SuperDracos attached on Dragon seem to induce roll moment quite a lot... is it because i didn't install them correctly?One issue with the video is it is showing a Falcon 9 (not a Falcon 9v1.1) and is slightly outdated. Though it is still the best, and maybe only, information to go on when it comes to the reusability portion of the Falcon rockets. I'll have to take a look at the KOSMOS pack.For the SuperDracos, I was having the same problem. The only downside of removing the nodes I guess. I'll try out what Laz said, but if you're not already, you should also use RCS build aid when you place those as it will tell you if there will be any rotational forces without having to find out in flight. Link to comment Share on other sites More sharing options...
Agathorn Posted January 25, 2014 Share Posted January 25, 2014 Still playing around with this but wanted to impart some information I've come by. First off, ScriptO, THANKS for pointing out that RCS Build Aid mod. That thing is AMAZING! Using it I found that if I placed all 8 outboard engines so that they lined up with the socket, then my roll control was perfect on 6 out of the 8 engines. A couple tweaks on the last 2 and now I have a cluster assembly with near perfect roll control. I say near perfect because there is the slightest, like 0.001% drift but I couldn't get it any better. Link to comment Share on other sites More sharing options...
Agathorn Posted January 26, 2014 Share Posted January 26, 2014 Thought i'd share this to make it easier for others. Here is a link to a subassembly which contains the empty engine housing, and all 9 engines perfectly rotated so as to provide even yaw, pitch, and roll. I'm using HoneyFox's Gimbal plugin to allow roll, but presumably it should work with any gimbal plugin that does roll, since there are not plugin specific things, just rotating the engines to be all the proper alignment.https://www.dropbox.com/sh/3mujvwkj0c9c3uk/p8lInl9XEG Link to comment Share on other sites More sharing options...
Agathorn Posted January 26, 2014 Share Posted January 26, 2014 To eliminate roll, the best way I've found to install the SuperDracos is to rotate the capsule by 45 degrees (SHIFT+Q, 9 times), install them in a set of 4 and then rotate the capsule back 45 degrees.I don't understand why the heck this works. You are still putting the engines on the EXACT same spot of the capsule. This works, but why?FYI if you don't do this trick, then in order for the engines to be balanced you have to put them in a DIFFERENT spot, which is over the ladder/chute insets which is bad. But if you rotate the capsule exactly as Lax says, then put them in the logical place (between the RCS engines), then rotate the capsule back, then all is fine.Still makes no sense to me! Link to comment Share on other sites More sharing options...
HoneyFox Posted January 26, 2014 Share Posted January 26, 2014 I don't understand why the heck this works. You are still putting the engines on the EXACT same spot of the capsule. This works, but why?FYI if you don't do this trick, then in order for the engines to be balanced you have to put them in a DIFFERENT spot, which is over the ladder/chute insets which is bad. But if you rotate the capsule exactly as Lax says, then put them in the logical place (between the RCS engines), then rotate the capsule back, then all is fine.Still makes no sense to me!For this issue, i would rather request the author to tweak the engine model & part.cfg, i don't understand why there're two "Lock Gimbal" options in its context menu, are there two engines inside the part.cfg?Plus, with some tests the roll control provided by my plugin should be able to eliminate the roll issue if the gimbal angle is big enough...Plus 2, it seems like the RCS thrusters on Dragon don't produce much pitch/yaw moment, and don't produce roll moment at all... Perhaps some adjustment about these thrust transforms should be considered? Link to comment Share on other sites More sharing options...
Scripto23 Posted January 26, 2014 Share Posted January 26, 2014 (edited) Agathorn, I have no idea why that works either. Seems to defy logic, but hey, if it works it works.HoneyFox, I'm pretty sure there are indeed two engines in each nacelle (at least there's two exhaust plumes) but one lock gimbal button should maybe be used to control both since I can't think of scenario where you'd only want to disable half the nacelle. Also I agree with you about the RCS on the Dragon. With Realism Overhaul the overpowered reaction wheels are disabled so the capsule is relying solely on RCS. Not sure if the real Dragon RCS has roll control, I would assume it does, but Laz seems to have pretty accurately modeled the thrusters and placement compared to the real thing so I'm not sure. And Laz, the new FX on the SuperDracos look awesome btw Edited January 26, 2014 by Scripto23 Link to comment Share on other sites More sharing options...
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