Docking Advice

[jakeb1993]

Hello, i am trying to attempt my first ever docking, however it is not going well and despite all the tutorials i read and watch i can not get the ship to dock, i cant even get the ship to touch the docking port because of the way the navball is rotated. Here is the station and ship:

 

The docking pot is on the side of the station (between the lights) and the probe has it at the front. Any advice on how to dock this?

[Hodari]

Right click on the docking port of your ship and select "control from here".  Right click on the port on the other ship and "Set as target".  Turn your ship so it is pointing towards the target.

If you can, switch control to the other ship and do the same from there.  Now your docking ports will be facing towards each other and it will be much easier to do your final approach.

Then just use RCS to VERY slowly(When I'm this close, I usually keep it to about 0.2m/s) approach and also make sure you keep the target and prograde markers aligned and keep your ship pointing toward them.

[LeeBomb20]

14 minutes ago, Hodari said:

Right click on the docking port of your ship and select "control from here".  Right click on the port on the other ship and "Set as target".  Turn your ship so it is pointing towards the target.

If you can, switch control to the other ship and do the same from there.  Now your docking ports will be facing towards each other and it will be much easier to do your final approach.

Then just use RCS to VERY slowly(When I'm this close, I usually keep it to about 0.2m/s) approach and also make sure you keep the target and prograde markers aligned and keep your ship pointing toward them.

Id probably also advise you to set your camera mode to "LOCKED" mode so your nav ball and camera view are in sync.

[jakeb1993]

48 minutes ago, Hodari said:

Right click on the docking port of your ship and select "control from here".  Right click on the port on the other ship and "Set as target".  Turn your ship so it is pointing towards the target.

If you can, switch control to the other ship and do the same from there.  Now your docking ports will be facing towards each other and it will be much easier to do your final approach.

Then just use RCS to VERY slowly(When I'm this close, I usually keep it to about 0.2m/s) approach and also make sure you keep the target and prograde markers aligned and keep your ship pointing toward them.

I have already done that, just like every video says, i just end up drifting left and right up and down all the time. I can never reach 0.0m/s its always 0.2 etc.

While locked camera has helped alot its still proving to be idfficult

[LeeBomb20]

The drifting apart at slow speeds is caused by slight differences in the orbit of your craft and the thing you are trying to dock with nothing you can do about it really, and  as long as your not travelling at silly m/s relative to the other craft then you'll be fine, past that i cant really say more than what Hodari said in the first answer. 

[KocLobster]

If you're struggling that badly, I might suggest using MJ to do the docking for you. Personally, I don't usually ever use autopilot, but it can be helpful to see how it's supposed to be done. Go to MechJeb's docking autopilot section.

[TouchyHands]

Which set of rcs controls are you using? Do you switch to docking mode? Are you using linear rcs (ijklhn keys) to move up down left and right as well as turn?

 

There are a lot of different points where docking becomes difficult, just being successful at orbital rendezvous ( like you clearly are) is something to feel accomplished with. 

 

All I can say without knowing what exactly the hang up is, is that docking is VERY similar to getting a Kerbal on eva to get back into a hatch. The linear rcs controls are the most important at those low speeds, not turning. 

[OhioBob]

One thing that I notice is that your RCS thrusters are way up on the front end of your ship near the docking port.  This is going to make it very difficult to translate in a controllable way.  With the arrangement you have, firing a thruster is going to cause you to rotate.  There's nothing you can do about that now, but next time place your RCS near the ship's center of mass.  This will allow you to translate without rotating.  Then, if you are slowing drifting left, right, up or down, you just fire a thruster to null the motion.

 

Edited March 27, 2016 by OhioBob

[N_Danger]

 As someone who just learned to dock without an auto pilot, I've found an alignment mod was necessary for me to get the last 100 meters done. I used the Docking Port Alignment Indicator by NavyFish only because it is large and easy on my old guys eyes. I think there are ones that only add a marker on the HUD that can help line it up. 

 Matching up the inputs with the visual orientation is the key.  For me that means when I input left translation I see my craft move left on the screen. Also the caps lock key for fine control is a must.

[KocLobster]

43 minutes ago, N_Danger said:

 As someone who just learned to dock without an auto pilot, I've found an alignment mod was necessary for me to get the last 100 meters done. I used the Docking Port Alignment Indicator by NavyFish only because it is large and easy on my old guys eyes. I think there are ones that only add a marker on the HUD that can help line it up. 

 Matching up the inputs with the visual orientation is the key.  For me that means when I input left translation I see my craft move left on the screen. Also the caps lock key for fine control is a must.

+1 to this, this is a fantastic mod to help with docking.

[Empiro]

11 hours ago, jakeb1993 said:

I have already done that, just like every video says, i just end up drifting left and right up and down all the time. I can never reach 0.0m/s its always 0.2 etc.

While locked camera has helped alot its still proving to be idfficult

If you switch to Fine Controls mode by pressing "Caps Lock", it will help reduce the rotation when you try to translate your ship.

I tend to only use the NavBall for docking (or a docking alignment mod). The camera is only used to confirm that I'm lined up, and if I need to make corrections, I go back to looking at the NavBall.

One trick I like to use is that if you're a moderate distance (10-50m), and not moving very quickly relative to your target (like say, 0.2 m/s), instead of turning, use the IJKL keys to move your velocity vector around on the navball (it doesn't matter if you're looking at the retrograde or prograde marker). It's fairly intuitive because J/L will move it left or right, and I/K will move it up or down. Move the velocity vector around until the velocity vector is right under where your nose is pointing. Then press H/N to go forward or backward to completely arrest your relative motion.

You can then do the point both ships at each others' docking port trick as above, and then just press H to move in.

Edited March 27, 2016 by Empiro

[Plusck]

In addition to all the fine points above (and in particular about using IJKL / HN rather than "docking mode"), I'd add that you might want to micro-warp from time to time, because the thing that really makes docking a nightmare is if the target is turning. This can also help if you have badly placed RCS thrusters: you can therefore "translate" with IJKL in order to move prograde over the target marker, then warp up and back down instantly, to stop your vessel rotating, thereby reducing the corrections you'll need to do using WASD.

[Vegetal]

Like what Ohiobob said, with the RCS thrusters placed where they are, you *will* suffer to dock. You need to place them correctly (close to the CoM), especially if you aren't proficient at docking yet.

[merlinux]

As other have said here, your RCS thrusters look misplaced. Also your craft do not look  balanced which doesn't help. I can see you have mechjeb. Try the autopilot. If MJ fails to dock, you probably will not be able to do so yourself... Design a proper craft with thrusters aligned with COM.

[jakeb1993]

I have finally managed to dock, it took some patience, two thing though:

1) The image of my ship was not at its final stage, the large fuel tank decouples away, so RCS is better aligned, but still not perfect.

2)I have MJ but am playing career, i don't have Autopiliot/Autodock yet

[KocLobster]

43 minutes ago, jakeb1993 said:

I have finally managed to dock, it took some patience, two thing though:

1) The image of my ship was not at its final stage, the large fuel tank decouples away, so RCS is better aligned, but still not perfect.

2)I have MJ but am playing career, i don't have Autopiliot/Autodock yet

If you so desire and know how, you can edit the cfg files in MechJeb so that you don't have to go way down the tech tree to unlock everything.

[GoSlash27]

1 hour ago, jakeb1993 said:

I have finally managed to dock, it took some patience, two thing though:

1) The image of my ship was not at its final stage, the large fuel tank decouples away, so RCS is better aligned, but still not perfect.

2)I have MJ but am playing career, i don't have Autopiliot/Autodock yet

jakeb1993,

Congratulations! We knew you could do it!

For future reference, Hodari had it exactly right. Do everything he said and just let the docking ports drift together at .2 m/sec.

Best,
-Slashy

[OhioBob]

Congratulations.  With a little more practice you'll be an old pro.

2 hours ago, jakeb1993 said:

1) The image of my ship was not at its final stage, the large fuel tank decouples away, so RCS is better aligned, but still not perfect.

I'm sure that helped.  With the configuration shown in your image, I'm not sure you would have been able to do it.

In the future, when you are designing your vehicle in the VAB, strip it down to just the part that will perform the docking and figure out where the center of mass is.  Place your RCS around the vehicle at that point.  Furthermore, if your vehicle will be docking with partially depleted fuel tanks, you can dial back the amount of fuel and oxidizer to the amount you think will be remaining.  That way you can see were the CoM will be at the time of docking.  (Don't forget to return the fuel/oxidizer to 100% after you've located the CoM.)  You can be off a little without causing a problem, but you want to be as close to the CoM as practicable.  You definitely want to avoid having your RCS out on the ends because that will induce too much unwanted rotation.

 

Edited March 27, 2016 by OhioBob

[KocLobster]

This mod helps me a ton when trying to determine exactly where to place my RCS thrusters in the VAB, I highly recommend it.

 

Edited March 28, 2016 by KocLobster

[Oafman]

On 26 March 2016 at 10:18 PM, jakeb1993 said:

I have finally managed to dock, it took some patience, two thing though:

1) The image of my ship was not at its final stage, the large fuel tank decouples away, so RCS is better aligned, but still not perfect.

2)I have MJ but am playing career, i don't have Autopiliot/Autodock yet

Congrats!

The first time you dock in KSP is hugely rewarding, especially if you've been trying to do it for a while (which was the case for most of us). After that, I went through a phase where I really enjoyed docking, doing everything manually and getting the hang of it. As a tip, I also found that playing Blue Danube by Strauss (the music from 2001) made me better at docking. I can't support this assertion with evidence, but it definitely helped. Probably. If nothing else it puts you in the mood.

I use MJ autopilot features all the time, for routine stuff (circularisation, RVs, landing etc). But, I hardly ever use it to auto dock, because it takes ages and wastes vast quantities of monopropellant. But I do use Navyfish's excellent mod to line myself up very quickly, and when you combine that with lots of use of timewarp you can dock very efficiently in just a minute or two of real time.