Clamp o tron question

[NextgenerationX 5]

I'm planning on making a long journey to moho, so far I have my giant rocket orbiting earth, I've rendevou'd with it a few times to refuel it and it's nearly full. I have 4 docking ports on my rocket.( one on each side). My original plan was to fuel up, then add 4 more fuel containers to each docking port What I've noticed when clamping on is there's a little wobble. If I fire my main engines, will my fuel containers come off the docking ports? If so, any tips for securing these containers before I start my burns?

[Aeroboi 351]

Use Rigid attachment on the docking ports. This can be done in flight. Enable advanced tweakables in the main menu general settings to enable that option when right clicking any part (except experiments and batteries)

[mystifeid 570]

 I think it's a lot easier to launch what you need from KSC and forget about refuelling or adding pieces. Below is what I've been using to move 23 ton miners from KSC to the surface of Moho in my current career. (These miners can refuel any of my other ships that land on the surface.) It's expensive. It's overkill. It's also quick and easy. And a pleasure to launch.

All of the bottom tanks and all of the mammoth engines are used to get the ship to around 10km. Then they're staged all at once.

The bottom tanks and engines are staged and Rhino's take over. The top tanks are asparagus staged.

In a 130 km orbit around Kerbin, the craft still has more than 7500m/s dV. The twelve or more ships I've sent to Moho in this career have required between 4800m/s and 5500m/s for the transfer and capture burns so there is plenty of fuel left for landing. And if you decide you need more it's pretty easy to make the booster bigger again.

[jost 121]

Try setting the auto-struts of your fuel containers to root. You might need to enable advanced tweakables in the settings

Edited June 22, 2019 by jost

[cantab 3,145]

A screenshot will help.

Docking connections are unlikely to completely break unless you're really violent with them, but they may bend quite a lot. Depends on the type of docking port and the size of the fuel tanks.

As mentioned, you can try autostrut or rigid attachment, or you can add struts in flight with the mod Kerbal Attachment System.

[NextgenerationX 5]

I forgot to mention, I'm on ps4 so I'm unable to use any mods or anything to stop me from getting trophies ( Not sure if tweakables void trophies or not ) I will post pictures when I get back home

[bewing 3,073]

Advanced Tweakables, Rigid Attachment, and Autostruts are all stock features -- and I'm nearly certain they are all available in the current console version of the game. But (as said above) you need to enable it in your Main settings menu.

 

[NextgenerationX 5]

Here's a pic, has 2 rockomax x200 tanks. Also, I enabled tweakables and enabled autostrut. It's giving me a few options; heaviest part, root part, grandparent part. Don't know what they are all ment for but I'm guessing I'd for for heaviest part.. 

[Zhetaan 922]

3 hours ago, NextgenerationX said:

Here's a pic, has 2 rockomax x200 tanks. Also, I enabled tweakables and enabled autostrut. It's giving me a few options; heaviest part, root part, grandparent part. Don't know what they are all ment for but I'm guessing I'd for for heaviest part.. 

With respect to @jost, don't set autostrut to root.  That can cause problems when you undock later and the root part changes.  Your best choice is to autostrut to grandparent part.  Here's the basic idea behind the autostrut settings:

Root:  Autostruts go to the first part you placed when you built the rocket.  That's usually the command pod or probe core, but not necessarily--perhaps you open in chess with your knight, too.  This can give rigidity to a tall rocket's core stage if you strut from the bottommost engine to the topmost command pod, but it is not recommended for side boosters and definitely not for anything that needs to undock.  The root-choosing algorithm for pieces that undock can be weird, and if you send two rockets in separate launches, then when they dock, one root part is favoured over the other.  All of those autostruts changing their connections all at once can cause explosive disassembly.  I'm not entirely certain of exactly how it works, but I do know that there are a lot of explosions that can be traced to root-type autostruts on complicated vessels and stations.  Don't use them on anything that docks.

Heaviest:  Autostruts go to the heaviest part of the rocket.  I do not know whether this ignores the mass of fuel in tanks; I have not tested it.  If it does not, then it means that the struts can change connections in flight.  I stay away from this one for the same reason that I stay away from root:  the heaviest part changes when you dock, undock, potentially also when you stage, and--should it not ignore fuel mass--also while you fly the rocket.

Grandparent:  Autostruts skip the part to which the current part is attached (called the parent) and go to the part to which that part is attached (called the grandparent).  For example, let's assume that you have a rocket with two side-mounted, detachable solid rocket boosters along with a core stack.  You attach these boosters using radial decouplers, which are themselves attached to a core fuel tank.  If you autostrut the boosters, then the struts go to the central fuel tank.  In essence, grandparent struts always go two parts up in the build tree--and if that doesn't make any sense to you, then use my example as a guide.  If you are within two parts of the root, then I don't know what the autostruts do--they'll either go to the root or turn off--but at that point, you don't need them and they won't hurt anything anyway.  Autostruts only cause problems when they are unnecessarily long, bridge too many complicated assemblies, or change suddenly in flight.

 

Actual flight advice begins here:

Your idea of detachable fuel tanks is not a bad one.  I think you should consider using a larger docking port, though.  The Clamp-O-Tron Sr. is much more rigid in its docking connections.  Another idea is to mount the docking port radially on the fuel tank (in other words, exactly like it's mounted on the main rocket) so that you keep the mass closer to the centre.  That will also reduce wobble.  Lastly, if you happen to enjoy doing things the difficult way, then you can double-dock, which is exactly what it says:  put two docking ports on your fuel tank and central rocket and dock with them both at the same time.  That will give a very rigid connection but at the cost of a lot of frustration unless you can dock on the head of a pin.

Edited June 23, 2019 by Zhetaan

[mystifeid 570]

What @Zhetaan said. Grandparent autostruts and radial clamp-o-tron snr's on the detachable tanks. Be aware that any oscillation will introduce inaccuracy to the transfer burn and a transfer to Moho is the last place you want this to happen. Moho transfers need to be precise.

[NextgenerationX 5]

Thanks for all the information! This is gonna help me a ton! Definitely gonna take the advice to update my fueler to a more tank role ones she's fully fueled. Lower to the center of mass. I will update on my progress.

[Kryxal 251]

You might want to avoid long tanks sticking out sideways.  Consider using an adapter then Rockomax to keep the mass closer in, and ramp up thrust gradually.

[NextgenerationX 5]

Created a video of my rendezvous and refueling, she's almost ready for the long journey.