Using the Claw- are there minimum requirements?

[Waxing_Kibbous]

I had a World First to dock two vessels over Minmus, problem was I wasn't getting orbital rescues so I put a very small probe made up of a spark, the really small tank (oscar I think), probe core, 3 single solar panels, and an antenna. Next I launched a ScanSat satellite with a claw to grab the little guy to complete the contract. No matter what I did, going really slow or charging at the small probe it kept bouncing off the claw. Previously I did claw some debris from the Mun so I doubt it's a bug, maybe there is a minimum force required to activate it? Any ideas/experiences?

Edited November 20, 2016 by Waxing_Kibbous

[Geschosskopf]

Possibly stupid question, but did you arm the Klaw?

Otherwise, it helps but is not strictly necessary to control-from-here on the Klaw and set the other object as the target.  Then it's just a matter of hitting it not too hard but not too soft.  If you did all that, then it could be that your target is simply too light.

[bewing]

No, there is no requirement, except that you grab your target just right.

For flat surfaces, you need to be very close to perpendicular to the target for the klaw to grab it.

For cylinders and other partially-curved surfaces: you need to be very close to perpendicular to the straight directions (lengthwise), and the centerline of the curved part must contact the exact center of the klaw. This is very easy for big cylinders like 2.5m fuel tanks -- and it is much much harder for the little .625m cylinders. You have to control your approach with tremendous precision.

(But once you get pretty good at grabbing little stuff with klaws, any other kind of docking is pathetically easy.)

Edited November 21, 2016 by bewing

[Tyko]

Klawing asteroids was the bane of my existence this weekend. Sometimes it would work, but oftentimes I would just bounce off. On the times it did work I couldn't identify what I'd done differently other that just trying again. I'm pointing at the asteroids COM, aligning with a flat area and approaching at 1.5-2m/s. Not sure what else to try besides repeating until it works.

[bewing]

@tjt: you probably need to align better with the flat area, and forget about the CoM until after you've got the thing grabbed.

[Vanamonde]

Does clawing something count as docking for the purposes of a contract? You may have a problem there whether the claw works or not. 

[bewing]

I'm pretty sure it does count, yes.

[IWanttobeEVA]

On 11/20/2016 at 3:04 PM, Waxing_Kibbous said:

I had a World First to dock two vessels over Minmus, problem was I wasn't getting orbital rescues so I put a very small probe made up of a spark, the really small tank (oscar I think), probe core, 3 single solar panels, and an antenna. Next I launched a ScanSat satellite with a claw to grab the little guy to complete the contract. No matter what I did, going really slow or charging at the small probe it kept bouncing off the claw. Previously I did claw some debris from the Mun so I doubt it's a bug, maybe there is a minimum force required to activate it? Any ideas/experiences?

Zen like patience is needed. I usually do best with the claw by lining up the target icon, the prograde vector, and the front of the ship exactly together on the navball and approaching at 0.3~0.6m/s. Make sure to remember to click 'control from here' on the claw so it points to the target. If anyone of these is even slightly askew the target will bounce off the claw because I guess it won't hit dead center and any tangential velocity will cause it to spin-off, making it even harder to grab on the next try.