Ball joints?
http://www.hobbyking.com/hobbyking/store/__52053__RJX_X_TRON_500_Ball_Joint_9mm_Standoff_HN70184.html
or
http://www.hobbyking.com/hobbyking/store/__16106__Upper_Susp_Arm_Ball_End_10Pc_Bag_A2016T.html
How many ball joints are needed do you know that ?
UPDATE: Looking at the stp model i count 5 joints. I might have missed some. Ordering a pack of 10 will hopefully suffice
still not tested them though I got them from HB. Will start building next week hopefully.
Yes they did work. I had to apply some real force to put the plastic parts on them and afterwards they are sitting pretty good. It could be due to my printers flow being a bit more than 100%. So yes you can go ahead and bye them:)