I've designed a few effectors for my Kossel Minimax (a Kossel Mini derrivative) to hold various hotends. Included is effectors that support: The Ubis, E3D, and J-Head hotends have a standard Kossel Mini effector radius of 20mm. The Dual J-Head and E3D-v6 effector have an effector radius of 25mm. The Kraken effector has an effector radius of 30mm. apologies if any of the STLs need to be flipped over before printing.All STL files should be ready to print. The J-Head will use a 1/8" bowden fitting, or drill out to whatever size you need. Make sure you update your firmware if you're changing effector sizes. The dual hotend has one extruder at Y+12mm and the other at Y-12mm (assuming you orient the effector so the nozzles along the Y axis) The kraken is centered with each hotend being +/- 10mm on both axes from the center of the effector.