LTek_FanDuct_SidewinderX2_5020_v4 with bltouch

I modified LTek's excellent 5020 fan duct for the sidewinder X2 by just adding an attachment point for an aftermarket bltouch/crtouch upgrade.

This is because while compatible with the stock bed level sensor, and after-market upgrade bumps into the fan in it's default position, with this modification that problem is avoided by mounting the sensor directly to the duct outside the space needed for the fan.