The new desing of the nose landing gear retraction mechanics requires the installation of  a lock to keep it in the up position. Looking around for such a locking mechanism didn’t bring up anything usable.  They all were either too heavy, too weak, only electricly activated or  prohibitively expensive. I was left with the only solution to build one myself, based on a patent drawing found on the internet.

The lock latches mechanicly when the gear reaches the up position. A proximity switch signals the fully latched position.
The opening of the lock works through a pull wire connected to the landing gear lever in the cockpit which releases the gear.

All parts are designed to carry the maximum expected hookload of 270kg by factor 1.5.