Question:  My Mig 21 included some parts that look like two servo tray sets made from plywood. What these for?

Answer: The Mig21 is retract ready. The extra plywood servo tray sets are for retract servos if fitted and can be placed where ever suitable for your retract setup and your servos

Question: My Mig 21 came with fixed landing gear pre-mounted into blocks with a metal retaining plate. There are also pre-drilled mounting holes in the wing and fuselage that match with the retaining plate. What screws do you recommend for attaching the gear to the wing and fuselage?

Answer: Early production runs of the Mig 21 came with 12 metric Phillips head wood screws. Depending on market preferences around the world some modelers did not like the Phillips head and other modelers did not like the metric threads. The factory no longer provides the screws with the model leaving the choice of screws open the modeller.

Generally we suggest a pan head #6 or #8 wood or self tapping sheet metal screw about 5/8" long. Try the #6 first. Thread it into the pre-drilled holes and ensure that it bites into the mounting rail wood properly. If it does... go with the #6 screws. If the pre-drilled holes are too large for a #6 screw, try a #8 but if it is a tight fit, do not screw it in all the way. Back it out and redrill the holes first. You do NOT want to split the rails by forcing a large screw into a small pilot hole.

Question: On page two of the Assembly and Operators Manual that came with my Mig21 (version 20050329 per back cover) there is mention of four lock nuts in addition to four butterfly nuts. I cannot find these four lock nuts. What should I do?

Answer: The lock nuts were difficult to install and remove when used in conjunction with butterfly nuts. We are now using a better grade of butterfly nuts that do not require the use of additional lock nuts. Lock nuts are no longer included with the Mig21. If you do not wish to remove the wings for transport and want a longer term solution to ensure the butterfly nuts remain snug, use medium thread locker such as Z42 from Pacer.

In any event, check the butterfly nuts before each flying outing to ensure they are snug (do not overtighten or you will strip the studs) and retain the wing securely attached to the fuselage.

Question: I can not find the engine mounts for my Mig 21. What should I do?

Answer: The engine mounts are wrapped in foam and packed by the factory into the fuselage. Remove the fuselage hatch from the bottom of the fuselage and the power module firewall from the front of the fuselage and retrieve the engine mounts.  

Question: The control rod for the rudder on my Mig 21 connects to a vertical torque rod that activates the rudder. All of this is internal within the aft end of the fuselage. Given that the rudder hinge line is swept back, how can I have this work properly?

Answer: The Mig21 has undergone several upgrades since the Mark I production lot was released in mid 2005. The rudder connection has since been changed to an external connecting rod and horn system.

For Mark I models with the internal rudder control rod system, there are two simply approaches to having this work better.

1) Leave the control rod system internal to the fuselage but change to a ball link on the arm that is connected to the torque rod. Leave the end of the control rod itself free to move laterally side to side but use a ball link to accomodate the difference in angle caused by the rotation of the swept rudder.

2) Change the control rod for the rudder to be external and connect to a traditional external rudder control horn. The further addition of a ball link on the horn itself may make for a smoother movement.

 

Question: On page two of the Assembly and Operators Manual that came with my Mig21 (version 20050329 per back cover) there is mention of wing root gaskets. I cannot find them. What should I do?

Answer: The Mig21 wing fits into cavities in the sides of the fuselage. The wing root joint is therefore recessed and not exposed directly to air flow. The wing root gaskets are not necessary and not included with the Mig21 due to this unique method of recessing the wing roots into cavities in the sides of the fuselage.