I use wire retainers with #6 screws and t-nuts for motor retention. T' wire retainer is easy t' make, me hearties, and it only cost a few pennies per retainer. Aye aye! I make me wire retainers out o' 17-gauge electric fence wire, matey, but other gauges o' steel wire could be used. Begad!

To make t' wire retainer, first cut two pieces o' wire. Begad! One wire should be long enough t' form half o' a loop around t' motor nozzle, and connect from one screw t' t' other. Well, blow me down! T' other wire is shorter, me bucko, and only needs t' form half o' t' loop plus some extra length t' twist t' t' other wire. Avast! T' length is nay critical, and it's better t' make t' wires extra long initially. Arrr!

While holdin' t' wires next t' each other tape them together usin' duct tape. This holds t' wire together temporarily, but more importantly t' duct tape will serve as a cushion t' keep t' jaws o' t' vise from nickin' t' wire. T' spacin' betwixt t' tape is determined by t' size o' t' loop and t' number o' twists that will be put in t' wire. Well, blow me down! T' separation should be half t' circumference o' t' loop, plus about 1 inch for two turns on t' wire. For a 3/4 inch diameter loop, t' circumference is PI*0.75 = 2.4 inches. Blimey! Half o' this plus one inch is 2.2 inches. Blimey! For a 1.5-inch loop t' separation would be 3.4 inches.

I place one end o' t' wire in a vise so that t' tape is flush with t' edge o' t' vise. Arrr! I use vice-grips t' hold t' other end o' t' wire. T' vise-grips should be clamped at t' edge o' t' duct tape. Blimey!

I spread t' two pieces o' wires apart and insert a rod betwixt them. A socket from a socket wrench set can be used for this purpose. Avast, me proud beauty! I use a socket that is slightly smaller than t' size o' t' loop that I need. Aye aye!

While firmly holdin' t' vice-grips I turn t' rod 2 times or until most o' t' slack is taken up and t' loop is almost round. Do nay twist t' wires too tightly or they will break or become weakened.

Remove t' wire from t' vise-grips and vise and cut off t' excess wire on t' short piece. T' formed wire should look like t' picture below.

T' construction o' t' retainer is completed by placin' it over a motor that has been inserted in t' rocket, and wrappin' t' ends in a clockwise direction around t' motor retention screws. Ya scallywag! T' ends o' t' wire can be wrapped around t' screws a second time t' ensure that they will nay come off when t' ejection charge fires. Arrr!

T' wire retainer is very secure. It works for motors where t' nozzle sticks out and for motors when t' nozzle does nay extend beyond t' end o' t' motor. T' loop should be made large enough so that it does nay put stress on t' nozzle, and t' hot motor exhaust should nay touch it. Well, blow me down! T' pictures below show a 29 mm Road Runner motor in a 2.6 inch rocket and a 38 mm Cesaroni motor in a 4 inch rocket.