Dan
not being too technically gifted, i put all i had into the bubble car-
heres two important tips to good operatoin
first, and without a doubt-pony up for the pustefix brand bubbles
i thought 'bubbles are bubbles'-but after trying several brands from a toy store-nothing comes close-its worth the price-you can buy them on amazon
second-voltage is critical to the fan motor-i know as i actually used my n scale transformer to determine optimum voltage for best bubbles-it happens to be 6 volts-just what you get from fresh AA batteries-so keep them fresh-older batteries dont do well
2 other things i did, which also help-is to gently prise open the box, find the red plastic wind conduit, and seal the open edge toward the motor-this makes the chamber more air tight for bigger velocity,
next, using a small sprue of plastic, i block the drainage hole in the up/down spout for the air-(the spout has a tiny hole so that if accidentally filled with soap or water wehn rinsing clean, it will drain and bubbles will blow-i dont plug tight it but i partially/loosely block it-also adds to velocity-but minimally
finally, to reduce motor whir, i used a small bit of foam rubber right against the motor-between the motor top and the shell-holds the motor and dampens vibration and sound-however should the foam become wet, you must remove it and dry it to avoid rust to the motor
finally, keep the well for the bubbles clean and well rinsed after each use-seems to help -as the soap dries it becomes less elastic-so the well must be clean, and the soap fresh from the bottle-i re-use soap from the well by pouring it back-sometimes a drop (one) in the well will also help (but im in colorado so in the summer it can dry out rather quickly changing viscosity
i can get mine to blow five to six out of the wands-no misses or rarely
these look so nice in the sun and in the garden-silly but really cheerful