Dave Hederich
05-30-2002, 12:11 PM
Anyone interested in a quick,simple and cheap power boost for the popular GWS IPS geardrives? Dave Robelen has determined that you can get a 40 percent increase in thrust with reduced current by using the hotter GWS EDF-50 motor with lower gearing and the optimum prop (see Radio Control Zone link below).
Since the GWS IPS is so widely used, it would really be interesting and useful to a large number of people if there were a simple formula to determine the best gearing and prop combination for substituting the EDF motor in a variety of IPS applications. More specifically, which IPS geardrive would you substitute when switching to the EDF motor if you wanted to retain the same prop and battery pack?
As an example, the popular GWS Tiger Moth comes with an IPS A, with a 9x7 prop recommended for outdoor use and a 10x4.7 for indoor flying. Let's say that you are one of the many people flying the TM outdoors with the 9x7 prop and the surplus Qualcomm 830mAh Li-ion pack. If you wanted to switch to the EDF motor while staying with the same aircraft, prop and battery pack, which IPS geardrive would you select? My guess, based on Mr. Robelen's successful application, is that it would be either the D or E. From an A to a D or E would be a drop down in gearing of three or four in the IPS line, which consists of eight different ratios from S2 (3.5:1) to F (11.77:1).
If there is no simple formula, the best combinations could be arrived at by trial and error, as Mr. Robelen did for his specific application. However, we all don't have to go through trial and error for all of our applications if we all share information here on what works. If anyone already has extra EDF-50 motors, IPS geardrives and props to play with, this could be a fun and rewarding project. I am in the process of making up my parts order list right now!
http://www.radiocontrolzone.com/forums/showthread.php?s=&threadid=82642
Since the GWS IPS is so widely used, it would really be interesting and useful to a large number of people if there were a simple formula to determine the best gearing and prop combination for substituting the EDF motor in a variety of IPS applications. More specifically, which IPS geardrive would you substitute when switching to the EDF motor if you wanted to retain the same prop and battery pack?
As an example, the popular GWS Tiger Moth comes with an IPS A, with a 9x7 prop recommended for outdoor use and a 10x4.7 for indoor flying. Let's say that you are one of the many people flying the TM outdoors with the 9x7 prop and the surplus Qualcomm 830mAh Li-ion pack. If you wanted to switch to the EDF motor while staying with the same aircraft, prop and battery pack, which IPS geardrive would you select? My guess, based on Mr. Robelen's successful application, is that it would be either the D or E. From an A to a D or E would be a drop down in gearing of three or four in the IPS line, which consists of eight different ratios from S2 (3.5:1) to F (11.77:1).
If there is no simple formula, the best combinations could be arrived at by trial and error, as Mr. Robelen did for his specific application. However, we all don't have to go through trial and error for all of our applications if we all share information here on what works. If anyone already has extra EDF-50 motors, IPS geardrives and props to play with, this could be a fun and rewarding project. I am in the process of making up my parts order list right now!
http://www.radiocontrolzone.com/forums/showthread.php?s=&threadid=82642