Large Model Association Forum

Does anybody know the recommended throws for the control surfaces and the speed brake for the Jerry Bates 1/4 scale DH Moth Minor. Also, the recommended position of the C of G? I can find no mention of them on the plans. Thanks in advance, David Jones.

Hi Dave ,
I built one of these last year - strange the cg isn't mentioned on the plan - however it is 4" behind leading edge at centre.
The control throws are quite large - 11/2" on elevator,rudder 2" each way and 1" or so on ailerons.I used about 21/2" at rear edge on the speed brake,this has a strange effect when deployed for landing in that it raises the nose a bit in a sort of floaty manner,works well though.
Hope this helps - Pete

Cheers Pete, I did get a reply from Jerry Bates, he couldn't remember the control surface throws, said he just has them at full travel and "uses what he needs" (interesting). He did say the C of G was back 5", I'll start at 4" as you recommend (better nose heavy than the other way round). The control throws sound about right, I might be tempted to put a bit of differential on the ailerons. As for the speed brake, I did think we would have to mix in some down elevator with it, all trial and error I suppose. We are going to test fly it in primer, when the paint job is completed I'll probably do a build thread for it as I have taken plenty of photo's. Thanks again for your response. Best regards, David Jones.