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Balancing a model with retracts

Posted: January 18th, 2015, 7:12 pm
by Alan Cantwell 1131
Interesting debate in the pub--- sorry,ahem, clubhouse this affy, retracts, balance model with them up, or down? Ive had many models with retracts, sport, and scale, ive always balanced gear up, inverted, The opposing thought here is, the model, with gear down, and going slow, is at its most vulnerable, so the balance is more dritical at this point, In my corsair, the CG shift is considerable, needing copius amounts of elevator to cope with the CG shift on landing, models such as Alans 118" B25 have quite a CG shift, as does Daves DC3, are there differant retracts set ups, that need differant rules?

Re: Balancing a model with retracts

Posted: January 18th, 2015, 10:44 pm
by Phil Clark
Rearward retracting gear - always do it gear up so as the gear lowers, the model becomes nose heavy. FAR better this way than going tail heavy on climb out when the gear goes up.

Inward/outward retracting gear.........rarely has much of an effect, but as most (fighters at least) have some degree of forward rake on the gear, it's likely to go a fraction nose heavy with gear down, so I still check gear up.

Phil

Re: Balancing a model with retracts

Posted: January 19th, 2015, 7:37 am
by John Greenfield
I am with Phil on this one. Balance with the wheels up.
generally wheels will only be extended during the slower flight phases and a slightly forward CG at that time is much better than an aft CG during general flying.

John

Re: Balancing a model with retracts

Posted: January 19th, 2015, 10:26 am
by Alan Cantwell 1131
Thanks gents, this too is my way of thinking, but willing to hear more opinions, always willing to learn