Erfolg Posted December 30, 2009 Share Posted December 30, 2009 I am building a TN kit, which calls for 370A motors. I have undertaken a web search including the TN Nitro models site. I have found no information on this motor. Does any one know anything about the motors I am replacing them with Max 2822 brushless motors. They are supposedly good for about 150w in. I assume that that TN motor is a brushed unit. I am also assuming that it will be working hard at 80w in. I am also assuming that putting this power through a gearbox, so as to swing a 9 inch prop will drop this to the equivalent of 70-75 w in. The instructions suggest a 9.6v, 1100 Mah Nimh to drive the two motors, I cannot see one of these supplying to many peak watts. Or am I mistaken? I do not like having to many assumptions so any information which preferably reassures will be appreciated. Erfolg Quote Link to comment Share on other sites More sharing options...
scott cuppello Posted December 30, 2009 Share Posted December 30, 2009 This is why the power to weight formula is always the way to go.....sorry, know nothing about them, but your assumptions look safe.....if not terribly relevant if you stick to the afformentioned? Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted December 30, 2009 Share Posted December 30, 2009 This site has load of info on 370 brushed motors which suggests what you say is correct. I also think you logic re gearboxes is correct too. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 30, 2009 Author Share Posted December 30, 2009 Hi Scott The instructions list a flying weight of 740g, if my assumptions are reasonable this would be approx 189w kg^-1. For the standard configuration. In my case this is approx, 405w kg^-1. Again it indicates a loading for the wing of 17.8dm^2, Unfortunately I do not know id this wing loading is low/med/high. I will have to sit down and work out the working area and assess the wing loading in oz ft-^2. I would hope for the 9oz ft-^2. Which will help me assess the battery I can use. I will confess that yet again I have assumed that a brushless outrunner will weigh less than a brushed motor and gearbox. Although I will require two speed controllers rather than one. I am also assuming that a Lipo will weigh less than a Nimh. A lot of assumptions, Which reminds me of a story that supposedly involves Isambard Kingdom Brunel. Talking with one of his draughtsman, he asks what assumptions have you made? Receiving an assessment involving a number of assumptions, he replies, I have made one assumption and it is to small, make it bigger. Erfolg Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 30, 2009 Author Share Posted December 30, 2009 I have undertaken a rough conversion, which indicates a wing loading of 13 oz ft-^2. This higher than anticipated, of course I could be wrong. Erfolg Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 30, 2009 Author Share Posted December 30, 2009 Thanks Bruce. I never thought that the motors would be GWS. Erfolg Quote Link to comment Share on other sites More sharing options...
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