Ash N Posted June 13, 2015 Share Posted June 13, 2015 Hi All, I had a glider with a speed 600 motor with a 2.8:1 gearbox running a 12-10 propeller. The gearbox is broken and now only have another speed 600 motor with no gearbox. Now what propeller should I use with the non-geared motor? It is on an old kit build 100" glider and no i dont want to convert to brushless. many thanks! Ash Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 13, 2015 Share Posted June 13, 2015 Hi Ash. That gearbox was there to increase the efficiency a fair bit by being able to use a large propeller. If I remember correctly we used to use something like a 9x6 prop for direct drive. I don't think it will pull your glider as well as the 12x10 though. Quote Link to comment Share on other sites More sharing options...
Malcolm Fisher Posted June 13, 2015 Share Posted June 13, 2015 My Easy Pigeon had a direct drive 600 motor and used an 8x4.5" folder on a seven cell NiMH battery if that's any help. Performance was good I thought, and ought to be enough for a reasonable climb rate with your glider but don't expect vertical OOS type. Malcolm Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted June 13, 2015 Share Posted June 13, 2015 I don't think an old direct-drive S600 is going to manage a 100" glider. tim Quote Link to comment Share on other sites More sharing options...
Phil Green Posted June 13, 2015 Share Posted June 13, 2015 Neither do I Tim. Its just not moving enough volume of air. Why the reluctance to fit a brushless I wonder? Quote Link to comment Share on other sites More sharing options...
PatMc Posted June 13, 2015 Share Posted June 13, 2015 A direct drive S600 should be able to take a 100" glider up so long as it isn't too porky - but not at a very fast rate. One of my first ventures into electric flight was the conversion of 110" glider using 7x1.2Ah nicads squeezed in to the fus on the cg with a 600 can motor mounted on a ply pylon. It had an ic prop 'cause there was no such thing as an electric prop then nor were there speed controlers & a normal 4.8v 600mA nicad was also needed. To avoid a 3rd servo the motor control was achieved by a micro switch turned on with a dab of up + full up trim & off was a dab of full down + full down trim. That combo was enough for about 3 slow climbs to about bungee height per charge but switching the motor off invariably resulted in some switchback antics with a loss of altitude. Inevitably, the model met it's end when one day I tried to switch the motor off a bit too low. Ash, what gearbox did you use ? I may still have an old Master GB & a 12" folder lying around. OTOH as Phil said - why the reluctance to go brushless, even if you're using nickel cells it would give an worthwhile increase in power & with ability to use a big prop if a low KV motor was chosen. Quote Link to comment Share on other sites More sharing options...
Ash N Posted June 21, 2015 Author Share Posted June 21, 2015 Hi everyone, thanks so much for all of your responses. Chris and Malcolm - I found an folding 8 X 4.5 and thought id give it a try. it took it up relatively well but as you suggested it doesn't quite have the smooth pull it had before. it did the job though. Patmc - Im not sure what gearbox it is. It looks to have come already on the graupner motor (i bought if off someone a long time ago) so not really sure how else to describe it apart from it being a 2.8:1... I have all of the other bits (esc, new Nicad) and dont want to have to go through adapting the fuselage for new bits. but i may have no choice... Thanks! Quote Link to comment Share on other sites More sharing options...
eflightray Posted June 21, 2015 Share Posted June 21, 2015 Any chance of a picture, as I have a lot of gearboxes and belt drives from old 600 motors, (and 600 motors), from when I changed over to brushless motors. I still can't bring myself to throwing them away. Edited By eflightray neath on 21/06/2015 18:01:25 Quote Link to comment Share on other sites More sharing options...
eflightray Posted June 21, 2015 Share Posted June 21, 2015 See if you can spot anything the same here from my collection. Quote Link to comment Share on other sites More sharing options...
Ash N Posted June 24, 2015 Author Share Posted June 24, 2015 hi eflighttray neath, please see images below. would be great if you had one. the one with the red gearbox looks very similar but looks a little smaller from here, maybe just the light though.. thanks for your help! Ash Quote Link to comment Share on other sites More sharing options...
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