Tim Kearsley Posted January 16, 2008 Share Posted January 16, 2008 Hi all,I've just purchased a Ripmax Spitfire and I'm pondering on what motor to put in it. Any recommendations, bearing in mind ease of fitting etc? I've seen that quite a few people are using the Axi 2820/10 but a hobby shop fairly local to me stock the Dualsky range and I'm wondering if there's a reasonable equivalent there.Anyway, just be very interested to here what you've kitted your Spit out with.Cheers,Tim. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 16, 2008 Share Posted January 16, 2008 Well that particular AXi is suited to 12 -13 " props, on at least 3 LiPo cells ( which I presume you will be using ? )and has a KV of around 1000. Maximum current is around 35A, so I guess we are talking about 350 Watts plus. Just look for an equivalent with those sort of specs.This would probably be OK, but use a small pitch prop to keep the amps down to around 25+dualsky motor at Als Quote Link to comment Share on other sites More sharing options...
Tim Kearsley Posted January 16, 2008 Author Share Posted January 16, 2008 Sorry Timbo, forgot to give all the facts didn't I?! Yes, I'm planning on using a 3-cell LiPo. The motor you link to was certainly one of the ones I was considering. I did wonder whether this one:Another Dualsky motorwould be a good bet. Perhaps over-egging the pudding though do you think?Tim. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 16, 2008 Share Posted January 16, 2008 No, I think this will be fine also, although slightly heavier....and you know what that means dont youhaving now bothered to to look up your intended model, I see the quoted weight of the model is only 3.2 lbs, so for a reasonable scale like flight ( and you wont want to be racing this around like a hotliner WILL YOU! ) Assuming that is the AUW.75 watts per pound should be plenty, so you only need about 250 watts, which on a 3s pack @ roughly 10.5V is.....24A. So I would aim to prop it for 25A WOT, which just happens to be the peak efficiency range for the second motor you found...well done my boy Quote Link to comment Share on other sites More sharing options...
Tim Kearsley Posted January 17, 2008 Author Share Posted January 17, 2008 You are quite right Timbo in that I don't want to be tearing around the sky like a maniac! My only reservation really is that I don't know what the quality of the DualSky brand is like. I've used their ESCs on two occasions now, so far without any problems. The advantage for me is that the stockist is just a five-minute drive from my place of work, so I can nip in there on the way home and I avoid postage costs etc., plus I satisfy my impatience to get on with the build!!Cheers,Tim. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 17, 2008 Share Posted January 17, 2008 They are good budget motors IMO Quote Link to comment Share on other sites More sharing options...
scott cuppello Posted January 17, 2008 Share Posted January 17, 2008 I can tell you that the E-Flight "0.15" works a treat in this with a 12x6 prop, Lipo wise, a 15c 33-3600mAh will work a treat [and save a few pennies.......you won't be drawing eough current to justify 20c]. What is a must is to re-glue the engine mount/firewall area with epoxy.......they "undo" themselves. Quote Link to comment Share on other sites More sharing options...
Kelly Posted January 17, 2008 Share Posted January 17, 2008 I agree with ScottTis a bit fragile.Worth a mention is the elevator, some reports of failure due to the strip of balsa joining the two halves not up to the job. may be a good idea to beef it up with a bit of piano wire. .Kelvin Quote Link to comment Share on other sites More sharing options...
Tim Kearsley Posted January 17, 2008 Author Share Posted January 17, 2008 Thanks very much for the comments guys. The fragility of the motor mount is noted and I'll beef it up a bit. I too have read a few reports of elevator failure so will think about some strengthening there as well. Having said that, a similar warning has been issued a few times in respect of the elevator on the Seagull Extra 300 EP but so far I've not had a problem. Then again, I don't do many elevator-testing aerobatics yet!Cheers,Tim. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 17, 2008 Share Posted January 17, 2008 If you do choose to beef up the elevator, c/fibre might be better than wire / steel as any weight right at the tail could impact on the cog. Quote Link to comment Share on other sites More sharing options...
Tim Kearsley Posted January 17, 2008 Author Share Posted January 17, 2008 Yes, my thoughts exactly Timbo (must be something about the name). I'm going to call in to my local hobby shop this evening and see if they have the DualSky motor in stock. I'm thinking of HS65 servos for this model. OK do you think?Tim. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 17, 2008 Share Posted January 17, 2008 yep...good servos. Quote Link to comment Share on other sites More sharing options...
scott cuppello Posted January 17, 2008 Share Posted January 17, 2008 But wrong size? They are Mini as opposed to micro servo's if I'm not mistaken in the Ripmax range? You will need [as the aileron is old fashioned single servo operation] an HS81MG or similar [GWS MG Mini is pretty good too....but noisy!] for Aileron, and to be honest, at least hi-torque, better MG for elevator.....on a hot set up, this thing tramps on. I really wouldn't bother trying to fit Sub-Micro's, others have tried....and failed! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 17, 2008 Share Posted January 17, 2008 Well it did say in the specs that I read, micro servos are recommended, and I always classed the 65s as micro. However, other sites recommend minis and Scotts recommendation of 81s is therefore better. The 81 has better torque too, and for around the same money. Serves me right for not checking the model specs properly first Quote Link to comment Share on other sites More sharing options...
Tim Kearsley Posted January 17, 2008 Author Share Posted January 17, 2008 Good point Scott - thank you. I hadn't picked that point up. It's a pity I'd bought the ******* HS65's before I read your post!! Never mind, they'll come in useful for another project I'm sure. I'll pick up some HS81's tomorrow.Thanks for your help chaps.Tim. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 17, 2008 Share Posted January 17, 2008 Tim.... email me via the forum ( on my profile ) about the 65s Quote Link to comment Share on other sites More sharing options...
Kelly Posted January 17, 2008 Share Posted January 17, 2008 I use HS81MG servos in my Spitfire and my Me109.Kelvin Quote Link to comment Share on other sites More sharing options...
Kelly Posted January 17, 2008 Share Posted January 17, 2008 I just remembered, you may have to add a bit of weight to the nose due to the brushless motor/lipoly set up being lighter than the original spec of a 600 brushed motor. Quote Link to comment Share on other sites More sharing options...
scott cuppello Posted January 17, 2008 Share Posted January 17, 2008 Yep, you will, that's why I usually reccomend the 0.15 over the 0.10 motor, more power, cuts the dead weight with a slightly heavier motor. Quote Link to comment Share on other sites More sharing options...
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