gadyrdal Posted January 16, 2010 Share Posted January 16, 2010 Thanks. I have had a couple of flights now, and I feel it is a bit sensitiv on the elevator... Will try to re-link the servo, so it uses the whole range for the movement.Edited By gadyrdal on 16/01/2010 18:27:03 Quote Link to comment Share on other sites More sharing options...
IanN Posted January 17, 2010 Share Posted January 17, 2010 Gadyrdal, that's an interesting and informative set of build photos. Thanks for that link Quote Link to comment Share on other sites More sharing options...
Steve Barton Posted June 16, 2010 Share Posted June 16, 2010 its a long story but I no longer have the plans and would appreciate to know the COG from the leading edge for the Midget Mustang I am making mine with removable wing and canopy, and electric. All measurements indicate it is too front end heavy. Any one else with a heavy end - so to speak? many thanks Quote Link to comment Share on other sites More sharing options...
Peter 'Ivanna Crashalot' Savage Posted June 17, 2010 Share Posted June 17, 2010 It is 60mm from the leading edge! found the plan the other day Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted November 22, 2010 Share Posted November 22, 2010 Hi Steve.....maybe too late in the day but cog is 60mm from LE of wing measured at the wing root....... I'm just coming to end of my build of the Midget Mustang & yes mine is very nose heavy....even with the Rx battery just in front of the tailplane & the rudder/elevator servos behind the wing TE I'm still going to need about 2 oz of lead. AUW is looking like 3lb 4 oz which is a good way over TNs 2lb 8oz..... I think its probably my fault...I am a bit of a heavy builder plus I'm using an ASP32 up front which is a good bit heavier than the OS25LA (330g for the ASP, 200g for the OS)....anyone built a "heavy" Mustang?? How does it fly?? Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 1, 2010 Share Posted December 1, 2010 Well I've been having a think about my Mustang.....the bigger/heavier engine is causing me some grief getting the cog where it should be....even with standard servos fitted aft of the wing & a 4 cell Rx battery right back at the tail its STILL nose heavy.....I think I would only get the cog right with a much lighter motor (OS25LA). But then I had another thought....why not convert it to electric....a motor is much lighter than an engine & I could move the batteries into the middle of the plane, under the canopy/hatch & that should just about do it.... I thought I'd go for a fairly high kv & a small "fast" prop to suit the model.....probably aim at about 400watts....something like this perhaps turning a 9 or 10x6 on a 3S pack....I have the same motor but 1100kv turning an 11x7 prop in a Seagull Extra EP & peaking at just over 400watts & thats been a great combo... Gadyrdal, I'd love to know what you put in yours & how it went..... Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 1, 2010 Share Posted December 1, 2010 Steve I have bought and fitted one of these in my Ta 152H Tr 35 42B. Why I chose this particular motor I do not know now. I think it is broadly similar to the one you are considering. My model has 42" span. Not finished, as I have become bogged down with minor issues. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 2, 2010 Share Posted December 2, 2010 Thanks Erfolg.....its the same motor but with a lower kv...1200 vs the 1450 version I'm thinking about..... I guess there's not much point asking you about prop sizes or current draw until the model is finished though...... Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 2, 2010 Share Posted December 2, 2010 Steve you are correct i have not tested it yet. I think I chose that motor on the basis that from purchasers comments the motor draws :- 10 * 5 = 220w 10 *7 = 280w 11* 7 = 281w and that the 152 has an annular radiator (looks like a radial), and that a smaller propeller could suffer from masking. My smaller (36") 152 has now flown very well on 9 * 6 = 160w. The largish propeller looks about right. I have just re-motored my Sagitta (2m glider), for the second time with another inrunner, as the last bestowed the model with all the performance of a ruptured duck on crutches. I needed an inrunner due to the fine small diameter nose. This is the motor which draws 246W on a 10 * 6. It has not flown as the ESC was only 25A. I just received a 40A ESC yesterday. There is another which may be worth considering motor, being a higher Kv. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 2, 2010 Share Posted December 2, 2010 H'mmm....I would venture that there is something not quite right with those current figures Erfolg.....I have an 1100kv version of this very motor & I can say with certainty that it pulls around 40A (400watts) on an 11x7 & 3S.....the version you are looking at has a higher KV & would therefore pull much more current trying to drive the same prop but faster......unless the power figures mentioned are based on a 2S battery of course!!! Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 2, 2010 Share Posted December 2, 2010 Steve These figures as measured by myself on a 3s, using an overlander watt meter. This is the motor which draws 246W on a 10 * 6. It has not flown as the ESC was only 25A. It certainly appears to push back the air, I am very hopeful of the set up. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 3, 2010 Share Posted December 3, 2010 Very odd......this is my motor & as I said it pulls about 40A on a 3S when turning an 11x7 APC E prop......your motor appears to be the same motor as mine but with a higer kv value which should mean it will draw more current on the same prop...... I wonder whats going on....is your LiPo voltage holding up OK? Mine holds about 10.5v under load..... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 3, 2010 Share Posted December 3, 2010 My database records of eagle tree logging shows that on a 12 x 6 and decent 3s battery, I got 41 A with this motor. However, it is no longer alive, after the model it was in became depressed and suicidal Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted December 3, 2010 Share Posted December 3, 2010 I know how it feels Tim.......... Which motor are you referring to.....Erfolgs 1250kv version or my 1100kv unit....? Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 3, 2010 Share Posted December 3, 2010 Yesss, I became confused, about which motor we are talking about. My 35-42B has not run, I suspect that I blame Timbo, as I suspect my selection was in part influenced by some discussion. In my case I intend running a smaller prop than those so far referred to, probably initially a 10*6. In the case of the Turnigy 480 L V spec, the figures are my own recorded figures of 246w on a 10*6, 3s. Which replaced a Black Mantis B2846 1100kv, which gave 160w on a 10*6, 3s. Which replaced a Tornado 2025/4243 with epicyclic gearbox, which produced 175w on 10*6, 3s. Before burning out. The Turnigy 480 motor I have, in principal has many merits at the practical installation level (for narrow, confined noses). What is of interest, I guess, is that the same motor case seems to be tailored to provide a wide range of characteristics. At one extreme, for use as a EDF motor and at the other end a high torque, low rev. motor. Now I have tachometer I will be measuring revs to try and get a better handle on how much useful work is being done. I have also become convinced that the type of rig that Timbo has would be very useful in obtaining a better grip of performance. I have given serious thought of building my own rig, with an additional measurement on "Y" axis (assuming "X" is measuring trust) to measure torque. Then using W=2Pi,*N*T, where N is from the tachometer, T is the torque. This will give a clue how much power is wasted in the ESC and motor, the already measured thrust being by far the most useful bit of data. Edited By Erfolg on 03/12/2010 12:19:40Edited By Erfolg on 03/12/2010 12:23:36 Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 3, 2010 Share Posted December 3, 2010 Posted by Steve Hargreaves on 03/12/2010 11:15:19:I know how it feels Tim.......... Which motor are you referring to.....Erfolgs 1250kv version or my 1100kv unit....? 1100Kv. As you say, if Erfolg's is higher Kv then it will definitely pull more current on the same prop. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 3, 2010 Share Posted December 3, 2010 Err, what I am getting blamed for now Erfolg Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 3, 2010 Share Posted December 3, 2010 Timbo You are being blamed for guiding me towards the Turnigy 35-42B, which has not been used, so I am unable to comment. I think we then have an misunderstanding, or a break down in communication. I have Turnigy 480L, which seems to draw current as per the data on the site. I think this is being questioned on the basis that (I think Steve) has another in the series which draws twice the current. In both cases I suspect that the issue comes down to my preference for lower Kv motors to turn larger propellers. I tend to look initially at 1000 to 1500Kv. Then try and decided where to look further. I think we started with one motor, where I said I had a similar motor of lower Kv, explained I had recently purchased another motor, which may have merits with reference to the application of powering a TN Pylon type model. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 3, 2010 Share Posted December 3, 2010 Hmm - bit unfair to "blame" me for suggesting a motor that you haven't even tried yet then. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted December 3, 2010 Share Posted December 3, 2010 Timbo I have no problem with the motor. The more we write more confusing things are getting. I think the problem is the Turnigy 480l, I have found it to date to do what it says on the label. I think others say there experience is that it rubbish, though it seems that they have a different model to the one I have. Of course I could have hold of teh wrong end of the stick Quote Link to comment Share on other sites More sharing options...
Kevin Posted April 26, 2011 Share Posted April 26, 2011 Hello All Has anyone flown the Cosmic wind yet as a friend asked me to maiden one today, I refused until he sorted the C of G out as it was so nose heavy. I believe he had an OS 40 or 46LA and see here it should be a 25 size engine. Thanks for any replies. Kevin. Quote Link to comment Share on other sites More sharing options...
Kevin Posted April 27, 2011 Share Posted April 27, 2011 I flew the Cosmic Wind today which had an OS 25LA not the 40 as I thought in the last post. After sorting the C 0f G out she flew great and looked a treat in the air, the owner is very pleased too. Kevin. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted April 28, 2011 Share Posted April 28, 2011 Hi Kevin....I found my Midget Mustang to be very nose heavy too. I had planned to put an ASP32 up front but this is about 5oz heavier than the OS25LA & meant I had no chance of achieving the correct CoG...even with the Rx battery balanced on the tailplane!!! I did wonder about going the electric route as this meant I could put the batteries under the cockpit to help achieve the CoG.... However I have just bought an OS25FP off ebay for a few quid & I think that with the lighter motor & putting the (small) R/E servos in the tail I can just about achieve the CoG position. Its probably my fault as I am a bit of a heavy builder but had I known I would have taken much more care to make the front end a lot lighter.......... Quote Link to comment Share on other sites More sharing options...
Kevin Posted April 28, 2011 Share Posted April 28, 2011 Hello Steve Even with the OS 25 LA we needed some lead on the tail to get the correct CofG. The model flew very well though and surprisingly fast. Hope you're happy with your fist flight. Kevin. Quote Link to comment Share on other sites More sharing options...
sceadu498 Posted June 1, 2011 Share Posted June 1, 2011 What do you think of using a .15 size engine in it? I have a Magnum XL 15 BB that might work in it. That should lighten it up a bit I would think. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.