Adrian Day Posted January 8, 2013 Author Share Posted January 8, 2013 Hi Ian thank you Yes its going to be a second wing for the pix-e to see if its able to have ailerons or not i have a little dihedral planed but i was going to ask that question when and if people posted .. seems you was thinking same as me the only reason i was going to add a little was then it may self straighten as i don't want this plane to spiral just bank when turning as i want to keep 95% of the models original character not make it a sports plane I could be wrong on this Idea (Any one else advice would be good too) Rgds Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 8, 2013 Share Posted January 8, 2013 I would reduce the dihedral right down to about 1/2" under each tip Adrian....otherwise the ailerons & the dihedral tend to fight...... Think about how you turn with ailerons....you rol slightly & then centre the ailerons.....the model stays banked & part of the lift force turns the model. With dihedral the model will want to return to S&L so you are forever adding a bit of aileron to regain the bank angle & you end up "thre'penny bitting" around the turn..... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 9, 2013 Author Share Posted January 9, 2013 Hi Steve thank you for that info i will do that .. i wasn't sure how much to put as didn't know if the effects would cancel out each other, I can see what you mean now .. thinking about it you would have to feather it as you go.. so would you think that doing it with out any is better than 1/2" i was going to do 3/4" before you put not to put much so wasn't to far out. I don't want to take to much away from the real design that Tim has done .. but just add to what i would like from this model. may use the wings on my redesign of the PIX-E .. may call it the Pix-e Plus also Steve while your here can i ask do you think that a little 9g servo is ok to use to move the ailerons or do you think that its not up to the job?? rgds Adrian Edited By Adrian Day on 09/01/2013 02:25:56 Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 9, 2013 Share Posted January 9, 2013 Adrian, The ailerons look to be a great idea, although don't expect it perform 3D aerobatics! I'd guess that, as long as your linkages are absolutely free, then a 9g servo will be quite adequate for the job, and won't add too much weight. tim Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 10, 2013 Author Share Posted January 10, 2013 thank you Tim like that it wont be able to do 3D just want a little more manoeuvrability nothing too over the top .. Do you think that the size of the ailerons are going to give enough authority being the size they are??? the way Im hoping to do it is to sit the servo between the 2 wings and using the push rod on a bell crank.. seems very free and moves with the lightest touch so was hoping to just have a little 9g servo.. as want the weight low .. i think i have added about 2g doing what i have, so its not to bad.. thanks for the help Tim.. do you think the redesign looks ok? or would you do it different at all Adrian Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 10, 2013 Author Share Posted January 10, 2013 been working on the second wing today got most of the parts cut and some redesigning of the push rod and bell crank sorted And now looking forward to the build side get this one up and running see how it looks when covered should be ready for covering in the next few days Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 13, 2013 Author Share Posted January 13, 2013 a few more pictures of the new wings ... just some simple glueing to do now and then build the servo box then its ready to go, think she looks ok let me know what you all think.. Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 13, 2013 Author Share Posted January 13, 2013 well got some more done today all the wings are now joined together so and push rods now in place so here are th elastest pictures Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 13, 2013 Share Posted January 13, 2013 Looks good! I'm interested to hear how this one flies compared to the standard model. tim Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 14, 2013 Author Share Posted January 14, 2013 thanks you Tim , I have both wings for this model so will fly it with both and see if its any better I think it could be a different small model .thats designed not having ailerons . not sure if its going to change the CG much. but soon as i get it powered will work that out do you think it will fly ok with the this style of wing or can you see future issues Regards Adrian Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 31, 2013 Author Share Posted January 31, 2013 hey all sorry been a little while building just been looking up power set.. please could you let me know if this all goes together ok??? BATTERY ESC MOTOR Let me know more soon as pos please RC friends as need to order this soon as i can Quote Link to comment Share on other sites More sharing options...
Ruprect Spode Posted January 31, 2013 Share Posted January 31, 2013 This power set up is meaningless without the selection of an appropriate propellor producing enough wattage relevant to the aircrafts weight.. You must select a suitable propellor. I shall do some sums and let you know which one should do, but first you must tell me the weight of the aircraft including the power set up. Edited By Ruprect Spode on 31/01/2013 22:45:59 Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted January 31, 2013 Share Posted January 31, 2013 Adrian, This looks very good! Having scanned the reviews I'd start with a 7x5 prop and see how you get on. tim Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 31, 2013 Author Share Posted January 31, 2013 thank you tim and ruprect .... the prop i was going for before Tim commented was going to be 8x4 slowfly prop and a model thats under 1.5lb that the motor says its able to pull, upto 800g think that about 1.7lb thank you tim will go with what you said will order the 7 x 5 do they do a slow fly in that size or just go with a standard??? as now got ailerons fitted, if that makes any difference to the equation ??? regard Adrian Quote Link to comment Share on other sites More sharing options...
Pete B Posted January 31, 2013 Share Posted January 31, 2013 Posted by Ruprect Spode on 31/01/2013 22:43:22: This power set up is meaningless without the selection of an appropriate propellor producing enough wattage relevant to the aircrafts weight.. You must select a suitable propellor. I shall do some sums and let you know which one should do, but first you must tell me the weight of the aircraft including the power set up. Hi Ruprect, welcome to the forum! If you look back at page 3 of this thread, you'll see that Tim and Steve had deep discussions on the power setup a couple of weeks ago and it looks as if Adrian has followed their advice..... Pete Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted January 31, 2013 Author Share Posted January 31, 2013 thank you Pete i have tried to keep to their advice the best that i can .. not sure if i had or not .. wasn't sure if the 20c 1300 battery was ok or the esc with said battery regards Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 1, 2013 Share Posted February 1, 2013 Hi Adrian....I'm late to the party AGAIN!!!!!! Your motor/battery/ESC look fine to me.....much as I hate to disagree with my learned friend Mr Hooper (what does he know anyway....he only designed the model!!!! ) I think your idea of an 8x4 slow fly prop should work just fine.....If I recall some tests I did on that motor for Lee Damms Matador I think you should get around 75-80 watts on that set up & around 100watts if you go up to a 9x4 ish slow fly propellor......more than enough for Pix E.... Don't forget to order a prop adaptor too..... Incidentally the ESC doesn't care what battery it is connected too (so long as you don't exceed the voltage limit of the ESC)....you could connect it to a 2S 500mAh battery or a 3S 5000 mAh battery. The only thing it cares about is how much current you try & stick through it. This is determined by the load...ie the motor/prop combo.....exceed the max current & its magic smoke time..... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted February 1, 2013 Author Share Posted February 1, 2013 good morning Steve welcome to the party thank you for your input its always welcomed, with open mind. and a grin good to hear that you think i have chosen right on the prop size i wasn't sure like the idea of about 80W that would fly characteristically , not wanting the model to fly like a sports plane but i may order 9x4 to go on the new model just for the extra push.. if i order all 3 then test all see how it all goes from there, .. dont want to over load anything had a laugh as i was putting together my setup i remembered you saying about the prop adaptor earlier in the posts .so last night i was talking about it to may partner .. then when reading this, this morning, made me smile lol this is the prop adaptor i was thinking about getting PROP ADAPTOR think its right for the job 3mm shaft.?? thank you again for the last part in your post too, good to know that details and that the setup its pretty good to go.. will keep this in mind for future use... looks like what you had put before in your previous lessons may have gone in a little lol thanks again and regard Adrian Quote Link to comment Share on other sites More sharing options...
Ruprect Spode Posted February 1, 2013 Share Posted February 1, 2013 Pete: Thank you for your welcome to the forum, I had read page 3 and it seemed to me that no definitive propellor had been agreed on. Adian: I have the following test results for you based on your set up with different propellors. 7*5 E 45W 8.9amp 8*4 SF 53W 11.1amp 8*6 SF 65.2W 17amp (motor maximum is 15amp) I replaced the battery with a Zippy 800mah 3s and got the following results. 7*5 E 92W 14amp. 7*6 SF 114W 17,4amp These are the results I observed with an EMAX CF2812 1650kv motor and a 20amp esc through a GT Power multi function power meter. Different propellor manufacturers may acheive differing results. You may choose to use or disregard this information as you wish and I bear no responsibility for your ultimate choice of set up. Regards Ruprect Edited By Ruprect Spode on 01/02/2013 12:06:15 Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted February 1, 2013 Author Share Posted February 1, 2013 thank you for your hard work there Ruprect thanks also for all the info on the power set and the watts / Amps out.. looking to go with one of 2 a 7 x 5 and a 8 x 4 .. i think they seem to be giving watts needed also the amps are pretty good when it comes to the 15amp motor rating, as i thinks 15 is only a burst rate. with the selected props all being under @ around 11a and 9a i like the last part of your post was / are you a solicitor .. I would think that all posts are just a guide not a perfect outline, due to the changes in manufacturing and conditions that the experiments or flying was undertaken, as theses change by the second so the only person who would be at fault would be the person undertaking the controls at said moment.. Regard Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 1, 2013 Share Posted February 1, 2013 Gotta be something wrong with your battery there Ruprect.....45W & 8.9A equates to 5volts....53W @ 11.1A equates to 4.8V......& off the 3S 92Watts @ 14A equals 6.6volts.......those sound like dead batteries to me.....I'd expect around 7 volts off a 2S & 10.5volts off a 3S under load..... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted February 1, 2013 Author Share Posted February 1, 2013 Hi Steve The watts i was looking for would be about 75w-90w so if my math's works right it would be around 10.7a - 12.9a max on a 2s does this sound right Steve??? that's why i went with the 18a ESC so if needed the burst rate would be around 15a..... not sure what size prop i would need to accomplish it though as from previous workings we found the 8x4 to be best suited??? (maths of w / v= A) Regards Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 1, 2013 Share Posted February 1, 2013 75-90 watts sounds perfect for a PixE...thats what I would go for... Watts is simply Volts multiplied by Amps so for a 2S battery your calculations are bang on. The important point to remember is that the battery voltage will sag slightly when its loaded.....I usually try & work off 3.5volts per cell as an "under load" figure. Most batteries will probably do better than that but it means I get slightly more power than I calculated.... So yes your ESC will be fine...a 15A unit would probably do but the extra cost & weight of an 18A unit over a 15A unit are negligable.....start with an 8x4 & see how you get on...I think it will be fine....you can always go up to a 9x4 or similar if you want some hot doggin' prop hangin' action from your Pix E. You do have a wattmeter handy don't you?? It will be interesting to see what the numbers come out like... Quote Link to comment Share on other sites More sharing options...
Adrian Day Posted February 1, 2013 Author Share Posted February 1, 2013 my teacher should be happy lol(mr Hargreaves) I'm learning thank you thats how i did it working off the watts and working back to get the right safe Amps .. so V x A= W Simple when you remember these things not got a meter yet but going to invest as starting to get back into things more now.. so going to need one.. they dont cost much when you think about the price you could lose out when you mess up on the motor / esc / battery front and could end up in loss of everything model included .. on the prop front was going to get a 7 x4 8 x3.8 and a 9 x4.7 all SF 2 motors 2 esc and 2 batteries order all in one go save some on p&p Adrian Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 1, 2013 Share Posted February 1, 2013 You might like to add a wattmeter to your shopping list Adrian.... Pretty essential really & at £12 it could pay for itself the first time you use it if it stops you melting an ESC..... Oh & please please please make sure you don't fit the prop until you are ready to go......if it starts up accidentally you WILL get hurt so be sensible & leave the prop off......one little trick I use is to use a negative mix of the throttle with itself.....this basically disables the throttle stick so if you nudge it the motor stays stopped.... 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.