Myron Beaumont Posted February 23, 2008 Share Posted February 23, 2008 Before installing my recently aquired EDF gear in "the Hawk " have decided to make up an EZE-FAN (RCM&E July 2007 free plan ) as a test bed to get the hang of lekky stuff .Has anyone built one as I am thinking of scaling it up to 36" span from 30" as my calculations lead me to believe that the wing loading will exceed the recommended 19 oz per square foot if I dont since I'll be using a 4s lipo (Total wt of all gear comes to 18 oz / 500 gms leaving the model alone needing to be no more than 4 oz 'ISH . The increase in wing area I calculate will allow me with this modification to get a loading as stipulated .Or should I save going to the drawing board & build as is ? Would appreciate comments etc. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 23, 2008 Share Posted February 23, 2008 I suspect that the fan and motor battery combo will be too much for the EZE fan - what dya reckon Scott? Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 23, 2008 Author Share Posted February 23, 2008 Timbo Thanks for reply Have drawn it up at 1.2 X size on plan -makes it 36" span .Looks right if nothing else ! Will make up a wing of thin ribs covered in 1/16 " balsa 'cos that's what I have in my spares box( not 3/8 soft balsa) & will use pine as on the plan for LE 5 mm square not 4mm(have it in the same box) Wing area will be approx 260 square inches Seems about right Should be a bit more docile I think and certainly be able to be hand launched .Hope micro servos will do their job OK ?One per aileron & one for elevator ! Will make the fan assembly removeable with clamps(beer can material ) held with servo screws ! so as to be able to fit in the Hawk later .Really enjoying this venture into the unknown.As long as it turns out to be a good test bed that is OK with me.Shall make it tomorrow !Grumpyish! Myron Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 23, 2008 Share Posted February 23, 2008 Well done matey....especially glad that you are enjoying the trials and tribualtions....all part of the rather steep leaning curve my friend. Please let me know when you are ready to do a static bench test of the fan though....you MUST do this before fitting it into ANY airframe. Servo screws to clamp down a 70 / 90mm fan unit...I dont think so my friend !! Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 23, 2008 Author Share Posted February 23, 2008 OK Point taken. Will do bench test of course before installation in anything. Will reinforce fuselage for mounting screws or bolts .Probably a thin layer of GRP (getting very weight concious though) not knowing what to expect yet on the first run up .'ER indoors is going to write down whatever I shout out on the first run up -Quickly ! She has her uses & tell you the truth I think she's nearly as excited as me .I'm going to wear my safety glasses aswell (before you tell me to)Thanks again Myron Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 23, 2008 Share Posted February 23, 2008 Funny that my missus is pressed into service for exactly the same thing whenever I do static runs - I prepare the paper for her, with the columns marked out ready...... Amps I Volts I Watts I RPMI then stand at the rig watching the wattmeter and RPM counter ( except for fans which I have not yet found an RPM meter for ) and go straight to WOT for around 20 seconds SHOUTING out the numbers for her .These then get entered into my little home made spread sheet ( excel format if you want a copy ) to analyze and compare, this S/sheet formulates the watts per pound , duration, maximum current versus available current ,etc etc -over a nice cup of coffee and sticky buns of course Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 27, 2008 Author Share Posted February 27, 2008 Timbo EZE -fan 1.2 X size just needs covering Weight is 8 oz !Built up wing and all .With all the other bits Fan/Lipo/ESC /Servos/ should weigh approx. 24 oz . Same as the original max.weight .Wing loading works out to be 13.71 oz /square foot Not bad Eh .!What do you think? Am waiting for postman to bring my connectors & servos .Have made airflow into the fan more aerodynamic as well not just a tapered pod Extremely inefficient in my book .. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 27, 2008 Share Posted February 27, 2008 Well I should think it will go well at that weight with a 70mm fan and 4s battery. remember to email me b4 you are ready for static bench tests. Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 27, 2008 Author Share Posted February 27, 2008 Definately .Still waiting for bits from Scott .Cheers Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 27, 2008 Share Posted February 27, 2008 Oh...I thought you had received them. Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 28, 2008 Author Share Posted February 28, 2008 Connectors & servos should arrive today. Still have solarfilming & canopy (foam) to make so no panic .I think Royal Mail has been blown off course by high winds & eartquakes! Quote Link to comment Share on other sites More sharing options...
roy hill 2 Posted December 10, 2016 Share Posted December 10, 2016 Can't find the build photos to this Quote Link to comment Share on other sites More sharing options...
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