GliderIreland - Ireland RC Forum - Flying Model forum in Ireland
Planes => Scale => Topic started by: johnfireball on January 04, 2012, 00:03:57 AM
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Hi all,
I have began my next project, it's a first world war DH2 of the type my grandfather flew, bought in kit form (aerographics), 28" span and my plan is to convert it to 3 channel rc with electric power.
Some work done on dummy engine
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2%20engine.JPG)
And the lewis gun, wicker seat and inst panel
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh33.JPG)
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh22.JPG)
More to follow,
John.
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Hey John,
That’s a very intricate looking little model. Keep up the good work.
It might be that you already know the following, in which case ignore it, but just incase you don't :wink: ...............
Regarding powering the model………There are probably many web sites that’ll tell you how to work out the right type of motor, esc, prop & battery but for your info this is the one I use http://www.modelmotors.cz/index.php?page=1
Personally I’ve found AXI motors to be one of the best motor manufacturers, but that’s only my opinion.
If you look at the right hand side of this page you’ll see the heading “Fast Axi Set Up”
Use the drop bars to tell AXI what style of model you’re building and it’s weight and it’ll give you some suggestions of appropriate motors from it’s range.
If you then click on any of the motors that the selection has offered you, and scroll through their details, you’ll see what type of esc , battery & prop is recommended for that motor depending on what style of flying you intend to do.
Just going on from there; If you don’t want to buy an AXI motor (incidentally, most of the big European retailers sell them) then make a note of the recommended motors’ RPM/v
This is the number of rpm the motor produces per volt applied to it.
If you then want to check for a similar motor from another manufacturer then use that RPM/v figure to see what a comparable motor from, say,…Hacker, or E-flight or any other manufacturer would be. (The number of rpm per volt is a good indication of the power of the motor.)
Just before to whiz off the the AXI site,………..little more info for you. Some brushless motor manufacturers show the spec of their motors’ rpm/v as “ Kv “ (1000rpm per volt)
Good Luck
Keith
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Hi Keith,
Thanks for help. Here's the setup I ordered, hopefully it'll work out. What do you think? It will be my first foray into electric. My guess is that the final weight of the model with gear will be around 150grms I would like the model to fly quite slowly to look more scale.I have also ordered a voltage regulator to power reciever and servos from one lipo.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9386
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6455
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9028
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9670
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8044
This kit is actually quite simple but I seem to always have to complicate things. I think I'll get to fly my quark this weekend.
John.
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From what I can see you’ve ordered an in-runner motor with a reduction gear. In-runner motors tend to have high rpm and low torque.
(Personally I’ve always preferred out runner motors which have more torque and lower rpm,…..It saves the weight of the reduction gears.)
I have no experience of using in-runners and from what I read on the website there is little detailed info about the motor/reduction gear.
The esc you’ve ordered should be okay, and I notice that it has a Battery Elimination Circuit (B.E.C.) which means that the esc will power your rx and servos from the Li-Po battery.
I don’t know which of the two props you intend to use. Although three /four bladed props look good on scale models when the model is static, I understand the don’t work very well in actual flight. Two bladed props work better, aerodynamically speaking. I know some scale flyers use two bladed props when flying and then change the prop for multi bladed ones to show the model when stationary, for a better scale appearance.
Because of the lack of detailed info on the motor/reduction gear I have no idea if you have a the right size prop or not. The esc and motor are matched, and the battery is probably an okay size as well. I have no idea how long a flight time the battery will give you because I can’t equate how much current that prop will draw through the motor. (Due to lack of details about the motor)
Certainly you should get a few minutes of flight at least.
Best thing is to try the set up you’ve got and if the flight time is too short, try a bigger battery.
Keep an eye on the temperature of the motor and esc. If the prop is too big for the motor it will start getting hot. (The motor that is, not the prop! :lol: )
If the motor or the esc gets hot to the touch I’d get a reduced pitch or dia. prop. (If I were you I’d run a timed static test first before trying to actually fly it.)
If you’ve already ordered these parts then really it’s a suck-it-and-see situation. It’s all part of a learning curve John.
Good, ain’t it!
K.
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Hi Keith,
Thanks for assistance, as you say I'll have to suck and see. So I don'tneed a voltage regulator as the esc does the job (more weight saved). The gearing on the motor is 7:1 and the long output shaft appealed as it has to go through the dummy engine. I just hope it has enough oomph to drag this fully rigged biplane through the air.
Some more done on the cockpit
Inner side panels added ( showing rigging wires) cockpit surround added. I'm very attatched to my home built wicker seat just need to add seatbelts and a pilot.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2%20inner%20panel.JPG)
These are the outer side panels originally fabric stitched around the airframe. I have used brown leatherlook embossed paper used for fancy box manufacture, will add stitching and attatch after painting.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2%20sidepanel.JPG)
John.
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Very intricate work you’ve done there John. :clap: You certainly have more patience than me!
Ah!. So the gearing is 7:1.…..Let’s see what that means:
Voltage 7.4 x 4500Kv = 33300rpm :- 7 = 4757 prop. rpm. I would have thought that was a wee bit slow for a 4inch pitch prop, but as you’ve already ordered the parts see how you go. My guess would be that you’ll need a slightly greater pitch prop. If it does fly with a 7x4 prop you should get a good flight time. (Probably a good 6 minutes)
Just another thought that’s come into my head John, relating to mounting the motor/reduction gear. Maybe you’ve already seen this coming but when you mount the motor I’m thinking that, obviously the output shaft of the reduction gear will have to be in the centre of the fuse, which means the in-runner motor (the heaviest part) will be off centre.
I remember when I had a spell of flying little indoor planes (180grm biplane) I found it most important to have the model laterally balanced. (As with all planes of course but I found it more so with the smaller models.)
Maybe other more experienced flyers of these type of models will know a trick or two but I’d have thought you’ll have to mount the unit so the motor is above or below the output shaft. If the motor is to one side then I’d imagine you’ll have to add weight to counter that of the motor.
As for the voltage regulator, no you wont need it for this model. You’ll find the esc has a plug on it that fits into your rx. (Throttle position.) As soon as you connect the battery to the esc the rx will power up. :D
The voltage regulator could come in handy though, in your gliders! :shock: If you wanted to use a 2 cell Li-Po instead of a metal Hydride battery because Li-po’s are lighter and hold more current 8) )
Keep up the good work John, & good luck.
Good heavens, look at the time. I’m off to bed to cuddle my teddy. :oops:
Keith
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Hi all,
I'm back to bore you all again. Thanks again to keith for electric advice, I believe the motor will fit in symetrically so hopefully no problem there. You could well be right about prop pitch. This is a beautiful little kit, it's my first laser cut build all others I have done were from paper plan only (what a difference in accuracy), however it's not for the novice the instructions are nonexistant and a good knowledge of build techniques and plan + parts studying is required or you will end up making a major cock up. The wood used is strong but heavy and I fear the final weight may be more than I anticipated.
Anyway some photos of wing build showing modification for ailerons and dihedral setting. I plan on covering the wings in one go using the covering material as a hinge so note the angle of the aileron leading edge to allow down throw.
As an aside John from up north I notice from a photo in your workshop a tigermoth GAYIT, I flew in this plane in the seventies, loops, spins, etc at a gliding event in Kilkenny. It was a friend of the Dads Jeremy Bryson who piloted. We wore leather caps and all the gear, a memory I will cherish.
John. (http://www.gliderireland.net/forum/images/uploads/johnfireball/aileron%20mod.JPG)
(http://www.gliderireland.net/forum/images/uploads/johnfireball/aileron%20mod1.JPG)
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Hi John
Well impressed, looks great!
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Hi all,
A little more progress made and experimented with a different covering film. I found a discussion group on the net and the idea looked good.
http://www.rcgroups.com/forums/showthread.php?t=274520
So I got hold of a roll of this stuff and I can honestly say I am a convert. It's very light preglued and quite easy to use,I covered this wing in one piece for top and one for the bottom. Available in 3 thicknesses (30 micron, 42 micron and 70 micron) and either matt or gloss finish only disadvantage is transparent only so needs to be painted. I opted for matt finish as I think it takes paint better. The water based paints that the warhammer shop sells take very well and can be airbrushed.
A few pics of covering procedure
Lay covering over frame on flat surface
(http://www.gliderireland.net/forum/images/uploads/johnfireball/cov%20lay.JPG)
Tack the edges down with the iron set on silk, Dont need to be too fussy.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/covering.JPG)
Retack all edges with iron set to wool and be sure they are well stuckand then shrink all over on wool setting .
(http://www.gliderireland.net/forum/images/uploads/johnfireball/covshrunk.JPG)
Finished wing (not one wrinkle) with 200 meter roll of covering film, a lifetimes supply. The roll cost approx €50.00
If anyone wants to try some let me know, you wont be disappointed.
John.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/covfin.JPG)
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Hi john, great idea and cheap too! would it work on foam I wonder. John I would like to give it a try. I found a place in England that supplys the film, however if there is a company local, I would try them.
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Hi John,
This film is available at any graphic art printing consumables supplier it is called laminating film not to be confused with encapsulating film. The gloss finish type is cheaper but not sure about paint adhesion. If you wish I could send you some of the 30 micron in the post. This stuff is a pleasure to work with.
John.
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Hi John,
I tested my roll on pink foam and it takes no problem. I'm not sure if all roles of film will behave the same as on the forum link it is suggested that high iron temperatures are needed where mine will melt if iron is too hot.
http://www.presco.eu/sub-category.php?ID=4&parentCatID=1
Link to where I got mine it's the 30micron roll on the top right.
John.
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Hi All,
A little more done and testing of all the gear in progress.
Tailplane construction
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2tailplane.JPG)
Laminating fin outline
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2finlam.JPG)
Gear installation
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2gear.JPG)
Overall view with base colour applied to flying surfaces
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2covered.JPG)
Hi Keith,
I think you may be correct about prop pitch. With testing I can run at full power for 18+ mins per charge but feel I'm lacking thrust. No signs of overheating. Amazing power for such a small motor. Do the gears need lubrication? The motor is also turning the dummy engine and doesn't seem to be a problem. This motor could not be a better fit in this model. I could fit an 8" prop with more pitch to try gain some more push as I feel the rpm of the prop is quite low. Any suggestions welcome.
John.
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Hey John,
As I think I mentioned before, I’m sure someone experienced with these types of models has told me that three (or more) bladed props don’t work very well at these very small diameter sizes. :!: (Some of the racing model lads use single bladed props. Yes you read that correctly! i.e. “half” a propeller)
If I were you I’d remove that three bladed prop and fit the two bladed one. Then run it up and see if it produces any more thrust. I would imagine it would, and that the run time per charge would be reduced, showing that the motor is doing more work.
As for the gears: yes they will need lubrication, but I have no idea what would be the correct lubricant to use on them I’m afraid.
You said that the dummy engine is turning with the prop. So presumably the full size plane used a rotary engine rather than a radial one, yes?
Where are you intending to fly this home made marvel?
K.
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Hi all,
Thrust problem solved with use of an 8" slow fly prop which suits my low rpm geared motor. Yes Keith dh2 was powered by a 100hp gnome rotary engine
http://www.youtube.com/watch?v=CYc-H8Wg-MQ
Apparently this engine was a barn find
Undercarriage and new prop
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2wheels.JPG)
John.
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Yes Keith dh2 was powered by a 100hp gnome rotary engine
They’ve always fascinated me, those Gnome engines. They had no way of regulating how much fuel/air mixture was sucked into the combustion chambers. So they regulated the engine speed by switching the ignition on & off. :shock: You can hear that happening in the You Tube clip.
The problem really became evident when trying to land. If the pilot left the engine switched off for too long the spark plugs would get wet with un-burnt petrol and refuse to spark when the ignition was switched back on. So the engine wouldn’t re-start.
Of course if the pilot left the engine switched on for too long, while trying to land, the plane would have too much airspeed to be able to land!
I’ve often thought how much workload there must have been trying to land a plane with such an engine. Not only would the pilot be having to consider all the normal matters, wings level, airspeed, glide angle, distance from runway, but also having to think about whether he should switch the ignition on for a couple of seconds to clear the cylinders of fuel so that should he need to go round he would be able to start the engine to do so!
And people talk about the “Good old Days!”………. Good riddance I say!! :lol:
Keith
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http://www.youtube.com/watch?v=DEf2GvEBWQI&feature=related
Listen to this Sopwith Pup landing
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:clap: nice video
sounds like the pup has a bad case of wind :oops: on the landing :lol:
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No Andy, that’s not the sound of the pup.
It’s the sound of the pilot suffering from a bad case of wind while landing :lol:
Frankly I wouldn’t blame him!
K.
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Hi All,
Love this model, I have cut and chopped this kit to make it more scale and am really enjoying the build. Sorting out the wire rigging(there's an awful lot). Control surface cables are ready for connection as per full size ie on the outside. The aileron control was a wire led along the leading edge of lower wing to a pully to turn 90 degrees to lower aileron horn then both ailerons connected at trailing edges by cable and connection from top aileron horn to leading edge of top wing by spring on top wing aileron. Should work ok I'm using fishing trace coated wire for the control wires and painted fishing line for the rigging. I dont like the nose on this kit as I think it's way off scale and may modify it to suit. The model is getting a bit heavy but I have tried some runs in my living room under power and I think she's gonna fly albeit just like the real thing (barely). Just what I'm looking for.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2%20rigged.JPG)
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2%20rigged2.JPG)
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Meautiful job. I wish my building was half as good :(
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Hi all,
I had some fun with my DH2 today. It's not finished yet but is flyable so I decided to give it a test run to check out the power output and just as well I did. It needs about twice as much thrust as I'm getting so I'm guessing I need an outrunner powered with a 3 cell lipo. The weight of the model without battery is 240 grms.
http://www.hobbyking.com/hobbyking/store/__5428__AX_2306N_2000kv_brushless_Micro_Motor.html
http://www.hobbyking.com/hobbyking/store/__5430__AX_2308N_1800kv_Brushless_Micro_Motor.html
http://www.hobbyking.com/hobbyking/store/__5427__AX_2306N_1300kv_Brushless_Bell_Motor.html
http://www.hobbyking.com/hobbyking/store/__6784__ZIPPY_Flightmax_800mAh_3S1P_20C.html
http://www.hobbyking.com/hobbyking/store/__6457__Hobbyking_SS_Series_18_20A_ESC.html
These are my choices as they have the beam mounts and will fit with little mods required. OK what do I choose? I want to run an 8" prop for scale reasons and I don't really want a revving noisy fecking thing. The model at present has a 10 amp esc fitted in it's bowels and if possible I would like to leave it there, but if necessary will replace. Prop suggestions? Perhaps running with 2 cell lipos and less rpm. I'm new to this electric and perhaps need a little guidance. I broke the undercarriage today and I am now redesigning for strength which is difficult due to its gangly nature.
John.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/broken%20ds2.JPG)(http://www.gliderireland.net/forum/images/uploads/johnfireball/brokends2.JPG)
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I'm not up on electrics John, but I would suggest due to the draggy nature of the airframe it's going to need something with plenty of torque, but that you don't want something which will make it hurtle round the sky in an unscale manner.
Have you had a look at the calculator, (now FREE) on RCAdvisor?
http://rcadvisor.com/free-calculator
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lovely model john all the best for the maiden flight :clap: :clap:
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Hey John,
You say that the esc is bedded into the bowls of the model, you need to be aware that it requires a cooling airflow to stop it overheating.
Another thing I’ve thought about relates to that dummy engine. Is it balanced? and is it strong enough to withstand being rotated at around 10000rpm? which is the sort of speed you’re heading towards with an out runner.
Of the outrunners you are thinking of getting, probably the 1300Kv model would be most suited. I see it draws 8 amps current, so to be safe I’d be thinking of using an esc able to handle around 15 amps. (Personaly I'd stick to a two cell battery.)
Here are some facts about props:
As for prop sizes; changing the diameter of the prop will vary the rate of acceleration and rate of climb i.e. changing the the diameter doesn’t change the top speed of the model.
Changing the pitch of the prop varies the overall speed of the model but also varies it’s rate of climb and rate of acceleration. Confused yet? :!:
Look,…….If you have (say) an 8” diameter prop with a 4” pitch. The thrust it produces at (a given rpm) will cause the plane to climb at a certain rate, and have a certain top speed.
If you maintain the 8” diameter and reduce the pitch size, the plane will climb faster but it’s overall top speed will be slower. (Like using a lower gear in a car.)
If you want to maintain the same top speed and increase the rate of climb you would have to increase the diameter.
All of these variations however will effect the amount of current being drawn by the motor, esc and battery, because they all form part of what's called the ‘Power Train’
( At a given rpm, doubling the propellers pitch will increase the power requirement by 50%. Maintaining the same pitch but doubling the diameter of the propeller will increase the power requirement by 100%)
As converting this plane to electric flight has never been done before there are no known facts for what would be the best power train for this model, so you are going to have to do a little bit of ‘suck-it-and-see’ John.
To ensure you don’t over load the power train you really need a “Watt Meter” to connect between the esc and the motor as you try different props. This will display a host of information about the different voltage on the battery, current being drawn, current used, and power being consumer at different throttle settings and with different props.
(http://www.gliderireland.net/forum/images/uploads/Happy%20Days/O-IPWM.jpg)
Don’t get disheartened John, Smile! This is all part of the fun of experimenting with model flight, 8) (so I’m told! :roll: )
K.
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Hi Keith,
Me disheartened! never. I relish a challenge. Yea with the higher rpm I think I will not turn the engine but perhaps try for a little friction freewheeling. I'm going with your motor recommendation which is what I also felt would be best and have ordered 8"x4" and 9"x6" props and also an 18amp esc. I ran the current motor flat out until the battery died and there was very little to no heating of the esc, I realise the new setup will be different due to higher loading so will test. If v/i=r then running on lower voltage(2 cell lipo) means pulling less amps so maybe 10amp esc will suffice. The worst part is waiting for the bits to arrive from Hong Kong but I am now getting stuck into the restoring of my dads old glider, it's an electric powered precedent from the mid ninties. The 1300mah nicad battery weighs more than the glider.
John.
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Oh, very impressive John! Personally I think you’ve made a good decision vis the dummy motor. :D
Now I don’t recall ever seeing “ v/i =r ” being quoted on this forum and before I start sounding like an electronics expert, which I’m not, (in fact I’m not an expert on anything,…….except, perhaps, making spelling mistakes, thank you Dave! :roll: ) So for your info, in case you don’t already know this, I’d just point out that when the motor is swinging the propeller it’s creating mechanical power. That’s obvious I know, but think on a little………
Power (measured in Watts) = volts x amps. Let’s suppose the prop needs (say) 100watts to spin at a given rpm.
Working the above formula ‘backwards’ 100watts divided by 7.4volts = 13.5amps
So what would happen with a 3cell battery?…..let’s see :-
100watts divided by 11.1volts = 9amps
So higher voltage batteries actually mean less current being drawn, for a given power requirement.
One more thing that, again, you might already know, but just in case you don’t…….
Li-Po batteries die if the voltage on them drops below a certain minimum level. Most esc’s have a “Low Voltage Cut out” to protect the battery from going too low and dying. (As the esc senses the lower voltage, it cuts off the power to the motor.)I assume your esc has an LVC or else you wont be able to recharge your batteries.
The point I’m coming to it that, for safety’s sake I suggest not to run the battery right down to the LVC level every time you fly,……..just to be on the safe side!
Oh, and one more thing.......Li-Po's don't like being stored at full charge. Best to keep them at around half charge.
I hope you're making notes on all these matters John, there'll be an exam at the end of term!!! :lol:
Keep up the good work John.
Keith.
p.s. Been out on the bike lately? :P
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Hi Keith,
I think my only worry will be the maximum amp value.
Supposing the max power is 100watt with a 3 cell lipo at 11.1 volt = 9 amp
Max power with a 2cell will be approx 66watt (2/3 of 100) at 7.4v = 9 amp
So yes for a given achievable power output the lower voltage does draw more current but both at full power will draw the same. Does this look correct?
John.
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Hhmmmmmm,……………I have a feeling that this is going to be a long post, so just hang on while I go and put the kettle on……………
I’m not too sure where you are coming from with your question John. As it stands your assumption is incorrect.
Let me give you some facts and hopefully you will be able to put together a concept of how the system works in your head.
I have no idea what you already know and don’t know, so I’ll assume you know nothing. (Forgive me if I’m wrong on that point)
For the sake of ease of understanding I’m going to generalize. So let me state first and foremost that some of the things I’m going to write might be only 95% correct. i.e. there may be some exceptions to what I say.
The maximum power that any battery can produce at any given moment is equal to the voltage of the battery x the total current it can produce,…. at a given time.
Lets talk about Li-Po’s and look at the following picture.
(http://www.gliderireland.net/forum/images/uploads/Happy%20Days/7.4.jpg)
Here is a little two cell Li-Po of the type you already have.
The markings show that it’s basic current capacity is 450mAh. Just to remind ourselves what that means………it means that the battery could discharge 450milli amps of current over the course of one hour. This is known as it’s 1C rating. (‘C’ standing for capacity)
However the marking “28C” tells us that this same battery is also capable of discharging up to 28 times it’s 1C rating of 450milli amps, (but for a much shorter period of time of course.)
So, for a short while this little battery could discharge 28 x 450mA.
That equals 12600 milli amps, or 12.6amps. (This figure is also shown on the battery.)
“This is all very well,” I hear you say, “but it’s only referring the battery’s current, how much power will it produce?”
Well, we know that power (measured in Watts) = VxA
The nominal voltage of this battery is 7.4volts. The max rate of discharge is 12.6amps, so it’s max power output is 7.4 x 12.6 = 93.24 watts
Therefore,……………oooppss the kettle has just boiled, wait while I make a cuppa!
(Slurp) Ar! that’s better. :D You can’t beat a nice cup of Earl Grey. It’s so refreshing! 8)
Now where was I?…… Oh yes, we were doing some maths weren’t we.
So the maximum amount of power in the “Power Train” system that this battery is connected to can never be more than 93.24watts.
Now let’s suppose we were using a 3cell Li-Po (11.1volts) which could only supply a max current of 8.4amps. How much power would it produce? Surprise Surprise 11.1 x 8.4 = 93.24 watts
So both batteries produce the same amount of power, but one of them does it by way of using less current. (But a higher voltage)
So it is possible to derive higher power amounts without drawing more current. The trade off is that the system has to be able to handle higher voltages. (Hang in there John, we're nearly home :P)
If you have managed to stay awake through all this I’d be very surprised, but just in case you have here comes the final bit.
The more amps a device uses the hotter it gets. So there is always an incentive to keep the current down. However as we’ve seen the esc and motor have to be able to handle higher voltages.
There, well done John, you can go to sleep now. ZZZZzzzzzzzzzz
BUT just in case you’re still awake here’s another Li-Po.
(http://www.gliderireland.net/forum/images/uploads/Happy%20Days/22.2v.jpg)
It says it can produce 240amps. How is that so when it’s only a 4000mAh battery. And what do you think it’s max power output is? (Answer = 5.328Kw but how do I know that?)
Sleep tight!
K
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I'd rather be a hammer than a nail, yes I would, if I only could, I surely would. Yes I've played guitar all day to get this electrickery out of my head. Anyhow this is my pilot( back to basics), just have to carve him now, will try foam and see how I get on. Will post pics good or bad.
John.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2pilot.JPG)
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Ah well guess I'm pants at carving foam. I may try a balsa one at a later date.
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2pilo.JPG)
(http://www.gliderireland.net/forum/images/uploads/johnfireball/dh2pilo2.JPG)
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johnfireball,
Excellent job on the build, hope it flies half as well as it looks. Wish you the best for the test flight. Freedom Flyer
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Hi all,
I finally got to test fly my model, just 2 short flights until I broke the undercarriage and I have now beefed it up a bit to handle John landings. It flew very well but needs slight right rudder trim to track straight . The bigger motor is just the job (thanks Keith, maybe a bit overpowered), it gets airborne on half throttle in two feet, I am using an 850mah 2s lipo as it balanced just right with this fitted. I also added some scale features (the wing mounted oil tank), finished the rigging and dirtied it up a bit. Cant wait to fly it again. Sorry no flying vid (too busy trying to fly). My freewheeling engine works a treat.
http://youtu.be/GRiVi-MnPy4
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Well done John! :clap: :clap:
So where did you fly it? Do you live in a big house? 8) You’ll have to get one of your kids to film it flying, it would be good to se it in the air. :D
If you’ll allow me, I’d just mention a quick word about “beefing up” parts of a plane.
“Beefing up” is normally a metaphor for unintentionally “adding weight.”
Adding weight to a plane increases its wing loading. :arrow:
Increasing wing loading increases the stall speed :arrow:
Increased stall speed equals higher landing speed :arrow:
Higher landing speed often results in damaged airframe,… and so on, and so on.
A wise old man once told me that, “Building an aeroplane, is a question of compromise.” :!:
Keith