Eflight Blanik 4.2m with turbine?
#126
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Hi Guys, I have taken delivery of my Blanik and I am asking , again, of anyone how the universally accepted (apparently) measurement of 4 degrees down thrust for the turbine is arrived at ? What I am looking for is what datum the 4 degrees is relative to i.e. is the stab at zero (as the yardstick we use in pattern),or is it based on a centre line through the wing section joining leading edge centre to trailing edge centre,or is it from some easily determined datum through the fuselage or,worst case is it a guess? Heaven forbid !
I am really keen to learn from the experience of those who have successfully flown this model in turbine configuration, please help. Thank you.
My turbine is a Jetcat P60.
Cheers Dambuster.
I am really keen to learn from the experience of those who have successfully flown this model in turbine configuration, please help. Thank you.
My turbine is a Jetcat P60.
Cheers Dambuster.
#127
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For me.... it's just a guess and it works just fine. I leveled the fuse on a stand with just my eyes and put in what I thought was about 4%, using just my eyes. I don't think it is a critical measurement and you can always change it after the first flight. Just my opinion. I got about 9 great flights on mine.
http://www.youtube.com/watch?v=WilrzKCXNhk
http://www.youtube.com/watch?v=WilrzKCXNhk
#129
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Hi Joe,Great video,what camera? Thank you for your reply,unless you are using lots of mixes the model seems to fly fine with plenty of power. It is a pity no one seems able to give a definite explanation of how they arrived at the down thrust number.
As my main aeromodelling centres around pattern where we measure thrust angles,wing and stab incidences to the Nth degree I guess we all get a bit hung up on exactitude !!!
I suppose I should set about getting a setting in relation to the stab and take it from there.
Another question for you,how much flap were you using in the video? It seemed quite a small amount.
So thanks again.
Cheers Dambuster.
As my main aeromodelling centres around pattern where we measure thrust angles,wing and stab incidences to the Nth degree I guess we all get a bit hung up on exactitude !!!
I suppose I should set about getting a setting in relation to the stab and take it from there.
Another question for you,how much flap were you using in the video? It seemed quite a small amount.
So thanks again.
Cheers Dambuster.
#130
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No mixing required... If I remember right, in pattern, you put a setup together then adjust it after a few flight to tune it in. That is the same here. I have 4 standoffs of equal length and have an additional 4 washers under the rear standoffs. You can add or take away from there. There is more going on than just the turbine angle. The wing appears to have a positive angle against the fuse. Even if you had the turbine flat turbine, I think it would fly ok and could be adjusted. Its no big deal.
In my opinion again, turbine angle is not the critical focus. The vertical stab and rudder hold the most interest for me. My P-60, when throttled up on the ground, will make the vert stab shutter. I am sensitive in not damaging the stab/rudder with max thrust. I would not be comfortable in the long term with a turbine more than the P-60. The 60 is an ideal match for the 30lb sailplane. Plus you have the issue of the heat damaging the covering. I removed the stickers on the rudder because they don't fix with a heat gun or covering iron and you will be fixing the rudder coving after just a few flights. I have long term plans on removing the covering from the rudder and replacing it with "flightskin" or something that can handle a little heat.
BTW... the camera is a GoPro Hero 3
In my opinion again, turbine angle is not the critical focus. The vertical stab and rudder hold the most interest for me. My P-60, when throttled up on the ground, will make the vert stab shutter. I am sensitive in not damaging the stab/rudder with max thrust. I would not be comfortable in the long term with a turbine more than the P-60. The 60 is an ideal match for the 30lb sailplane. Plus you have the issue of the heat damaging the covering. I removed the stickers on the rudder because they don't fix with a heat gun or covering iron and you will be fixing the rudder coving after just a few flights. I have long term plans on removing the covering from the rudder and replacing it with "flightskin" or something that can handle a little heat.
BTW... the camera is a GoPro Hero 3
#132
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Hi Joe, Again thank you for your prompt reply. Yes in pattern there is an almost standard set up for initial flights and from there the model is "fine tuned" almost everything is up for adjustment !!
As you say there is positive wing incidence ( all wings must have this or the plane won't fly!),but this is relative to the stab incidence and motor thrust lines must be "amicable" with these settings.It looks like you hit the sweet spot!!
I take on board your trepidation in regard to the models structure, in particular with regard to the heat sensitive vertical stab and rudder. I am not aware of any structural failure of these models but there is always a first !!
Regarding the flaps and slowing the model down do you think the optional air brakes would be worthwhile ?
I really appreciate you taking the trouble to discuss this with me.
Cheers Dambuster.
P.S. Peter Goldsmith the designer of the Blanik is a pattern pilot/designer from way back and a multiple Australian champion who also competed at the TOC in Las Vegas,so the "heritage" is in the genes !!
As you say there is positive wing incidence ( all wings must have this or the plane won't fly!),but this is relative to the stab incidence and motor thrust lines must be "amicable" with these settings.It looks like you hit the sweet spot!!
I take on board your trepidation in regard to the models structure, in particular with regard to the heat sensitive vertical stab and rudder. I am not aware of any structural failure of these models but there is always a first !!
Regarding the flaps and slowing the model down do you think the optional air brakes would be worthwhile ?
I really appreciate you taking the trouble to discuss this with me.
Cheers Dambuster.
P.S. Peter Goldsmith the designer of the Blanik is a pattern pilot/designer from way back and a multiple Australian champion who also competed at the TOC in Las Vegas,so the "heritage" is in the genes !!
#133
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Hi all,I may be the only one still on this thread,but here goes...... the covering on the wings of my Blanik is very poor I estimate I have spent over 4 hours continually going over and over and over it ! Am I special ? Also of more concern to me is that the flaps when fully up sit about 5mm below the aerofoil moulded into the fuselage,again am I special? Please let me know where your flaps retract to and if like mine does the model still fly well. I must say that in some regards this model is not well made, I dread to think what the wings would look like without the covering !!!!!
Cheers Dambuster.
Cheers Dambuster.
#134
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Mine is still ok. I keep the flaps maybe 1-2 mm down, to keep servo travel on the safe side..
http://www.purilend.ee/v/users/alari...geViewsIndex=1
http://www.purilend.ee/v/users/alari...geViewsIndex=1
#135
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Hi,Thank you for your prompt reply. It seems the flaps rise enough to give a flat bottom to the trailing edge aerofoil. It is a pity that the wing aerofoil does not match the fuselage profile.Given the lousy wing covering and I dare not think what lies beneath the covering, the quality of the model leaves a lot to be desired. My best hope is that it flies as good as people,on here, say.
Cheers Dambuster.
Cheers Dambuster.
#138
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A friend and I both picked up a Blanik this week with the aim to fit an EDF to mine and a P-60 to the other.
First thing off the line is the turbine mount design - here's the first CNC cut for the wing root, done in 4mm plastic. By the way, if any one would like the DXF for this cut, don't hesitate to ask, it's open to all. Also prelim CAD of turbine mounting system.
First thing off the line is the turbine mount design - here's the first CNC cut for the wing root, done in 4mm plastic. By the way, if any one would like the DXF for this cut, don't hesitate to ask, it's open to all. Also prelim CAD of turbine mounting system.
#141
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Today's work, shaping and fitting the metal joiners for the G10...just to make it clear, this is not my work, this is my mates, I'm just posting on his behalf and I also act as a sounding board to bounce and nut out ideas - also play the role of test pilot for some of the more outlandish stuff we've tried like a 1000 size electric 3D heli and a 64mm EDF powered 500 size heli...all in the name of "because we can"!
#144
Wren 44Gold Blanik JIDER!
Hello
I thought I would post a few photos now that I have got my glider working well.
I have a Wren 44 Gold with about 10 lbs thrust, it's mounted using some DLE Standoffs, thrust is about 4 degree down.
An extra nose wheel is a must for paved runways, but be sure to reinforce the stock wood tray, I re-glued the tray with Hysol and then a carbon plate with carbon cloth up fuse sides to spread the load.
I did the same for the main wheel, it's also a weak point.
I balanced at 20mm as per instructions, holy crap I stopped weighing at 5 lbs, It takes a lot of lead.
after about 12 flights the fuse started to crack at back side of the canopy, I used some uni directional carbon ( good 1/4 inch diameter bundle) around the inside top of fuse ( by the top window in fuse) then laid up a few sheets of carbon cloth along the fuse sides and up to where the wing bolt goes into wing.
The tail needs to be protected from heat, at first I had some red bull cans cut up as shields, but they have since deteriorated, for now I just have heat tape, it's ugly but works.
I am having a blast with this setup, I never thought my smallest turbine would be mounted to such a large airframe, and preform so well.
I have since drilled out some of the lead, but still figure there is about 5 lbs in the nose.
Recently I had the pleasure of meeting Ali Machinchy, what a nice guy. I was so excited when he was kind enough to fly my glider, I was ready for a list of things to change but was pleasantly surprised when he thought it was the best combination for this airframe he had flown.
Seams that most he has flown are over powered and exhibit trim changes at different thrust settings.
Anyways building this was a breaze and flying it very fun, it really has presence in the air, I had more compliments from spectators in Kentucky about the glider than any of my other jets.
Richard.
I thought I would post a few photos now that I have got my glider working well.
I have a Wren 44 Gold with about 10 lbs thrust, it's mounted using some DLE Standoffs, thrust is about 4 degree down.
An extra nose wheel is a must for paved runways, but be sure to reinforce the stock wood tray, I re-glued the tray with Hysol and then a carbon plate with carbon cloth up fuse sides to spread the load.
I did the same for the main wheel, it's also a weak point.
I balanced at 20mm as per instructions, holy crap I stopped weighing at 5 lbs, It takes a lot of lead.
after about 12 flights the fuse started to crack at back side of the canopy, I used some uni directional carbon ( good 1/4 inch diameter bundle) around the inside top of fuse ( by the top window in fuse) then laid up a few sheets of carbon cloth along the fuse sides and up to where the wing bolt goes into wing.
The tail needs to be protected from heat, at first I had some red bull cans cut up as shields, but they have since deteriorated, for now I just have heat tape, it's ugly but works.
I am having a blast with this setup, I never thought my smallest turbine would be mounted to such a large airframe, and preform so well.
I have since drilled out some of the lead, but still figure there is about 5 lbs in the nose.
Recently I had the pleasure of meeting Ali Machinchy, what a nice guy. I was so excited when he was kind enough to fly my glider, I was ready for a list of things to change but was pleasantly surprised when he thought it was the best combination for this airframe he had flown.
Seams that most he has flown are over powered and exhibit trim changes at different thrust settings.
Anyways building this was a breaze and flying it very fun, it really has presence in the air, I had more compliments from spectators in Kentucky about the glider than any of my other jets.
Richard.
#146
I'm just building a Blanik for the Formation Jet Masters (P-60) have you plugged the middle of the carbon tubes? I think the glue joint is designed as part of the strength on the fin.
Dw
Dw
#147
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Yes I have Dave , used a 6mm carbon rod stuffed it with glue and rammed it into the 8mm Cf rod now nice and strong..hold down really well wont be moving off there,in saying that the elevators should have also been glued for strength as they pretty much do as much control as the vertical fin but they not glued either ..ive seen Airline vertical stabs held in place with pins and bolts too seem pretty ok so far hehe! the screws go all the way through and into the other side wall as well as its underneath the 4mm top plate so the bolts are in sheer I think the only way you are going to remove this fin is to remove all of the airframe in front of it
cheers
H
cheers
H
#150
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after testing a mount with thin upright arms decided against it because of sideways flex...went with the stronger A frame design the full size used here, now with turbine mounted on solid faces..no flex at all anywhere, will also be making airfoils like the original experimental Full size glider
like this
there is a centre mount design that clean and practical, but cannot be removed for Slope Soaring like the other design can...once I remove my Turbine no adjustment to CG will be necessary because the Turbine is directly over the CG point so less muking about with weights at the slope
like this
there is a centre mount design that clean and practical, but cannot be removed for Slope Soaring like the other design can...once I remove my Turbine no adjustment to CG will be necessary because the Turbine is directly over the CG point so less muking about with weights at the slope
Last edited by jet junkie; 07-23-2014 at 03:54 PM.