| 10th Scale RC Aluminum Test Rig Log, Pictures and Video |
12/20/06
I'm rebuilding after the 12/18/06 crash. Good thing I went with the cheaper motors with better availability. I
hope the parts will be in shortly after Christmas and be flying again before the New Year. I'm pretty sure
the problem was the BEC that controls the servos. It comes off one of the batteries that drives the
corresponding motor. As the battery ran down, the noise in the control circuit gets greater, and the servos
and motors go haywire. A separate battery for the controls should solve the problem.
With the latest setup, I hope to get better control in pitch by moving the batteries to the CG and lengthening
the body for a greater moment arm between the fore and aft propellers. I've also ordered a wireless video
camera to put on board. It should be in next week sometime. This can help me diagnose flight
characteristics as well as maybe get some cool flight videos. Check back around New Years for more
video.
Click here for the 12/17/06 hover video. Click here for the 12/18/06 crash video.
11/24/06
The landing gear seems to do what I want, but when I tested the systems in the back yard (I was
supposed to go out to a big open field shortly after) the model got a little too close to a holly bush, and the
holly bush won (sorry, no video - it was supposed to be a short test, but I got carried away.) And yes, the
grass is much gentler on the props and servos. But, 1 holly bush vs 1- 4 mm prop shaft @ 4000 rpm =
victory holly bush.
This just re-confirms my justification with going with a different motor. It will be an outrunner motor with a
strategically weakened prop adapter so hopefully when this happens again, I can just replace a $5 prop
adapter (which I will keep plenty of) instead of waiting a month+ for a repair, or waiting 2+ weeks for a
$140 motor.
I will take this opportunity to concentrate on the fuselage plug and to do some flight testing on the
simulator. No flight videos for probably a month or so until I get the new motors. But maybe I will get some
simulator videos posted in the near future. And maybe re-do the web site a little since this page is about
filled up.
11/20/06
I figured out what caused the crash earlier. Now the controls seem more responsive with my new control
arrangement and software algorithm. Click on the picture to the left to check out the video. It's definitely
harder to control while in ground effect, but smooths out as it gets higher. I'm just too chicken to take it
very high. I'll get Shannen to do some flying with it when I get the controls the way I want.
I've ordered a different motor with more power to test. This should help give a more positive control
response. I should have it outfitted with the new motors sometime in December.
I've been building a new landing gear so I can do some open field testing. By the weekend after
Thanksgiving I should have it ready. Hopefully a grass field will be a little more gentle on it. I've been using
the Master Airscrew 14x7-3 blade props because they are so much more durable. I will try the custom
blades after some testing with the new landing gear.
I'm also starting on the fuselage plug and hope to have it ready in a few weeks. Stay tuned!!
11/3/06
IT FLIES!!!!!!!!!!
After I was just about ready to throw in the towel on this platform, I decided to try an unconventional control
method to keep this thing stable in roll. IT WORKED!! You won't see this method for controlling roll on any
airplane, guaranteed. God does answer prayers, and he is good!!! Click on the picture to see the video.
Even though I crashed on this test, I believe it proved this platform is workable. The controls still need
tweaking and the operator needs more practice. I will proceed with this platform for a flight model that will
transition from vertical to horizontal flight.
I will work on this during my spare time for the next few months, so things may come a little slower. But I
will keep moving forward. Keep checking back every few weeks.
11/2/06
I believe this is about as close to flying as I can get this thing. I bumped into the wall and broke one of the
blades (click on the picture to the left to see the video). I don't know if I can make it controllable enough to
make a transition flight.
This will terminate the flight trials for this test bed, for now. After working non stop for about a month on
this project, I need to tend to some other things. Maybe after reviewing the videos a few dozen times and
after a couple of months, I might try another thing or two. I will probably start the variable pitch 1/5th scale
model sometime early next year. Email me with comments.
11/1/06
After several attempts to set the gyro gains and the pitch & roll mixing to the new custom propellers, I'm
not sure this beast can be tamed. I believe it may be a combination of too much pitch on the blades, and
the motors not reacting fast enough to the manual and gyro inputs. I had 2 of the propellers strike the
ground during testing yesterday (click on the picture to the left to see the video.)
I will repair the blades and rework the landing skids to try and make it less susceptible to
propeller-ground strike, then try one last time. The next version will be a 1/5th scale model with variable
propeller pitch. But that model will take a lot more time and money. I will make a decision by Sunday to
either make a 1/10th scale flying model from this test bed which may require a rolling takeoff then
transition to horizontal flight, or go to the next level and build the 1/5th scale version.
10/26/06
Finally, all props have been pulled from the molds. 3 of the props are balanced and tested, ready to go.
The 4th is being touched up today and will be balanced and tested by this weekend.
I would have been ready to flight test this weekend. But I ASSmeD the parts I ordered after the crash could
be installed and ready to go. But one of the brand new speed controllers for the electric motor was bad
right out of the box. I will order a new speed controller and send the other back for warranty so I can have
a spare. One of the batteries packs may be weak, also. I will test the batteries over the weekend and order
new ones, if necessary. Maybe the 1st weekend in November I can start flight testing.
10/16/06
I finally have one completed CW propeller, balanced and ready to go. The second CW blade should
hopefully be ready this week. One CCW blade may be ready this week, but the second CCW propeller
may be a while longer. I am still having some issues with the mold.
I did run a thrust test on the CW propeller and compared it to Master Airscrew 14x7 - 3 prop. Both blades
produced 2.5 lbs of thrust at 165 watts and about 3 lbs at 200 watts. The 2 blade custom prop is about
20.5" in diameter with about an 8" pitch at the tip and about 6" at the hub.
9/18/06 Update
After sending the wrong propellers twice, we found that the 15x4 pusher props were not available. The
next choice would be the 16x5 or 18x5. Those blades would be really wide and probably still have too
much pitch, so I'm not sure how well they would work. I don't think I'll order any more blades just to play
around with at this point. By the time they get here, I hope to have the custom props done (or close to
being done). I have all the materials for the latest design of the custom prop now, so hopefully in a week
or so, I'll be ready to fly.
9/6/06
It was my hopes to get at lease one of the props pulled from the molds to use as a plug so I could make a
stiffer fiberglass mold, if necessary. But that didn't happen. The blades pulled up fine, but the hub wouldn't
come out of the mold. Even with care (as much care as I could manage after waiting for months), plenty of
wax and PVA mold release agent, the sides of the mold broke while trying to pry out the hub.
I have a modified design I will try after some supplies come in. The repairs will probably take a couple of
weeks. Meanwhile, I have ordered 15x4 - 2 blade wooden props that shouldn't stall during hover, but the
pitch is much too low for the forward flight speed I want. I can hopefully configure the test rig for hover
while the repairs are made to the mold, and maybe have some videos of hover by the weekend of the 16th.
I'm rebuilding after the 12/18/06 crash. Good thing I went with the cheaper motors with better availability. I
hope the parts will be in shortly after Christmas and be flying again before the New Year. I'm pretty sure
the problem was the BEC that controls the servos. It comes off one of the batteries that drives the
corresponding motor. As the battery ran down, the noise in the control circuit gets greater, and the servos
and motors go haywire. A separate battery for the controls should solve the problem.
With the latest setup, I hope to get better control in pitch by moving the batteries to the CG and lengthening
the body for a greater moment arm between the fore and aft propellers. I've also ordered a wireless video
camera to put on board. It should be in next week sometime. This can help me diagnose flight
characteristics as well as maybe get some cool flight videos. Check back around New Years for more
video.
Click here for the 12/17/06 hover video. Click here for the 12/18/06 crash video.
11/24/06
The landing gear seems to do what I want, but when I tested the systems in the back yard (I was
supposed to go out to a big open field shortly after) the model got a little too close to a holly bush, and the
holly bush won (sorry, no video - it was supposed to be a short test, but I got carried away.) And yes, the
grass is much gentler on the props and servos. But, 1 holly bush vs 1- 4 mm prop shaft @ 4000 rpm =
victory holly bush.
This just re-confirms my justification with going with a different motor. It will be an outrunner motor with a
strategically weakened prop adapter so hopefully when this happens again, I can just replace a $5 prop
adapter (which I will keep plenty of) instead of waiting a month+ for a repair, or waiting 2+ weeks for a
$140 motor.
I will take this opportunity to concentrate on the fuselage plug and to do some flight testing on the
simulator. No flight videos for probably a month or so until I get the new motors. But maybe I will get some
simulator videos posted in the near future. And maybe re-do the web site a little since this page is about
filled up.
11/20/06
I figured out what caused the crash earlier. Now the controls seem more responsive with my new control
arrangement and software algorithm. Click on the picture to the left to check out the video. It's definitely
harder to control while in ground effect, but smooths out as it gets higher. I'm just too chicken to take it
very high. I'll get Shannen to do some flying with it when I get the controls the way I want.
I've ordered a different motor with more power to test. This should help give a more positive control
response. I should have it outfitted with the new motors sometime in December.
I've been building a new landing gear so I can do some open field testing. By the weekend after
Thanksgiving I should have it ready. Hopefully a grass field will be a little more gentle on it. I've been using
the Master Airscrew 14x7-3 blade props because they are so much more durable. I will try the custom
blades after some testing with the new landing gear.
I'm also starting on the fuselage plug and hope to have it ready in a few weeks. Stay tuned!!
11/3/06
IT FLIES!!!!!!!!!!
After I was just about ready to throw in the towel on this platform, I decided to try an unconventional control
method to keep this thing stable in roll. IT WORKED!! You won't see this method for controlling roll on any
airplane, guaranteed. God does answer prayers, and he is good!!! Click on the picture to see the video.
Even though I crashed on this test, I believe it proved this platform is workable. The controls still need
tweaking and the operator needs more practice. I will proceed with this platform for a flight model that will
transition from vertical to horizontal flight.
I will work on this during my spare time for the next few months, so things may come a little slower. But I
will keep moving forward. Keep checking back every few weeks.
11/2/06
I believe this is about as close to flying as I can get this thing. I bumped into the wall and broke one of the
blades (click on the picture to the left to see the video). I don't know if I can make it controllable enough to
make a transition flight.
This will terminate the flight trials for this test bed, for now. After working non stop for about a month on
this project, I need to tend to some other things. Maybe after reviewing the videos a few dozen times and
after a couple of months, I might try another thing or two. I will probably start the variable pitch 1/5th scale
model sometime early next year. Email me with comments.
11/1/06
After several attempts to set the gyro gains and the pitch & roll mixing to the new custom propellers, I'm
not sure this beast can be tamed. I believe it may be a combination of too much pitch on the blades, and
the motors not reacting fast enough to the manual and gyro inputs. I had 2 of the propellers strike the
ground during testing yesterday (click on the picture to the left to see the video.)
I will repair the blades and rework the landing skids to try and make it less susceptible to
propeller-ground strike, then try one last time. The next version will be a 1/5th scale model with variable
propeller pitch. But that model will take a lot more time and money. I will make a decision by Sunday to
either make a 1/10th scale flying model from this test bed which may require a rolling takeoff then
transition to horizontal flight, or go to the next level and build the 1/5th scale version.
10/26/06
Finally, all props have been pulled from the molds. 3 of the props are balanced and tested, ready to go.
The 4th is being touched up today and will be balanced and tested by this weekend.
I would have been ready to flight test this weekend. But I ASSmeD the parts I ordered after the crash could
be installed and ready to go. But one of the brand new speed controllers for the electric motor was bad
right out of the box. I will order a new speed controller and send the other back for warranty so I can have
a spare. One of the batteries packs may be weak, also. I will test the batteries over the weekend and order
new ones, if necessary. Maybe the 1st weekend in November I can start flight testing.
10/16/06
I finally have one completed CW propeller, balanced and ready to go. The second CW blade should
hopefully be ready this week. One CCW blade may be ready this week, but the second CCW propeller
may be a while longer. I am still having some issues with the mold.
I did run a thrust test on the CW propeller and compared it to Master Airscrew 14x7 - 3 prop. Both blades
produced 2.5 lbs of thrust at 165 watts and about 3 lbs at 200 watts. The 2 blade custom prop is about
20.5" in diameter with about an 8" pitch at the tip and about 6" at the hub.
9/18/06 Update
After sending the wrong propellers twice, we found that the 15x4 pusher props were not available. The
next choice would be the 16x5 or 18x5. Those blades would be really wide and probably still have too
much pitch, so I'm not sure how well they would work. I don't think I'll order any more blades just to play
around with at this point. By the time they get here, I hope to have the custom props done (or close to
being done). I have all the materials for the latest design of the custom prop now, so hopefully in a week
or so, I'll be ready to fly.
9/6/06
It was my hopes to get at lease one of the props pulled from the molds to use as a plug so I could make a
stiffer fiberglass mold, if necessary. But that didn't happen. The blades pulled up fine, but the hub wouldn't
come out of the mold. Even with care (as much care as I could manage after waiting for months), plenty of
wax and PVA mold release agent, the sides of the mold broke while trying to pry out the hub.
I have a modified design I will try after some supplies come in. The repairs will probably take a couple of
weeks. Meanwhile, I have ordered 15x4 - 2 blade wooden props that shouldn't stall during hover, but the
pitch is much too low for the forward flight speed I want. I can hopefully configure the test rig for hover
while the repairs are made to the mold, and maybe have some videos of hover by the weekend of the 16th.
Pictures
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1/15/07
I've tried a couple of different hardware configurations, which didn't improve pitch stability. So I went back to
the pre- 12/18/06 crash configuration, with the exception of putting the batteries, computer and rc receiver at
the center of gravity.
When I put on the temporary cardboard wings (to simulate disc-masking of the propeller), stability
deteriorated significantly. I went from the 3 blade 14x7 blades to the 2 blade 15x8 to see if stability
improved, and it did. But not enough for my liking. I have ordered 2 blade 16x8 and 16x10 propellers to see
if this will help. I may also try a 3 blade 16x10 depending on the 2 blade results. I have another trick I may
try as well.
The next step is an accurate representation of the wings I will use with the new blades. This may take a
couple of weeks or more.
The 2 blade 15x8 propellers are the most stable I have tried yet (without the temporary cardboard wings.)
Here is a on board spy cam video (9+meg).
I've tried a couple of different hardware configurations, which didn't improve pitch stability. So I went back to
the pre- 12/18/06 crash configuration, with the exception of putting the batteries, computer and rc receiver at
the center of gravity.
When I put on the temporary cardboard wings (to simulate disc-masking of the propeller), stability
deteriorated significantly. I went from the 3 blade 14x7 blades to the 2 blade 15x8 to see if stability
improved, and it did. But not enough for my liking. I have ordered 2 blade 16x8 and 16x10 propellers to see
if this will help. I may also try a 3 blade 16x10 depending on the 2 blade results. I have another trick I may
try as well.
The next step is an accurate representation of the wings I will use with the new blades. This may take a
couple of weeks or more.
The 2 blade 15x8 propellers are the most stable I have tried yet (without the temporary cardboard wings.)
Here is a on board spy cam video (9+meg).
Testing the lift capacity of the motors and the rest of the flight systems.
Trying to learn the controls before going un-tethered.
Better known as the crash. Remarkably, little damage was done.
| Early videos in the first quarter of 2006 |
2/20/07
I've ended up shrinking the wings and going to the 16 inch propellers to keep the stability in hover within
reason (See latest video with cardboard wings to represent disc masking. The title says 2/25/07 but it was
actually on 1/25/07. View this on full screen mode and turn your volume up ;-)
Now that the wing and propeller size have been selected, it was time to see if the propeller would produce
the required thrust at speed. Check out my latest test instrument, the Corvette Wind Tunnel (See picture at
left. And yes, people do stare at you when you ride around like this.)
The propeller is not efficient as I had hoped. It only produced about 8.4 oz pulling 170 watts at 45 miles per
hour (I'm estimating total drag to be about 2.1 lbs at 47 mph, so each propeller will need to produce 0.525
lbs or 8.4 oz.) It will produce the thrust I need at higher speed, but with higher current draw and lower flight
times. So, I have set the design cruise speed at 47 mph.
The wings have been designed (check out Solidworks CAD picture to the left) and tested in the simulator.
I'll be building the wings and fuselage over the next few weeks. Keep checking back for the latest progress.
I've ended up shrinking the wings and going to the 16 inch propellers to keep the stability in hover within
reason (See latest video with cardboard wings to represent disc masking. The title says 2/25/07 but it was
actually on 1/25/07. View this on full screen mode and turn your volume up ;-)
Now that the wing and propeller size have been selected, it was time to see if the propeller would produce
the required thrust at speed. Check out my latest test instrument, the Corvette Wind Tunnel (See picture at
left. And yes, people do stare at you when you ride around like this.)
The propeller is not efficient as I had hoped. It only produced about 8.4 oz pulling 170 watts at 45 miles per
hour (I'm estimating total drag to be about 2.1 lbs at 47 mph, so each propeller will need to produce 0.525
lbs or 8.4 oz.) It will produce the thrust I need at higher speed, but with higher current draw and lower flight
times. So, I have set the design cruise speed at 47 mph.
The wings have been designed (check out Solidworks CAD picture to the left) and tested in the simulator.
I'll be building the wings and fuselage over the next few weeks. Keep checking back for the latest progress.
4/3/07
I decided to build the fuselage using a CNC router. Over the past few weeks, I have been trying different
CAM software to turn my Solidworks files into G code that can be used on any CNC machine. I settled on
VisualMill Basic, because it seemed to do the job and give the most bang for the buck. Luckily, Sessions
Sign Co. here in Valdosta, GA has a CNC router that will work with VisualMill. We can now cut 3D parts as
much as 6" deep by 4 feet wide by 8 feet long.
If you need for 3D parts cut out of high density foam, call Joe Davis at (229) 269-4505 or JR Sessions at
(229) 259 9595 or email me by clicking here. Click on the picture to the left to check out the video of the
CNC router making a 1/40th scale test fuselage.
My decision to evaluate and invest in the CAM software added several weeks to my time frame, but I hope
to have the fuselage and wings done by (at the earliest) late April or (more than likely) well into May.
I decided to build the fuselage using a CNC router. Over the past few weeks, I have been trying different
CAM software to turn my Solidworks files into G code that can be used on any CNC machine. I settled on
VisualMill Basic, because it seemed to do the job and give the most bang for the buck. Luckily, Sessions
Sign Co. here in Valdosta, GA has a CNC router that will work with VisualMill. We can now cut 3D parts as
much as 6" deep by 4 feet wide by 8 feet long.
If you need for 3D parts cut out of high density foam, call Joe Davis at (229) 269-4505 or JR Sessions at
(229) 259 9595 or email me by clicking here. Click on the picture to the left to check out the video of the
CNC router making a 1/40th scale test fuselage.
My decision to evaluate and invest in the CAM software added several weeks to my time frame, but I hope
to have the fuselage and wings done by (at the earliest) late April or (more than likely) well into May.
5/16/07
I know I haven't posted much lately, but I am getting things accomplished. After making a realistic timeline, I
expect the 10th scale fiberglass model to fly sometime around July. I'm trying to fly the simulator at least a
few hours a week so hopefully I can be ready to fly when the time comes.
The on board computer was having to wait to receive the Pulse Widths from the receiver and caused the
servo motion to be jerky when I added the Tilt signal to the on board computer. Osprey Electronics built a
custom Pulse Width Frequency Increaser for me to speed up the frequency of the signal, and it works fine.
I took the aluminum test rig out to the sod farm where the local RC'ers fly and it was generated a lot of
interest. It was a bit too windy to fly much, but I did manage to hover it for a few seconds so everyone could
see it fly.
After nearly having the fuselage plug finished, I nicked it trying to fit it in the parting board. I thought I could
make some easy repairs with a little epoxy and paint, but ended up making a mess since the plug already
had several coats of wax on it. Repairs will take at least a week.
The foam wings have finally been cut, so I will focus on those while the fuselage gets repaired by
somebody who knows what there doing.
I know I haven't posted much lately, but I am getting things accomplished. After making a realistic timeline, I
expect the 10th scale fiberglass model to fly sometime around July. I'm trying to fly the simulator at least a
few hours a week so hopefully I can be ready to fly when the time comes.
The on board computer was having to wait to receive the Pulse Widths from the receiver and caused the
servo motion to be jerky when I added the Tilt signal to the on board computer. Osprey Electronics built a
custom Pulse Width Frequency Increaser for me to speed up the frequency of the signal, and it works fine.
I took the aluminum test rig out to the sod farm where the local RC'ers fly and it was generated a lot of
interest. It was a bit too windy to fly much, but I did manage to hover it for a few seconds so everyone could
see it fly.
After nearly having the fuselage plug finished, I nicked it trying to fit it in the parting board. I thought I could
make some easy repairs with a little epoxy and paint, but ended up making a mess since the plug already
had several coats of wax on it. Repairs will take at least a week.
The foam wings have finally been cut, so I will focus on those while the fuselage gets repaired by
somebody who knows what there doing.
8/16/07
Still no transition flight. I do have the fuselage mold complete and have pulled one part from it, which will be
my replacement plug since the original was damaged when I removed it from the mold.
Originally, I had planned on just building the fuselage with minimal structure and put fixed landing gear on
it. But since I eventually plan on putting retract landing gear on it, I decided to go ahead and build most of
the structure in Solidworks and do the FEA testing on it with COSMOS, since I have it. The retract design is
complete and I hope to have the rest of the structure done in a couple of weeks. Hopefully, this will speed
up the build process and minimize the in flight testing, which will be expensive if something breaks.
I've added FMA's Co-Pilot to help me with my limited RC pilot skills and it should help with the transition
flight. I will try to test it and some new blades (by some miracle, APC has started manufacturing propellers
in the size I need for electric motors ) in the next couple of weeks on the aluminum test bed, in hover only. I
have made the code more efficient on my microprocessor to help speed things up. I calculated the update
rate was about 52+milliseconds on my old setup, and I found out the servo controller I was using was
causing my servos to jitter. The interim electronics should speed things up to about 36+milliseconds. It will
be interesting to see how much 16 milliseconds will make on stability. With some custom electronics I am
working on, I plan on getting the update rate to 8 to 12 milliseconds for the transition flight. That should
make flight much more stable.
For the long run, I hope to have a custom mixer with up to 20 input channels and 20 output channels
commercially available in the next few months. This would allow unlimited mixing on all channels for more
complex RC projects. For more information, email me.
It will still be probably a couple of months before transition flight. Maybe if I predict flight by Christmas, I
could hit that target. Sometimes it seems like building a house, 90 percent done and 90 percent to go.
I am making some progress on my transition flying in X-Plane. Here is a video of one of my flights on
YouTube. Hopefully, I can fly this good for real when the time comes.
Here is a video on YouTube of my landing gear design.
Still no transition flight. I do have the fuselage mold complete and have pulled one part from it, which will be
my replacement plug since the original was damaged when I removed it from the mold.
Originally, I had planned on just building the fuselage with minimal structure and put fixed landing gear on
it. But since I eventually plan on putting retract landing gear on it, I decided to go ahead and build most of
the structure in Solidworks and do the FEA testing on it with COSMOS, since I have it. The retract design is
complete and I hope to have the rest of the structure done in a couple of weeks. Hopefully, this will speed
up the build process and minimize the in flight testing, which will be expensive if something breaks.
I've added FMA's Co-Pilot to help me with my limited RC pilot skills and it should help with the transition
flight. I will try to test it and some new blades (by some miracle, APC has started manufacturing propellers
in the size I need for electric motors ) in the next couple of weeks on the aluminum test bed, in hover only. I
have made the code more efficient on my microprocessor to help speed things up. I calculated the update
rate was about 52+milliseconds on my old setup, and I found out the servo controller I was using was
causing my servos to jitter. The interim electronics should speed things up to about 36+milliseconds. It will
be interesting to see how much 16 milliseconds will make on stability. With some custom electronics I am
working on, I plan on getting the update rate to 8 to 12 milliseconds for the transition flight. That should
make flight much more stable.
For the long run, I hope to have a custom mixer with up to 20 input channels and 20 output channels
commercially available in the next few months. This would allow unlimited mixing on all channels for more
complex RC projects. For more information, email me.
It will still be probably a couple of months before transition flight. Maybe if I predict flight by Christmas, I
could hit that target. Sometimes it seems like building a house, 90 percent done and 90 percent to go.
I am making some progress on my transition flying in X-Plane. Here is a video of one of my flights on
YouTube. Hopefully, I can fly this good for real when the time comes.
Here is a video on YouTube of my landing gear design.
9/3/07
I stripped the code I wrote in the BX-24 microcontroller to just what was necessary for hovering flight, and
took out the servo controller that was slowing it down. I was able to get the update rate to 22 to 25
milliseconds, about half the time as before. I am able to hover in light winds now with descent
controllability. I won't be able to use this configuration for transition flight as there are not enough channels
on the BX-24.
I also tried the APC 16x10 electric blades. I don't think there quite as stable as the Zinger 16x10 wooden
blades, but they use about 15% less power. If I can make the APCs work on the fiberglass model, I'll
definitely use them to get longer flight times.
I also tried 14.8v batteries instead of the 11.1v batteries hoping for more stability with more power. But it
made it worse. I could liftoff at 1/4 throttle instead of 1/2 throttle and I don't think the ESCs had the
resolution to work in that narrow band at the bottom of the throttle range. Stability was uncontrollable and I
broke one of the new APC blades (more on the way with spares).
I have the electronics I'm going to use for transition flight and I'm in the process of writing code and
assembling the parts for that. I also have parts coming for the landing gear. Maybe I'll have some pictures
of progress in the next couple of weeks.
Click here or on the picture to the left to see the latest YouTube video with the electric blades and faster
microcontroller code.
I stripped the code I wrote in the BX-24 microcontroller to just what was necessary for hovering flight, and
took out the servo controller that was slowing it down. I was able to get the update rate to 22 to 25
milliseconds, about half the time as before. I am able to hover in light winds now with descent
controllability. I won't be able to use this configuration for transition flight as there are not enough channels
on the BX-24.
I also tried the APC 16x10 electric blades. I don't think there quite as stable as the Zinger 16x10 wooden
blades, but they use about 15% less power. If I can make the APCs work on the fiberglass model, I'll
definitely use them to get longer flight times.
I also tried 14.8v batteries instead of the 11.1v batteries hoping for more stability with more power. But it
made it worse. I could liftoff at 1/4 throttle instead of 1/2 throttle and I don't think the ESCs had the
resolution to work in that narrow band at the bottom of the throttle range. Stability was uncontrollable and I
broke one of the new APC blades (more on the way with spares).
I have the electronics I'm going to use for transition flight and I'm in the process of writing code and
assembling the parts for that. I also have parts coming for the landing gear. Maybe I'll have some pictures
of progress in the next couple of weeks.
Click here or on the picture to the left to see the latest YouTube video with the electric blades and faster
microcontroller code.
9/25/07
Version 2 of the mixer is done. I tested it today in moderate winds, and it works great. The IR sensor I
added to this version didn't seem to help the stability, so I'll probably just use it to get out of unusual
attitudes in an emergency (provided everything else is working.
The aluminum test rig crashed after about 3 minutes of flight. I'm not sure if it was an ESC that quit, but it
looked like one of the motors stopped. I'll do extensive testing before the next flight. Overall, I'm happy with
the performance of the mixer. I'll tweak and test as necessary as I continue work on the fiberglass
transition model.
I'll probably finalize the design (or as much as I'm going to do) in SolidWorks and start a more dedicated
effort to the fiberglass model. I'll say Christmas will be a good target for transition flight.
Click on the picture to the left or here for a YouTube video of the latest flight.
Version 2 of the mixer is done. I tested it today in moderate winds, and it works great. The IR sensor I
added to this version didn't seem to help the stability, so I'll probably just use it to get out of unusual
attitudes in an emergency (provided everything else is working.
The aluminum test rig crashed after about 3 minutes of flight. I'm not sure if it was an ESC that quit, but it
looked like one of the motors stopped. I'll do extensive testing before the next flight. Overall, I'm happy with
the performance of the mixer. I'll tweak and test as necessary as I continue work on the fiberglass
transition model.
I'll probably finalize the design (or as much as I'm going to do) in SolidWorks and start a more dedicated
effort to the fiberglass model. I'll say Christmas will be a good target for transition flight.
Click on the picture to the left or here for a YouTube video of the latest flight.
12/9/07
Still making progress. Fixed the problem the caused the crash on the last post (the BEC from the ESC
couldn't handle the digital servo). It was really handling good and made quite a few uneventful flights. Then
the yaw gyro crapped out, thankfully while I was on the ground and haven't fixed it yet. Just flying the
simulator to try to keep in practice.
I've been working on the design and the molds and have made some test samples of the materials I plan
on using. I finally think I'll be pulling parts this week. I predict I won't be predicting when I'll be making a
transition flight any more. It won't be Christmas for sure, but progress is being made.
I'll be doing more detailed posts of progress in the RCGroup forums. There's a lot of good information and
helpful people there. I'll still post major milestones here. Check out my Build Log for Quad Tiltrotor here.
The biggest change I've made was going from V tail to T tail. It will be much easier to make and adjust the
horizontal stabilizer during testing. I still may make the V tail at some point in the future.
Keep checking back, hopefully things may go a little faster from here.
Still making progress. Fixed the problem the caused the crash on the last post (the BEC from the ESC
couldn't handle the digital servo). It was really handling good and made quite a few uneventful flights. Then
the yaw gyro crapped out, thankfully while I was on the ground and haven't fixed it yet. Just flying the
simulator to try to keep in practice.
I've been working on the design and the molds and have made some test samples of the materials I plan
on using. I finally think I'll be pulling parts this week. I predict I won't be predicting when I'll be making a
transition flight any more. It won't be Christmas for sure, but progress is being made.
I'll be doing more detailed posts of progress in the RCGroup forums. There's a lot of good information and
helpful people there. I'll still post major milestones here. Check out my Build Log for Quad Tiltrotor here.
The biggest change I've made was going from V tail to T tail. It will be much easier to make and adjust the
horizontal stabilizer during testing. I still may make the V tail at some point in the future.
Keep checking back, hopefully things may go a little faster from here.
