I watched a few videos on sleeving cables, and did a bit of fiddling tonight.
Strider mini quad build log
- Thread starter joshuabardwell
- Start date
PHugger
Church Meal Expert
Did you shorten your cables at all?
I'm almost ready to start down that rabbit hole.
(waiting for parts)
Your sleeving looks good. It becomes an addiction.
What type of shrink tubing did you use?
I've been using the adhesive backed type and it works quite well - no slipping.
Best regards,
PCH
I'm almost ready to start down that rabbit hole.
(waiting for parts)
Your sleeving looks good. It becomes an addiction.
What type of shrink tubing did you use?
I've been using the adhesive backed type and it works quite well - no slipping.
Best regards,
PCH
I did customize the length of this cable. It's a custom cable, with the power lead and a separate, single-pin lead for the video. I used regular shrink tubing since I didn't have any adhesive-backed, but I can see that adhesive-backed would be very good.
I know that some people would find this scandalous, but I decided to put 2mm bullet connectors on my motors/ESCs. This will help as I am working through the options on my first build, and also make it easier to get the braided sleeve on the wires.
My goodness, the braided sleeve really does look nice. FWIW, this is black paracord liner.
My goodness, the braided sleeve really does look nice. FWIW, this is black paracord liner.
Wrapping wires is addictive!
I decided to move the camera mount to the bottom plate to allow removing the top for maintenance more easily. There's a screw hole presumably intended just for this purpose. It is far back enough that the camera is completely inside the frame, but on the flip-side it does limit a little bit how much up-tilt you can put in the camera, before the top plate comes into view. Not sure if this will become an issue or not.
I decided to move the camera mount to the bottom plate to allow removing the top for maintenance more easily. There's a screw hole presumably intended just for this purpose. It is far back enough that the camera is completely inside the frame, but on the flip-side it does limit a little bit how much up-tilt you can put in the camera, before the top plate comes into view. Not sure if this will become an issue or not.
First flight came ... and went.
http://forum.flitetest.com/showthre...quad-build-log&p=191267&viewfull=1#post191267
The FPV camera I'm using can run off of between 5 and 25 volts. I used to run it off of the 5v regulated output from my FatShark vTX. The Strider has a 5v and 12v camera hookup near the front of the frame, so now I have my pick. I did a little testing to see which was better. Which one is better depends a lot on the internal voltage that the camera runs at. If it runs internally at 3.3v (hypothetically) then the lower input voltage I can give it the better, since regulator efficiency goes down as Vin - Vout gets larger. If it runs internally at 12v and has a boost converter, then I'm better off feeding it 12v.
With no camera plugged in, the frame pulled 28 mA. This is just the OSD circuitry. With the camera plugged in to 5v, a total of 153 mA was pulled. With the camera plugged in to 12v, a total of 83 mA was pulled. So there you go. Looks like the camera is running closer to 12v than to 5v, and I'll be using 12v.
With no camera plugged in, the frame pulled 28 mA. This is just the OSD circuitry. With the camera plugged in to 5v, a total of 153 mA was pulled. With the camera plugged in to 12v, a total of 83 mA was pulled. So there you go. Looks like the camera is running closer to 12v than to 5v, and I'll be using 12v.
I got my new ESCs from RTFQuads on Monday, less than a week after ordering, so I have no complaints about this particular customer service experience. There is a known issue with these ESCs and Cleanflight with Oneshot, where the motors "chirp" at zero throttle. This is fixed by setting min_command=1000, max_throttle=2000, then recalibrate ESC's, then set min_command=960.
These ESCs come from RTFQuads pre-flashed with BLHeli 13.1--the latest version. The BLHeli bootloader is pre-installed, so you can flash and configure the ESCs via the signal wire and the BLHeli Suite app. Lovely. The ZTW Spider ESCs I originally chose had no bootloader installed, which would have made flashing them much more difficult. Lesson learned: only bootloader-pre-flashed ESCs for me from now on!
ESCs installed. Signal wires shortened. The product page for the ESCs says they have switching BECs, so I pulled the power pin on three of them.
Motor wires carefully wrapped. It was a huge pain in the butt, but boy it really looks lovely. The arms have holes for a zip tie, which seems like a good idea given how low the props are on these 2204 motors.
I also decided to add a zip tie to the motor wires at the ESC, again, just to secure the wires firmly down against the arm, to keep them from straying too close to the prop.
I want to give credit to Bruce at RCModelReviews for this idea of how to hold up the antennas. Zip ties. Trim to length. Then...
Place the antennas against them and shrink wrap. This holds them up in a good angle for diversity, but still allows them to bend out of the way in a crash. If the angle is not quite 45 degrees, just bend the zip ties a bit.
These ESCs come from RTFQuads pre-flashed with BLHeli 13.1--the latest version. The BLHeli bootloader is pre-installed, so you can flash and configure the ESCs via the signal wire and the BLHeli Suite app. Lovely. The ZTW Spider ESCs I originally chose had no bootloader installed, which would have made flashing them much more difficult. Lesson learned: only bootloader-pre-flashed ESCs for me from now on!
ESCs installed. Signal wires shortened. The product page for the ESCs says they have switching BECs, so I pulled the power pin on three of them.
Motor wires carefully wrapped. It was a huge pain in the butt, but boy it really looks lovely. The arms have holes for a zip tie, which seems like a good idea given how low the props are on these 2204 motors.
I also decided to add a zip tie to the motor wires at the ESC, again, just to secure the wires firmly down against the arm, to keep them from straying too close to the prop.
I want to give credit to Bruce at RCModelReviews for this idea of how to hold up the antennas. Zip ties. Trim to length. Then...
Place the antennas against them and shrink wrap. This holds them up in a good angle for diversity, but still allows them to bend out of the way in a crash. If the angle is not quite 45 degrees, just bend the zip ties a bit.
A few steps not to forget: enable failsafe on the FC; enable failsafe on the receiver. The D4r-II defaults to holding the last received position when the link is lost, which would be problematic if you were climbing when the link was lost.
A brief note: for some reason, Cleanflight doesn't seem to enable Oneshot mode when it's being powered via the USB port. The ESCs give two confirmation beeps when they power on if Oneshot is enabled. Whenever I power the quad with the battery alone, I get both beeps. When I power the quad via USB, I only get one beep. Who knows...
EDIT: The two-beeps was actually a bug and has been fixed. If you have Oneshot enabled in Cleanflight and your ESCs work at all, then Oneshot is working.
A brief note: for some reason, Cleanflight doesn't seem to enable Oneshot mode when it's being powered via the USB port. The ESCs give two confirmation beeps when they power on if Oneshot is enabled. Whenever I power the quad with the battery alone, I get both beeps. When I power the quad via USB, I only get one beep. Who knows...
EDIT: The two-beeps was actually a bug and has been fixed. If you have Oneshot enabled in Cleanflight and your ESCs work at all, then Oneshot is working.
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Maiden number two happened today, with much lower rates. Nothing dramatic happened. Just for kicks, I set looptime=0 on the Naze, which causes the looptime to be as short as possible. Nothing dramatic happened. The system was showing a looptime of about 1300. Since I'm still not 100% sure which PID controller I'm going to end up with, and since some PID controllers are happier with a consistent looptime, I set the looptime to 1600. This is faster than my ESCs' refresh rate, but still has a little head-room to keep the looptime consistent.
The main thing remaining to do is to install the vTX. I'm waiting on an antenna and SMA cable to come from surveilzone for that.
The main thing remaining to do is to install the vTX. I'm waiting on an antenna and SMA cable to come from surveilzone for that.
A couple of extra notes.
While flying today... or more likely during a crash, I lost one of the screws that the arms lock into. These screws come up from the bottom of the quad, into captive nuts in the frame. I thought I had them in there plenty tight, but the results speak for themselves. Anyway, I'm going to put blue Loctite on them to keep from losing them. This may not be the best idea, as it may be necessary to loosen these screws a bit when folding the quad up for travel. But I don't intend to fold the quad very often, and it'll be super annoying to lose those screws constantly.
Speaking of folding: if you go with bullet connectors and if you put sheathing on your motor wires, there is an unfortunate outcome. When you pull the arms out to fold the quad up, or when the arms fold in a crash, the bullet connectors can be pulled apart. I still intend to keep my bullet connectors, but I'm going to open up the sheathing and put a piece of shrink wrap over the connectors to hold them together.
While flying today... or more likely during a crash, I lost one of the screws that the arms lock into. These screws come up from the bottom of the quad, into captive nuts in the frame. I thought I had them in there plenty tight, but the results speak for themselves. Anyway, I'm going to put blue Loctite on them to keep from losing them. This may not be the best idea, as it may be necessary to loosen these screws a bit when folding the quad up for travel. But I don't intend to fold the quad very often, and it'll be super annoying to lose those screws constantly.
Speaking of folding: if you go with bullet connectors and if you put sheathing on your motor wires, there is an unfortunate outcome. When you pull the arms out to fold the quad up, or when the arms fold in a crash, the bullet connectors can be pulled apart. I still intend to keep my bullet connectors, but I'm going to open up the sheathing and put a piece of shrink wrap over the connectors to hold them together.
Here's a video walkthrough of the OSD's menu system. Pardon the weird looking thumbnail--I don't know why it's like that.
The build is getting close to complete. The main thing that is missing is the SMA cable to let me connect my vTX antenna to the hole in the top plate, but for the time being I'm just hanging the antenna off the back of the quad. There is a small risk of the antenna being ripped off in a crash, or falling into the prop, so I do want to get it onto the top plate eventually, but shipping from China is only so fast.
CG in this config is about 1 cm back from the front of the FC. Good enough, and there is plenty of room to shift the battery.
I've decided to remove the sheathing on the motor wires. As nice as it looked, maintainability comes first. I need to be able to get at the connectors. Using velcro like shown above also means that I can remove the zip ties at the ends of the wires, giving more slack to the wires to allow the arms to be folded if desired.
CG in this config is about 1 cm back from the front of the FC. Good enough, and there is plenty of room to shift the battery.
I've decided to remove the sheathing on the motor wires. As nice as it looked, maintainability comes first. I need to be able to get at the connectors. Using velcro like shown above also means that I can remove the zip ties at the ends of the wires, giving more slack to the wires to allow the arms to be folded if desired.
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One more photo of the finished build, this time with the FPV antenna mounted correctly, in flying form.
AUW 566 grams. Basically half the weight of my Electrohub, which starts to explain why I'm getting almost identical flight times (8-9 minutes of hover, 4-5 minutes of thrashing) on batteries that are about half as big!
Regarding tuning, I'm using Cleanflight with PID controller 2, Luxfloat. Pitch PIDs are REDACTED BECAUSE THESE NUMBERS ARE TERRIBLE Roll PIDs are REDACTED I have used a custom mix to compensate for the fact that the motors are slightly closer front-to-back than they are side-to-side. I believe this is why the pitch and roll PIDs are so similar. In case it matters, I'm using looptime=1600, and I have Oneshot and damped light enabled on my ESCs.
The custom mix is:
At this point, I think the build is basically done!
AUW 566 grams. Basically half the weight of my Electrohub, which starts to explain why I'm getting almost identical flight times (8-9 minutes of hover, 4-5 minutes of thrashing) on batteries that are about half as big!
Regarding tuning, I'm using Cleanflight with PID controller 2, Luxfloat. Pitch PIDs are REDACTED BECAUSE THESE NUMBERS ARE TERRIBLE Roll PIDs are REDACTED I have used a custom mix to compensate for the fact that the motors are slightly closer front-to-back than they are side-to-side. I believe this is why the pitch and roll PIDs are so similar. In case it matters, I'm using looptime=1600, and I have Oneshot and damped light enabled on my ESCs.
The custom mix is:
Code:
# cmix
Custom mixer:
Motor Thr Roll Pitch Yaw
#1: 1.000 -1.000 0.750 -1.000
#2: 1.000 -1.000 -0.750 1.000
#3: 1.000 1.000 0.750 1.000
#4: 1.000 1.000 -0.750 -1.000
Sanity check: OK OK OKAt this point, I think the build is basically done!
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Well, it's a good thing I made that post above, because I re-flashed my FC and forgot that configuration backups in cleanflight don't save CLI commands such as motor mixes. In fact, they don't appear to save every single GUI parameter, such as the Mode and Adjustment tabs. So lesson learned: don't use "backup" and "restore". Dump the CLI to a text file.
Here's a video of the Strider in flight. My first ever loops and rolls with a quadcopter.
Here's a video of the Strider in flight. My first ever loops and rolls with a quadcopter.
PHugger
Church Meal Expert
Nice. I looped my Fortis tricopter yesterday on it's maiden flights.
It wasn't exactly intentional though.
It drifted over my head and slightly behind. I got disoriented and it started coming down.
My son was yelling DUCK!
I was starting to panic so I naturally pulled full up elevator......
A short ceremony was held to honor the Titans first sacrifice to the prop-god.
Other than one prop - no other damage.
Best regards,
PCH
It wasn't exactly intentional though.
It drifted over my head and slightly behind. I got disoriented and it started coming down.
My son was yelling DUCK!
I was starting to panic so I naturally pulled full up elevator......
A short ceremony was held to honor the Titans first sacrifice to the prop-god.
Other than one prop - no other damage.
Best regards,
PCH
PHugger
Church Meal Expert
Your Mobius footage is much better than what I was able to capture.
After looking at the horrible dynamic range on my video (any time the sky was visible, the ground was dark) I checked the firmware.
I was still running v1.2. The latest is v2.33 and it has some high dynamic range features that I want to check out.
Best regards,
PCH
After looking at the horrible dynamic range on my video (any time the sky was visible, the ground was dark) I checked the firmware.
I was still running v1.2. The latest is v2.33 and it has some high dynamic range features that I want to check out.
Best regards,
PCH
Two other suggestions for getting the most out of your Mobius are to use the white balance lock feature, and to adjust your picture settings according to this video:
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