Yes about Zenmuse.
I am afraid to maiden my new S800 EVO
- Thread starter Louis O'Dwyer
- Start date
Louis O'Dwyer
Skydiver
Hi Chris,
Finally got the S800 build finished and here is my maiden flight...
I did a little take-off before this one, using the lower gains you suggested, then I used the gains from the manual.
Works really well with those gains. Video a bit wobbly because the gimbal is not working yet with the MC.
Flying it was a pleasure...
http://youtu.be/wv71GnymY5g
Cheers,
Louis
Finally got the S800 build finished and here is my maiden flight...
I did a little take-off before this one, using the lower gains you suggested, then I used the gains from the manual.
Works really well with those gains. Video a bit wobbly because the gimbal is not working yet with the MC.
Flying it was a pleasure...
http://youtu.be/wv71GnymY5g
Cheers,
Louis
Thanks for posting! I think that's the first documented EVO build and maiden flight documented here. Keep us posted as you gain more flight experiences.
Steve
ChrisViperM
Active Member
Hi Lois
I am really glad that all went well.....looked like you S800 didn't let you down.
Just one word of warning: NEVER EVER fly that close to your kid or in low altitude towards your position. If anything goes wrong, you got not even one second to decide what to do next to rcover your copter, judge if the copter will hit or miss you / your kid, and what to do if you realize it's going to hit you....believe me, I know what I am talking about. Kids tend to be very exited if dad spends a lot of time on that flying monster and finally takes it out for the first flights. Even very experienced pilots get hit by surprise if after 20 sucessful flights the copter starts to act weired.......
Just have a bit of reading here:
http://www.thelocal.ch/20130711/remote-control-helicopter-kills-operator-in-lucerne
That guy died by a Single-rotor heli with only 2.5 kg.....you are dealing with 7 kg. The S800 got basically 6 Shuriken blades, each spinning with about 2100 rpm's
http://www.heliguy.com/nexus/dangers.html
Some more SR-heli stuff.....
http://www.multirotorforums.com/showthread.php?2294-look-what-happened-to-Chuck&highlight=stitches
http://www.multirotorforums.com/showthread.php?2888-Lesson-learned-the-hard-way&highlight=stitches
http://www.multirotorforums.com/showthread.php?1207-Ouch!&highlight=stitches
http://www.multirotorforums.com/sho...take-the-props-off-!/page2&highlight=stitches
http://www.multirotorforums.com/showthread.php?9917-I-got-bit-badly&highlight=stitches
Wish you lots of more successful flights...
Chris
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Louis O'Dwyer
Skydiver
Hi Chris,
Thanks for that - you are, of course, quite correct. I need to be more careful/responsible ! ...
Cheers,
Louis
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Hi Louis would be able to tell me if the battery tray assemble from your standard s800 is the same as the new s800 evo or is it different I was trying to go ahead and get the parts I needed in because I am still waiting to get my new s800 evo and didn't want to have to wait on those parts after my new s800 evo finally comes in Thanks for any help Mick
Louis O'Dwyer
Skydiver
Hi Mick,
I got my new S800 EVO a few weeks ago so everything you see on my video is the new S800 EVO. I don't know what the older battery trays look like
Cheers,
Louis
I got my new S800 EVO a few weeks ago so everything you see on my video is the new S800 EVO. I don't know what the older battery trays look like
Cheers,
Louis
Wow Chris, good information. I was just wondering yesterday how many reports of attacks by heli/multi copters. I was thinking this while being close to my hex flying yesterday and then deciding to take some steps back. Would not be happy if it throws a prop or some other malfunction and then heads my way. Ouch!!!!
gottabebrett
Member
Hi Chris, I have been reading through some of your good posts and was wondering if you could help me. I have an S800 EVO + ZENMUSE Z15 and everything on bottom (zenmuse and battery tray, etc) are shaking like crazy as you can see in my video link. I have never balanced the props or motors -- didn't think I needed to (or didn't think the stock props would cause THIS much shaking). One person suggested I try loosening the prop screws so the two props can freely spin true via centripetal force. I am at a loss, all I know is the Zenmuse is shaking so much that the footage is entirely unusable until I figure this out. I recently moved the IMU from the hex frame to the IMU bracket, thinking it would help, and it didn't seem to do anything for the vibrations. Do gains have anything to do with this shaking? I do get white LEDs once in a while, too, but I don't know what they mean. I saw you say LAND IMMEDIATELY. any help would be very helpful. thanks! http://www.youtube.com/watch?v=mc74jWA3ERY&feature=c4-overview&list=UUHzMg_w6HcAPlrpMv2gLLBA
While waiting for input from experienced s800/Z15 pilots here are a few things to consider if you haven't already. Indeed looks like way too much vibration being created during flight, suggesting issues with motor and/or prop balance and possibly with vibration isolation, as you've noted. Also as you've noted, over-tightened prop blade screws could prevent proper blade alignment even at flight rpms. Check for consistent freedom of movement for each blade. Consider removing all blades (sorting into CW and CCW sets, of course). For each set, weigh each of the 6 blades and then pair blades such that differences between blades for each prop are minimized. As part of this exercise, also consider removing or adding weight to individual blades to achieve better balance between the two blades that form each prop. Check freedom of rotation of the motors, any indication of friction or bearing issues?
Also check for horizontal tracking for the blades. I believe CW and CCW motors are set a slight opposing angles. Check for proper canting of the motors relative to the arms. You have two sets (CW and CCW) of 3 arms each arms. Each of the 3 arms within a set should have identically oriented motors (ie angle between motor shaft axis and the horizontal axis of the arm itself).
Not surprised that moving the IMU had little effect as these do not appear to be FC-related effects. The white flashes you've seen likely reflect periods of excessive IMU vibration, despite the demping isolators. Check for proper assembly and vertical alignment of the 6 vibration dampers connecting the arms to the H-frame. Consider using tripod mounted video or some other method to record and monitor the motion of each arm during stable hover to see whether there are anomalies.
While one hopes for a simple or obvious fix, some other questions may be pertinent. Did you fly the s800 EVO previously without the Zen? If so, was vibration an issue prior to the extra weight? If you didn't evaluate flight w/o the Zen, consider whether doing so would be potentially useful in diagnosing the problem.
I hope you get some posts with more helpful things to consider as you've probably already exhausted these. Please let us know how you fare in solving this problem.
Steve
Also check for horizontal tracking for the blades. I believe CW and CCW motors are set a slight opposing angles. Check for proper canting of the motors relative to the arms. You have two sets (CW and CCW) of 3 arms each arms. Each of the 3 arms within a set should have identically oriented motors (ie angle between motor shaft axis and the horizontal axis of the arm itself).
Not surprised that moving the IMU had little effect as these do not appear to be FC-related effects. The white flashes you've seen likely reflect periods of excessive IMU vibration, despite the demping isolators. Check for proper assembly and vertical alignment of the 6 vibration dampers connecting the arms to the H-frame. Consider using tripod mounted video or some other method to record and monitor the motion of each arm during stable hover to see whether there are anomalies.
While one hopes for a simple or obvious fix, some other questions may be pertinent. Did you fly the s800 EVO previously without the Zen? If so, was vibration an issue prior to the extra weight? If you didn't evaluate flight w/o the Zen, consider whether doing so would be potentially useful in diagnosing the problem.
I hope you get some posts with more helpful things to consider as you've probably already exhausted these. Please let us know how you fare in solving this problem.
Steve
gottabebrett
Member
Thanks, Chris. I feel really dumb after reading one of your other posts. Rather than the attention on balancing and other precision corrective actions, I am starting to think I am chasing a vibration issue caused by a rookie configuration oversight on my part: gain values. As you can see in the following chart, DJI gives recommendations. As you will also see, which confused me, is that there is a row for the standard S800 with a Z15 and then a row for the new S800 EVO, but it doesn't mention the Z15. Looking at the weights of the configurations that they have in their chart, I think now I realize that their S800 EVO row is indeed referring to a configuration that does in fact have the Z15 equipped. Before I realized this, I had been using gains that were roughly the middle point between the "S800 + Z15" recommendation and the "S800 EVO" recommendation. So my gains were up in the 200s in some instances. I don't fully understand gains yet, but I think they were too high, and your one description of basic gains seemed to state that once gains get too high, you get vibration. Not to mention, I ignored the DJI instruction to further reduce gains when moving the IMU from the hex base to the IMU bracket (which is underneath the anti-vibration assisting measures). Last night, I reduced my gains down to the S800 EVO recommendations (though I still haven't lowered them even more to account for the new IMU location). While the vibration is still there, it seems to have improved by at least double -- a major improvement. So, I think I'm moving in the right direction; keep lowering gains by 10-15% until vibration disappears completely? View attachment 13873
Attachments
RPInnovationsSG
RP Innovations SG
Any info on the X, Y, Z numbers for setting the IMU and GPS? Tks.
Maybe I'm reading this wrong. If you suspend a MR (or anything else for that matter) from a string and let it come to rest, the line of the string if extended across the MR is guaranteed to pass through the COG. However unless you are certain about a lot of other unspoken assumptions, there is NO guarantee that the point at which this extended straight line crosses the 'center' of the MR will be the COG. However if you repeat the string hanging process hanging the MR from a different point, the extension of the new straight line defined by the string at rest will also pass through the COG. And these two lines will cross at the exact COG. In practice, do this 3 or more times, hanging from different points around the perimeter of the MR and find the point where they all intersect.
To get the right answer with just one line, you would need to have essentially a flat object with a known exact centerline. With a MR, *if* you have perfect left vs right balance along some centerline, that midline defines a plane in which the COG lies. Then the intersection of a single extended line with that plane would locate the COG. I'd still recommend multiple assessments to get the best estimate.
Steve
To get the right answer with just one line, you would need to have essentially a flat object with a known exact centerline. With a MR, *if* you have perfect left vs right balance along some centerline, that midline defines a plane in which the COG lies. Then the intersection of a single extended line with that plane would locate the COG. I'd still recommend multiple assessments to get the best estimate.
Steve
gtranquilla
RadioActive
It's all dead simple once one understands the basic concepts.
1) Laws of physics require that the center or gravity belongs at the center of the MR hub (but only on the horizontal plane)
otherwise you MR motors would not all be able to carry equivalent share of the MR weight which would create undue strain on some of the motors.
Only after this critical 1st step can one expect to enter appropriate values for the x, y, and z values...
The are offset values needed for the FC to understand the x,y,z positions of the various FC components that obviously cannot all be mounted in the one and only COG location.
1) Laws of physics require that the center or gravity belongs at the center of the MR hub (but only on the horizontal plane)
otherwise you MR motors would not all be able to carry equivalent share of the MR weight which would create undue strain on some of the motors.
Only after this critical 1st step can one expect to enter appropriate values for the x, y, and z values...
The are offset values needed for the FC to understand the x,y,z positions of the various FC components that obviously cannot all be mounted in the one and only COG location.