SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Oct 10, 2012, 02:13 PM
Registered User
Joined Aug 2005
238 Posts
[ATTACH]Name: Arm reinforcement-1.jpg
Views: 310
Size: 192.8 KB
Description: [/ATTACH]

The Arm reinforcement that I have done looks like this....
It's great to see all of these ideas to improve those arms with a little more rigidity. But FWIW I decided that anything hung below the arms i.e. tubes etc. can only stiffen the arm in the direction of lift. What we need is to stop the torsional movement. Torsionals are what can move the motor shaft off-axis which will amplify the vibration. So, the stresses that occur during a torsional movement are focussed around the outer surface of the arm, so my solution was to fill the webbings with Loctite 9462 mixed with carbon nano tube fibers. The webbs are only filled about half way from the top surface which is sanded to a smooth surface finish that provides the outer skin which increases the torsional strength quite dramatically without gaining much more than about 10 - 14 grams per arm.

I would say that anyone doing a CFD analysis on the stock arms would find that it focusses most of the torsionals around that waisted area in the middle so that is were most of the strength has been added.
dennyrowland@mac is offline Find More Posts by dennyrowland@mac
Last edited by dennyrowland@mac; Oct 10, 2012 at 02:21 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 10, 2012, 02:15 PM
Registered User
Joined Dec 2011
296 Posts
Quote:
Originally Posted by UAV.Pilot View Post
Ok I'll give it a try next. Thanks

Miza

I have not weighed it as of yet, but the only thing I am flying with is 1x 8000mah 6s battery zip tied to the bottom center. No payload yet.

Im downloading the short vid I just made, it looks like it will be uploaded in about an hour, so you will see how quick it is..
I wanted to add my two cents to any conversation regarding 'usable load' for the S800 as I have been through the wringer on this one. I live and work in Colorado. The elevation that I shoot at can be anywhere from 6,500 ft. msl to 8,500 ft msl. When I first built my S800 I foolishly did so with DJI's maximum weigh of 7 kgs. in mind. I am a pilot and I should have known better as elevation (part of the density altitude equation) is a VERY important factor when performing an accurate 'weight and balance' on any aircraft... including the S800. Imagine my disappointment when I had all sorts of issues with this brand new 7 kg multirotor at a 7,500 foot elevation that just wanted to drop like a rock on a moments notice and refused to fly laterally across the ground. no matter how high the vertical gains were dialed in.

I had to start stripping things off of the craft just to get it off the ground and make it hover efficiently. First to go was one of the two 5,000 mAh lipos. Then I had to eliminate my brand new Canon T2I camera and opt for a new Sony NEX5N at a significantly lower weight. I have a PH AV200 gimbal on board and had to also eliminate the nice twin lipo battery holder that I had fabricated because it became very apparent that every ounce was going to count in the end. Still no FPV or down-link stuff either.

So, if you are going to be shooting at a higher elevation you may want to take this into consideration. I sure wish I had.
rancherpete is offline Find More Posts by rancherpete
Reply With Quote
Old Oct 10, 2012, 02:27 PM
Registered User
Joined Dec 2011
296 Posts
Quote:
Originally Posted by dennyrowland@mac View Post
[ATTACH]Attachment 5220824[/ATTACH]

The Arm reinforcement that I have done looks like this....
It's great to see all of these ideas to improve those arms with a little more rigidity. But FWIW I decided that anything hung below the arms i.e. tubes etc. can only stiffen the arm in the direction of lift. What we need is to stop the torsional movement. Torsionals are what can move the motor shaft off-axis which will amplify the vibration. So, the stresses that occur during a torsional movement are focussed around the outer surface of the arm, so my solution was to fill the webbings with Loctite 9462 mixed with carbon nano tube fibers. The webbs are only filled about half way from the top surface which is sanded to a smooth surface finish that provides the outer skin which increases the torsional strength quite dramatically without gaining much more than about 10 - 14 grams per arm.

I would say that anyone doing a CFD analysis on the stock arms would find that it focusses most of the torsionals around that waisted area in the middle so that is were most of the strength has been added.
This is a great idea. I had thought about filling in those little voids too for the reasons you mentioned but was not sure what material to use so I just tried it with the 16mm tubes and silicone as I explained earlier. I just came in from a brief real estate shoot (video only this time) and while I do see a huge improvement over the original setup it could certainly be better. I am using an AV200 and Sony Nex5N 16MM and I think that unless a person has a Zenmuse this S800 is not delivering very smooth video at all. I have agonized over ways to improve it but I'm far from satisfied with it. Fortunately the Warp Stabilizer feature of Adobe Premiere Pro goes a long way to help out in this area.
rancherpete is offline Find More Posts by rancherpete
Reply With Quote
Old Oct 10, 2012, 02:30 PM
Registered User
Joined Apr 2012
483 Posts
Quote:
Originally Posted by rancherpete View Post
I wanted to add my two cents to any conversation regarding 'usable load' for the S800 as I have been through the wringer on this one. I live and work in Colorado. The elevation that I shoot at can be anywhere from 6,500 ft. msl to 8,500 ft msl. When I first built my S800 I foolishly did so with DJI's maximum weigh of 7 kgs. in mind. I am a pilot and I should have known better as elevation (part of the density altitude equation) is a VERY important factor when performing an accurate 'weight and balance' on any aircraft... including the S800. Imagine my disappointment when I had all sorts of issues with this brand new 7 kg multirotor at a 7,500 foot elevation that just wanted to drop like a rock on a moments notice and refused to fly laterally across the ground. no matter how high the vertical gains were dialed in.
.
I think its important for a professional system to have actually tested and documented limits and specifications. Any approvals to fly this system professionally will require manufacturers limits and specifications, does DJI understand this??. I will need to submit all this to the aviation authorities before they will allow me to use this for professional photography. This includes such things as electrical systems and filtering and electrical interference issues.
Where Can I find such information, it's not in the manuals.
flyingbiscuit1 is online now Find More Posts by flyingbiscuit1
Reply With Quote
Old Oct 10, 2012, 02:35 PM
Registered User
Joined Dec 2011
296 Posts
Quote:
Originally Posted by flyingbiscuit1 View Post
I think its important for a professional system to have actually tested and documented limits and specifications. Any approvals to fly this system professionally will require manufacturers limits and specifications, does DJI understand this??. I will need to submit all this to the aviation authorities before they will allow me to use this for professional photography. This includes such things as electrical systems and filtering and electrical interference issues.
Where Can I find such information, it's not in the manuals.
I am sorry that I can't help you with any of this. I am always amazed at how little info is provided with most of this stuff. It just seems to be a huge guessing game that could be made so much easier if someone would sit down and take the time to offer up some details... like; "usable load and a given elevation" and plenty of other things that they don't mention.
rancherpete is offline Find More Posts by rancherpete
Reply With Quote
Old Oct 10, 2012, 02:58 PM
Registered User
Joined Sep 2012
275 Posts
[QUOTE=flyingbiscuit1;22964662]I think its important for a professional system to have actually tested and documented limits and specifications. Any approvals to fly this system professionally will require manufacturers limits and specifications, does DJI understand this??. I will need to submit all this to the aviation authorities before they will allow me to use this for professional photography. This includes such things as electrical systems and filtering and electrical interference issues.
Where Can I find such information, it's not in the manuals.

rancherpete
I am sorry that I can't help you with any of this. I am always amazed at how little info is provided with most of this stuff. It just seems to be a huge guessing game that could be made so much easier if someone would sit down and take the time to offer up some details... like; "usable load and a given elevation" and plenty of other things that they don't mention./QUOTE]

++1

Very true statement, all of the Professional Mil Spec. Systems I have operated have had a manual containing Flight Envelops ext...High Altitudes are an eye opener for sure, last year 2011 I flew from 7800 msl in the mountains of Afghan. our aircraft suffered performance tremendously, but so long as we flew by the numbers it "would" do our missions...
these models fly great at sea level, not so in the thinner air
UAV.Pilot is offline Find More Posts by UAV.Pilot
Reply With Quote
Old Oct 10, 2012, 03:10 PM
Registered User
Namibia, Khomas, Windhoek
Joined Jul 2012
181 Posts
@rancherpete... your story reads like an exact copy of my experience. My S800 is still on the ground with lots of cash spent and not a single usable video frame. I have now downgraded to an NEX5 camera (arriving soon) in the hope of getting some (sub broadcast standard) footage. Currently it's just a pile of CF junk. and I might as well throw the fatshark goggles also into the trash can since the nex5 only has HDMI out. What a disappointment!
Better to spend some cash on a case of beer and drink this nightmare away?
Sorry for rant but I'm just (currently) frustrated.
Chilli Paste is offline Find More Posts by Chilli Paste
Reply With Quote
Old Oct 10, 2012, 03:23 PM
Registered User
Joined Dec 2011
296 Posts
Quote:
Originally Posted by Chilli Paste View Post
@rancherpete... your story reads like an exact copy of my experience. My S800 is still on the ground with lots of cash spent and not a single usable video frame. I have now downgraded to an NEX5 camera (arriving soon) in the hope of getting some (sub broadcast standard) footage. Currently it's just a pile of CF junk. and I might as well throw the fatshark goggles also into the trash can since the nex5 only has HDMI out. What a disappointment!
Better to spend some cash on a case of beer and drink this nightmare away?
Sorry for rant but I'm just (currently) frustrated.
I am sorry to hear that you have had the same frustrating experience. I have spent so many months trying to make something useable out of this thing I just can't tell you. Luckily I got in on the pre-purchase at roughly a grand so I can live with it but it will never be a professional rig by any means. You may want to set your sights on something else and use this one for the high risk stuff like over water, rocky terrain, etc. That is what I am going to do. Good luck! By the way: The nex5N is a fantastic little camera so I'm sure that it will grow on you. I love mine... even though I did not want to have to buy one.
rancherpete is offline Find More Posts by rancherpete
Reply With Quote
Old Oct 10, 2012, 03:34 PM
Registered User
Namibia, Khomas, Windhoek
Joined Jul 2012
181 Posts
Quote:
Originally Posted by rancherpete View Post
You may want to set your sights on something else and use this one for the high risk stuff ....
"high risk stuff" no need for cliffs & water... just the mere thought of flying the S800 is "high risk stuff" ?

Unfortunately I've spent too much on this rig and it does not deliver what it is advertised to do. I might string a gopro to a kite and get better results.

I really hope I can report back in a few days with better news.
Chilli Paste is offline Find More Posts by Chilli Paste
Reply With Quote
Old Oct 10, 2012, 03:39 PM
Registered User
Joined Sep 2012
275 Posts
Quote:
Originally Posted by Chilli Paste View Post
@rancherpete... your story reads like an exact copy of my experience. My S800 is still on the ground with lots of cash spent and not a single usable video frame. I have now downgraded to an NEX5 camera (arriving soon) in the hope of getting some (sub broadcast standard) footage. Currently it's just a pile of CF junk. and I might as well throw the fatshark goggles also into the trash can since the nex5 only has HDMI out. What a disappointment!
Better to spend some cash on a case of beer and drink this nightmare away?
Sorry for rant but I'm just (currently) frustrated.
Chilli Paste, dont get discouraged just yet, here is what I can offer you in the way of advise.

The Nex5N may be a small camera but I assure you, you will be able to get some good results from this little Gem...just think for a second of how many reality shows are filmed with the use of GoPro's...the Nex5N is IMO better than the GoPro...

Just down size your battery to maybe 1x 8000 mah pack and add the miniHDMI to composite Video and you will have FPV through your Nex...you can pick these converters up through various places.

Props might be something to be considering at this point...but I really think you can get your S800 to fly up to 8000 msl...

You might have to sacrifice all the goodies, but if you lighten yours up, you should be able to use it...

Or just sell it and try something else...your choice.

Me personally, I will always keep on hand my 2x 800e's for the real work...at least until I get a few things worked out...

Good luck!
UAV.Pilot is offline Find More Posts by UAV.Pilot
Reply With Quote
Old Oct 10, 2012, 03:41 PM
Registered User
Joined Dec 2011
296 Posts
Quote:
Originally Posted by Chilli Paste View Post
"high risk stuff" no need for cliffs & water... just the mere thought of flying the S800 is "high risk stuff" ?

Unfortunately I've spent too much on this rig and it does not deliver what it is advertised to do. I might string a gopro to a kite and get better results.

I really hope I can report back in a few days with better news.
Did you see my earlier post about adding the carbon fiber tubes beneath the S800 arms? This helps a great deal. Also: be sure to balance the crap out of the S800 CF props. They can be way off! If you are not using the DJI Zenmuse gimbal then you will also have to come up with some pretty slick silicone dampening system for your gimbal. I have built several of these and they have all worked perfectly for VERY smooth video on my other multirotors but this S800 has a sh**load of vibration that just just won't go away. As I said earlier; if not for Adobe Premiere and Warp Stabilizer in post production I would not have anything that would be useable from this craft for video. Still sare another story as long as you can shoot at a very high shutter speed.
rancherpete is offline Find More Posts by rancherpete
Reply With Quote
Old Oct 10, 2012, 03:51 PM
Registered User
Joined Dec 2011
296 Posts
Quote:
Originally Posted by UAV.Pilot View Post
Chilli Paste, dont get discouraged just yet, here is what I can offer you in the way of advise.

The Nex5N may be a small camera but I assure you, you will be able to get some good results from this little Gem...just think for a second of how many reality shows are filmed with the use of GoPro's...the Nex5N is IMO better than the GoPro...

Just down size your battery to maybe 1x 8000 mah pack and add the miniHDMI to composite Video and you will have FPV through your Nex...you can pick these converters up through various places.

Props might be something to be considering at this point...but I really think you can get your S800 to fly up to 8000 msl...

You might have to sacrifice all the goodies, but if you lighten yours up, you should be able to use it...

Or just sell it and try something else...your choice.

Me personally, I will always keep on hand my 2x 800e's for the real work...at least until I get a few things worked out...

Good luck!
He's right. You can get this to do some work for you and as I said; the NEX5N will be a pleasant surprise for you. No comparison to a GoPro2 by the way. Far superior in my opinion and I have both. I get GREAT video from it and even the stills in RAW are very good too. I ordered an Intervalometer from James at "Gentled" and it works great for the NEX5N. I set it for a short interval (like 2-4 seconds) and it does an amazing job. Digital film is free and I learned a while back that using the intervalometer works better for me than a trigger for each shot (I have one of those too). But this way I always get stuff that I might not otherwise have gotten.
rancherpete is offline Find More Posts by rancherpete
Reply With Quote
Old Oct 10, 2012, 03:52 PM
Registered User
Namibia, Khomas, Windhoek
Joined Jul 2012
181 Posts
Thank you UAV.Pilot for the words of encouragement. I really appreciate it.
For reality shows yes I do agree that the gopro will suffice but for documentary film making... well maybe I'm just spoiled with the XF300 & 7D. (had the XF100 on the rig as well)
I'm getting 6 minutes of flying time out of 10 000 mAh (2x Hyperion 5k). And for getting any kind of spare parts or HDMI converters in this country? LOL Drive 2000 miles to the next possible shop or be prepared to wait eons for something like that. Batteries are even more of a nightmare to get. Prohibitively expensive and not available on the African continent (i.e. 8000 mAh etc).

But I will continue my (our) quest and hope that I (we) can get a return on my (our) investment.
Chilli Paste is offline Find More Posts by Chilli Paste
Reply With Quote
Old Oct 10, 2012, 04:20 PM
jab
Unregistered User
Joined Aug 2007
1,081 Posts
Quote:
Originally Posted by Chilli Paste View Post
... well maybe I'm just spoiled with the XF300 & 7D. (had the XF100 on the rig as well)
As mentioned, the NEX5 will surprise you. Don't let the small body size and compact camera look fool you. It actually has a slightly larger sensor then the 7D you mentioned. The standard 16mm lens used together with the Z-15 gimbal is a bit soft, but I hear good things about the 19mm Sigma lens (not tested myself yet).
jab is offline Find More Posts by jab
Reply With Quote
Old Oct 10, 2012, 04:23 PM
Registered User
Namibia, Khomas, Windhoek
Joined Jul 2012
181 Posts
Quote:
Originally Posted by rancherpete View Post
Did you see my earlier post about adding the carbon fiber tubes beneath the S800 arms? This helps a great deal. Also: be sure to balance the crap out of the S800 CF props. They can be way off! If you are not using the DJI Zenmuse gimbal then you will also have to come up with some pretty slick silicone dampening system for your gimbal. I have built several of these and they have all worked perfectly for VERY smooth video on my other multirotors but this S800 has a sh**load of vibration that just just won't go away. As I said earlier; if not for Adobe Premiere and Warp Stabilizer in post production I would not have anything that would be useable from this craft for video. Still sare another story as long as you can shoot at a very high shutter speed.
Sorry rancherpete, I didn'nt spot your post earlier. But yes, I read each and every post in the last few weeks and actually bought some CF "arrows" (from the local bow shop). That's as close to CF what I can get. I'll fit them to the arms over the weekend and in conjunction with the NEX5 I really hope to report back with positive news. again many thanks for the great posts. You guys rock!
Chilli Paste is offline Find More Posts by Chilli Paste
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion My DJI Spreading Wings S800 just came in the mail and I think I'm in trouble jasper7821 Multirotor Talk 219 Oct 16, 2012 05:11 PM
New Product DJI Spreading Wings S-800 Hexa multi-rotor sidneyw Multirotor Talk 930 Jun 22, 2012 10:14 AM
Discussion DJI Spread Wings S800 and Zenmuse Z15 prices are out! tpnitro Multirotor Talk 120 Jun 19, 2012 01:27 AM
Discussion DJI S800 Spreading Wings has landed at Quadcopters UK Headquarters QuadcoptersUk Multirotor Talk 8 May 14, 2012 01:27 PM
Discussion Dji Spreading Wings (S800) coming Huluhulu Multirotor Talk 7 Apr 27, 2012 03:11 AM