Can’t wait for you to analyse the Apex frame. I’ve tried quite a few frames and the Apex seems to be on another level, I can turn a lot of filtering off completely but leave it turned down so I can fly back safely when I bend a prop. It’s also an incredibly tough frame without being super heavy.
The Apex has a secret to it's good performance, I can't wait to share it with you. I think it might be a happy accident but I'll leave it to you to judge! As for weight the Apex is reasonably heavy for a performance 5in frame at 125g so you would expect excellent durability at that weight.
@@ChrisRosser Interesting, I didn’t think the frame was that heavy, I was just looking at my AUW using standard hardware with caddx vista, 2306 motors, GoPro session in tpu mount, 6S battery, the plastic feet and bumper installed along with the thick battery pad and tpu antenna mounts is only around 650 grams. I am using a 20x20 stack though which probably saves some weight. Look forward to your video on the frame.
@@MUNKYFPV The AUW of 650g is pretty good with a GoPro. But even a light frame would only save you 30g or so. The frame isn't a big proportion of the AUW if you run a go pro 😁
Hi Chris, great videos! A breath of fresh air to bring some scientific rigour to the hobby. Would love for you to do a video on the impact of motor material dampening on the frame resonance modes and frequencies. Cheers Nick
I know its a tradeoff! But it really does make the video quite a bit smoother in my experience. If you have a 7in with Jello and you are confident you can stay out of trees this could still be a good option. Where do you fly?
I'm really liking these videos! Great job with how you manage to break it down into something fairly easy to understand. Are those HQ 7x3.5x3 V1S props? I had bad experiences with those, the blades seem to bend up or down easily making it go out of balance. Also the ones I was using had an indent at the hub that not all of the prop nut would screw up against. I just got some HQ 7x4x3 PC I think they were listed as. Pretty sure they are a bit heavier but they seem smother in flight and all have nice straight blades. Speaking of props, there's another interesting test, HQ 7" VS Dal 7" fold. The joints in the fold might help to reduce vibrations? Also they have a pitch of 3 on the blades so they should be able to be run at a higher RPM without too much extra amp draw. If I get the time I'll record blackbox logs of both to see if there is any frequency or amplitude difference.
Good eye Conrad! Yes they are 7x3.5x3 HQ V1S props. I've not had any issues with blades bending but I don't freestyle that drone so I've never crashed it. Still on the first set of props. I've tried DAL folding props and they feel much the same but you are right WE NEED TO APPLY SCIENCE! 😋 I will do a comparison log of floppy props vs HQ V1S and see how it affects vibration. Could make a good video or short, Thanks!
I love this insights on how different design tricks affect the vibration performance. Now the structure is more stiff, can you reclaim extra weight the braces added by narrowing the arms? How arms of variable width respond to the vibrations and resonance? For example thicker at the base and tapering to the ends. What shape would be theoretically more beneficial?
Glad you like the video, have you seen the other ones on my channel? Great thought about narrowing or tapering the arms to reclaim weight. I think narrowing the arms would negatively affect the resonant modes that don't flex the braces. A different design could mitigate that. I've been working on something so stay tuned for a video on that. In terms of the best shape in theory a tapered arm would be best but it would really need to taper in thickness which is not practical with traditional CF plate arms. Some taper in the width could be beneficial but there is a school of thinking that you want the arm to break at the root rather than the tip to minimise the risk of damage to the motor. That thinking would lead you to prefer a rectangular arm.
@@ChrisRosser I've seen all the videos on your channel :) And eager to see more. Considering better frame design have you thought of using square carbon tubes? Square section provides flex rigidity, circular hole reduces the weight while maintaining twisting rigidity. I was thinking about 6x6 profile for A arms or 8x8 for single beam arms. Should be massively lighter and stronger then typical arms
Hi Chris , thanks for the great video. I have 2x GepRc Mark 4 HD6 frames (with custom 5.5mm arms) and one GepRc Mark 2 6" , i use them for comercail work and mid range crusing. I was wondering if you could share the files for the carbon fiber stringers it would be intresting to see difrance in performace on a 6" version of the frame. Keep up the good work :)
I'd be happy to share the files. They are for 7 inch but I'm sure you can modify them. Can you drop me an email (my address is in the about section for the channel)
A hexacopter could be really interesting, thank you for the suggestion! Do you fly this frame? how does it handle? Are you able to source blackbox logs?
@@ChrisRosser I do fly this frame and can absolutely log both bf and inav. It flys great on BF It have it on inav as a long range rig and am still figuring out inav filtering. On inav the center motors get warm if flown hard with alot of filtering. BF with the filtering much reduced they are cool. Would be great if you looked at the logs
@@RubyS.1 Wonderful! If you can send me the betaflight blackbox logs at a 2kHz logging rate with debug mode = gyro_scaled that would be perfect and I'll take a look 😁
Fantastic content. I wonder if changing the center of gravity on a quad (eg, top mount battery vs. mid mount vs. bottom mount) would bear any significance in dealing with vibrations? Personally I really like how mid mount frames (like the Remix) fly, and all those slammed builds, I always assume that putting the battery at the level of the powertrain could reduce the force required to swing that 200g weight thus putting less stress on the carbon. Could you share your thoughts on the relationship, if any, between vibrations and the cog? (I have zero science background so sorry if this sounds like bro science)
Yes you can identify the mode by the frequency. Usually the frequency in the simulation is relatively close to the frequency in the backbox logs (~10%). You can also look at the mode shape and see if it appears to move the flight controller in a way that would be detectable on roll, pitch, or yaw. I find it easier now after having looked at many frames!
@@ChrisRosser so if I see a peak in an axis, I just need to see what frequency and go directly to your mode shapes video and look up the mode I assume? Oh and I'm big fan of your work!
@@marukothekid if you have the same frame absolutely. If you have a different frame then the frequencies may be different but often the mode shapes are similar so you can figure out which is which 😁
I have the same frame GEPRC Mark IV, its very soft and vibrating on pitch axis, i have also stiffen it up but closer to the bottom plate, it's better but not perfect. Emax Eco 2807 1300kV on 4S is perfect but at 6S it;s a drama, motors to powerfull, and frame is bending.
i am sorry but the stringers dont fit a usual GepRc mark4 7". the hole distance in the stringers are wrong. the GepRc mark4 Arms have only 16x16mm holds for the Motors, your stringers are for 16x19mm hole distance. please correct that before more people (Like me) let them CNC milling and Need to rework the Holes to fit the Mark4 Motor Holes. thank you
I don't know what to tell you? They fit both of my frames... The arms for the Mark 4 7inch have 16x16 and 19x19 mounting. They should even fit 16x19mm (but I don't know of any motors with that pattern) I'm sorry to hear that you had problems.
Can’t wait for you to analyse the Apex frame. I’ve tried quite a few frames and the Apex seems to be on another level, I can turn a lot of filtering off completely but leave it turned down so I can fly back safely when I bend a prop. It’s also an incredibly tough frame without being super heavy.
The Apex has a secret to it's good performance, I can't wait to share it with you. I think it might be a happy accident but I'll leave it to you to judge! As for weight the Apex is reasonably heavy for a performance 5in frame at 125g so you would expect excellent durability at that weight.
@@ChrisRosser Interesting, I didn’t think the frame was that heavy, I was just looking at my AUW using standard hardware with caddx vista, 2306 motors, GoPro session in tpu mount, 6S battery, the plastic feet and bumper installed along with the thick battery pad and tpu antenna mounts is only around 650 grams. I am using a 20x20 stack though which probably saves some weight.
Look forward to your video on the frame.
@@MUNKYFPV The AUW of 650g is pretty good with a GoPro. But even a light frame would only save you 30g or so. The frame isn't a big proportion of the AUW if you run a go pro 😁
Get hyped, the Apex video is finished and scheduled to drop tomorrow 5pm my time. 😎
@@MUNKYFPV how the hell do you get 650g auw? mine weights 770g with hero6 in tpu, 1300mah 6s and two strong straps
Hi Chris, great videos! A breath of fresh air to bring some scientific rigour to the hobby. Would love for you to do a video on the impact of motor material dampening on the frame resonance modes and frequencies. Cheers Nick
I'm actually hoping to work on damping with some students in California. Watch this space!
Just discovered your channel, look like a beaut.
no stringers or that quad would never come off a tree. :D
I know its a tradeoff! But it really does make the video quite a bit smoother in my experience. If you have a 7in with Jello and you are confident you can stay out of trees this could still be a good option. Where do you fly?
I just had drone call out the sky and hit a tree. Thank God didn't get stuck
I think FPV shops should sell equipment to climb the trees like lumberjacks do.
This actually helped!
I got jello eliminated on my 6" quad.
I'm really liking these videos! Great job with how you manage to break it down into something fairly easy to understand. Are those HQ 7x3.5x3 V1S props? I had bad experiences with those, the blades seem to bend up or down easily making it go out of balance. Also the ones I was using had an indent at the hub that not all of the prop nut would screw up against. I just got some HQ 7x4x3 PC I think they were listed as. Pretty sure they are a bit heavier but they seem smother in flight and all have nice straight blades. Speaking of props, there's another interesting test, HQ 7" VS Dal 7" fold. The joints in the fold might help to reduce vibrations? Also they have a pitch of 3 on the blades so they should be able to be run at a higher RPM without too much extra amp draw. If I get the time I'll record blackbox logs of both to see if there is any frequency or amplitude difference.
Good eye Conrad! Yes they are 7x3.5x3 HQ V1S props. I've not had any issues with blades bending but I don't freestyle that drone so I've never crashed it. Still on the first set of props. I've tried DAL folding props and they feel much the same but you are right WE NEED TO APPLY SCIENCE! 😋 I will do a comparison log of floppy props vs HQ V1S and see how it affects vibration. Could make a good video or short, Thanks!
I love this insights on how different design tricks affect the vibration performance.
Now the structure is more stiff, can you reclaim extra weight the braces added by narrowing the arms?
How arms of variable width respond to the vibrations and resonance? For example thicker at the base and tapering to the ends. What shape would be theoretically more beneficial?
Glad you like the video, have you seen the other ones on my channel? Great thought about narrowing or tapering the arms to reclaim weight. I think narrowing the arms would negatively affect the resonant modes that don't flex the braces. A different design could mitigate that. I've been working on something so stay tuned for a video on that. In terms of the best shape in theory a tapered arm would be best but it would really need to taper in thickness which is not practical with traditional CF plate arms. Some taper in the width could be beneficial but there is a school of thinking that you want the arm to break at the root rather than the tip to minimise the risk of damage to the motor. That thinking would lead you to prefer a rectangular arm.
@@ChrisRosser I've seen all the videos on your channel :) And eager to see more. Considering better frame design have you thought of using square carbon tubes? Square section provides flex rigidity, circular hole reduces the weight while maintaining twisting rigidity. I was thinking about 6x6 profile for A arms or 8x8 for single beam arms. Should be massively lighter and stronger then typical arms
Can you please analyze the frame design like TBS Source One Aureo? Single plate, but with four strigners
Damn maybe I should add my stringers to my quad. Getting a lot of wobble and drone pitch and roll at full throttle
Hi! Do you have an stl file for the piece you used in the video? I have the same frame and would like to try it :)
Drop me an email and I'll send it to you. Email in the channel about section :D
Now in my resources folder as well: drive.google.com/drive/folders/1md9Vc2l-PnY5jVDQSH7HXB_FSh5z8dr_?usp=sharing
Armattan should make optional stringers
How does adding the stringer in horizontal way affect vibration differently?
Its a great question. I'll be talking about it in a future video. Can't say too much more just yet. Stay tuned!
Hi Chris , thanks for the great video. I have 2x GepRc Mark 4 HD6 frames (with custom 5.5mm arms) and one GepRc Mark 2 6" , i use them for comercail work and mid range crusing. I was wondering if you could share the files for the carbon fiber stringers it would be intresting to see difrance in performace on a 6" version of the frame. Keep up the good work :)
I'd be happy to share the files. They are for 7 inch but I'm sure you can modify them. Can you drop me an email (my address is in the about section for the channel)
@@ChrisRosser Thank you very much 😁
I would be curious to see the fr5. 5 hex. The files are online.
A hexacopter could be really interesting, thank you for the suggestion! Do you fly this frame? how does it handle? Are you able to source blackbox logs?
@@ChrisRosser I do fly this frame and can absolutely log both bf and inav. It flys great on BF It have it on inav as a long range rig and am still figuring out inav filtering. On inav the center motors get warm if flown hard with alot of filtering. BF with the filtering much reduced they are cool. Would be great if you looked at the logs
@@RubyS.1 Wonderful! If you can send me the betaflight blackbox logs at a 2kHz logging rate with debug mode = gyro_scaled that would be perfect and I'll take a look 😁
@@ChrisRosser ok logged a bunch at 2k gyro scaled where do you want me to send it
@@RubyS.1 if you could send it to my email. You can find it in the about section of my channel! Thanks😁
How did you attach the stringers and did you make a video on best way to attach the stringers?
I used longer motor screws.
@@ChrisRosser I got it 👍 that's what I was thinking just wanted to make sure
Fantastic content. I wonder if changing the center of gravity on a quad (eg, top mount battery vs. mid mount vs. bottom mount) would bear any significance in dealing with vibrations? Personally I really like how mid mount frames (like the Remix) fly, and all those slammed builds, I always assume that putting the battery at the level of the powertrain could reduce the force required to swing that 200g weight thus putting less stress on the carbon. Could you share your thoughts on the relationship, if any, between vibrations and the cog? (I have zero science background so sorry if this sounds like bro science)
I've added this to my content list. Thanks for the suggestion.
no props in view in dc arms ? using dji o3 ?
Hi, how do you know which mode is which? Are they frequency specific? Thanks
Yes you can identify the mode by the frequency. Usually the frequency in the simulation is relatively close to the frequency in the backbox logs (~10%). You can also look at the mode shape and see if it appears to move the flight controller in a way that would be detectable on roll, pitch, or yaw. I find it easier now after having looked at many frames!
@@ChrisRosser so if I see a peak in an axis, I just need to see what frequency and go directly to your mode shapes video and look up the mode I assume? Oh and I'm big fan of your work!
@@marukothekid if you have the same frame absolutely. If you have a different frame then the frequencies may be different but often the mode shapes are similar so you can figure out which is which 😁
great job👍🏻when analysis of the hglrc sector5 v3 frame?;)
That frame looks super similar to the iFlight XL5. I hope my video on that frame gives you the info you need!
@@ChrisRosser thnx for your answer chris I will look at it 👍🏻👌🏻
Can you glue in a rubber damper on the frame to eliminate vibrations?
I have the same frame GEPRC Mark IV, its very soft and vibrating on pitch axis, i have also stiffen it up but closer to the bottom plate, it's better but not perfect. Emax Eco 2807 1300kV on 4S is perfect but at 6S it;s a drama, motors to powerfull, and frame is bending.
Sorry to hear that. I hope the video helped!
@@ChrisRosser this vid made me sure in my doubts about the frame. Awesome job!
How would one go about getting some of these stringers? I have a Chimera7 on order.
If you can design the parts you can get them cut by any local CNC machinist who works with carbon fibre. I use CNCMadness.
any preference front back or side to side?
So i guess there is a reason the flywoo lr included stringers
Exactly, they knew their arms were a little bendy on their own!
Hope you team up with Marc Spatz 🤘🏻 @uavtech
I'm in touch with @UAVTech. We share a very scientific approach to quadcopter design and tuning. Kindred spirits!
@@ChrisRosser
Yes and I very much appreciate your approach...
Too much „it feels so good and locked in“ posts by many others 😄
i am sorry but the stringers dont fit a usual GepRc mark4 7". the hole distance in the stringers are wrong. the GepRc mark4 Arms have only 16x16mm holds for the Motors, your stringers are for 16x19mm hole distance.
please correct that before more people (Like me) let them CNC milling and Need to rework the Holes to fit the Mark4 Motor Holes.
thank you
I don't know what to tell you? They fit both of my frames... The arms for the Mark 4 7inch have 16x16 and 19x19 mounting. They should even fit 16x19mm (but I don't know of any motors with that pattern) I'm sorry to hear that you had problems.
@@ChrisRosser No Problem, i Just Open one hole to a Long hole with my dremel to fit the 7" frame. IT works Like this. 👍