Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Mar 06, 2013, 11:27 PM
Will fly for food
ilektron's Avatar
United States, CA, Carlsbad
Joined May 2011
532 Posts
I've stalled in my efforts to parallelize my sim to get it to generate a large number of plots that I can compile into a video to illustrate a change in a single parameter and the effects it on a range of PID values.

An example datapoint is included. The vertical axis is the sensitivity of the modeled system. According to Octave, a good value is between 1.3 and 2. In this particular series I was varying controller delay. Any place where it 0, the system is unstable.

I threw in a sample step response and a 2d plot of the 3d data
ilektron is offline Find More Posts by ilektron
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 06, 2013, 11:31 PM
Registered User
--Oz--'s Avatar
United States, CA, Costa Mesa
Joined Mar 2006
1,888 Posts
The guys pylon racing where using the DJI Flamewheel 330mm, one guy also had both 330mm and 450mm with exactly the same flight gear (DJI motors/ESC/4s-battery/KK2), he tells me the weight is basically the same within a few percent (just the plastic arms are a little longer) and the DJI 450mm does not have a chance against the 330mm from his experience.

I almost bought the Armattan CNC 258 (mm)
http://i10.photobucket.com/albums/a1...n/IMAG0087.jpg

But seeing pictures posted in the thread "Show Us Your Scratchbuilt Multirotors", building a quad is quite simple, and I had the 4 motors/ESC's and was waiting for HK to ship my F330 frames, until CNY was causing a delay, so a band saw / drill press / couple beers and 30 minutes later I have a frame (sorry it costs a little more than $18 )

I want to try the Gorilla glue and white glue mix, sounds like the results (weight & strength) are pretty good, what ratio should I start with?

What post number has all the latest $18 quad parts list? (I am in too many threads/forums and to old to remember, lol)

I started quads with the Syma X1 ($35 from Amazon), it's very stable, tough and it taught me how to fly a quad, then i built my own, but I would like a small version like the $18 quad in this thread. My main concerns are the motors failing after a few weeks of 6-8 batteries a night (9 minute flights) and it's too stable and less agile (do to FW in the FC). So my two questions are, what is the best FC for stunts and best motors for longevity?

Sorry for so many questions, thanks in advance.
--Oz-- is offline Find More Posts by --Oz--
Reply With Quote
Old Mar 07, 2013, 06:55 AM
Registered User
LittleMo's Avatar
United States, VA
Joined Dec 2006
1,480 Posts
Quote:
Originally Posted by --Oz-- View Post
I want to try the Gorilla glue and white glue mix, sounds like the results (weight & strength) are pretty good, what ratio should I start with?
Dave can correct me but I personally found that the stuff I mixed up was always more brittle with the white glue in it. I tried a bunch of different mixture ratios. Maybe my white glue is no good.

I have been using straight PU glue. Just stirring the glue for a little bit in the open air (as if you were mixing epoxy or whatever) will make it foam pretty good if there is any humidity at all. If I want a lot of foam with large bubbles then I mix in a very tiny amount of water.
LittleMo is offline Find More Posts by LittleMo
Reply With Quote
Old Mar 07, 2013, 10:55 AM
RC beginner
New York
Joined Oct 2008
5,912 Posts
its true that pu gets harder as the days go by but personally dont consider it gets brittle. and dont notice any difference between straight and foam there. the foam does set MUCH faster and weighs a LOT less so thats the way i go. note that the only difference between water and white glue is the glue is easier to mix (shear mixing). its the water in the glue that does the trick, no other magic ingredients.

straight is somewhat stronger than foaming it so good idea to use it straight in places like the hub. i dont see much problem with using it everywhere else though.
dave1993 is offline Find More Posts by dave1993
Reply With Quote
Old Mar 07, 2013, 03:26 PM
Registered User
Israel
Joined Mar 2012
422 Posts
Regarding glues:
I found that the PU glue is very good for gluing wood to wood but when it came to gluing the paper tubes to wood I found that it broke pretty easily (1-2 crashes).
Now I am using hot glue for the paper tubes and nothing breaks it - no matter how hard I crash.

I have been having some issues with lift on my quad. I used tongue depressors for the frame which are pretty sturdy. The quad takes off ok but lowers to the ground after 5-10 seconds - even at full throttle. After I zero the throttle, it would take off again and lose altitude in the same manner. I am using Turnigy 260mah 35-70C batteries and my quad weighs 39.7g with battery.
Is my quad too heavy?
gilcd85 is offline Find More Posts by gilcd85
RCG Plus Member
Latest blog entry: Bixler FPV into the sunset
Reply With Quote
Old Mar 07, 2013, 05:01 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,384 Posts
Hi G,
What motors and props are you using? It sounds like it could be a combination of low Kv motors the weaker UDI props and the 40g AUW of your micro. Most micros weigh about 30g with lipo and can only comfortably lift about 8g and still have any performance and flight time.
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index
Quote:
Originally Posted by gilcd85 View Post
Regarding glues:
I found that the PU glue is very good for gluing wood to wood but when it came to gluing the paper tubes to wood I found that it broke pretty easily (1-2 crashes).
Now I am using hot glue for the paper tubes and nothing breaks it - no matter how hard I crash.

I have been having some issues with lift on my quad. I used tongue depressors for the frame which are pretty sturdy. The quad takes off ok but lowers to the ground after 5-10 seconds - even at full throttle. After I zero the throttle, it would take off again and lose altitude in the same manner. I am using Turnigy 260mah 35-70C batteries and my quad weighs 39.7g with battery.
Is my quad too heavy?
jesolins is offline Find More Posts by jesolins
Reply With Quote
Old Mar 07, 2013, 05:49 PM
Registered User
Israel
Joined Mar 2012
422 Posts
Thanks jesolins, I am using LB motors and props. These were considered the strongest I thought.. Maybe I need to build another frame from bamboo sticks and give it another try..



Quote:
Originally Posted by jesolins View Post
Hi G,
What motors and props are you using? It sounds like it could be a combination of low Kv motors the weaker UDI props and the 40g AUW of your micro. Most micros weigh about 30g with lipo and can only comfortably lift about 8g and still have any performance and flight time.
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index
gilcd85 is offline Find More Posts by gilcd85
RCG Plus Member
Latest blog entry: Bixler FPV into the sunset
Reply With Quote
Old Mar 07, 2013, 08:13 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,384 Posts
Hi G,
Yes those are fine and among he best performers in the micro quad arena.
The Walkera QR Ladybird weighs in at 25g minus the 8g lipo. Try to beat that total weight and you will be fine.
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index

Quote:
Originally Posted by gilcd85 View Post
Thanks jesolins, I am using LB motors and props. These were considered the strongest I thought.. Maybe I need to build another frame from bamboo sticks and give it another try..
jesolins is offline Find More Posts by jesolins
Reply With Quote
Old Mar 08, 2013, 06:10 AM
Registered User
Israel
Joined Mar 2012
422 Posts
ok. I am giving it another shot with a bamboo frame.
Thanks jesolins!
gilcd85 is offline Find More Posts by gilcd85
RCG Plus Member
Latest blog entry: Bixler FPV into the sunset
Reply With Quote
Old Mar 08, 2013, 06:19 AM
Registered User
Joined Aug 2011
219 Posts
Ive built a hybrid with the v939 frame but when flying it I notice that it loses altitude/power after a quite fast banked turn. Is it the lipo that cant deliver the power (too low c-rating)?
xardinen is offline Find More Posts by xardinen
Reply With Quote
Old Mar 08, 2013, 04:07 PM
Registered User
Ad_Astra's Avatar
Joined Dec 2012
308 Posts
Quote:
Originally Posted by ilektron View Post
I've stalled in my efforts to parallelize my sim to get it to generate a large number of plots that I can compile into a video to illustrate a change in a single parameter and the effects it on a range of PID values.
Wow, what an ambitious approach. Are you going to write this up in more detail, perhaps make the sim source code public? I'd like to play with something like this, if it's not too difficult to use.
Ad_Astra is offline Find More Posts by Ad_Astra
Reply With Quote
Old Mar 08, 2013, 04:28 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,384 Posts
Hi X,
Well that and the original V939 lipos if you are using those, were the poorest performers in my lipo tests:
--Micro quad OEM and Turnigy Nano-Tech lipo tests 101
Cheers,
Jim
Quadrocopter and Tricopter Info Mega Link Index
Quote:
Originally Posted by xardinen View Post
Ive built a hybrid with the v939 frame but when flying it I notice that it loses altitude/power after a quite fast banked turn. Is it the lipo that cant deliver the power (too low c-rating)?
jesolins is offline Find More Posts by jesolins
Reply With Quote
Old Mar 08, 2013, 05:03 PM
RC beginner
New York
Joined Oct 2008
5,912 Posts
actually the stock lipos did a great job when i first started builing these last summer. a month or so back those same cells behaved pretty poorly. kinda like you guys are describing. im not sure if its the cold temperature or they are wearing out. probably a combination of both. i did get over a hundred flights out of those original batteries so cant complain. when i swapped out with the nano-tech 70c (yeah...right!) that quad really came back to life again. for a buck ea i definitely cant complain there either.
dave1993 is offline Find More Posts by dave1993
Reply With Quote
Old Mar 08, 2013, 05:06 PM
Registered User
LittleMo's Avatar
United States, VA
Joined Dec 2006
1,480 Posts
Quote:
Originally Posted by jesolins View Post
Hi X,
Well that and the original V939 lipos if you are using those, were the poorest performers in my lipo tests:
Those UDI batteries seem nice. I can't find them at BG. They have a 240 mah battery for around $3 though.

Do you know how physically wide those batteries are?
LittleMo is offline Find More Posts by LittleMo
Reply With Quote
Old Mar 08, 2013, 05:27 PM
Fly Fast, Fly Hard, Fly Fun
rexless's Avatar
Canada, BC
Joined Apr 2012
1,425 Posts
Quote:
Originally Posted by --Oz-- View Post
I almost bought the Armattan CNC 258 (mm)
http://i10.photobucket.com/albums/a1...n/IMAG0087.jpg

But seeing pictures posted in the thread "Show Us Your Scratchbuilt Multirotors", building a quad is quite simple, and I had the 4 motors/ESC's and was waiting for HK to ship my F330 frames, until CNY was causing a delay, so a band saw / drill press / couple beers and 30 minutes later I have a frame (sorry it costs a little more than $18 )

I want to try the Gorilla glue and white glue mix, sounds like the results (weight & strength) are pretty good, what ratio should I start with?

What post number has all the latest $18 quad parts list? (I am in too many threads/forums and to old to remember, lol)

I started quads with the Syma X1 ($35 from Amazon), it's very stable, tough and it taught me how to fly a quad, then i built my own, but I would like a small version like the $18 quad in this thread. My main concerns are the motors failing after a few weeks of 6-8 batteries a night (9 minute flights) and it's too stable and less agile (do to FW in the FC). So my two questions are, what is the best FC for stunts and best motors for longevity?
Nice job on the very inexpensive quad build!! I started on the V929 but rarely fly it anymore. I got sick of the arms twisting on me.

I'm in the Armattan camp - I'm on my third one now and I'm very happy with them. The first one was built for me by Chris. The second I ordered the DIY kit and assembled it myself. The third I just bought the M Frame and sourced my own parts. I would recommend these to anyone - I love flying them. I think I'm going to build a CNC 258 as my main acrobatic quad. I like the Armattan frames as they're really strong.

Anyway, I've also ordered a cheap plastic 450 frame off of banggood so I can build one up from there. I'm really a fan of the KK2 - but I think I'll try a multiwii on the plastic 450 and see what it's like in comparison. Most guys I've talked to say the KK2 is great for acrobatics, starters, etc. I'm an aggressive beginner planning to work into acrobatics this year and I think the KK2 will do the job.

My other desire is for FPV. If hobby king ever gets their FPV kits back in stock I'll pick one up and try it out. For that I might use the multiwii pro so I can try everything (GPS, barometer, magnetometer, programmable flights).
rexless is offline Find More Posts by rexless
RCG Plus Member
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Lets Build a DIY FPV Spider Quad Together Nick_P Scratchbuilt Multirotors 171 Jun 23, 2014 12:18 PM
Sold DIY Open Pilot CC micro/mini quad BNF for sale Hamanu Aircraft - Electric - Multirotor (FS/W) 4 Aug 03, 2012 07:29 PM
Discussion Any good premade DIY Centre plate for AP Quad? redblur Multirotor Talk 2 Jun 24, 2012 08:10 PM
Discussion DIY Quad Frame hits snafu... srs5150 Multirotor Talk 5 Apr 30, 2012 10:46 AM
Discussion Looking for a good DIY guide for a 450 sized Quad nige838 Multirotor Talk 2 Apr 28, 2012 02:44 AM