New source for UAVP components- UAVP Info thread - Page 39 - RC Groups
Thread Tools
Jul 20, 2008, 05:46 PM
13brv3's Avatar
Quote:
Originally Posted by simonjardine
No Jim, i was not teasing you with those battery prices, just keep a eye on that Ebay store, most the time no one bids. Which means it is yours for the taking. I am pretty sure Rusty just bought ten of them. So no bidding whilst he is around.
I bought batteries from Hobby City, but I can verify that Simon did in fact buy his at the price he said. He sent me the link a few weeks ago.

Quote:
Originally Posted by simonjardine
Rusty the motor mounts are so light they are invisible. I just placed the booms into my vice and cranked hard, 3 nuts and bolts. I bet you were scratching your head, thinking is Simon Exaggerating?
I thought that's what I saw in the video. As an aluminum aircraft builder, squishing a tube like that violates my senses but if I don't have to ride in it, I suppose it's OK

Quote:
Originally Posted by simonjardine

I will be trying out the 12's today, I also have the DF 12's. I will also be trying the 1050 3 blade Props. Today is FPV, should have some video up in a matter of hours for your pleasure.
I'll look forward to the video. I notice that MPI has a note that the props will be shipping on the 30th now. I hope that's for new orders, not for people who already had theirs in. I've run into a few snags while trying to perfect my motor testing setup, so it's just as well.

A cool ESC is a happy ESC. More later...

Rusty
Sign up now
to remove ads between posts
Jul 20, 2008, 06:50 PM
Registered User
Old Man Mike's Avatar
Quote:
Originally Posted by simonjardine
Morning Old Man Mike, .... I have been watching more of your movies Mike, you are our leader.
Great Work. Really well done, 1200feet! Your FPV flying is wickedly good. Are you using a stock 2.4 receiver?
Simon
Thanks, Simon!

There may be some confusion about what I am flying. Although I have both UAVP and Spectrolutions based quads, all my FPV flying demos are with the Spectrolutions (Documented in Kquad thread) controller. While I have flown the UAVP in FPV, I just don't feel as comfortable flying it. I know that it is more a matter of experience than one having better performance.

As for the 2.4 Ghz R/C, I am using my RX converter board (that Rusty now sells) to allow the Futaba FASST system to work with the Spectrolutions controller. Aside from that, it is the stock Futaba system.

OMM
Jul 20, 2008, 07:46 PM
MultiRotor Jedi
simonjardine's Avatar
[QUOTE=Old Man Mike]Thanks, Simon!

There may be some confusion about what I am flying. Although I have both UAVP and Spectrolutions based quads, all my FPV flying demos are with the Spectrolutions (Documented in Kquad thread) controller.

You are using a Spectolutions board? Why? How come you dont use the UAVP?
My understanding was the DF brushless board was like a toy?
Obvioulsy not if you are taking it up to 1200 feet!

What do you think of the board? Is it as stable as my UAVP? Would you recommend one? You got me thinking now..

Simon
Jul 20, 2008, 07:56 PM
Tri-Quad-Hexa-Octo-copters!!
Here Simon, you'll see part of the quad journey we have been on with the Experimental brushless DF V1 & V2: https://www.rcgroups.com/forums/showthread.php?t=768115
Cheers,
Jim
Jul 21, 2008, 05:39 AM
Registered User
Old Man Mike's Avatar
Quote:
Originally Posted by simonjardine
You are using a Spectolutions board? Why? How come you dont use the UAVP?
My understanding was the DF brushless board was like a toy?
Obvioulsy not if you are taking it up to 1200 feet!

What do you think of the board? Is it as stable as my UAVP? Would you recommend one? You got me thinking now..

Simon
Simon,

The quad I and others have built based on the Spectrolution board perform well beyond the original DF quads. As Jesolins noted, we have a very long thread where the evolution has taken place. There are other threads where the performance of the three primarly quad designs have been discussed. This is a recent one:

https://www.rcgroups.com/forums/show...84#post9923573

Rather than distracting from the UAVP focus of this thread, I'll leave it at that.

OMM
Jul 21, 2008, 07:38 AM
Registered User
for the uavp board, what is the diff. between ppm and normal.?
I would be useing a berg7p not too sure how to mod it, so would I need normal for the programming/ also I can changed this in the future if I want.?

I think I read to the point of confusion.
Jul 21, 2008, 09:04 AM
gke
gke
Registered User

Param Tuning


Quote:
Originally Posted by 13brv3
Greg,

I took a quick look at this today, and immediately realized that I'm not sure what you're calling oscillation. If you mean the point where the UAVP continuously oscillates, then that would be way up there around -90. If you mean a few oscillations after being disrupted, then that could be in the -20's.

FWIW, I had my favorite settings at -18P, -6I, and 9D, and they work OK, but don't handle gusty wind well. I tried some higher numbers of -30P, -8I, and 30D today, and don't really like them much better in the wind. I was playing with these a few minutes ago, in the beginnings of the gust front from the approaching thunderstorm. The -18P group wobbles farther, at a slower rate, compared to the -30 that wobbles in short quick movements. I'd have to say I prefer the -18P set.

With the -30P set, I tried changing impulse cycle from 1 to 8, and maybe the 1 setting was a bit more stable. My usual setting is 4, and if anything 4-6 is typically smoother.

Rusty (hoping for calm and cool after the storm so I can go fly)
Hi Rusty,

Just back from up North to a frightening email backlog!

I will go through your numbers asap but as far as your question on definition of "oscillation". I mean when you disturb a QC that it commences and keeps oscillating in a stable manner (equal amplitude swings) around the axis of interest. You can then compute the proportional gain directly from the gain at which this occurs. The integral gain requires the frequency which should be about 3Hz for most.

The method gives in theory gives gains that will reduce the magnitude of any disturbance to one quarter the value at each oscillation e.g 10 deg of disturbance will drop to 2.5 deg then to 0.6 deg .... good enough for most purposes. Unfortunately there is significant cross coupling between the axes and for perfection one drifts off into horrendous math, Kalman filters etc.

Back in Oz (jet lagged) in 10 days and well get onto some testing. I think I have a good handle on how Wolfgang's program works now, or at least will have

Greg
ps good to see Jim has cracked his problem.
Last edited by gke; Jul 21, 2008 at 09:11 AM.
Jul 21, 2008, 09:10 PM
13brv3's Avatar
Quote:
Originally Posted by taxexempt
for the uavp board, what is the diff. between ppm and normal.?
I would be useing a berg7p not too sure how to mod it, so would I need normal for the programming/ also I can changed this in the future if I want.?

I think I read to the point of confusion.
For the sake of parameters, PPM means you have a modified receiver that outputs all the channels on one wire as a string of pulses. Normal means you are connecting the odd channels from your receiver to the UAVP (1,3,5 and optionally 7).

I would try the Berg7p as "normal", using the odd channels first. If it doesn't work that way (some receivers don't), you can change to PPM if there's a mod for that receiver. I've never had one, so I don't know anything specific about it.

If you're asking because you're ordering a board from Quadroufo, it's not all that critical, because you can reflash the software to a different version yourself. The only choice you don't want to screw up is I2C vs PPM (PWM really) motor controllers. If you aren't going to use I2C, then don't chose that option, or Ken will help you out by installing a couple resistors on your board that you won't want

Rusty
Jul 21, 2008, 09:32 PM
13brv3's Avatar

High ESC temp reduces power


Greetings,

This is going to be fairly brief, because I don't have much time to write everything up at the moment. I was working on developing a test rig that would allow me to make realistic comparisons of motor and prop combos.

The first test was to be my current favorite TP2410-09 motors, Turnigy Plush10A controllers, and EPP1045 props as a baseline. I'll post all the test method stuff later, but the goal was to record the weight that the combo could lift at a given throttle setting. The problem was that the power seemed to be falling off steadily, and I couldn't pick a good value. I've seen this happen before, and just assumed it was the battery voltage going down as the motor ran.

Since no self respecting scientific method would allow that sort of behavior, I pulled out my 50V 20A bench supply, and used it instead, so the voltage would remain locked at 11.1V. Confident that my troubles were over, I ran another test. You're likely ahead of me already, but it was just the same.

The next conclusion was that the temperature was causing a problem. I had the ESC about 1" from the end of the prop, just like I have it on my UAVP's. While I thought that would certainly get some airflow, it does not. After a couple experiments blowing shop air at the ESC, it became obvious that it is a temp issue.

A few more tests were performed, each time for 5 minutes, at 80% throttle, measuring the temp of the FET on the ESC, and recording all the other goodies with the Eagle Tree. I tested the 1" from the prop location, then move the ESC directly in the prop blast. BIG difference. I next removed the heat shrink from the FET area, and saw a big change in temp, but not much further increase in power. Finally, I tried the 1" position again, without the heat shrink, and it was almost the same as with the heat shrink because there's just no airflow out there.

The lesson here is lots of airflow for the ESC. The heat shrink removal isn't going to gain much, so I'm not sure I'd recommend that to most people.

At about 3 minutes, temps and power generally stabilizes. At the end of 5 minutes, I measured the RPM for each test as follows.

1" from prop tip, with heat shrink- 5220 RPM
1" from prop tip, without heat shrink- 5213 RPM
Directly in the prop blast, with heat shrink- 5436 RPM
Directly in the prop blast, without heat shrink- 5469 RPM

As you can see, airflow is your friend. Finally, the attached picture shows a test where I had the ESC 1" from the prop tip, without heat shrink. I ran it for 3 minutes, then blasted it with shop air for the next two minutes. Not too hard to see the effect

More about the actual motor/prop testing tomorrow (maybe). Still lots of questions about whether this only happens with this particular ESC, or all of them. Funny how one thing leads to another.

Rusty
Jul 21, 2008, 09:59 PM
Registered User
Thanks Rusty. Thats what I was thinking when i placed my order. I placed it today so hopefully by weeks end I'll have everything.
Thanks again guys.

Respectfully,
Joe
Jul 21, 2008, 10:27 PM
Registered User
Old Man Mike's Avatar
Quote:
Originally Posted by 13brv3
... The problem was that the power seemed to be falling off steadily, and I couldn't pick a good value. I've seen this happen before, and just assumed it was the battery voltage going down as the motor ran.
.....

1" from prop tip, with heat shrink- 5220 RPM
1" from prop tip, without heat shrink- 5213 RPM
Directly in the prop blast, with heat shrink- 5436 RPM
Directly in the prop blast, without heat shrink- 5469 RPM

As you can see, airflow is your friend. Finally, the attached picture shows a test where I had the ESC 1" from the prop tip, without heat shrink. I ran it for 3 minutes, then blasted it with shop air for the next two minutes. Not too hard to see the effect
Russty
Wow, I love to see discoveries like this!

It appears that this is not an efficiency change but rather a response to throttle change. Two possibilities come to mind:

1) The "on" time of the FETs changes with temperature

2) The controller telling the FETs when to turn on is changing the period, perhaps because it's oscillator is changing frequency.

More experiments are needed to determine if this is true for all ESCs are just selected units. Also, if this temperature dependent throttle sensitivity varies among ESCs then you would expect a lot of retrimming would be needed as the ESCs heated up in flight. I can't say that I've notice much change during my flying. However, I have noticed less power at the end of the flight which I've always assumed was because of the lower voltage. While the lower voltage will certainly reduce the maximum power, this effect could be compounding the problem.

I'm on the edge of my seat ....

OMM
Jul 21, 2008, 10:52 PM
Registered User
well my stuff is ordered and it looks like they are on their way !.. I am soo looking forward to this project.
I began making my center out of 1/8 plywood. Perhaps I should make it out of aluminum. the length between prop shafts will be 500 mm. the motors are the tried and tru tp's..lol.

Here it is in a rough setup. more work to come on this.
I'm not trying to hijack this thread, its just you guys seem to welcome everything that is being done with this uavp.

Respectfully
Joe
Jul 22, 2008, 04:04 AM
MultiRotor Jedi
simonjardine's Avatar
Wow, nice pod Joe, I like it. What is the weight?
Remember to keep it light, very important.
I have gone back to my 900mm frame, more stable for video, photo's.
I received my 3 bladed props today, GWS 9x5 were pretty crap, lot's of rpm.
The 10x6 GWS 3 bladed props work really well, although they are affected by the wind.
This will change soon, hopefully. I am designing some Duct's for my 1045 and 10x6 GWS. Anyone here tried duct's? I reckon i will see a huge difference.

Hoping anyway.
Jul 22, 2008, 04:28 AM
Registered User
AndrésMtnez's Avatar
Hi Simon,

What´s the size of your previous frame?

900mm is the distance between oposite motor axis?

How would you compare the epp 10x4,5 versus the gws 9x5x3? Someone said the gws are better to lift heavy payloads, because they are stiffer and do not bend as much as the epp...


Thanks,
Andres
Jul 22, 2008, 05:30 AM
Tri-Quad-Hexa-Octo-copters!!
@Rusty,
Interesting test. For comparison my 2410's and Turnigy ESC's are always cool to the touch compared to the Scorpion motors and 25A Towerpro ESC's on the UAVP that I inherited. Both types are in the airflow, but shrink wrapped, so really not efficient cooling. Are you thinking it is worth modding ESC's for better heat disapation to get more flight time and ESC life? For example, put a heat sink on the FET in the airflow, or in your case use thermal grease and mount it so it uses the alumiinum tube as a heatsink in the airflow?
Cheers,
Jim
Last edited by jesolins; Jul 22, 2008 at 07:49 AM.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New source for 32p 9t pinion for corona darthdrk Electric Heli Talk 5 Feb 17, 2004 03:09 PM
New source for depron....... Summer Foamies (Kits) 0 Nov 13, 2003 12:02 AM
New Source For Micro Plans!!!! Taniwha314 Scratchbuilt Indoor and Micro Models 4 Aug 09, 2003 02:11 PM
new source for control surface centereing rubber bands Dylwad Scratchbuilt Indoor and Micro Models 6 Jul 05, 2002 09:06 PM
Need a new source for Li-ion GHarvey Parkflyers 3 Jan 02, 2002 10:51 AM