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Old Aug 24, 2012, 06:15 PM
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United States, NM, Clovis
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Originally Posted by Maxthrottle View Post
The 70HV. I spoke with Mark about it and he said it does show up now and then but didn't have an explanation for it. But for some reason its starting to happens more than I care for. I've changed the timing but that only shifts when it happens.

I should ask up in the EDF talk thread.
Does it make a weird sound when it happens? If so, I had the exact same thing happen on my last flight on roll out right before I lifted off. A few seconds later a motor smoked and I lost the plane. I think I have video of it somewhere I'll try to find and post.
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Old Aug 24, 2012, 07:30 PM
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It sound like the ESC brake function keeps kicking in for a fraction of a second at different points of the throttle curve.

Mark builds these daily and said it shows up now and then but just don't sit on that throttle setting.
But its showing up at all different points now.

Jcdfrd may be on to why it may be happening inconsistently. I thought I did a good job on my soldering but no point in being over confident. It could be as simple as a cold solder. The resistence on each wire was the same going in but and cold solder could show up after a few hard run ups. Likely one of the motor wires. It would explain why one side runs hotter and cuts out sooner..... ???? Actually in my discussion with Mark, I swapped the ESC motor wires and the issue stayed on with the motors; though its happening on both just more on one side. So it may be the motor connectors.
Process of elimination I guess. I just don't have the time to fiddle......
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Old Aug 24, 2012, 08:37 PM
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It would be quickest (?) to change one ESC to something different to test that.
The only cases of such a 'weird stutter" I have seen is when the ESC 'does not like' the motor. It must be something to do with the back EMF and its detection, and response (programming/firmware code) to it by the ESC. Very much like some wrong timing thing.... but the reason it alters, and is random, is because the fluke timing of the interactions involved only reach a 'notably big point' when the stars align, LOL. eg two or three factors fluke their peaks at the same time. (or any near peaks, near times).

So... a different ESC should show that up. Chances of fluking another type of ESC that does it...... well, still possible, but for eg in my case I have seen it in certain Amp Birdies - a pair both did the exact same thing, so it is firmware, or their components/design based. Yet they work fine on tons of other motors. They just 'hated' eachother as a pair - motor/esc.

And from what you said, Mark's case just backs up that with more evidence too. (A bit odd to say just "dont use that throttle area" - I would say "dont use those ESC's"!!)
I am sure you can imagine the 'shock waves' etc that such as case will inject.... not great for bearings, shaft to armature, fans.... just not a good thing to have occur at all !!
So... change an ESC to another brand/type to test/prove that.....
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Old Aug 24, 2012, 11:33 PM
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"The Don" recommends soldering the bullet connectors together to avoid this. Never have tried it but I check for cold joints.

Heard this called "cogging" and it causes Esc to fry.
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Old Aug 25, 2012, 01:53 AM
John
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United States, NV, Las Vegas
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A few things... First, I apologize for some of the clarity in the video. The lens was a little dirty and was making the focus shift awkwardly...
Secondly, ok now that the negative is out of the way, I have a few things to say about this plane. THIS PLANE IS FREAKING AWESOME!!! The plane is so stable in the air and flies on rails. But man once you kick in the thrust vectoring, it becomes a whole new plane altogether. The possibilities while flying this plane are endless. With a little imagination and a whole lot of practice, I see this plane being, by far, one of the most dynamic edfs to date. Also, my motors are super quiet. I think this might be the quietest setup in a SU-35 video put out on the web to date. But they still have power!!!

For those who are interested, my power setup is as follows:

2 ExtremeRC Alloy Setups, both dynamically balanced by vendor:
2 Changesun 10 Blade 70mm rotors
2 HET 2W-30 Brushless Inrunner Motors
2 ExtremeRC Custom Shaft Adapters and spinners
2 Hobbywing Platinum 100A ESC: Medium Timing
1 CastleCreations 10A UBEC
Turnigy Nano-Tech 6S 5000mah 45C-90C
7 Detrum 9g Servos, 2 Hextronic 19g MG Servos, and 1 T-Pro MG90S(Steering Servo)


Freewing SU-35 Twin 70mm EDF Jet Maiden and 2nd Flights (10 min 20 sec)
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Old Aug 25, 2012, 08:48 AM
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Well nicely done John! That without a doubt shows the CS10 to be an excellent EDF for this model and any of the FW TV setups for that matter.

This should impress the guys over in the CS10 thread. It looked fine on my phone but on a monitor I notice your wife had the auto focus on. Do a take two without the auto focus and Mark/ExtremeRC may get a good CS10 alloy demo vid out of this. And that's without an intake ring!!! Wonder what it'll be like with it in.

Gonna need some Telem now to tell if its still running or not. Man you're pattern is full escorting all the airliners out of Vegas

Very good maiden too! About 3.5-4min each on Nano's. Several say neg things about Nanos but they seem to have held up well. Let us know how their life cycle goes.
Did you use a lot of throttle management to get to 4 min? Since we can't hear it over the airline engine wine.

Good job man. Finally a CS demo you can't hear but can see, a little better at least.
Thanks.
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Old Aug 25, 2012, 10:40 AM
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I also usually get 4 - 4'30'' minutes time flying aggressive 3D maneuvers with 5000mAh packs.

It'd be nice to play a glider role and see how long can I keep the thing flying!
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Old Aug 25, 2012, 10:58 AM
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Taiwan, 北市
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Hi all, sorry for the cross-posting but since all the big Freewing jets have similar vector nozzles, I figure I should for advice here as well:

I just finished building my Freewing F-18. As I was testing everything, I noticed one potential problem - one of the vector nozzles can be moved around with my hand because the little plastic peg that holds the nozzle in place from the inside (in addition to the servo rods) is broken. The nozzle tracks true without any unwanted loose movements when I use the transmitter to move it left/right/up/down. But manually, I can move it around with my hand.

Is it safe to fly the plane with a somewhat loose vector nozzle like this? Or do I need to glue something to where the peg used to be to hold down the nozzle?

Thanks in advance for any advice!

Kevin
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Old Aug 25, 2012, 11:47 AM
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I wouldn't fly it with TV on.
But I guess you can keep flying with TV off with little risk until you get a solution. Maybe if you talk to your dealer, they can supply you an spare nozzle or something.
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Old Aug 25, 2012, 03:03 PM
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United States, CA
Joined Dec 2010
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Okay so went flying today and my thrust doesn't seem to be what it used to be, went through about 4 batteries. Got home and did a static thrust test (nose down into scale) with the batteries that I didn't use and thrust is down to 2500-2600g. Any ideas what may be happening? I check my blades and they are fine no chips or cracks. Maybe I should try to rebalance em?

Below is original thrust test back in January.

Quote:
Originally Posted by v8truckin View Post
Weight with gens ace 5300mah

3061g

Static thrust

2812g (peak) 2788 (constant)
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Old Aug 25, 2012, 05:27 PM
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United States, FL, Hollywood
Joined Aug 2010
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Quote:
Originally Posted by kchen95 View Post
Hi all, sorry for the cross-posting but since all the big Freewing jets have similar vector nozzles, I figure I should for advice here as well:

I just finished building my Freewing F-18. As I was testing everything, I noticed one potential problem - one of the vector nozzles can be moved around with my hand because the little plastic peg that holds the nozzle in place from the inside (in addition to the servo rods) is broken. The nozzle tracks true without any unwanted loose movements when I use the transmitter to move it left/right/up/down. But manually, I can move it around with my hand.

Is it safe to fly the plane with a somewhat loose vector nozzle like this? Or do I need to glue something to where the peg used to be to hold down the nozzle?

Thanks in advance for any advice!

Kevin
I have a spare nozzle but not sure it will fit yours.
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Old Aug 25, 2012, 05:44 PM
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Originally Posted by jk671 View Post
A few things... First, I apologize for some of the clarity in the video. The lens was a little dirty and was making the focus shift awkwardly...
Secondly, ok now that the negative is out of the way, I have a few things to say about this plane. THIS PLANE IS FREAKING AWESOME!!! The plane is so stable in the air and flies on rails. But man once you kick in the thrust vectoring, it becomes a whole new plane altogether. The possibilities while flying this plane are endless. With a little imagination and a whole lot of practice, I see this plane being, by far, one of the most dynamic edfs to date. Also, my motors are super quiet. I think this might be the quietest setup in a SU-35 video put out on the web to date. But they still have power!!!

Love the way it sounds; much better than stock IMO.
Camera person needs to zoom in a bit while you are flying though, not just when you are landing. Camera will not go out of focus so much, but it is incredible how he/she kept the bird in frame even when it was too distant to be seen on video. of course better to set the focus b4 filming. Thanks for sharing.
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Old Aug 25, 2012, 07:13 PM
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This is a direct quote by The Don from the Me262 thread.



Bullet connectors cause issues such as cogging, stuttering, surging, and it is not just the bullet connection it is the soldering to the bullet connector. Many people unknowingly get rosin/flux in between the male bullet connector pieces. Remember the same "cheap of cheap" quality is in that chinese made stamping on the male bullet connector. Not to mention loosening from EDF vibrations and sometimes you get wire cracking/fatigue where the wire comes out of the solder on the back of the bullet connector. Soldering takes so little time if servicing is needed that the risk is not worth it. I can easily see one of these solder joints coming unsoldered in flight with the amps being drawn. As soon as it does the motor is only connected by 2 of three wires, then the motor will cogg sending huge amp surges through the ESC then blow the ESC in a few seconds and it may or may not burn a phase of the motor. I have seen it many times in the past. All due to bullet connectors. Once I started to include the "direct solder" warning with all my EDF motors I sell, the issues all stopped with my customers.
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Old Aug 25, 2012, 07:25 PM
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Australia, VIC, Melbourne
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Boy is it a big task rebuilding 'half confetti' EPS foam!!
20 rejoins later....... I might be half way!
But it is working well.
I will need to run some carbon fibre rods, or flats, up the length of the nose area for strength. And then add all the internal plywood bracing - where I should have done it from day one!! That whole front end is just pathetically weak. And the 'poor excuse of a jigsaw' construction is all but designed for catastrophic failure to occur in any crash!
It could have been done, oh... about, 500% more intelligently!
But I suspect they were actually intelligent.. in their own favour! LOL.
Or..... not....

A few more evenings......
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Old Aug 26, 2012, 01:35 AM
John
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United States, NV, Las Vegas
Joined Mar 2011
436 Posts
OK guys, here's the 3rd flight of my SU-35... I love this plane! Near the end of the flight, however, I was messing with the thrust vectoring and ended up inverted, heading towards the ground. I didn't have much I could do. The plane was travelling too slow to turn her around. I just pushed both sticks all the way up and started praying! I don't know how, but my ExtremeRC CS-10 Alloy setup with the HET 2w-30's kicked in and lifted her to safety!!! Also, we were able to get much better footage as the sun was going down. Hope you enjoy the video and thanks for watching!

Freewing SU-35 Twin 70mm EDF Jet Flight #3 Near Crash Saved by Thrust Vectoring (4 min 12 sec)
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