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-   -   EDF powered backpack problems (https://www.rcuniverse.com/forum/electric-rc-jets-198/11684372-edf-powered-backpack-problems.html)

NewTinkerer 11-02-2020 03:34 PM

EDF powered backpack problems
 
Okay so I'm new to the RC world, but I love to tinker and make things I'm constantly building things and just messing around. Not too long ago. I came across some videos of EDF's and thought if I could mount a couple of those on a backpack that houses the batteries and electronics I could jump on rollerblades skateboard whatever and that would just be cool for no other reason but I think that'd be cool. not knowing it was going to get expensive quick. I ordered a whole bunch of stuff after reading and researching. I recently got everything put it all together and my 105 millimeter ducted fans just beep and do nothing else. I brought the setup to the RC store. the kid there had no ideas for me and didn't really know how to make it work which was not too comforting so I thought let's get on a forum. Hopefully someone can help me out. So here goes. I have
2- 105 mm HSD jets 11 blade 44v EDF's,
2-150 amp aerostar 12s optio esc's
2- 6s 60c lipos for each fan
1- cheap trigger style remote w/receiver
2- different cheap servo testers thinking I could use 1 of those to control both fans so I didn't have to use a remote and receiver.
so I hooked everything up first with the receiver and remote control and the EDF just beeped non-stop a slow steady beep and each time it beeped it kind of jerked a little. also it did this when I tried to hook up the servo tester now upon further reading I came to the conclusion that the speed control did not have a BEC so when I went to the RC store today. the kid hooked up his BEC to the cheap receiver and remote trigger I had and it's still beeped non-stop so I'm already in this little project over $1,000. The kid at the RC store said I should probably get new speed controls. I already spent $130 each on the two I have. I'm desperate and in very much need of assistance. Thank you in advance.. PS. I have not tried the servo tester with the external BEC yet because the external battery pack is coming in the mail tomorrow. and I forgot to bring the servo tester with me to the RC store earlier, but something tells me something else is wrong and this also will not work.???:confused:

mongo 11-02-2020 07:20 PM

throttle calibration of the esc


generally,
turn on tx and move throttle to max, and hold there,
power up the esc/receiver,
after it beeps(probably3 quick ones),
move throttle to low,
should be an acknowledgment
then try working the throttle.,

NewTinkerer 11-02-2020 08:43 PM

Okay thanks I will try in the morning and see if this works, I'll report back my findings...

ron_van_sommeren 11-03-2020 04:16 AM


Originally Posted by NewTinkerer (Post 12642203)
... I came across some videos of EDF's ...

Too late probably but propellers have higher effectivity than EDFs. Double???


Originally Posted by NewTinkerer (Post 12642203)
2- 105 mm HSD jets 11 blade 44v EDF's,
2-150 amp aerostar 12s opto esc's
2- 6s 60c lipos for each fan ...

What current do you expect? Have you calculated it?
www.ecalc.ch → fanCalc

Calculators only get you in the ball park, IF the input is correct.
Without a watt-meter you are in the dark.
Until something starts to glow :( ;)

Originally Posted by NewTinkerer (Post 12642203)
... came to the conclusion that the speed control did not have a BEC ...

In a true opto controller a BEC is useless. Because it is optocoupled for complete electrical insulation between controller and ESC.
A fake opto controller also has no BEC on board, and also no optocoupler, but is not insulated from the receiver. A bit like calling a car with no brakes an ultra high speed car. Thank you HobbyKrap for creating confusion (once again) with this lovely bit of ... eeeh ... marketing :mad:

Vriendelijke groeten ;) en wees voorzichtig, Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
E-flight calculatorswatt-metersdiy motor tips&tricksCumulus MFC

ron_van_sommeren 11-03-2020 04:18 AM

15 Attachment(s)

Originally Posted by NewTinkerer (Post 12642203)
... EDF's and thought if I could mount a couple of those on a backpack that houses the batteries and electronics ...

If you cannot but extend, extend the motorwires instead of batterywires and keep controller(s) close to battery(s). No need for extra input capacitors :)

Too long wires batteryside will kill ESC over time: precautions, solutions & workarounds - RCG
Contents
  • Two problems
    • Voltage spikes higher than battery voltage: transistor/FET/chip breakdown.
    • Current through input capacitors too high
    .
  • Example: four costly controllers consecutively cremated :(
  • Solution I: simply lengthen the motor wires instead :)
  • Solution II: add extra capacitors, rules of thumb
    Calculation spreadsheet
  • Capacitor type and polarity/orientation!
  • How & where (not) to add extra capacitors
    All capacitors as close to or on controller, do not distribute along batterywires.
  • DIY capacitor pack pictures
  • Capacitor & pack suppliers
  • Expert/manufacturer opinions & their rules of thumb
    They all say the same ... noise_reduction_101, switching_power_supply_design_101.
  • Cause, explanation, water hammer/knock analogy&video, theory
    References
  • Measurements & scope traces

Attachment 2268525 Attachment 2268526

Attachment 2268527 Attachment 2268528

Originally Posted by NewTinkerer (Post 12642203)
Okay so I'm new to the RC world ...

Some well-structured reading for rainy/windy days, and some handy e-tools as well. Will save you, and us :D a lot of questions. Notably the 'what went wrong?' kind of questions :( Will also prevent you from burning up several controllers and/or motors and/or battery:
E-flight primer and tools

And pleasepleaseplease, do your RC equipment, wallet, ego, battery, controller, motor, house/garage/car a big favour ... get a watt-meter. It will more than pay for itself, will save you at least one fried motor and one fried controller. Will also help you finding the best setup.
Keep battery-/-watt-/multi-meter wires short!
too long wires batteryside will kill ESC over time: precautions, solutions & workarounds

Vriendelijke groeten ;) en wees voorzichtig, Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
E-flight calculatorswatt-metersdiy motor tips&tricksCumulus MFC

rgburrill 11-03-2020 04:45 AM

So tell me Ron, how does this wattmeter work? How does it measure watts? To my knowledge (BSEE in 1969, MSE in 1974) watts cannot be "measured", they are calculated by measuring volts and amps. Show me a wattmeter that has a "Watts" input port.

BTW, while your info is informative it has nothing to do with his request. He is not flying a plane. He wants to terrorize pedestrians by strapping EDFs to his back and race down the sidewalks on a skateboard. Or worse yet, race down the streets.

NewTinkerer 11-03-2020 07:02 AM

I was actually thinking of the voltage before I read your post. I do have meters The voltage on the 12s batteries is 50.5 volts and being that the ESC and fan are 44 v. I was thinking maybe the voltage is too high. so at this moment I am discharging my lipos down closer to the 44 volts and then I will give it another try. also, my battery side total length of the wires is about 8 in and the same on the load side of the ESC., lol, I do not plan to terrorize anyone and will play with my toy in the most respectful way possible. :-) if I can ever get it to work. what is life? If you cannot have a little fun.. I very much appreciate the suggestions and help. I will continue on....

ron_van_sommeren 11-04-2020 03:00 AM


Originally Posted by rgburrill (Post 12642290)
So tell me Ron, how does this wattmeter work? ...

A shunt for current measurement, a port for voltage measurement, and processor I guess.
Mark Conolly is the designer, see:
www.rcgroups.com/forums/showthread.php?974563-Hyperion-s-New-Emeter-II-RDU&postid=45631117


Originally Posted by rgburrill (Post 12642290)
... while your info is informative it has nothing to do with his request. ...

He's new to RC stuff, and designing his own power train.
Most of that e-flight 101 info deals with electrics, electronics, motors and equipment, wings not so much. You got me thinking, maybe I should use a better description e-power systems 101?

Vriendelijke groeten ;) en wees voorzichtig, Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
E-flight calculatorswatt-metersdiy motor tips&tricksCumulus MFC

Joseph Frost 11-04-2020 09:47 PM

You better off sticking it in the Twin EDF jet, what this Forum is all about, it will hardly push you along with your intentions, (may be down-hill, LOL) total waste of time.
PS- make sure you load up some entertaining footage when you work it out, I can't wait to see it.

Joseph Frost 05-16-2021 09:52 PM


Originally Posted by NewTinkerer (Post 12642338)
I was actually thinking of the voltage before I read your post. I do have meters The voltage on the 12s batteries is 50.5 volts and being that the ESC and fan are 44 v. I was thinking maybe the voltage is too high. so at this moment I am discharging my lipos down closer to the 44 volts and then I will give it another try. also, my battery side total length of the wires is about 8 in and the same on the load side of the ESC., lol, I do not plan to terrorize anyone and will play with my toy in the most respectful way possible. :-) if I can ever get it to work. what is life? If you cannot have a little fun.. I very much appreciate the suggestions and help. I will continue on....

So, what ever happened to your invention???


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