START HERE |
|
Register | FAQ | PM | Events | Groups | Blogs | Calendar | Mark Forums Read |
Unregistered
|
Finless Bob's Helifreak Tech Room Finless Bob's Helifreak Tech Room - Tips and how-To Videos |
|
LinkBack | Thread Tools | Display Modes |
10-31-2012, 02:10 PM | #161 (permalink) | |
Registered Users
|
Quote:
I'll let these other guys recommend your pinion choices. Steve Sent from Tapatalk using my Inspire 4g through ATT (meaning it's a wonder you can see this!)
__________________
Regards, Steve |
|
Sponsored Links | |||
Advertisement |
|
11-08-2012, 12:04 AM | #162 (permalink) |
Registered Users
|
Tony your knowledge in ESC's is simply fascinating thanks for sharing it with us now and into the future.
__________________
Team Lynx Team Mad 4 Heli Gens Ace Batteries Citizen # 310 |
11-08-2012, 01:14 AM | #163 (permalink) | |
Registered Users
|
Quote:
Steve Sent from Tapatalk using my Inspire 4g through ATT (meaning it's a wonder you can see this!)
__________________
Regards, Steve |
|
11-13-2012, 06:02 AM | #164 (permalink) |
Registered Users
Join Date: Mar 2011
|
I've been having a look at some rc cars of late and have a question in regards to passive free wheeling. As long as the heat can be dissipated is there any issue with running at say 10% throttle for long periods of time?
|
11-13-2012, 09:37 AM | #165 (permalink) | |
Registered Users
|
Quote:
You can always cut a hole in the body or add a duct like you would in a gas car as well. Regards, Steve Sent from Tapatalk using my Inspire 4g through ATT (meaning it's a wonder you can see this!)
__________________
Regards, Steve |
|
11-13-2012, 12:52 PM | #166 (permalink) | ||
Registered Users
Join Date: Nov 2010
|
Quote:
Quote:
I don't think there's necessarily any whiz-bang technology going on there. Anyway, I've really enjoyed this thread guys, thanks a lot. Now I have a question. I am trying to develop small UAV's based on electric helicopters. So my use criteria is quite a bit different from aerobatics. This has led me down a strange path. First, I need to be able to send a rotor speed command from the UAV Flight Controller to the ESC. I also want to send rotor speed feedback from the ESC to the FC. Obviously this is not available on the market, so I'm developing an external governor which will basically go between the FC and the ESC, with the ESC operating in a simple straight-through-throttle mode. This part is all fine, though I really would love to develop an ESC that does this all internally. Anyway, the main point is this: One of the goals, is to be able to change rotor speed in-flight, depending on the flight profile. If we're hovering, I want to slow the rotorspeed down to 1200 rpm for maximum efficiency. (I'm talking about using Assymetric blades here). But then if we want to start flying fast forward, we need to increase the rotor speed, possibly to 1800 rpm. So obviously I'm going to be running with a wide speed range. I'm afraid of this effect where, if you run at too low of a throttle setting, you can burn out the ESC. But is this only a problem if the load is very high at part throttle? This is what I'm getting out of this thread. For example, if I'm only drawing 20-40A in a hover at 50% throttle with a 120A ESC, am I going to have a problem? Is it simply the case that, if the amperage draw from the battery, divided by the duty cycle of the PWM is less than the maximum rated amperage of the ESC, we should be OK? For example, with a 120A ESC, if I stay below 60A at 50% throttle, this should be OK? But then what about spikes.... Say I'm hovering, and then go to full maximum collective at the lower headspeed, is this going to blow it? Is what I want to do impossible? I know that I can run the power system in my Multi-Rotor all day long at 20% throttle, and ~12.5% rated amp draw all day long without any issue at all.
__________________
-Rob Former Managing Director of Maxxum Robotics Inc. |
||
11-13-2012, 01:52 PM | #167 (permalink) |
Registered Users
Join Date: Jun 2012
|
@ub3r
Tony, what's up? Your last post was two months ago. Have you stopped testing the ESCs?
__________________
Banshee 700 LE #50 and some others ... |
11-16-2012, 10:18 AM | #168 (permalink) | |
Registered Users
Join Date: Dec 2011
|
Quote:
Your load profile is outside most folks' experience, so you'll probably need empirical testing.
__________________
Blade 4503D ZYX-S Tarot DFC mCP X v2 BL HP05s/XP-7A/twin coreless |
|
11-16-2012, 10:34 AM | #169 (permalink) |
Registered Users
Join Date: Nov 2010
|
Thanks. So I'd want to put some thermocouples on the diodes? Well, I guess you're talking about the body diodes which are in the FETs. In that case could I just monitor the heatsink temperature? What might be a good Max Temp setting?
I was also thinking about putting a current monitor which is watched by the Governor driver chip. It would look for things like this overload condition (for example, more than 50% rated current at 50% load). Does that make sense? It sounds like an AFW ESC would help a lot.
__________________
-Rob Former Managing Director of Maxxum Robotics Inc. |
11-16-2012, 12:53 PM | #170 (permalink) | |
Registered Users
Join Date: Dec 2011
|
Quote:
__________________
Blade 4503D ZYX-S Tarot DFC mCP X v2 BL HP05s/XP-7A/twin coreless |
|
11-18-2012, 08:25 AM | #171 (permalink) |
Registered Users
Thread Starter
Join Date: Dec 2011
|
Hi Guys,
Sorry for the delays in replying here. Ive a mix of family and work problems that ive been trying to attend to, and as a result ive been interstate and had a lack of time.. Ill try to get to the PMs asap. I have a couple of vids between the YGE, CC120 and the PJ to post up shortly. Over the weekend i was experimenting with a new constant current (CC) active load i made. The old load bank was a constant voltage (CV) type. The need for the constant current load arose when i was doing preliminary "heli simulations' with my function generator. The CV type had non-linear characteristics with the input reference voltage. Anyways.. This new load cell allows me to: 1) Create and arbitrary function using the function generator, and feed the Function generator (FG) output (voltage reference) into the load-bank. 2) The absorbed current is directly proportional, and linear with input reference voltage, from the FG. 3) Also allow me to plug batteries straight in, and stress test the batteries, into a controlled constant current load. So far the results are good. The New Load-bank basically consists of a current-shunt, an op-amp, and a High Power dissipation FETs. |
11-18-2012, 08:34 AM | #172 (permalink) | |
Registered Users
Thread Starter
Join Date: Dec 2011
|
Quote:
The load (in Nm) the drive motor is seeing is proportional the dyno's torque constant x output current. The dyno motor is Johns HK4540. Remember.. In all PM motors, RPM is proportional to voltage, and Torque is proportional to Current. This is also true for Dyno's (or Generators). Im sure scorpion will have some figures on the torque constant for this motor. Basically the load will be the 100amps x Torque constant. |
|
11-18-2012, 09:57 AM | #173 (permalink) | |
Registered Users
|
Quote:
I know all the math is there, unfortunately tossed my motors book. Anyway, I'm more of a hands on guy that likes testing. Load cell would get rid of all the friction, resistance, etc that goes into those constants. Just been burned by manufacturer specs in the past, and this was for servo motors in the engineering world. Gotta be worse in the hobby setting. Regards, Steve Sent from Tapatalk using my Inspire 4g through ATT (meaning it's a wonder you can see this!)
__________________
Regards, Steve |
|
11-18-2012, 10:03 AM | #174 (permalink) |
Registered Users
Join Date: Apr 2010
|
This thread is amazing!
I have a doubt... what is the relationship between Throttle % and other parameters (in a non gov ESC, of course)?? I mean, when the Rx sends 60% to the ESC, what this value affects?? Is it passed through the PWM??? |
11-18-2012, 10:54 AM | #175 (permalink) | |
Registered Users
|
Quote:
Regards, Steve Sent from Tapatalk using my Inspire 4g through ATT (meaning it's a wonder you can see this!)
__________________
Regards, Steve |
|
11-18-2012, 11:02 AM | #176 (permalink) | |
Registered Users
|
Sorry, this was supposed to be edited into above post, hit the wrong button :
Quote:
Regards, Steve Sent from Tapatalk using my Inspire 4g through ATT (meaning it's a wonder you can see this!)
__________________
Regards, Steve |
|
11-20-2012, 12:55 PM | #177 (permalink) | |
Registered Users
Join Date: Nov 2012
|
Quote:
Thanks in Advance. Gamini |
|
12-06-2012, 11:25 AM | #178 (permalink) |
Registered Users
Join Date: Oct 2007
|
Nice controllers do you have there. The KOSMIK controller has the shunts to measure the phase current in the phases itself. I am wondering which chips they are using to amplifier this low voltages? I think the 3 SOIC8 chips (2 on the top and 1 on the bottom) in combination with the 2 TSSOP14 chips amplifier the signal. Can you make maybe some detail pictures of the controller PCB?
|
12-19-2012, 03:31 PM | #179 (permalink) |
Registered Users
Join Date: Sep 2011
|
So? which is next?
scorpion commander? HW? We people can't wait....GREAT thread! PLEASE test some more!
__________________
2 X X7 | Scorpion 4525 Ultimate 4+6T YY / Xnove 4530 525 | scorpion Tribunus 200II ESC | Edge 713 | Logo 690SX | Pyro 440 7+8T YY | Castle 120HV | X3 | 4S | HW 50A V2 ESC | Scorpion 2221 2050KV 9T D | SK540 / Brain2 | Mks |
Thread Tools | |
Display Modes | |
|
|