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RE: 2.4ghz receiver antenna question...
I got my antenna inside hull, and I got severe range problems. By severe, I mean that cut down from its supposed "up tp 2,5 km range" its now more like 250 meters. For my boating, thats not a problem so I leave it that way. But its worth a concideration, I got just 10% range, maybe even less, with antenna inside GF hull. CF would be even worse off. BTW, my radio system is FrSky ACCST. Princippally the same as Futaba FASST, allthough not compatible with each other.
Posted on: 9/11/2012 9:21 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11225074
RE: Need help on 40c, 50c, 65+c ratings..
Hey, Sundogs. Ryan is right, and hes trying to explain it to you. If you ask, and you want an answer, be grateful that someone bothers to explain it to you. Or don't bother asking at all. You are getting a simplified explaination from Ryan, because Ryan is getting the impression that you would probably not understand, or not bother to read the full blown explaination. I'll try to give you a simplified explaination aswell, but from a different angle. Maybe the 2 explainations together will give you the correct picture. Long story short, if a battery had 0 internal resistance, the load on the ESC would be similar no matter what C rating you had. In the real world, the internal resistance of the battery is ever so slightly lower if you got a higher c rating battery, meaning your motor can ask a little bit more power for it before voltage drop sets the limit. By the description of the problem, it appears to me that minicat racing hadn't done they homework proplery, and that warranty clausule was, as previously pointed out, a bandaid solution. Minicat racings boat apears overpropped, and the ESC undersized. However, in stock configuration it wouldn't fry because the battery was also too weak, and the power output of the system was (incorrectly) capped by the battery (voltage drop). Battery shouldn't cap the power output of a system, because that can damage the battery itself. Power output of the system should be capped by the load put on the motor (prop size). Minicat racing had been bad engineers and not done their homework properly, and to cover their own backs they made a ridicilous warranty clausule so that people would: 1. most certainly break the warranty through ordinary usage, and hence the problem was on the users shoulder. 2. cap the power to the motor with using a too weak battery, so the battery would overload instead of the ESC. However, the battery takes damage slowly over time, while the ESC goes all at once in a puff of blue smoke, so having the battery taking the blow instead might not make users notice anything at all, before warranty time is over anyway.
Posted on: 9/9/2012 2:30 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11222489
RE: How to configure Hobbyking multiboard 3.0 for Y6?
Another, more thorough flight test of Minsoo Kim v2.5 firmware loaded to the HK multirotor controlboard V3.0 Yaw problem is partly hotfixed by configuring a rudder-throttle mix in the transmitter (not acceptable to sell as a working unit, but if you got a computer radio you can make it work this way). Then I ran into another problem which happened 3 times on one and single charge of battery. That was the tail loosing lift for no apparent reason at all. despite giving it full stick forwards, it just fell on the back until crashing, and on the final crash breaking the lower tail propeller. This thing doesn't belong on the market at all, its an unfinished product with very rough edges and it's not working properly.
Posted on: 9/6/2012 11:15 AM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11219674
RE: How to configure Hobbyking multiboard 3.0 for Y6?
Y6 firmwares tested on the HK multirotor control board so far: Minsoo Kim v2.9: Doesn't arm Minsoo Kim v2.5: Throttle responds more than yaw, to input on yaw stick Minsoo Kim v2.4: Throttle responds more than yaw, to input on yaw stick Minsoo Kim v1.6: Doesn't arm Mike Barton V1.5i: Doesn't arm Mike Barton V1.1b: Got 1 successful flight of it, then its just dead (No thottle response). Tried to unplug and replug battery repeatedly, to same result. ESCs arm, but no throttle response. So much for the "Y6 compatibility" of this control board :( Best result so far is the Minsoo Kim V2.4 and V2.5, because they can (just barely) fly at all. Repeatedly. However the throttle pumping yaw control is annoying, and I just spotted another problem. The CCW rotating tail propeller barely rotates at all, and even stops in light CCW turns. This makes the CW tail propeller work much harder to keep enough lift on the tail, and ESC getting noticeably warmer. As per newtons laws of action an reaction, the CCW rotating front propellers must also work harder to counteract the CW net torque from the rear propeller pair. Further implying that the front CW propellers has to work lighter, to keep net torque at 0, and not overproduce lift in the front. Front CW propellers aren't visibly rotating slower, but they have to be at least to some degree, for the net torque to become 0, and stable flight achieved. I guess the final conclusion for me is: I need a better flight control board. Anyone know of a good one? Otherwise I guess my Y6 will just become an expensive ornament :/
Posted on: 9/5/2012 12:52 PM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11218518
RE: How to configure Hobbyking multiboard 3.0 for Y6?
First test flight: This leaves a poor impression. While its overly sensitive on pitch and roll control (easily fixed with dual rate though), the yaw control is much worse. Yaw control is very sluggish, however when operating yaw stick, the copter gains altitude rapidly! Googling around tells that this is a common problem with the older firmwares, and is "easily" fixed by flashing to the up to date firmware. Just a pity that the newest firmware doesn't work with this HK Multirotor controlboard then :( Back to square one.
Posted on: 9/5/2012 12:11 PM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11218474
RE: How to configure Hobbyking multiboard 3.0 for Y6?
Signs of life. And damn about time! I now flashed it with Minsoo Kim v2.5, and finally it appears to be running in Y6 configuration. However, battery is dead, and I got it just briefly of the ground before it went all dead, so I have to recharge before further testing. However, I maintain my statement that claiming this board is Y6 compatible is optimistic at best! The firmware i used is 3rd party, and there is no manual pointing in the direction of what firmware I had to use. I found it by blind trial and error testing, and that just doesn't cut it for saying "Y6 compatible". Its the same as if someone sells you a PC saying "windows compatible", and you get the computer with a blank harddisk, having to install everything yourself from a CD you found randomly on the street. Anyway, if someone for some reason desperately wants this HK multirotor board v3.0 for something else than a quadcopter, then it actually is possible. If you can guess your way to the right firmware, and if the firmware exists at all. O... and I almost forgot. I hope you enjoy solving driver issues, because thats AVR's way of signing their work. unsigned drivers, putting windows into test mode, poor 64 bit compatibility, thats everyday life for an AVR developer. So cope with that aswell, as you try to control your temper, flashing the board with the right firmware. Enjoy!
Posted on: 9/5/2012 11:36 AM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11218445
RE: How to configure Hobbyking multiboard 3.0 for Y6?
I might add that even after flashing the board to a Y6 compatible firmware (Minsoo Kim v2.9) it still doesn't work. Board won't arm, after following the manual step by step (correct servo normal/reverse configuration, increment throttle travel volume, and "arm" stick positions). This control board, is, with all respect, pure junk.
Posted on: 9/5/2012 9:33 AM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11218321
RE: How to configure Hobbyking multiboard 3.0 for Y6?
Ok, I figured it out. The "Y6 Compatibility" is a blatant lie. There is no support for Y6 in the stock firmware. To make this card work with Y6, new 3rd party firmware is needed, and developer tools (software and hardware) is also needed to get the new firmware flashed to the µC. The HK Multiboard is only compatible with quadcopters, despite what the description says. Flashing it to work with other configurations is a headache for anyone not familiar with AVR.
Posted on: 9/5/2012 7:36 AM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11218223
How to configure Hobbyking multiboard 3.0 for Y6?
Hi all! Title says it all. According to hobbyking, their multiboard 3.0 flight controller shall support Y6 copters, but I can't find anything about setting up the board for Y6 in the manual. Help would be greatly appreciated.
Posted on: 9/4/2012 11:31 PM by Author "Von Ohain"
in the forum "Multi Rotor Helicopters"
http://www.rcuniverse.com/forum/fb.asp?m=11217948
RE: Batteries
I agree on the part of getting a real charger. Definetly one that can charge a battery at its maximum charge rate, and preferably one with 2 or more charging ports, so you can change several batteries independently. On batteries, the price isn't so much a defining factor in charging time. Cost effective brands has released series with up to 5C charge rate, meaning fast charge in 1/5 hour (roughly 12 minutes). The price of the batteries does, in my experience, affect how well the individual cells are capacity matched. Some people stress a lot about this, saying that "the pack isn't stronger than its weakest cell". Which is true. But with the price difference of a cheap brand and a high end brand, the cheapo is still way more power for the same amount of money, even if you characterize the entire pack by its weakest cell. If you aren't into competition, there is really just one answer. Go cheap china. Price difference is much much larger than quality difference.
Posted on: 8/16/2012 11:01 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11195878
RE: Very Good Batteries on Ebay
No more details, just like that?
Posted on: 8/2/2012 6:12 PM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11179117
RE: Made by you. Diy vs. dishing money out.
Looks neat, and I'm sure they'll do for the application with brushed motors. If I were to make flex shafts for a high power application, brushless, gas or nitro, I would stretch out 3-4 bigger piano wires as a nucleus the full lenght of the flex shaft, and then coil up a finer piano wires wrapping around the nucleus (keeping direction of rotation in mind). And then cut it at the right length, and braze the ends of it. That would be a flex shaft totally up to spec. Actually, I might just do that, as I'm now in my 4th week of waiting for a new shaft from HOR. Edit: Sorry HOR, its actually my bad that its been so long, payment hadn't been sent :(
Posted on: 7/26/2012 11:43 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11169846
RE: Made by you. Diy vs. dishing money out.
If its steel strings, it might be worth a try. I would, however, use several lengtes of the coarsest unwrapped treble string for a nucleus, and then spinning the finest string around it for wrapping. Again, keeping direction of rotation in mind. A wire without a wrapping will wist under tension, and a wrapped wire without a nucleus will just be a tangled mess. You need a wrapped nucleus shaft for anything with a significant amount of torque to it. Sure a bass string is a wrapped wire around a nucleus, but I think its too thin to serve as a flex shaft alone.
Posted on: 7/26/2012 11:43 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11170174
RE: Made by you. Diy vs. dishing money out.
DIY. definetly. perfectly usable 2nd hand workshop tools costs less than what 4-5 motor and escs do. If you actually intend to use this equipment, its a no-brainer. It will pay itself no matter how big or small things you use it for. If you got the hours, and the knowhow, you kan make everything you need for a gas turbine yourself, given that you got a welder, a lathe and a mill in addition to basic workshop tools. Sure you can obtain the parts you need otherwise, but it will be more expensive, and its unbearably annoying to wait 2 weeks to obtain the single little part you need to get going, when you could make it yourself in less than a hour with the right tools. Lathe, mill and welder is minimum equippment in a well stocked workshop, and a well stocked workshop is mandatory in this hobby, in my opinion. DIY flex shafts is also extremely simple if you got some thin piano wire, a lathe, and brazing equippment.
Posted on: 7/23/2012 11:09 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11165931
RE: Feigao 540xl ???
Motors with slotted stators shall cog, motors with ring stators has no cogging, exept for very slight feeling of the remanence of the stator. Feiago is a ring core motor, and as previously pointed out it shall not cog.
Posted on: 7/12/2012 6:43 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11152415
RE: DIY brushed speed controller
That will not work well, if it works at all. First of all, you need pulse width mobulation, or the efficiency will just be rubbish. That connection, using bipolar transistors active analog area to regulate motor speed will be just as inefficient as the really old "3 way switch + resistor" regulation that some really old cheap brushed electrics had. Second, the output voltage of the servo PCB board will be 0-5 volts. Thats what its using to drive the servos motor. The the analog active area of a bipolar transistor is 0,7 volts, +/- 0,1 to 0,2 volts. The voltages the servo pcb board will output is not compatible with the voltages needed to drive the servo. This will result in a horrible "on-off" feeling on hte throttle stick. You will move the throttle stick a bit up with nothing happening. Then suddenly the stick will be very sensitive for a very small travel. Third, the the drawing lacks a lot of data, its barely a scetch to show a (bad) idea. You need to know a lot more to actually be able to build it. For example, what transistors to use? What servo pcb board? Which connections on the servo PCB board shall you use? How to defuse the potmeter of the servo? If the potmeter is allowed to travel, the regulator will be all over the place in operation. Fourth, a brushed ESC is so cheap that I can hardly see the point of trying to build one like this. The parts list will probably be more expensive than a ready off the shelf unit. But if you do it as an exercise, then its a fine exercise. But find a different diagram, preferably one with specified parts, and a pulse width modulated one.
Posted on: 6/30/2012 3:00 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11137410
RE: CopterX 500 / HK 500 CMT tail rotor grip failing in flight
Morgan: I replaced the tail bolts with some generic machine screws. So far they are holding up well. Better than the chinascrews anyway. How they compare with Align stock parts I wouldn't know. The tail of the HK-500GT is a well knows problem (plastic blade grips), I think it should be added to the story that you should not just replace to alloy blade grips, but replace the screws aswell. Thanks for the tips guys =) Barbie: the bolts unscrewing wasn't the problem I had. The bolts were secured with threadlock and they were definetly broken In half, as the other half was still properly secured with threadlock into its hole, after the failure.
Posted on: 6/23/2012 8:45 AM by Author "Von Ohain"
in the forum "T-Rex heli"
http://www.rcuniverse.com/forum/fb.asp?m=11128750
RE: wire and connections adding to heat creation
It finished as a B. Sc. thesis at school. You'll find it on the online bachelor database of my university college, http://www.hekta.org/~hpe1116/ It ended up being built up from scratch, also with homebrew firmware for the µC, written on behalf of an external customer.
Posted on: 6/15/2012 6:38 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11118993
RE: wire and connections adding to heat creation
I see where you are going Goldenduff, and you got a point. however how good the solder is doesn't directly relate to the cross section of the connector. For example, a 5.5mm connector can perform much better than a 8mm connector, if the 5.5mm connector has better soldering surfaces than the 8mm. But your point is valid, swapping to a connector with better soldering surfaces will improve performance of the connection.
Posted on: 6/15/2012 6:18 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11118998
RE: wire and connections adding to heat creation
Maths is always wrong, sundogs is correct.
Posted on: 6/14/2012 8:51 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11117994
RE: wire and connections adding to heat creation
Well, as proven by common sense, and now also by maths, having connectors with a cross section larger than the wire itself doesn't make much sense. So unless you got 50.26mm² (that is 1 AWG) wires, then 8mm bullett is overkill.
Posted on: 6/14/2012 1:10 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11117686
RE: wire and connections adding to heat creation
Yes my mind is set because the reasoning here behind how to solve heat problems in connectors doesn't add up with science. Heat develops where resistance is greatest, as per (Where P = power, I = current and R = Resistance): P = I^2 * R Resistance is greatest where either cross sectional area is small, or resistivity is great, as per (Where R = resistance, � (rho) = specific resistivity of the material in question, L = Length of the unit in question in meters, and A = area of unit in question, in square meters) : R = � * ( L / A ) Substituting R in the power equation yields: P = I^2 * � * ( L / A ) And as you see, for a given current and length of conductor, the only factors dedicating heat loss is resistivity and cross sectional area. The connector itself is made of copper or aluminium, which has very low resistivity. The cross sectional area of the connector is larger than the wire. Hence, the connector has less resistance per length than the wire itself. No problem there. However, the tin used to solder the wire to the connector both has less cross sectional area than the connector (come on, how much thin do you use?). And the resistivity of tin is much higher than for both aluminium and copper. And bobs your uncle, mathematics tells you that you need to do proper soldering, not swapping to larger connectors :)
Posted on: 6/13/2012 11:51 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11116666
RE: wire and connections adding to heat creation
Sure, Goldenduff, and thats what I was saying in my first post: Learn to solder. Higher contact area (cross section) between wire and connector pin is better. Smaller distance from wire to connector pin is better. You can make Deans style T work incredibly well if you simply can make a good solder. But Deans style T has a rectangular pin, joining to a round wire. That doesn't automatically make good joints unless the solderer is giving this a thought. And thats also why so many people has trouble with Deans style T.
Posted on: 6/13/2012 8:19 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11116748
RE: wire and connections adding to heat creation
SRT10 is right, resistance is highest where the heat develops. If the soldering is whats getting hot, the wires isn't your problem. And neither is the connectors. Its the solder itself. If you haven't had the same experiences sundog, then just do some proper solders and test again. Or just do the maths.
Posted on: 6/12/2012 12:41 PM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11115811
RE: wire and connections adding to heat creation
Yes, that, or bad solders. Tin solder has a lot more resistance than the wires themselves, and this is a problem with connectors that is tricky to solder with a good contact between wire and connector (deans, for example). The deans connector itself might be taken way past 100A without any problems, if you got a good solder. But actually getting a good solder on a deans style T is easier said than done. Having a higher cross section on the connector than on the wires themselves makes little sense. Which in fact means that you can go quite extreme with just a humble 3.5mm bullett connector. And it works, as long as toe solder is good. Putting in 8mm bullets, which I see someone do makes no sense unless you are pulling 1000A. My tip to those using that is just: learn to solder.
Posted on: 6/10/2012 2:37 PM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11113520
RE: Apparition hull from hobbyking
_VERY_ neat! Incredible tidy wire and coolant line solution you got there. How is the performance? My friends boat got a 1600Kv 3674 Leopard, Suppo 200A aircraft ESC, modified for water cooling and 6s2p 2200 mAH turnigy batteries. I think his performance is pretty damn good for the value. I'm running a Turnigy 180A also, and I'm happy with it (recycled from my old Surge Cursher). batteries is 6s2p 4000mAH Turnigy packs, and a 4064 1400KV Leopard. I haven't really tested it yet, as I just changed the batteries and motor to the current setup. Last time I were on the lake, the motor collet span loose and didn't catch on the flex shaft, so I didn't get all power transferred to the prop. Inevitable resulting in him outrunning me :( Im curious to see how the Apparition will fair when i get my setup right. I think I will beat him on the straights, but damn how well his boat corners!
Posted on: 6/10/2012 8:46 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11113212
Apparition hull from hobbyking
Hi guys! Have any of you tried the Apparition? I tried my friends boat yesterday, and I think it was pretty good. It corners much better than my Genesis, and was quite stable at speed too, even with ripples on the water. Build quality seems to be the same as Genesis, quite thick fiberglass and the same rudder/prop arrangement. So why the hype for the Genesis, and not the Apparition?
Posted on: 6/10/2012 3:03 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11112999
RE: wire and connections adding to heat creation
Wiring is typically not inadequate in my opinion. Of course that is a can of worm in itself, so my opinion is based on that "fire hazard" question. Wires used in hobby applications is typically silicon insulated wires, while wires for permanent installation in your house is typically PVC insulated. Silicon can handle a lot more heat that PVC. Another aspect is that your hobby application has very little time in use, most of the time is just standing on the shelf. Your household wires is in use 24/7. Thermal breakdown of the insulation doesn't have to be catastrophic at a given temperature. It can also degrade slowly over time at a lower temperature which is acceptable for our hobby boats, but not acceptable in a permanent electrical installation. And another thing to remember about household installations is that wire lengths is much longer. Therefor cables need to be thicker or the voltage drop over the cable would be unacceptable. In out hobby applications we typically has just a few centimeters of wire, which means we can have a much greater voltage drop per meter than household installations, without having a problem.
Posted on: 6/10/2012 2:43 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11112992
RE: CopterX 500 / HK 500 CMT tail rotor grip failing in flight
Thanks madmorgan. The parts are original HK500GT parts ;) I didn't want to waste my money on western resellers before I actually knew Align stock parts are any better on this point. I tested it now with replaced bolts. So far so good. But the stock ones didn't break first flight either, it was after 8-10 flights. So lets see how it goes.
Posted on: 6/3/2012 2:42 AM by Author "Von Ohain"
in the forum "T-Rex heli"
http://www.rcuniverse.com/forum/fb.asp?m=11104462
RE: Genesis cat questions
Go for 4S, both because I think thats enough for the motor, also because the stock prop is plastic and will break with a hot setup.
Posted on: 6/3/2012 2:33 AM by Author "Von Ohain"
in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=11104458
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