17LikesHobbywing XERUN XR8 Plus
11-10-2015, 03:35 PM
#271
Tech Initiate
Ive had issues with cogging with this SMC motor. Ive ordered a Tekin PRO4 HD 4300 to try out. Hopefully it works better. If the cogging issues and sensor issues are resolved Ill send the SMC motor for repair.
11-11-2015, 05:03 AM
#272
Shame about the BEC. Having an good internal HV BEC is one of the main selling points from my standpoint.
Your particular issue sounds like a capacitor leak if your not getting any power to the Rx from the BEC at all. Likely one of the 4 inline capacitors between your battery terminals. Caps can go bad from many things, such as heat failure from excessive resistance, being shorted, to simply faulty manufacturing. The only way to know however is by removing them individually to run a small load test on with a digital voltmeter.
Knowing how long the XR8's BEC wire to the Rx is, it's a considerable length of small wire for high amperage draws to feed a power hungry HV servo.
I never trust the ESC caps alone to supply a steady stream of current. Especially on 2S with high KV motors. Voltage ripples from spikes or hard pulls on the throttle can rob your of consistency and also induce unwanted resistance, and ultimately help blow up your BEC.
With a low resistance glitch buster style cap installed to every Rx, the felt ESC load is considerably reduced and voltage consistency is drastically improved. It also keeps the stored current closer to the servo that will draw from it, which once again will reduce line resistance and improve on consistent and quick responsiveness.
I really don't understand why all Rx manufacturers still aren't installing an inline cap within case. Especially Spektrum.
Your particular issue sounds like a capacitor leak if your not getting any power to the Rx from the BEC at all. Likely one of the 4 inline capacitors between your battery terminals. Caps can go bad from many things, such as heat failure from excessive resistance, being shorted, to simply faulty manufacturing. The only way to know however is by removing them individually to run a small load test on with a digital voltmeter.
Knowing how long the XR8's BEC wire to the Rx is, it's a considerable length of small wire for high amperage draws to feed a power hungry HV servo.
I never trust the ESC caps alone to supply a steady stream of current. Especially on 2S with high KV motors. Voltage ripples from spikes or hard pulls on the throttle can rob your of consistency and also induce unwanted resistance, and ultimately help blow up your BEC.
With a low resistance glitch buster style cap installed to every Rx, the felt ESC load is considerably reduced and voltage consistency is drastically improved. It also keeps the stored current closer to the servo that will draw from it, which once again will reduce line resistance and improve on consistent and quick responsiveness.
I really don't understand why all Rx manufacturers still aren't installing an inline cap within case. Especially Spektrum.
I've handed my XR8 Plus to a friend of mine who knows more about ESC "guts", he will investigate further.
I'll install a glitch buster to a spare channel on my Rx for the RC8B3e, it surely won't hurt anything and may be a safety option.
Cheers!
11-11-2015, 01:42 PM
#273
Your information is incorrect. If you set your epa to 100% and then calibrate your radio to the esc, you are getting full throttle. Turning it up past 100% would just mean you would achieve full throttle before you actually pulled it full throttle.
11-11-2015, 01:46 PM
#274
Thanks for the input, Josh L!
I've handed my XR8 Plus to a friend of mine who knows more about ESC "guts", he will investigate further.
I'll install a glitch buster to a spare channel on my Rx for the RC8B3e, it surely won't hurt anything and may be a safety option.
Cheers!
I've handed my XR8 Plus to a friend of mine who knows more about ESC "guts", he will investigate further.
I'll install a glitch buster to a spare channel on my Rx for the RC8B3e, it surely won't hurt anything and may be a safety option.
Cheers!
11-11-2015, 02:02 PM
#275
I suppose it could depend on radio equipment, it works on Spektrum & Futaba. I've done this many times to show people who didn't realize their epa went above 100%. Calibrate everything at 100%, put car on a stand, plug everything in, pull full throttle and while doing that increase your epa to 120-150% whatever your radio is capable of and listen to the rpm increase.
11-11-2015, 04:10 PM
#277
Now wait a minute. ESC calibration basically tells the ESC at what signal from the transmitter/receiver it is supposed to open up fully* (i.e. not reducing the power via pulse width modulation, etc. anymore, but let through everything the battery has to offer, without any reduction of any kind.) Pretty much all ESCs show a light when they reach this point. Once you give that input on your transmitter, there is no power held back from the motor by the ESC any more - full power is full power.
If you setup the ESC to give full beans at a quarter trigger pull, it will give full power by then - and it will not increase any further if you give the trigger a full pull to 100% - much less 4 times as much. Why is EPA supposed to work differently? Playing around with it afterwards shouldn't magically create some sort of mysterious extra electrical power in the system, so how is this supposed to work? The ESC doesn't know what EPA you have set (so it can hold back something in reserve as long as you haven't set it to 125% or 150% - or whatever the maximum on your particular radio may be, just in case you might increase it later). All it knows is that "this input is full power, this input is full brake and that is neutral" and will do exactly that at the calibrated input values. And it interpolates all values in between. And even if it would extrapolate (which in my understanding it does not) - it cannot create any more power than the battery has - and that is already fully released at the calibrated setting - physics isn't negotiable.
All I could ever imagine is, that it might sometimes screw around with the turbo settings somehow, adjusting timing further, but that's all. In blinky mode however - I currently don't see any way how or why anything should change with higher EPA. But I'm open for an explanation how this could ever work the way you say.
Also I don't see why there should be any difference with different manufacturers either, as the principles above are the same for all. Could you explain your theory, please?
Unless of course throttle was reduced by dual rate before... increasing EPA afterwards then may actually really increase power/RPM (up to the point when the increase in EPA eliminates the decrease in D/R, but no further)... but again, not if it was calibrated with that D/R setting already.
On servos this is of course a different story, and it should work there - since you don't calibrate them like you do your ESCs.
*) of course also where to brake fully and where neutral is.
If you setup the ESC to give full beans at a quarter trigger pull, it will give full power by then - and it will not increase any further if you give the trigger a full pull to 100% - much less 4 times as much. Why is EPA supposed to work differently? Playing around with it afterwards shouldn't magically create some sort of mysterious extra electrical power in the system, so how is this supposed to work? The ESC doesn't know what EPA you have set (so it can hold back something in reserve as long as you haven't set it to 125% or 150% - or whatever the maximum on your particular radio may be, just in case you might increase it later). All it knows is that "this input is full power, this input is full brake and that is neutral" and will do exactly that at the calibrated input values. And it interpolates all values in between. And even if it would extrapolate (which in my understanding it does not) - it cannot create any more power than the battery has - and that is already fully released at the calibrated setting - physics isn't negotiable.
All I could ever imagine is, that it might sometimes screw around with the turbo settings somehow, adjusting timing further, but that's all. In blinky mode however - I currently don't see any way how or why anything should change with higher EPA. But I'm open for an explanation how this could ever work the way you say.
Also I don't see why there should be any difference with different manufacturers either, as the principles above are the same for all. Could you explain your theory, please?
Unless of course throttle was reduced by dual rate before... increasing EPA afterwards then may actually really increase power/RPM (up to the point when the increase in EPA eliminates the decrease in D/R, but no further)... but again, not if it was calibrated with that D/R setting already.
On servos this is of course a different story, and it should work there - since you don't calibrate them like you do your ESCs.
*) of course also where to brake fully and where neutral is.
11-11-2015, 04:34 PM
#278
Tech Initiate
Finally able to open pdf of instruction manual on my phone. Blinking green led and motor stops is motor or esc overheat condition. Blinking red and motor stops working is low voltage cutoff.
11-16-2015, 10:12 AM
#279
Installed my replacement XR8 at Gas Champs this weekend. Failed one lap in with another "Software Not Responding" error. Swapped one of my SCTpros back in and raced all weekend before we got rained out. This is back to back failures 
Protek 150T
SMC 1900KV
SMC 6500 mah
Spektrum
Protek 150T
SMC 1900KV
SMC 6500 mah
Spektrum
11-18-2015, 10:24 PM
#280
new hobbywing motor
when is the new hobbywing motor coming out?
12-07-2015, 03:28 PM
#281
anyone know where i can find a xr8 manual and i cant find it thanks
12-07-2015, 03:36 PM
#282
Reading all these failures makes me realize I stick with my Gen 2 tekin till it goes up in smoke and then I'll go back to the SCT Pro. Only thing that ever went wrong with that in 2 seasons of E-buggy racing was the internal BEC went out. I just used a tiny life pack till I sold the Serpent
12-07-2015, 03:44 PM
#283
Hi guys
I see most of you are having issues here with the xr8 plus please let me know what size batterys your running example cells ,Motors and radio equipment.
Im sure i will solve all your issues .
You can also email me at [email protected]
I see most of you are having issues here with the xr8 plus please let me know what size batterys your running example cells ,Motors and radio equipment.
Im sure i will solve all your issues .
You can also email me at [email protected]
12-07-2015, 04:00 PM
#284
12-07-2015, 08:37 PM
#285