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Old 05-18-2010, 06:31 PM   #14746
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Originally Posted by cosmo1974 View Post
I completely understand what twk-b is saying.
I'm not doubting the non-linear relationship that twk-b stated.
What I don't understand is why?

As I asked, is it something to do with the Torque vs RPM curve of BL motors?
But I'm not convinced on that, based on the resultant curve (the black curve) from a few posts back, looked roughly linear (not exponential) - assuming the x & y axis is linear.

Mr Tekin applies a linear algorithm - so its not the source of non-linearity.

Has it something to do with the fact that the optimal timing boost map for a given motor is not currently applied, so we get something less than optimal which just happens to have an exponential look about it?

If none of the above, where does the non-linear relationship kick in?

Thanks
For the record, I hand drew that graph to point out that there is an optimal timing at every rpm and going over said timing just adds heat. When 203 first came out people were acting like more timing always equals more power and the only downside is heat. It is based on nothing more than my knowledge about general torque curves and timing.

Going into the "why" this is the most straight forward way to think about it:
Horsepower is the product of torque x RPM divided by 5252. When you add timing you are not only increasing the torque, but also the RPM. This produces a squared result.
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Old 05-18-2010, 06:41 PM   #14747
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Quote:
Originally Posted by Krio View Post
For the record, I hand drew that graph to point out that there is an optimal timing at every rpm and going over said timing just adds heat. When 203 first came out people were acting like more timing always equals more power and the only downside is heat. It is based on nothing more than my knowledge about general torque curves and timing.
Yes, I greatly appreciated yours comments at the time.
They all made a lot of good sense.

Quote:
Originally Posted by Krio View Post
Going into the "why" this is the most straight forward way to think about it:
Horsepower is the product of torque x RPM divided by 5252. When you add timing you are not only increasing the torque, but also the RPM. This produces a squared result.
Thanks.
Its starting to become clearer.
Your comment about both torque and rpm increasing helped.

Thanks again
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Old 05-18-2010, 07:25 PM   #14748
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Originally Posted by cosmo1974 View Post
Yes, I greatly appreciated yours comments at the time.
They all made a lot of good sense.



Thanks.
Its starting to become clearer.
Your comment about both torque and rpm increasing helped.

Thanks again
Glad I could help then as well as now.
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Old 05-18-2010, 08:56 PM   #14749
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Just to add to this. There is also the "human" influence on the effects. Going from walking pace to jogging pace doesn't put much of a strain on your reflexes, but going from a jogging pace to 40mph in 1/2 second or so makes everything "seem" exaggerated when looking at it.
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Old 05-19-2010, 08:53 AM   #14750
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Default Y-Cable to connect HotWire?

Connecting the ESC again and again to the Hotwire has put some stress onto the ESC->receiver plug, because its very hard to remove from the receiver.
A simple extension would help, but a y-adapter would be even easier.

Is there anything that speaks against having a y-cable connecting the Hotwire to the ESC and receiver at the same time?
Would this harm the receiver?
Would this have an impact on the communication from HW to ESC?
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Old 05-19-2010, 09:10 AM   #14751
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Originally Posted by DrBen View Post
Connecting the ESC again and again to the Hotwire has put some stress onto the ESC->receiver plug, because its very hard to remove from the receiver.
A simple extension would help, but a y-adapter would be even easier.

Is there anything that speaks against having a y-cable connecting the Hotwire to the ESC and receiver at the same time?
Would this harm the receiver?
Would this have an impact on the communication from HW to ESC?
A y-harness disrupts the hotwire connection to the esc because of the receiver still being in "parallel". Grab a servo extention at your lhs and cut it down to size.
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Old 05-19-2010, 12:07 PM   #14752
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Quote:
Originally Posted by Krio View Post
A y-harness disrupts the hotwire connection to the esc because of the receiver still being in "parallel". Grab a servo extention at your lhs and cut it down to size.
Tidily wrap some tape (battery, elecetrical, etc) around the exposed part of the plug running up to say about an inch of the wires. You will fine this helps.
Alternatively, don't plug the receiver into the Y adaptor?
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Old 05-19-2010, 01:09 PM   #14753
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I cut the flat end of a zip tie off and glued it to the side of the receiver plug that was facing away from the servo plug and yank on this to get my RS Pro plug out now. I broke 2 wires on ESC plug before doing this. Now it comes out easily. I'll be adding the shortest servo lead I can get soon (3" I think) so I can remove the ESC from the extension rather than the receiver so I can mount the receiver in a less accessible location.
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Old 05-19-2010, 06:16 PM   #14754
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Quote:
Originally Posted by Krio View Post
For the record, I hand drew that graph to point out that there is an optimal timing at every rpm and going over said timing just adds heat. When 203 first came out people were acting like more timing always equals more power and the only downside is heat. It is based on nothing more than my knowledge about general torque curves and timing.

Going into the "why" this is the most straight forward way to think about it:
Horsepower is the product of torque x RPM divided by 5252. When you add timing you are not only increasing the torque, but also the RPM. This produces a squared result.
ok, this is just not true. horsepower is indeed torque *RPM /5252 but not the part about timing.
the maximum torque a magnet can make is when the North(or south) side of the rotor is at 90degrees of the spool of the stator. so, every time the magnets of the rotor pass the spool of the stator it changes its polarity, to not only 'pull' the magnet, but also 'push'. if you increase timing, you shift the maximum voltage over the spool a little, effectively generating less torque because the magnet of the rotor is not at 90 degrees anymore. however, at high speeds the magnet of the rotor actually works like a dynamo, generating a counter voltage. this is why an electric motor has a top rpm. this is when the voltage generated by the rotor is just as high as the voltage supplied from the battery. now when you add timing you can actually get extra voltage difference between the generator thing and the normal battery voltage. this is why extra timing makes your motor run a higher RPM. now indeed like previously posted each RPM has its own preferenced timing setting, but ofcoarse differs from motor to motor.
if in the holidays i have some spare time i will hook-up my tekin+nemesis 13.5 to a test-bench and start playing. i hope to get some measurements on the timing thing, getting the right timing per RPM. here at the university we can get all the measuring equipment needed so that wouldnt be a problem.
i dont know if my story is close to being clear but i figured this out myself just a couple weeks agoo by a fellow student in electronics.
my setup:
trinity Nemesis 13.5
Boost: max
turbo: 10
delay: 0.2
FDR: 6.3
start rpm: 8k
end rpm: 20k
turbo ramp: 2
motor timing: 15
rest = stock settings
temp: 85degrees C after 12 min of driving
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Old 05-19-2010, 07:37 PM   #14755
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Originally Posted by Markiempje View Post
ok, this is just not true. horsepower is indeed torque *RPM /5252 but not the part about timing.
the maximum torque a magnet can make is when the North(or south) side of the rotor is at 90degrees of the spool of the stator. so, every time the magnets of the rotor pass the spool of the stator it changes its polarity, to not only 'pull' the magnet, but also 'push'. if you increase timing, you shift the maximum voltage over the spool a little, effectively generating less torque because the magnet of the rotor is not at 90 degrees anymore. however, at high speeds the magnet of the rotor actually works like a dynamo, generating a counter voltage. this is why an electric motor has a top rpm. this is when the voltage generated by the rotor is just as high as the voltage supplied from the battery. now when you add timing you can actually get extra voltage difference between the generator thing and the normal battery voltage. this is why extra timing makes your motor run a higher RPM. now indeed like previously posted each RPM has its own preferenced timing setting, but ofcoarse differs from motor to motor.
if in the holidays i have some spare time i will hook-up my tekin+nemesis 13.5 to a test-bench and start playing. i hope to get some measurements on the timing thing, getting the right timing per RPM. here at the university we can get all the measuring equipment needed so that wouldnt be a problem.
i dont know if my story is close to being clear but i figured this out myself just a couple weeks agoo by a fellow student in electronics.
my setup:
trinity Nemesis 13.5
Boost: max
turbo: 10
delay: 0.2
FDR: 6.3
start rpm: 8k
end rpm: 20k
turbo ramp: 2
motor timing: 15
rest = stock settings
temp: 85degrees C after 12 min of driving
You are correct that the most torque is produced when the fields are at 90 degrees. I assume you also are under perfect conditions where the field is instantaneously created. You must take into account that while the field is created pretty dang fast, there are several factors in a "roar" 3 slot motor that slow down the creation of said field. The primary one being the iron stator that the copper wires are wrapped around. The iron provides a stronger magnetic field at the expense of the time it takes for the field to reach maximum "power". This also means the field stays in place for a while even when there is no current flowing through the coils. The reason we increase the timing at higher rpm's is so that the field is fully created when the magnet hits 90 degrees for maximum torque. If you are firing the coil too soon you have non of the "dynamo" affect on the coil and you have a lot of current running without a whole lot happening. This is why it is so easy to melt a motor with too much timing.
On a side note, this is the exact reason you should NOT run as much timing in slotless motors like the tekin sensorless series or the mamba motors. They have no "slot" of iron that each coil is wrapped around so the field is created much quicker.
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Old 05-20-2010, 02:08 AM   #14756
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Default Tekin Rs Pro results on Femca

W from Brunei Darussalam Tq'ed and won in the 11.5T Stock class 'Brunei Femca ISTC 2010'. Running on Orion Handout motor 11.5T pro stock powered by Tekin Rs Pro, he manage to even beat his own qualifying time in the open class category. There were only 4 other Tekins involved which qualified in B main stock and C main stock respectively but due to technical track layout and difficulty on chassis setting, it was hard work going against HW 422, and LRP TC spec. But W manage to beat those odds and once again i would like to congratulate W who also shares his Tekin settings with me. Once again, Tekin has prove itself due to the hardwork of W from Brunei Darussalam.

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Old 05-20-2010, 02:14 AM   #14757
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Hi Guys
I have an issue with my RS Pro, where as everytime I try and set my end rpm at 25000 and hit the calculate start button, then select say 10000rpm and click save settings, it shows it saved it, but when I close the programe down and reload it to be sure it has saved the new settings, it shows that the end rpm has set itself to 4800. If I set it at 10000 0r 12000 rpm all seems fine. Anyone got any ideas please.

Cheers Malc
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Old 05-20-2010, 03:20 AM   #14758
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This was discussed a few pages ago. I haven't had this problem, but the apparent solution is to click directly in the middle of the number you want for your start RPM, don't just trust that it's highlighted and should be saved.

Of course, recheck your settings as you have been, but I usually click my start RPM a couple of times, right on the numbers, and haven't had a problem loading the correct values.

Good luck.
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Old 05-20-2010, 05:00 AM   #14759
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Hotwire user interface allows a Boost setting of 55.
Is this really the max or is it actually limited to 50 ??
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Old 05-20-2010, 05:08 AM   #14760
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its 55
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