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ESC timing and PWM advice please

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Old 12-04-2012, 01:22 AM
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tbaysal2000
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Default ESC timing and PWM advice please

Any suggestion of ESC timing and PWM adjustment for my ESC/Motor/Prop combination?

- 200A water cooled ESC, Skywing with heat protection, BEC etc
- Topedge watercooled 2045KV Inrunner motor, 2-6S Lipo, max 50.000 rpm (my target is 30k rpms at full)
- Currently have a 4.5 mm diameter, 1.4 pitch prop which came with it but will try different props later
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Old 12-04-2012, 05:51 PM
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Default RE: ESC timing and PWM advice please

need to know if motor is a wye (Y) wind or a delta (D) wind
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Old 12-05-2012, 12:20 AM
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Default RE: ESC timing and PWM advice please

If you plan on running 50k rpm id get the fire extinguisher ready,you should be aiming for 30-35 k tops.With 6s on that setup im getting arround 45 k unloaded and 37 k loaded rpm which is a SAW setup.Your kv is way too high for 6 s in my opinion.
Mart
try this it might help you figure out a few things
http://www.radiocontrolinfo.com/RCca...Calculator.php
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Old 12-05-2012, 01:08 AM
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Default RE: ESC timing and PWM advice please

No, no, no, I don't dream of 50k rpms. Just wanted to give info on the motor specs as given by producer. I target max 30k as you mentioned. I saw that calculator, too but it doesn't consider if the motor is Y or D. And if I would consider the table, I should go for a X670 or S175 prop for top speed but for a 88cm hull, I think these are way too big props, or not?

I can't tell if it is Y or D, just emailed the producer the type and asked their suggestion of timing etc. I found another thread somewhere else and Y motors generally have 4 cables for neutrolizing the 4th one and the D ones having 3 cables. Mine has 3 wires into motor and they spin into each other right at where they enter the engine. If definition is correct, it tells a bit being Delta configuration? And then a Delta configuration at 2045kv sounds to much from what I've read and if I understood so far correctly.
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Old 12-05-2012, 01:42 AM
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Default RE: ESC timing and PWM advice please

Ok im with you now,yes those props too big lol.According to the calc if you look lower down it gives you a prop calculator to determine what size prop to look for based on kv and cell count.It says 40 mm its only an estimate based on 4 s lipos.
You could go to 5 s that would give you a loaded rpm of arround 31k which sounds about right.
Bare in mind if you go up to more cells you might need a smaller prop yours is 45 mm correct ?,might be ok but id start with 37-40 mm.
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Old 12-05-2012, 06:25 AM
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Default RE: ESC timing and PWM advice please

So higher cells, lower diameter? I thought as I have more power, it should handle bigger props at same revolution. So original design was for 3S lipo and it came with 45mm 1.4 pitch prop. So now with same motor/hull and safer ESC, better 45C 4 cell Lipo, I should aim 37-40 range. Any specific prop you suggest for 3/16" shaft?
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Old 12-05-2012, 11:12 AM
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Default RE: ESC timing and PWM advice please


Quote:
Any suggestion of ESC timing and PWM adjustment for my ESC/Motor/Prop combination?...I found another thread somewhere else and Y motors generally have 4 cables for neutrolizing the 4th one...
Total BS. Both winds have three wires exiting the can. The timing will depend on the motor wind, but start with low timing, that will at least get you going. Start with low PWM (8 is good).

Quote:
Topedge watercooled 2045KV Inrunner motor, 2-6S Lipo, max 50.000 rpm (my target is 30k rpms at full).....I target max 30k as you mentioned.
You cannot "target" 30,000 rpm with that motor and 6s packs. At 30,000 rpm WOT you will be pulling 300+ amps! That is a 3S or 4S motor, not well suited for 6S. It has an excessive Kv and inadequate torque. A 3660 motor is not adequate for most boats over about 80 cm and is a poor choice for 6S. You need to use a small prop to keep the rpm in check, but too small and it will not push the boat efficiently.

Quote:
So higher cells, lower diameter? I thought as I have more power, it should handle bigger props at same revolution.
No, an electric motor will draw more amps with the same prop at higher voltage. You need to either go to a smaller prop - see above - or a larger, lower Kv motor.

Quote:
So original design was for 3S lipo and it came with 45mm 1.4 pitch prop. So now with same motor/hull and safer ESC, better 45C 4 cell Lipo...
Wait, are you running 4S or 6S? For this motor 4S is better than 6S depending on the size and type of hull. Don't make us guess, tell us all about the setup.


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Old 12-05-2012, 01:37 PM
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Default RE: ESC timing and PWM advice please


Quote:
ORIGINAL: Got RPM

Quote:
Topedge watercooled 2045KV Inrunner motor, 2-6S Lipo, max 50.000 rpm (my target is 30k rpms at full).....I target max 30k as you mentioned.
You cannot ''target'' 30,000 rpm with that motor and 6s packs. => I have 4S 45C 5200Mah lipo.

Quote:
So original design was for 3S lipo and it came with 45mm 1.4 pitch prop. So now with same motor/hull and safer ESC, better 45C 4 cell Lipo...
Wait, are you running 4S or 6S? => 4S, 45C, 5200MAH.

For this motor 4S is better than 6S depending on the size and type of hull. Don't make us guess, tell us all about the setup.


.
Boat is a 35" DeepVee Stepped Offshore hull. Very thin fiberglass and I plan to strengten the bottom a bit as it already has stress lines.

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Old 12-05-2012, 06:33 PM
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Default RE: ESC timing and PWM advice please

Okay, I understand better now. First, this is not really a stepped hull. Those steps are non-functional, they do nothing for performance. Treat it like a regular vee hull.

Quote:
So now with same motor/hull and safer ESC, better 45C 4 cell Lipo, I should aim 37-40 range.
Second, that motor is way too small for the boat. And you are aiming far too high in the unloaded rpm!! Aim for 25,000 to 30,000 rpm by multiplying the voltage by the Kv. Example: 22.2 volts (6S) x 1200 Kv = 26,600 unloaded rpm.

You really need a motor with a 40mm diameter and at least 72mm long, 82 or 92 is better. That will provide the torque needed to spin a prop large enough to move the boat well. I suggest a 40x82 or 40x92 mm motor on 6S with a Kv between 1100 and 1300. This will spin props between 48 and 52 mm, large enough to really get the boat moving efficiently without pulling too many amps. If you want to run 4S then choose a 40x82mm motor with a Kv between 1800 and 1900.

Quote:
Wait, are you running 4S or 6S? => 4S, 45C, 5200MAH.
Then why did you tell us this??
Quote:
- Topedge watercooled 2045KV Inrunner motor, 2-6S Lipo, max 50.000 rpm (my target is 30k rpms at full)





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Old 12-05-2012, 06:57 PM
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Default RE: ESC timing and PWM advice please


Quote:
ORIGINAL: Got RPM

Okay, I understand better now. First, this is not really a stepped hull. Those steps are non-functional, they do nothing for performance. Treat it like a regular vee hull.

Quote:
So now with same motor/hull and safer ESC, better 45C 4 cell Lipo, I should aim 37-40 range.
Second, that motor is way too small for the boat. And you are aiming far too high in the unloaded rpm!! Aim for 25,000 to 30,000 rpm by multiplying the voltage by the Kv. Example: 22.2 volts (6S) x 1200 Kv = 26,600 unloaded rpm.

pretty sure he is talking about prop diameter when he says 37-40 range.




40mm prop is fairly small for a 35 inch boat. that is a small motor for this size of boat, but if you are ok with a lower top speed then you should be able to run a 40mm prop like a octura x440 and atleast get the boat out on the water. I'm sure you don't want to buy a new motor, esc, and battery at this point.
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Old 12-06-2012, 02:16 AM
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tbaysal2000
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Default RE: ESC timing and PWM advice please


Hi all:

Hull: It is already treated as a deep vee The original 99 Fountain boat has the steps, and for sure had a function though (photos attached, really nice ones - The boat is the winner of 2008 Malta P1 Evolution Class)

Motor/ESC/Lipo: At this point, I don't want to spend more. I have an ESC more then capable for the motor/lipo. The lipo is a high charge I've got for a good price. I'll still look around if I can find a Leopard for low cost but this boat has not even seen the water yet since I have it. For future plans, the proposed motor specs and lipo is noted. Thanks.

Target RPM: 14.8V x 2045kv in theory gives 30k so I will be happy to see the top speed for a short 5 to 10 seconds (with an on board GPS I have from Garmin) and test different props. But in general I don't tend to push more then 25k and get longer and safer runs. This will be my first brushless so I need a taste of it first.

Props I have:
- 45mm, 1.4 pitch which came with the boat (needs S&B)
- X452/3 (needs S&B)






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