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Old Feb 04, 2013, 03:06 PM
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Originally Posted by civic06 View Post
Getting ready to start my T-45 build and have a question. I thought the higher kv the more rpms = faster plane. Disho's set-up looks like BL32 2150 kv not high RPM? What am I not getting..BTW Disho's set-up scoots. I understand more volts = more RPM but isnt 6s putting too much load on the motor?
Thanks for the replies.
Hi there
The BL32 can handle 6s no problem, even my HK alloy 10 blade 3000kv kv 4s fan can handle 5s
I did some static tests with that fan on 5s the results where impressive but I'm not sure how long it would last, the eagle tree datalogger said 105Amps @ 1942 Watts
It would probably be ok in short bursts, the lipo that i used is too big to fit in the T45 so i can't test it in the air
On 4s my T45 was clocked 205kph not too bad for a cheap fan
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Old Feb 04, 2013, 04:40 PM
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A motor is not a motor......
LOL

KV only means the RPM it will do per volt. It doesn't mean anything about what power the motor can handle.
For a given voltage, AND the load the motor has on it (what fan, prop etc), it will TRY to run a Speed X (dictated by KV), but only be able to reach "X divided by Y" according to its construction versus that load. The situation it is in will make is draw Z Amps.
For the exact same motor and situation (fan it is in) if you raise volts you will cause the Amps to rise. Power = Volts x Amps, thus power rises too.

If the motor was only made to cope with Power X, it will fry if you cause it to run (or try to run) at higher power - they will all keep going higher than they are truly capable of, for X amount... to the point they fry. Too much heat basically..... via too much current (Amps) through the windings.

So.... KV on its own means little.
What matters is a total of a number of factors.

If someone says they had a motor of X KV, and another person had another motor type of the same X KV, you still need to know WHAT were all the other specs of each motor, to know which will do what for a given cell count and fan use.
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Old Feb 04, 2013, 04:49 PM
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Quote:
Originally Posted by Quadmad View Post
Hi there
The BL32 can handle 6s no problem, even my HK alloy 10 blade 3000kv kv 4s fan can handle 5s
I did some static tests with that fan on 5s the results where impressive but I'm not sure how long it would last, the eagle tree datalogger said 105Amps @ 1942 Watts
It would probably be ok in short bursts, the lipo that i used is too big to fit in the T45 so i can't test it in the air
On 4s my T45 was clocked 205kph not too bad for a cheap fan
Thanks for the info, do you run a cheater hole? 205 is really moving, I guess this airframe is slicker than I thought.
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Old Feb 04, 2013, 04:50 PM
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Those HK 10-blade alloys are Lander DPS fans. HK tend to list the correct lander specs for those (most HK numbers are wishy washy 'made up' specs. eg for other motors etc)
The 4S version is likely to be a 2950 motor (6S are 2960), I forget.
Typically capable of around 1000W.... but you can burst them out to higher some amount.
1000w/14.8v = 67Amps capable. Even that is a number that a 2950 (or even 2960) motor won't like long term. I would say by about 80Amps or so the windings are not going to be too happy! Getting very hot due to that current through their relatively thin gauge.
You would not really want to even burst run them through 80Amps much at all.
105Amps is very high and getting into the region of "Instant death"... windings fry in a split second!!

Irrespective of an alloy housing helping heat to be removed.... that is a slow long term process, and will not help fast instant heat problems... like running 80,,, 105 Amps will create.

They are a very nice fan unit. A good motor. Plus a good price at least from HK. But you don't really want to fry and ruin one for nothing! So I wouldn't advise hitting numbers over that 80Amps area for very long at all, and preferably never.
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Old Feb 04, 2013, 05:02 PM
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Quote:
Originally Posted by civic06 View Post
Getting ready to start my T-45 build and have a question. I thought the higher kv the more rpms = faster plane. Disho's set-up looks like BL32 2150 kv not high RPM? What am I not getting..BTW Disho's set-up scoots. I understand more volts = more RPM but isnt 6s putting too much load on the motor?
Thanks for the replies.

More KV means faster spinning more for the same number of volts, but there are more factors than how fast the motor spins. For example, number of blades on the rotor - some people in this thread have "unloaded" the stock fan by cutting 3 alternate blades off.

Motor power is a combination of RPM and torque. In the ducted fan design, slower turning motors like 2000kv may be run on more cells (like 4 or 6) so that's more volts, less amps. Faster turning motors like 5000kv are usually designed to run on fewer cells such as 3. (comparably less volts, more amps)
There even exist motors with ratings like 13500kv designed to run on 1 cell, or 12,000kv designed for 2 cells.
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Old Feb 04, 2013, 05:03 PM
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I would agree, I probably wouldn't bother trying that fan on 5S.

Any ideas on how fast the 2200kv 6S version would get the T45 up to? I'm guessing a 2650mah or 3000mah 6S would fit and balance nicely.
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Old Feb 04, 2013, 05:30 PM
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Originally Posted by nighthawk0077 View Post
Thanks for the info, do you run a cheater hole? 205 is really moving, I guess this airframe is slicker than I thought.
Yes cheater hole for sure
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Old Feb 04, 2013, 05:42 PM
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Originally Posted by m_ark View Post
More KV means faster spinning more for the same number of volts, but there are more factors than how fast the motor spins. For example, number of blades on the rotor - some people in this thread have "unloaded" the stock fan by cutting 3 alternate blades off.

Motor power is a combination of RPM and torque. In the ducted fan design, slower turning motors like 2000kv may be run on more cells (like 4 or 6) so that's more volts, less amps. Faster turning motors like 5000kv are usually designed to run on fewer cells such as 3. (comparably less volts, more amps)
There even exist motors with ratings like 13500kv designed to run on 1 cell, or 12,000kv designed for 2 cells.
Peter you talk allot, and have all sort of info but the proof is in the pudding I haven't seen any Video of your planes
you say ##They are a very nice fan unit. A good motor. Plus a good price at least from HK. But you don't really want to fry and ruin one for nothing! So I wouldn't advise hitting numbers over that 80Amps area for very long at all, and preferably never ####

I Have been running that fan on 4s pulling 85 amps for over 50 flights I have seen no loss of performance at all
So in my book this fan can handle 85 amps all day long
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Old Feb 04, 2013, 10:59 PM
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This below as WRONG.... as it is a 2970 motor in the 10blade 4S. Which is a very good motor size... and needed to fit the windings that can do 80A+ to get 1200w with 4S.
So it is a 1200w capable motor. (but still would not be happy doing that max long term. eg all flight etc).
You could still not use 5S.
(I was thinking of the 4S 5 blade DPS with all the numbers - it uses a 2850 1000w motor)
V
V
V

LOL, you wouldn't run 85A for 1 minute, let alone all day long.....

A 2850 (or 2950) is typically a 1000W motor. Your claim is for near 1200W
1000w at 4S (14.8v) is 67Amps. That is all they are rated for.
But they can be run higher than that, for peaks, short runs.... like 80A or your 85A area.
It is over the specs of the windings and may or may not last long. That is up to luck of the ambient temp... the real winding temp of that run (came from a lot cooler, or not... or how long it ran etc etc).
But basically, you are in the region of frying it and pure luck if you do or don't.
No technical merit, just luck.
If you choose to risk it, and the loss of the motor cost ($50 approx) then fine.
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Last edited by PeterVRC; Feb 04, 2013 at 11:45 PM.
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Old Feb 05, 2013, 12:45 AM
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Originally Posted by PeterVRC View Post
This below as WRONG.... as it is a 2970 motor in the 10blade 4S. Which is a very good motor size... and needed to fit the windings that can do 80A+ to get 1200w with 4S.
So it is a 1200w capable motor. (but still would not be happy doing that max long term. eg all flight etc).
You could still not use 5S.
(I was thinking of the 4S 5 blade DPS with all the numbers - it uses a 2850 1000w motor)
V
V
V

LOL, you wouldn't run 85A for 1 minute, let alone all day long.....

A 2850 (or 2950) is typically a 1000W motor. Your claim is for near 1200W
1000w at 4S (14.8v) is 67Amps. That is all they are rated for.
But they can be run higher than that, for peaks, short runs.... like 80A or your 85A area.
It is over the specs of the windings and may or may not last long. That is up to luck of the ambient temp... the real winding temp of that run (came from a lot cooler, or not... or how long it ran etc etc).
But basically, you are in the region of frying it and pure luck if you do or don't.
No technical merit, just luck.
If you choose to risk it, and the loss of the motor cost ($50 approx) then fine.
Don't really give a toss what you think.like I said before, you have all the numbers and figures over 4000 posts, can you actually show me a Vid of your T45 flying so i can see how well it really performs. you seems to be the guy who know it all.
I'll keep pushing this fan as hard as i can,and when or if it dies I'll just buy another motor, 50 bucks I make that in less than an hour LOL
PS: by the way I have always been very lucky
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Old Feb 05, 2013, 05:28 AM
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...

Quote:
Originally Posted by PeterVRC View Post
A motor is not a motor......
LOL

KV only means the RPM it will do per volt. It doesn't mean anything about what power the motor can handle.
For a given voltage, AND the load the motor has on it (what fan, prop etc), it will TRY to run a Speed X (dictated by KV), but only be able to reach "X divided by Y" according to its construction versus that load. The situation it is in will make is draw Z Amps.
For the exact same motor and situation (fan it is in) if you raise volts you will cause the Amps to rise. Power = Volts x Amps, thus power rises too.

If the motor was only made to cope with Power X, it will fry if you cause it to run (or try to run) at higher power - they will all keep going higher than they are truly capable of, for X amount... to the point they fry. Too much heat basically..... via too much current (Amps) through the windings.

So.... KV on its own means little.
What matters is a total of a number of factors.

If someone says they had a motor of X KV, and another person had another motor type of the same X KV, you still need to know WHAT were all the other specs of each motor, to know which will do what for a given cell count and fan use.
After reading your post, i understand much more about the relationship between KV, volt, amp etc.... I think the manufacturer should include the wire size of their motor so that we can estimate the current it can withstand.
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Old Feb 08, 2013, 07:23 AM
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TURNIGY PLUSH 80 amp esc

I have finished my t45 the same as dishos, but when I plugged the ESC in in continually beeps and nothing but the mother jiggling.
When I look on the instructions it says that it is possible that the voltage is to high. I don't get this as the packs have been used before and all are fine. I have noticed though when I conect the pacts there is a small spark. I have had this before but the small spark did not cause a problem. Another strange thing is when I gentle squeeze the ESP it starts working.

Any help would be great
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Old Feb 08, 2013, 10:17 AM
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Originally Posted by Frank2351 View Post
I have finished my t45 the same as dishos, but when I plugged the ESC in in continually beeps and nothing but the mother jiggling.
When I look on the instructions it says that it is possible that the voltage is to high. I don't get this as the packs have been used before and all are fine. I have noticed though when I conect the pacts there is a small spark. I have had this before but the small spark did not cause a problem. Another strange thing is when I gentle squeeze the ESP it starts working.

Any help would be great
Hi, have you checked that you have the throttle
trim all the way down on your transmitter ? as this will cause the esc to beep, also check the throttle chanel is not reversed, you do get a spark conecting the packs on 6s. its possable a faulty esc as i did have one that would work when i would gentle squeeze the esc
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Old Feb 08, 2013, 10:40 AM
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Cheers Disho

I don't know how, but I left it as I was getting pxxxxd off with it. An hour later I plugged it in and it worked, but the orange reciever keeps flashing. If I rebind it the orange light goes solid, but when the battrie is disconnected and plugged back in it starts flashing. The only way I can keep it solid is if I turn my DX6i off then then plug the bat in and then turn the transmitter back on.

Disho
Did you find that with a 6 cell 3300 when held in an upright position and full throttle would it hover or did it slowly drop.
Mine slowly drops, but I recon if I gently threw it level it would be off like a goodun. Tommorow is forecasted 7mph winds, so hopefully a maiden.
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Old Feb 08, 2013, 11:03 AM
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Originally Posted by Frank2351 View Post
Cheers Disho

I don't know how, but I left it as I was getting pxxxxd off with it. An hour later I plugged it in and it worked, but the orange reciever keeps flashing. If I rebind it .

Disho
Did you find that with a 6 cell 3300 when held in an upright position and full throttle would it hover or did it slowly drop.
Mine slowly drops, but I recon if I gently threw it level it would be off like a goodun. Tommorow is forecasted 7mph winds, so hopefully a maiden.
HI, i never use the orange recivers only spectrum,sounds like your out of sink, ie unplug lipo, then transmitter off, then transmitter back on and then plug lipo back in, the lightshould go solid, Mine slowly drops to remember its a big plane but dont worry look how well they fly. have you had the watt meter on ?
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