View Full Version : Pletty shadow KV?
TimisTim
08-15-2005, 05:28 PM
As you all have seen there is a pletty shadow on ebay I am thinking of buying. What is the kv of this motor? I like to run 11.1v lipos and am pretty sure this would not be a good setup for a shadow.
tcolesen
08-15-2005, 05:50 PM
The Shadow has ~6200kv. A 3s Lipo would push it past 65,000RPM, which is way too much. The Extreme would be better for 3s Lipo, as it has a kv of ~4500.
kufman
08-15-2005, 11:12 PM
The shadow is a good 6-cell motor and probably not much more than 6, maybe 7.
TimisTim
08-16-2005, 01:16 AM
Yeah I figured as much. 6200 is a pretty high rpm motor! Im trying to get all 11.1v lipos for all my cars so I can switch batts to each car and still have a good setup.
I am figuring a Lehner xl3600 for my xxx-t and Nitro MT2 conversion (I was told to get the "XL" because it would dissipate heat better). Now I just have to get a good motor for my TC3. Any suggestions?
tcolesen
08-16-2005, 03:38 PM
How much money are you willing to spend? I would say go for a Plettenburg Extreme, although you may be nearing the 50,000RPM limit with 3s Lipo. You could always go with a Lehner XL4200. That might be too much power though... Or for cheap (~$60) you could get a Feigao 380 size 9s. This motor has a small, lightweight rotor that would give a lot of off the line punch (as opposed to the heavier-rotor 540 motors).
TimisTim
08-16-2005, 04:53 PM
I'd be willing to spend around $150 for a good motor.
I've been hearing about the 380 motors for a while now and may give them a try. Where can I get an adapter plate?
Rtsbasic
08-16-2005, 07:17 PM
LMK make some for the Lehner 15xx series of motor last I checked.
Thats another type of 380 motor you could look into - the Lehner 1520, apparently they're good, faster than a C40 6s or any Feigao. Although they are around $200.
TimisTim
08-16-2005, 07:38 PM
Would you have a web site, I'll try to catch it on google.
Just wondering, I'm not familiar with those motors but what kind of can size is the plettenberg shadow? Is there a need for an adapter plate to fit in a 1/10 touring? I'm considering picking one up.
tcolesen
08-17-2005, 01:16 PM
The Shadow has a 540 size can, it's a direct drop-in to any 1/10 vehicle.
Thanks Tcolesen. Besides the shadow there is also the extreme (I think around 4500kv). I'm also running on 11.1v Lipo on a 1/10 touring - essentially what would be the better choice between the two?
tcolesen
08-18-2005, 10:01 AM
The Extreme would be better for 3s Lipo. But make sure that you gear properly, since 3s Lipo on the Extreme would be pushing it close to the 50,000RPM mark, so it will generate extra heat from that.
The Shadow on 3s Lipo would be too much. On full throttle, it would go past 60,000RPMs.
The Shadow is out of the question then. They also make two other motors in the same series:
indoor1 - around 3900kv
indoor2 - around 3900kv with around 20% more Torque to fill the gap between the Indoor 1 and the Extreme
With those two motors in mind would the Extreme remain a better choice for 3s Lipo?
tcolesen
08-19-2005, 09:55 AM
Those motors would be better for running only 3s Lipo. If you plan to run 2s (or 6 cells) and 3s Lipo, then get the Extreme. The Indoor series are still over 40,000RPM on 3s Lipo.
Thanks again Tcolesen. I will get the Extreme since I'll be running on 2s and 3s. Can't wait to run it with the U-Force75. A sensorless/6-pole system..what more can I ask for :D
TimisTim
08-21-2005, 12:00 AM
Cant the UF75 only handle 120,000rpms on a 2 pole motor? So does this mean that a six pole would have to be kept at 20,000rpms?
tcolesen
08-21-2005, 01:11 PM
I thought the Extreme was a 4pole motor. So it would need to be kept under 60,000 RPMs.
starluckrc
08-22-2005, 09:45 PM
250,000/# of poles
The Indoor II is 6 poles. The other Pletties are 4 pole motors.
Guys, I stand corrected. Thanks for clearing this up Jaimie.
Those motors would be better for running only 3s Lipo. If you plan to run 2s (or 6 cells) and 3s Lipo, then get the Extreme. The Indoor series are still over 40,000RPM on 3s Lipo.
I’ve just spoken with Etienne @ iCare down in Montreal with the intention of purchasing the Pletti Extreme. Surprisingly the kv rating on the two series mentioned were:
Extreme 4600kv
Indoor 4000kv
He had recommended the Indoor for running a combination of 3s and 2s LiPo. (Kokam 20C 3200)
The reason is that the Extreme configured with 3s translates to 51,060 RPM just above the 50,000 RPM mark. On the other hand the Indoor would be rated under the given limit at 44,400 RPM.
According to those calculations the Indoor series seem like a better choice but, a second opinion wouldn’t hurt :)
tcolesen
10-31-2005, 06:26 PM
You could get the Extreme, and then just limit the maximum throttle. Even if you didn't do that, there is only a slight possibility that it would rev to 50,000RPMs, because you have to figure the battery's voltage drop. If throttle was limited to 90%, then the motor wouldn't see more than about 46,000RPMs, which is a much better number, and would still provide plenty of power.
The Indoor would require a pretty good controller for running on 3s Lipo. It seems like 2pole motors run best with about 8khz frequency, and 4pole motors like 16khz frequency. This means that the Indoor would probably run best with 24khz. To get that, you need a programmable controller. But, at that high of a frequency, the controller is going to be working pretty hard. To add to that, a 6pole motor at 44,000RPMs requires 3 times the RPM requirement as a 2pole motor.
My opinion is that the Extreme on 3s Lipo limited to 90% throttle, or the Extreme on 2s Lipo would be a better setup than the Indoor on a 2s/3s setup.
OptimaMan
10-31-2005, 06:35 PM
The Indoor II being 6 pole is limited to 40,000 rpm with a Schulze controller.
starluckrc
10-31-2005, 10:24 PM
The Indoor is 4 pole though with the II getting it's extra torque kick from it's 6 pole design.
Good thing I asked before making this purchase. I was not aware or knowledgable enough to understand that the Indoor adds to the pressure on an ESC.
At this point I'm not clear on the frequency explanation. If a 4pole motor runs best on 16khz frequency as mentioned. The Indoor is also a 4pole just like the Extreme so wouldn't this mean 16khz may be a better frequency for either of the two?
I also intend on using my U-Force 75 with the Extreme and perform the required parameter changes via U-soft. For a closer look on what's available as option to program it looks like 14 and 16 should be changed.
[14] (3Phase) Set part throttle frequency to 16khz
[16] (3phase) RPM Limit (2pole engine)
I'm not quite sure what to set number [16] to? I'm guessing around 48,000?
For a better idea on how the parameters within u-soft appear here is a link . Please see post #103
http://forums.radiocontrolzone.com/showthread.php?t=169983&page=5
tcolesen
11-01-2005, 06:38 PM
Good thing I asked before making this purchase. I was not aware or knowledgable enough to understand that the Indoor adds to the pressure on an ESC.
At this point I'm not clear on the frequency explanation. If a 4pole motor runs best on 16khz frequency as mentioned. The Indoor is also a 4pole just like the Extreme so wouldn't this mean 16khz may be a better frequency for either of the two?
I also intend on using my U-Force 75 with the Extreme and perform the required parameter changes via U-soft. For a closer look on what's available as option to program it looks like 14 and 16 should be changed.
[14] (3Phase) Set part throttle frequency to 16khz
[16] (3phase) RPM Limit (2pole engine)
I'm not quite sure what to set number [16] to? I'm guessing around 48,000?
I was thinking of the Indoor II (6 pole) when I typed up my response. Regular Indoor would use 16khz.
You don't need to set an RPM limit if you can help it. You will probably need to with a 6 pole motor, though.
Thanks T. I've placed the order for the Extreme yesterday and should be here in 2 days.
Just need to remember adjusting throttle settings on the transmitter to 90% when using the Pletty/3s LiPo combo.
I'll get to compare it against the 2-pole kontronik twist42 (4200kv) using 2s and 3s format. The Twist/U-Force75 combo is very smooth but from what I hear the Extreme is even smoother especially upon gradual acceleration.
SpEEdyBL
11-02-2005, 10:36 PM
What actually happens if you reach the rpm limit? Does the motor stop accelarating or do bad things happen?
I think someone else may explain this better but if I'm not mistaken the magnets due to their exposure to high heat would gradually lose their properties, that is, demagnetize. At this point if you continue running with this inefficiency you may encounter sever cogging and a risk of overheating the ESC in a matter of a minute or less.
At least from experience this is what I've encountered when "frying" the magnets on a kontronik twist42 (2-pole) motor using 14.8 (4s) LiPo. High voltage it was but this was primarily a result of improper gearing.
e_lm_70
11-03-2005, 07:33 AM
What actually happens if you reach the rpm limit? Does the motor stop accelarating or do bad things happen?
One think is motor RPM limit ... one other think is over-heat the motor.
The neo magnet start to lose their property when they exceed 80 or 120 deg (depending of the type of neo magnet).
The rpm limit, it is for mecchanical reason, like ball bearing rpm limit (over that point they get too hot or they could crash/deform) ... or limit in the rotation mass ... for instance my HiMark 2816 6 poles, the rotor has 6 magnet glued on the shaft .. and I guess over the 40k rpm limit for this motor, I think they can get unglued due tue the centrifuge force.
Actully I don't belive any of my ESC is capable to rotate my 6 poles faster then 42k ... so I should be safe anyhow.
Some ESC are capable to configure the mar RPM, like UF75, Graupner Genius, etc ...
Some can also set the max current, like Graupner Genius.
So if you set max current and max rpm ... you motor should be safe in the 99.9% of cases ....
e_lm_70
P.S: The RPM limit I don't think it will cause any mayor arm to the motor if you exceed up to 10-20% of the RPM limit, just for few short moment in the full run of the pack ...
SpEEdyBL
11-03-2005, 09:07 PM
What I meant to ask is: What happens if you exceed the esc's rpm limit? For example, if you had a really bad esc that could only run 2 pole motors at 30,000 rpm max, what would happen if you added a motor that would normally spin at 40,000?
I've misunderstood your initial question.
If one uses a motor which is running with more rpm than the given controllers' limit the idea is that
it will not withstand the higher rate. As far as the outcome this may vary depending on firmware
installed within a paricular ESC model/make.
The general symptoms can be either of the following:
Remain at the highest RPM
May overheat
Will stop after a while (good decision)
Can be destroyed immediately by wrong phase commutation
-Key