Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Agreed

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Although it really doesn't need the 4s . I am also running out of spare parts. Once the whole thing is bombproof , once I am use to all the power on tap I am sure I will long for more power

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

2400 would be sweet... I mean Holmes is the one that thought us to "volt up, gear down"

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

drag break improve , my wraith is about 4.5kg , will the motor stress ?

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Thinking about running the 2200kv stubby in a wraith on 4s. What do you think?

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Should be a fine combo! A little underpowered as compared to running a 540, but not everybody wants to break parts constantly doing standing back flips :ror:

Motor temp can increase slightly when using lower frequencies, but it is better to have a cooler ESC! The four pole motors aren't loud at 8k, so it is not as annoying as something like an outrunner.



You all will be happy to know that we shall soon have 2200kv and 5000kv in the 540 size, and 2100kv in the 540XL! About two to three weeks.

The 540XL has such a long stator, that we only have 2100 and 2650kv as good winding choices. There is a speed between those with delta pattern, but the no-load went from 2.1 amps to over 8 amps due to recirculating currents- simply a bad choice. I chose 2100kv as it's low enough that folks could run 6s and get away with it. Also makes it a great 3s and 4s choice without losing too much grunt.



As a fun exercise in theory, I compared the numbers between a 540-S 2200 and 540-XL 2100 as it pertains to torque. The 540XL can produce more torque for any given voltage, based on terminal resistance and difference in KV. About 60% more, using 17.5mOhm and 11.1mOhm measurements for the two. This also means that it will keep a more consistent RPM under a specific load. To be specific, there would be 37% less voltage drop inside the XL. So if the Stubby lost 1000rpm under a specific torque load, the XL would lose only 630rpm. This torque is spread over 2.25 times the stator length (15mm vs 34mm), so we can consider localized waste heat to be 2.25 times less per unit output of torque. Take away message, the XL will handle about twice the torque of a Stubby over long periods without significant RPM loss or heating.


As a less technical comparison, the 540XL weighs 1.75 times a 540 Stubby. Since the difference in weight is almost all active materials like rotor and stator, we could loosely guess it is about twice the motor. A check of the stator lengths confirms, the XL has 2.25 times more active length (15mm vs 34mm). Same take away message without all the fluff, the XL will handle about twice the torque of a Stubby.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

My rant for the day:

Lower KV brushless motors DO NOT produce more torque. DO NOT!!! A motor is limited by the size and materials, there is no magic method to extract more torque. So if you want more torque, don't get a lower KV and expect a wild change.



The exception (and ensuing overthinking): Systems with undersized ESCs or ridiculously high KV reference motors. Your ESC will run HOT. The ESC is not happy about the phase current needed and drops a lot of voltage. In this case, a lower KV motor can "produce" more torque, as the ESC is providing more voltage with reduced phase amp requirements. So technically the lower KV motor doesn't make more torque, but the ESC is happier and allows more.

In this case of a puny ESC, if you want more torque you can get a bigger ESC, increase ESC cooling, increase geardown, or get a lower KV motor. The choice of lower KV will also reduce system power, so it must be met with increased voltage if overall system performance is to get better. This could be considered "volt up, KV down" method of gaining torque when the ESC is limiting.


common example- Using a 3300kv on 3s lipo VS 2500kv on 4s lipo. Let us assume the ESC is big enough and runs cool. Option one for more torque- just gear down. But you don't want to lose wheelspeed, you want it all? Ok, now you must try lower KV and higher voltage. At the least, phase amp requirements will be lower and thus voltage drop is lowered. Design of FET drivers and internal BEC is important, the ESC may actually run hotter while dealing with higher input voltage. That would counter act the phase current advantage of lower kv! You also have a bigger battery to deal with, more weight to eat up your newly found torque. So maybe you get better perceived torque, maybe you don't. Too many factors to say that "Volt up, KV down" will always work.


So what is the foolproof methods for more torque? Volt up, gear down! (if you can take some speed reduction). Don't want to lose speed? Bigger motor, bigger ESC, bigger battery! Whichever runs hot, make it bigger! If you are rock racing and the ESC is burning hot, go to 8th scale ESCs. If you are rock crawling and everything is cool, just get a bigger motor. If your battery is hot, a bigger battery will improve everything.


end rant.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

John, I love your insight and honesty about motors and esc's. Its how I do business and people seem to appreciate actual honest service. Keep up the good work, and I'll keep funneling my business through you.

ps. Love my Puller Pro 540s; tons of fun:mrgreen:

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

I think this may be my first brushless. My only concern is gearing. I run a 32P 56/14 setup currently. Is this gearing optimal for a 3500kv Puller Pro? I keep toasting cheap brushed motors, but I'm throttle heavy and run lots of dirt. My HH 35T Torquemaster Sport lasted awhile, but I've burned up a few cheaper cans since then finally frying my 35T integy cheapie last weekend. I run a MMP and 3s Lipos. Does the gearing look good?

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

with brushless, gearing doesn't really matter as much. I run 4:1 or taller on most of my brushless rigs. Your biggest concern will become the rest of your drivetrain, and not the motor.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Thats what I wanted to hear:mrgreen: I'm fine with yardsaling parts all day, I just dont want to keep toasting motors. Most of the drivetrain is steel, the rest needs to break to give me a reason to upgrade it. Thanks John, cant wait to get one and put it to the test!

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Please make the Puller Pro XL 2650kv.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

We will look into this specific KV for future manufacturing. If you want something for 4s use, the 2100kv version can be geared up for wheelspeed in most applications. You didn't hear it from me, but the 3500kv also seems to handle 4s pretty dang good if it doesn't overheat and soften the rotor epoxy. :twisted:


2100kv 540 XL motors and others should be here in about a week.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

I was running a PRO4HD 3000kv on 4S and the power was great right up until it locked up and started smoking, I think it overheated the rotor epoxy like you said.

Tekin says the limit for 4S on the RX8 is 3000kv so I'd like to stay at that or under. Put me down for 2 of the 2650kv if you make them.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Just as our customers requested, now we have a wider range of KV values in our sensored 4 pole Puller Pro line! Whether you are planning to run higher voltage or lower voltage, want more wheelspeed or less, we have you covered!


Now we get to test a 4500kv Puller 540 on 3s in a 4x4 slash. 30mph wheelies sound fun...


Holmes Hobbies LLC

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

Very interesting! :twisted:
What you recommend for a heavy Yeti 2 speed, running 3S (maybe 4S one day) doing mainly U4 races eventual trail and crawl? the 3500kV or 2100kV?
(ESC I'm still in between the BLE pro, Mamba Max Pro or Mamba Monster X)

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

3500kv and monster X (which we have in stock and need to add to the site). The aux wire drag brake control of the Monster X will be very useful for racing.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

So here's a somewhat related proposition for you, Sr. Holmes. Last year, I picked up a couple of VTX8s because of a unique feature - a 2-stage drag brake setting. It was designed for racing so that you could preset a higher drag brake at high engine speeds (quicker braking response when coming off a straight) and lower drag brake at lower engine speeds (allowing you to maintain speed in slower sections). I thought it would be interesting to flip it around in a crawler -- low drag brake for smoother operation at high speeds and high drag brake for more precise control at lower speeds. It turns out to be a neat little feature that works quite well for our purposes.

In the VTX8, the setting parameters are simple and can be set through their field programming card. You pick a threshold RPM (they call it trigger RPM) as low as 500 and up to 10k+, if I recall correctly. You then pick one drag brake setting below that threshold, and another above the threshold.

So here's the question - any chance you could work something like this into the BLE firmware, adjustable through Castle Link, since I'm not exactly interested in running bulky 8th scale ESCs in all of my brushless rigs? Even slicker than the binary, 2-stage setting of the VTX8 would be an adjustable curve. Maybe flat from zero up to a threshold RPM (which we would set high for crawling), then linear reduction from the threshold RPM to zero at max RPM? Or do I ask too much? ;)

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

I too would love a drag brake that had different strength at different RPM. I have mine set to work well for crawling but letting off anywhere near top speed on a high traction surface my Wraith ends up on it's roof. Not a huge deal but it would be neat.

Re: Puller Pro Brushless 4 pole Sensored motors- Lays down the Power!
 

I've read everything I can in this thread and others and while it was touched on a couple times I'd like a more specific answer if there is one. I have the Holmes 3500 puller pro standard in my 9lb Wraith. The motor stays cool, the ESC (MMP) stays coolish with the fan coming on now and then depending on the situation, and my 2200mah 3s batteries last about 1 and 1/2 hours. I've got great startup and have my throttle limited to 70% forward and 40% backward. I'm geared at 56/10 so I can't slow it down anymore with gearing. I could go to a 60 spur but that presents other issues. My question is, what would be the main differences, advantages, or disadvantages between running a 2200kv at 3s or running my 3500kv on 2s? Both of these options put me in the range of 25,000 RPMs motor wise. I feel like I'm running the wrong kv motor because I've done too much to get it to suit my purpose.