Have tech questions? Will answer.

[bbrigg]

As an instrument engineer I am familiar with star (Y or wye) and delta (and various combinations) for 3 phase transformers and motors. I have often seen RC motors described as 1Y, 1.5y, 2Y and so on.

What does that mean, performance-wise, to an RC hobbyist?

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[JohnRobHolmes]

Originally Posted by Rekreant

So I thought all drag brakes were basically the same; Im guessing there is an active and passive version. Can you explain the difference for me please?

Passive drag recharges the battery. Active battery drains the battery. Passive will only be as strong as the motor/esc/battery resistance will allow. Active can be as strong as the user wants.

Originally Posted by bbrigg

As an instrument engineer I am familiar with star (Y or wye) and delta (and various combinations) for 3 phase transformers and motors. I have often seen RC motors described as 1Y, 1.5y, 2Y and so on.

What does that mean, performance-wise, to an RC hobbyist?

Sent from my LG-H870DS using Tapatalk

To the average person, no difference at all. On the bleeding edge of some motors, the Delta will be punchier than a Wye due to lower inductance for the same kV. Generally, a delta or wye will be chosen based on whether or not a specific KV can be reached with it, and nothing more.

[phillymade]

John I have a question for you and the community. I am just an average guy looking to have some fun with my truck and do some crawling/trail driving, I have a Redcat Gen 7Pro and am looking to upgrade the ESC and motor. Currently I have a Sidewinder 3 with the stock motor. I am on the fence between two setups. Looking at the Castle Mamba Micro X Crawler edition or the Mamba X with the Revolver motor. I want to have a true to life feel, if it exist, and complete control of the drive line. What are the real differences between the two in regular guy terms?

[durok]

Either of those ESC will give you the Aux Wire function to allow on-the-fly switching from Crawler mode to Rock Racer Mode.

The Mamba X is capable of allowing you to run 4S LiPo through the Revolver, whereas the Micro X is capped at 3S.

Since the Revolver is a relatively low-kv motor, it really depends on what sort of driving you want to be capable of.

If you are mostly doing slow-speed crawling, the Micro X would be fine with the Revolver, but if you want some wheelspeed for cruising down the trail quickly - I'd get the Mamba X.

Alternatively, you could run a Puller Pro Stubby with either to get a higher-kv motor so you could get more wheelspeed out of 3S.

I'm sure JRH will come on here later and have more details.

[nedmo]

Hey John,

Any chance you will be working on a 380/390 brushed or even sensored brushless motor for the ECX Barrage sized crawlers?

[Jboucher]

Originally Posted by nedmo

Hey John,

Any chance you will be working on a 380/390 brushed or even sensored brushless motor for the ECX Barrage sized crawlers?

I asked a while ago and they said not in the plans for now.

I would put a Mamba micro X and a mini puller pro 380 in my yeti Jr! Drag brake on the fly for a true mini rock racer!

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[phillymade]

Originally Posted by durok

Either of those ESC will give you the Aux Wire function to allow on-the-fly switching from Crawler mode to Rock Racer Mode.

The Mamba X is capable of allowing you to run 4S LiPo through the Revolver, whereas the Micro X is capped at 3S.

Since the Revolver is a relatively low-kv motor, it really depends on what sort of driving you want to be capable of.

If you are mostly doing slow-speed crawling, the Micro X would be fine with the Revolver, but if you want some wheelspeed for cruising down the trail quickly - I'd get the Mamba X.

Alternatively, you could run a Puller Pro Stubby with either to get a higher-kv motor so you could get more wheelspeed out of 3S.

I'm sure JRH will come on here later and have more details.

Great option. I would like the best of both worlds, sounds like the Mamba X is probably more along the lines of what I am after. Did not think of the puller pro, I'll have to check into that.

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[whitrzac]

The microX is just smaller with no data logging.

I haven't seen or heard of anyone overheating them yet... Including my friend running a 12lb rig with one.

[bbrigg]

Originally Posted by JohnRobHolmes

Tough scenario. A GOOD brushless motorand speed controller engineered for crawling compared to a low cost brushed motor and good speed controller, they are pretty close but the brushed motor will typically start slower. A 20t Crawlmaster pro or Custom Pro and good speed controller, brushed will win by a good margin on control and startup RPM.

I just watched your Hobbywing AXE comparison and seeing the Revolver's slow speed capability it is difficult to imagine brushed being much better. Why are the only Revolvers available on site lower KV than the one you use in your videos? Surely you aren't just keeping the best for yourself.

One problem I have is that as an expat based in Indonesia I can't buy direct from your site and most of your motors on eBay are shipped courier and the import duties shown on eBay double the cost. The Indonesian Post Office works far better as they only charge the proper import duty. The sweet spot for me is for stuff from the US is USPS priority which allows tracking without huge rates. I haven't seen any Revolvers online but would like to try one.

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[Rekreant]

Originally Posted by whitrzac

The microX is just smaller with no data logging.

I haven't seen or heard of anyone overheating them yet... Including my friend running a 12lb rig with one.

I had an earlier thread about this and a few guys chimed in that they had heating issues with the microX in rigs around 8-9 lbs. I havent tried it myself, Ive been researching between it, the full sized X, and the BLE from HH. I still havent come to a conclusion/decision.

[bbrigg]

Hi JRH, I have some questions that have been bouncing around in my head since watching your HW AXE comparison and hearing you talk about minimum startup speeds for motors.

1. All else being equal, what difference does motor size make on the minimum startup RPM? Like HH 540 stubby vs 540L vs 540XL.

2. Does KV rating affect the minimum startup RPM? Does that work the same way for outrunners?

3. Your Revolver motor obviously had the best minimum startup RPM in the video. Another video showed the amazing torque this type of motor puts out when you held down a tyre and were able to have the rig lift the front off the ground smoothly. What factors are at work for these motors to perform the way they do?

Thanks for helping all of us out.

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[JohnRobHolmes]

Dang, some deep questions! Just got home from a vacation, I’ll catch up tomorrow.

[JohnRobHolmes]

Originally Posted by bbrigg

I just watched your Hobbywing AXE comparison and seeing the Revolver's slow speed capability it is difficult to imagine brushed being much better. Why are the only Revolvers available on site lower KV than the one you use in your videos? Surely you aren't just keeping the best for yourself.


One problem I have is that as an expat based in Indonesia I can't buy direct from your site and most of your motors on eBay are shipped courier and the import duties shown on eBay double the cost. The Indonesian Post Office works far better as they only charge the proper import duty. The sweet spot for me is for stuff from the US is USPS priority which allows tracking without huge rates. I haven't seen any Revolvers online but would like to try one.

Sent from my LG-H870DS using Tapatalk

We are currently out of stock on 1800kv revolver 540s. The site hides out of stock variations for some reason and we can't figure out how to change that. I have more being manufactured right now, but it might still be a few months because I use unique magnets and they take the longest to get manufactured.

Originally Posted by bbrigg

Hi JRH, I have some questions that have been bouncing around in my head since watching your HW AXE comparison and hearing you talk about minimum startup speeds for motors.

1. All else being equal, what difference does motor size make on the minimum startup RPM? Like HH 540 stubby vs 540L vs 540XL.

2. Does KV rating affect the minimum startup RPM? Does that work the same way for outrunners?

3. Your Revolver motor obviously had the best minimum startup RPM in the video. Another video showed the amazing torque this type of motor puts out when you held down a tyre and were able to have the rig lift the front off the ground smoothly. What factors are at work for these motors to perform the way they do?

Thanks for helping all of us out.

Sent from my LG-H870DS using Tapatalk

1. The shorter motors have less detent force, and will start up at a lower RPM. However, they also have less torque output at any given speed, so will be a bit "mushier" to load changes. I prefer the way the 540 drives compared to the stubby, some people prefer the stubby. The XL has a different stator and rotor design and does not have a smooth start up in comparison.

2. KV does not technically change the startup RPM as long as the ESC has the low end resolution. However, in practice, higher KV motors do need more phase amps and this causes a bit of voltage drop on the wires and mosfets. When the load is removed, they rev up a little more. So in practice, depending on the ESC size and motor KV, lower KV motors tend to be easier to control during startup. 3500kv is the sweet spot of wheelspeed vs control for BLE/ mamba X size controllers. 2200kv is the sweet spot for the Micro X. This is a constant no matter what motor topology.

3. A lot of testing and tweaking of the magnetics. I do finite element analysis on computers at first, then build and test on the rocks to see if the predictions are solid. With a good motor design, we then rely on the ESC to do a great job. The Sidewinder 4 and Mamba X platforms are currently the cream of the crop, but the BLE also has just as smooth of startup with sensored motors. Without a well performing ESC, the motor design doesn't mean much. But when both of them come together properly, it is beautiful!

[TheLetterJ]

I keep kicking around the idea of going back to brushless in my Wraith, but this time trying a revolver. I have access to (in other cars) a Micro X, and an SV3. I like the aux function on the X, but since Castle does not like to list amp/watt ratings, would it be able to supply sufficient amperage to an 1800kv 540 Revolver in a Wraith on 3s, or would the SV3 be the better of those 2 options? If I'm reading right, the Revolver should only require 35-40a?

[JohnRobHolmes]

The X will be the best choice, or an SW4 if you are buying a new ESC. No problem on power using either of them with the revolver.

[Inspector86]

PWM question. Does PWM actually send electrical pulses or does it simply adjust voltage to control motor speed?

[fyrstormer]

PWM cycles the MOSFETs on/off/on very rapidly to control how much amperage gets through to the motor. In low-power applications the PWM module can be combined with a voltage regulator to control both the amperage and the voltage, but for a high-power application like RCs the voltage comes straight from the battery with no regulation. Granted, RCs aren't "high power" in an absolute sense, but in terms of watts-per-cubic-centimeter they are very high power. There's no room for a voltage regulator robust enough to control the voltage going to the motor, because the voltage regulator would have to withstand peak throughput of 50 amps or more (for low-turn motors anyway), and that would require a LOT more cooling than the typical ESC has room for. Only the BEC gets a voltage regulator, because the power consumption of the rest of the electronics is very small compared to the power consumption of the motor.

I learned a couple things tinkering with power drivers for fancy overpriced LED flashlights. God, I thought I was nuts when I was buying $500 flashlights with custom-made Grade 5 titanium casings and power drivers that could be programmed using blink-codes on computer screens. Then I finally got around to trying RC, and I've spent probably 50x as much on this hobby as that one, and RCs break a lot more often and can't be sold for anywhere near their purchase price.

[MODC]

I have tried searching, but I couldn't find anything......
Is there ANY benefit to the Mamba X over the Sidewinder 4 for the Revolver 540?
Less noise, better features with Castle Link or anything?

[durok]

Originally Posted by MODC

I have tried searching, but I couldn't find anything......
Is there ANY benefit to the Mamba X over the Sidewinder 4 for the Revolver 540?
Less noise, better features with Castle Link or anything?

1. Auxiliary Wire feature for 3rd-channel on-the-fly switching from Crawler Mode to Rock-Racer Mode (simply put, drag-brake on or off can be chosen).

2. Ability to run more than 3S, which is a boon seeing as how the Revolver motors are quite low on the kv-scale, and can benefit greatly by being run on 4S.

3. More powerful BEC - Mamba X, 8A Adjustable BEC (5.25V-8.0V) - Sidewinder 4, 5.0 volts fixed, 2 amps.

[MODC]

Originally Posted by durok

1. Auxiliary Wire feature for 3rd-channel on-the-fly switching from Crawler Mode to Rock-Racer Mode (simply put, drag-brake on or off can be chosen).

2. Ability to run more than 3S, which is a boon seeing as how the Revolver motors are quite low on the kv-scale, and can benefit greatly by being run on 4S.

3. More powerful BEC - Mamba X, 8A Adjustable BEC (5.25V-8.0V) - Sidewinder 4, 5.0 volts fixed, 2 amps.

Cool, Thanks!