I bought a Hobbywing ESC - Is this our Holy Grail?

Just a heads up for anyone considering the HW Max4

It will NOT come with the sensor cable adapter. I purchased via hobbywing direct through Amazon and it came sealed in the box without the cable. I reached out to hobbywing and they were... less than helpful. They offered a coupon to their direct site which doesn't offer the cable for sale.
I mentioned this and they told me to take it up with amazon... who also doesn't offer the adapter for sale.

I'll probably juts chop off their proprietary connector at this point

EDIT:
Just wanted to update this. After some back and forth with hobbywing (read:complaining... which I hate to do to the poor customer service rep), they have agreed to send me the cable free of cost.
It looks like they are moving to offer the adapter as a separate item but it is still not available from them directly yet. So I'll leave the previous message as a heads up to anyone who's going this route at a later date.
 
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cmoalem said:
ok ... I just multiplied 300A (the esc rating) with 50V(~12s lipo esc and motor rating) since it is sold as a combo as is from HW ... maybe I have used too much "over the thumb" estimates 😉
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I too was doing the simple watts = volts x amps.
88 Fiero; I also wasn't saying that it was rated for a continuous anything. I figured a 340 amp pump might be an ok thing and yes, logging temps would be very important.

I'm personally straddling the fence on this as a cheap option and 'see how it goes' or 'buy once and cry once' with the MGM unit. The MGM guys have finally responded to my email after like three weeks, so I'll see what details I can get on it.
 
An intermediate price point possibility is an APD Pro 16S rated for 400 amps (180 seconds) and 600A burst. These are selling for $699 on Ebay. Also NeuMotor makes various 10 kW continuous, 20 kW peaks motors. For example the 3020 which is available in KVs from 165 to 700. Their website does not list a price but their similarly rated 8057 (lower KV) is listed for $489. I have talked to NeuMotor a couple of times on the phone and it is refreshing to be able to talk to someone who actually knows what what they are talking about.

I know that Alex blew up an APD ESC but we don't know why. That may have just been a fluke.
 
Actually we always need to keep our vision sharp and be ready to re evaluate.
On the other hand I know that Alex is
a) not shallow in his conclusions (unlike me sometimes shooting from the hip) and
b) has meanwhile burnt much more lesson cash than anyone of us.

My personal take with the APDs: from the 3D cad designs showing how much MosFET is stacked in multiple layers in that relatively tiny case APDs are very impressive. (Their firmware seems to be top notch too!)
But we already were wondering how they solve the heat dissipation (without having filled those cases with some heat conducting mass and only with passive cooling of the case from outside) and isloation topics around the caps ...
I am not an expert ... knowing only basic stuff and I keep wondering. Our bus bars in the battery packs are monstrous enough to handle multiple hundreds of amps and relatively low voltage increments (between the stages) ... and then I see multilayer smd boards handling 3 phases of AC voltage and those multiple hundreds of amps ... and cannot help to cringe.
(yeah I know ... some smart engineers have designed enough copper surface for the important connections into this tiny package ... but still cringing ... and somehow "we think" in china the engineers might be cutting corners for sales profit more than elsewhere)
 
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I posed the cooling question by e-mail to APD and let's see what they have to say. That's a litmus test for me. Do they respond? Do they seem to provide an intelligent answer?

For example, I called Speedmaster who seems to be associated with PCE and asked if they have compressor map for the P2 supercharger. The answer was we don't have one but we'll ask the Australian office and get back to you be e-mail. No e-mail forthcoming. I then called again and asked if the P2 was direct drive or had a step-up gear similar to a Vortech (one catalog showed step-up for PCE)). And if it is direct drive how do you drive it from an engine without a jack shaft to get enough impeller speed? The person on the phone did not know. He said you need to talk to Mr. X but he's not in. Here is his e-mail address. He'll get back to you. No e-mail forthcoming. So am I not
surprised that one person here got a P2 that was mis-assembled and another with bearings not rated for the advertised max rpms.

The specs that are published for the P2 are exactly the same as a Vortech V2 Si trim. So I think that PCE just cloned the compressor wheel and case.
I'm looking at a 2.8L V-6 with 10 psi of boost. At that boost the P2 would be in surge at low engine RPM and I don't want to just blow-off air (complicating controls and consuming battery power) to keep it happy. So I'm looking at a Rotrex C15-60 which is the right size. It's a bit spendy but I'm pretty sure that it is a better quality unit. I have e-mailed Rotrex a couple of times and they got right back to me.

Since a few Max4 ESCs have been purchased maybe someone could pop the hood and see what's in there MOSFET wise (besides a fan which will take up a lot of space.

More experience here may convince me that the Max4 is the way to go. I'm just a bit of skeptic. The power supply wires for the Max4 strike me as too small for a unit rated for 300 amps.
 
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Got an immediate response back from APD. They said that the APD Pro was intended for airplanes and that they would have concern about vibration when used in a car (personally I would think that a model airplane would have more vibrations than a car). I asked if the vibration concern was unique to the APD design. The components of concern are the bulk ceramic capacitors which are used to keep the size down. They couldn't comment on the type of capacitors used in other brands ESCs

As far as cooling I did find this on their website:
"Continuous current ratings are at a 100% throttle duty cycle. Continuous rating is defined as max sustained current at 100% throttle for 180 seconds with 10 m/s airflow"
 
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McMaster-Carr sells an 80mm by 80mm muffin fan that puts out 130 cfm. It draws 3A running on 12V DC. If the APD ESC was enclosed in an 80mm by 80mm by 125mm box with the fan at the end, the air flow would be over 10 m/s.
 
The P2 is indeed a clone of a Vortech Si trim - there was a court case over it. The only differences being the billet back plate (and therefore drive mechanism) and the P2 has metric hardware (Vortech is imperial). This is from a guy who was involved in the suit and wishes to remain anonymous (he still works in the business). I'd normally feel bad about something like this, but the chief engineer at Vortech isn't a very nice or forthcoming person, to put it mildly. This is a "reap what you sow" sort of thing.

As far as the APD stuff is concerned - yes, it's top notch stuff and they're great people to deal with. I still maintain the weakest link is lack of conformal coating and insistence of extremely tight packaging. I don't buy the vibration thing, since the other multiple computers in my car use stacked ceramic SMD caps and I haven't had any failures with them. That's just my opinion, and they're sticking with their opinion, but I feel pretty strongly about my opinion. There is one foible with their firmware in that it won't go above 300 amps, and they told me not to worry about it, but I don't know what that means for the datalogs and other settings. But again, as far as a company goes, they've been very responsive.

As for the cooling issue, I had the same worries - but found them to be unfounded. We're not pushing these things for very long, and particularly if you have the units in moving airflow, I think you'll be fine. My advice - get it working first, and then figure out how much more (if any) additional cooling you need.

And yes, this means I'm back from my month-long trip... I brought back a cold with me, but at least I'm back.
 
I did exchange a couple of more emails with APD and detailed my design parameters:

5-15 seconds runs with 50% duty cycle
1 second spool up time
240 amp compressor load at full speed (10,000 motor rpms)
90 amp compressor load at motor initial start-up
40 amps additional for inertial acceleration during 1 second spool up period
A micro controller which would out put a PWM signal to the ESC to proportion the motor rpm to the engine rpm (8800 to 10000 motor rpm range over 1500 to 5500 engine rpm range)

This is a quote from the email I got from APD. I complimented then on their candidness:

"With all the data you've provided, it sounds like it may work, but to be quite frank, we've had a lot of people try electric forced induction with our ESCs, and generally Neumotors, and I don't recall any of them working. Most of the time, we're not really sure why either, so it's hard to say what needs to change. They're not the cheapest controllers, and I don't want to sell you something that I can't guarantee will work.

You may not necessarily need sensored, but it depends on the initial torque you require. I imagine there's a reasonable amount of static friction in supercharger, and this could stop them from starting every time. The other reason is response time, but if you only need to spool in one second, I imagine any sensorless ESC could do this quite easily."

I queried Rotrex about break away torque. I don't know if their proprietary "traction drive" will help or hurt.

I'm about 6 months away from kicking off a project. The APD F series is cheap enough at $209 that I may take one for the team and give a go on a test stand

There are people in the model airplane world pushing the F series very hard - flight times of over 200 seconds
 
Similar to the motor summary, I am seeking a short list of ESCs to consider that are in the <$500 realm given the experiencial knowledge and collective wisdom of the forum.

What other specific models should be on the list? What should be crossed off this list? Are there other considerations? Country of manufacture? Other safeguards? Data logging? Are there any advantages to matching motor and esc manufacturers for a perfect pairing?

ESC Description​
VoltageProgrammableCont AMPt / Peak AMPPrice
Hobbywing EZRun Max46S-12S300A / 2000A$450
Castle3S-12SCastle link160A$315
APD$209
MGM
 
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The Castle ESC hasan MSRP of $315 usd, at least from what I can find. LMT doesn't make ESCs - they only make motors. MGM makes their ESCs. You might want to look here: https://www.mgm-controllers.com/esc...QrUZR6Or5Z1QOFYeGn2yRbgk8w1ayI5hoCS4sQAvD_BwE

I really like them, but they're hard to get and expensive. But they certainly can hold the most power. This is the one I run with the Sledgehammer (hold on to your wallet and sit down before you click):

TMM 80063-3 for Cars X2-SERIES PRO

The most powerful speed controller TMM 80063-3 for your RC car. With 1000A peak and 800A continuous current we are sure you will be in the lead.
www.mgm-controllers.com www.mgm-controllers.com

3 Hobbywing/Castle setups would still be cheaper than 1 MGM/LMT setup.
 
SpikeG said:
Just a heads up for anyone considering the HW Max4

It will NOT come with the sensor cable adapter. I purchased via hobbywing direct through Amazon and it came sealed in the box without the cable. I reached out to hobbywing and they were... less than helpful. They offered a coupon to their direct site which doesn't offer the cable for sale.
I mentioned this and they told me to take it up with amazon... who also doesn't offer the adapter for sale.

I'll probably juts chop off their proprietary connector at this point

EDIT:
Just wanted to update this. After some back and forth with hobbywing (read:complaining... which I hate to do to the poor customer service rep), they have agreed to send me the cable free of cost.
It looks like they are moving to offer the adapter as a separate item but it is still not available from them directly yet. So I'll leave the previous message as a heads up to anyone who's going this route at a later date.
Click to expand...
The battery cable was not that expensive on the hobbywing website, only $5. But that did not have any shipping options under $10. The same adaptor was also available from eBay for $10 free shipping but shipping from China.
 
So, I am trying to figure out if I made a bonehead move and purchased an incompatible motor Castle 1722 and ESC (hobbywing MAX4). I bought the castle because of the high RPM (rated at 90,000 max RPM 2400 KV motor at 8S) and want to run it in the 70,000+ RPM range.

I bought the castle MAX4 (still in wrapper and returnable) because of the massive power handling and this thread. But, I am now wondering if this ESC won’t be able to drive the motor fast enough. The spec says the motor limit is: 12S Lipo - KV≤600 70125 size motor. So does that mean the ESC can only handle a motor of < 600KV? Doing the math, 12S x 4.2 volt = 50.4 volt x 600 = 30,000 RPM limit. So, is this a no go for the high RPM castle 1721 2400KV motor? Does that make sense?

Any advice or thoughts? It would seem that I either need to:

A) return hobbywing MAX4 and get what ever castle recommends as a pairing for the 1722 motor, although not sure if it will be able to handle only the power required to spin a compressor for electrified boost.

B) keep the HW MAX4 ESC and get an LMT 2 pole motor wound for low KV. The 2 pole motor would get me double the RPM.

C) keep hobbywing ESC, get hobbywing motor and gear it up 2:1 to get to targeted RPMs

D) the pairing will likely work to deliver high RPMs of which the 1721 is caple. But I am just learning how to think about this.

I really want to make the direct drive work and want to give it its best shot of being viable under the $1,000 mark.

I am leaning towards just getting up and running using castle system (option A) at lower boost (5-7 psi) realm. Then I can upgrade ESC, motor, and battery in a few years as tech advances and prices come down as I get hungry for more boost.

Any thoughts?
 
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GTHound said:
So, I am trying to figure out if I made a bonehead move and purchased an incompatible motor Castle 1722 and ESC (hobbywing MAX4). I bought the castle because of the high RPM (rated at 90,000 max RPM 2400 KV motor at 8S) and want to run it in the 70,000+ RPM range.

I bought the castle MAX4 (still in wrapper and returnable) because of the massive power handling and this thread. But, I am now wondering if this ESC won’t be able to drive the motor fast enough. The spec says the motor limit is: 12S Lipo - KV≤600 70125 size motor. So does that mean the ESC can only handle a motor of < 600KV? Doing the math, 12S x 4.2 volt = 50.4 volt x 600 = 30,000 RPM limit. So, I am sensing this is a no go for the high RPM castle 1721. Does that make sense?

Any advice or thoughts? It would seem that I either need to:

A) return hobbywing MAX4 and get what ever castle recommends as a pairing for the 1722 motor, although not sure if it will be able to handle only the power required to spin a compressor for electrified boost.

B) keep the HW MAX4 ESC and get an LMT 2 pole motor wound for low KV. The 2 pole motor would get me double the RPM.

C) keep hobbywing ESC, get hobbywing motor and gear it up 2:1 to get to targeted RPMs.

I really want to make the direct drive work and want to give it its best shot of being viable under the $1,000 mark.

I am leaning towards just getting up and running using castle system (option A) at lower boost (5-7 psi) realm. Then I can upgrade ESC, motor, and battery in a few years as tech advances and prices come down as I get hungry for more boost.

Any thoughts?
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I think you will find it is capable of running the motor to full speed. I thought the same thing with mine but had no issues (yet) However I do not run it continuously but only for a few seconds at a time
 
matnrach said:
I think you will find it is capable of running the motor to full speed. I thought the same thing with mine but had no issues (yet) However I do not run it continuously but only for a few seconds at a time
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Thank you for the reply. Well that is interesting indeed. What is the max RPM you have hit with the HW Max4? 40K? 50K? 60K? 70K? 80K Motor RPM? If using a 4 pole motor, do we get the eRPM by multiplying by motor pole count? So for my 4 poled motor 80K motor RPM x 4 poles = 320,000 eRPM? I am just curious what the highest number eRPM you have seen, even for short bursts, because that means that the computer timing clock is capable. It sounds like maybe I should unwrap it and give it a try, but at $450, I want to make sure at least that the hardware is capable of my design goals as I don't have money to throw away on a bunch of expensive parts that I don’t use. I am trying to get this right based on the wisdom of those that have walked before me.

Regarding the length of the bursts, that sounds more like a heat issue, which is what steered me to the HW Max4 in the first place. I liked the heftiness (extra thermal mass) and the big cooling fan. Have you ever had it cycle off on one of its protection modes? Low voltage? High temp, etc?
 
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If the compressor is a GT3582R it needs to run at about 58000 rpm to make 7 psi of boost flowing 21 lbs/min of air. 21 lbs/min is what I estimate for 2.0L push rod engine at 5500 rpm. I’m riding in car right now
and don’t have access to the software needed to estimate kW required.

At 85000 rpm the boost would be close to 20 psi with this engine and I’d guess i’the compressor would need at least 20 kW from the motor. Don’t see it happening with the motor selected.
 
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Got back home from vacation and found an error in my spreadsheet that was over predicting air flow. So I went ahead and built of DynoSim5 model of a 2.0L push rod engine like the Opel GT. The base case N/A model predicted 97 HP at 4500 rpm which is close to what I can find on that engine. The N/A air flow at 5500 rpm was 9.2 lbs/min. I then ran a 7 psi boost case. The air flow was 12.3 lbs/min at 5500 rpm. This gave 132 HP at 5000 rpm. 7 psi of boost is about a 1.5 compression ratio. 12.3 lbs/min and 1.5 compression ratio are about at the surge line for a GT3582R compressor. The required power is 4.8 kW. A Garrett T3-60 would be a more appropriate size for this engine

At the surge line for 85,000 rpm, a GT3582R compressor requires 17 kW from a motor.

Castle does not publish any power output specs for the 1721 motor. Various sources say that it can pull a lot of amps like 500A on 8S and make a lot of power >15 HP (11 kW). A youtube video I watched mentioned an approximate power rating of 10 kW for 8 seconds. Clearly this is a powerful motor and capable of pushing the Max4ESC to its amp or temperature limits at full throttle. NeuMotor gives a continuous rating for their motors. This is the power at which the motor can continuously operate with the case temperature stabilized at 100 'C. With the Castle motor it is up to the user to generate the data and figure out where the limits are.
 
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