Revolt RV-series motor review and comparisons

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ElectricGod   1 GW

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Revolt RV-series motor review and comparisons

Post by ElectricGod » Jun 27 2018 4:01pm


The moderators have refused to take action against these people:
LARSB, Madden88, Punx0r and John in CR.

Their many personal attacks has completely ruined this thread.
It has ruined my desire to help the world by presenting things!
This thread has been locked and edited at least 8 times now!!!
ALL to get rid of their hate!

I 100% recuse myself from any further posts!
I have deleted all my content.
Now there is nothing but a few quotes.
There is almost zero actual content!

I apologize to the people that got benefit from my efforts.
I apologize to the future people who would benefit from my efforts.

I will NOT tolerate being attacked!

99.9% of the content ever posted in this thread is my own work!!!
My time and efforts!!!
My money spent!!!

Congratulations moderators on being absolutely toothless!!!
You have forced me to take matters into my own hands!!!
I have been MORE Than patient with your LACK of action!!!

I have only one question for the moderators:

Which do you want?
1. Quality content provided by people that care.
2. Assholes that ruin everything.

Deal with the assholes or my quality content goes away!!!
Just like it did in this thread!!!
NOW THEN F U C K I N G CHOOSE!!!
I didn't get a gigawatt rating by thrashing people!
I got it the legitimate way!
Posting worthwhile and valuable content!!!

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spinningmagnets   100 GW

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Re: Revolt RV-series motor review

Post by spinningmagnets » Jun 27 2018 4:52pm

The lack of epoxy on the wire strands is troubling (on the 80-100). When the motor is running, those wire bundles will vibrate, and the insulating wire lacquer will slowly rub off, causing a short.

I had assumed that Alien Power motors were at least slightly better than Turnigy, oh well. Thud has an excellent pictorial on rewinding these large RC outrunner with new wire, and making them a lower kV plus terminated in wye, with inductance being improved, then adding halls do it can be run by an ebike 12 Fet controller....if interested, check the motor section sticky index.

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Re: Revolt RV-series motor review

Post by ElectricGod » Jun 27 2018 5:28pm

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jun 30 2018 2:55am

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ltu   100 mW

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Re: Revolt RV-series motor review and comparisons

Post by ltu » Jul 01 2018 10:57am

hello electricgod

good report

do you have more about the 12090 outrunner?

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spinningmagnets   100 GW

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Re: Revolt RV-series motor review and comparisons

Post by spinningmagnets » Jul 01 2018 1:48pm

A link to this thread had been added to the motor pictures dis-assembled thread stickey.

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madin88   1 GW

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Re: Revolt RV-series motor review and comparisons

Post by madin88 » Jul 02 2018 4:23am

Thanks for your review and the pics.

To be exact the C80xx series don't have a 80mm stator diameter. This number refers to the outside diameter which can be really confusing sometimes when comparing differnt motors among different brands.

It would be best if you could measure the real dimensions of the stator together with other things like:
- phase to phase risistance
- phase to phase inductance
- lamination thickness.

What controller are you using and what's the no-load consumption at rated RPM?
3. Bigger magnets. These magnets look to be about 16mmx50mmx3mm. I believe the C80100 magnets are 11mm wide. Length and thickness look about the same. There's no gaps between the magnets like the C80100 has.
It doesn't mean the performance is better if there is a gap between the magnets or not.
Fact is that more advanced motor designs with surface mounted magnets have a gap between mostly in order to reduce the spinning mass.
It simply is not necessary to glue them side by side because the fields cancelling out in this area. having no gap would not contribute to more torque.

IMO the rotor of the C80 motor looks better designed as there is almost no visible gap between magnets and the back iron, while on the RV100 there is a huge gap. The larger the gap, the lower the field strength.
6. The outer bell shielding is better. I used an allen key. The C80100 grabs steel objects quite strongly. This motor does attract steel, but not as much as a C80100.
If revolt would have used bended magnets to get reid off the gap, it likely would grab steel objects much stronger. From the look, the thickness of the bell looks insufficient.

Yes copper fill looks really good on this motor, but without knowing any numbers of above mentioned measured values it is hard to say if the motor is good or not so..

Recently i built a mid-drive with an outrunner with 80mm dia and 57mm stator. This motor can take 10kw peak (controller at max settings) for quite a long time, and real continuous it is in the range of 5-6kW (temp does not climb above 110°C).
The type of controller (or the settings) are also very important in view of the the power you can get out of that kind of motors.
- 10kW belt drive with Neumotor 8057: [url]viewtopic.php?
- KTM Hardtail Pedelec / eZee V2 6T / 27,5" / Kelly KBSX @ 1,5kW / Torque PAS / CA-V3 / 13s4p Sanyo GA in Shark case

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ElectricGod   1 GW

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 04 2018 1:11am

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Re: Revolt RV-series motor review and comparisons

Post by madin88 » Jul 04 2018 3:01pm

ElectricGod wrote:
Jul 04 2018 1:11am
This is top down view of the stator and armature, there's a paper thin gap between them. You can't get much closer to touching than that! I don't know what you are talking about regarding a "huge gap" except at the left and right ends of the magnets...where it matters the least. I had previously posted that curved magnets are used on the RV-100-pro and -E versions, but not on the base model (RV-100-regular...this motor). This is the low end or base model Revolt motor, NOT the best of their product line.
I was talking about the gap between the magnets and the back iron (the rotor).
The back iron is there to increase (roughly double) the strength of the magnets.
As there is quite a big gap the strength is way lower as it could be, which leads to lower torque and probabaly to earlier saturation.

Whereas a gap between the magnets side by is usually a good thing or a sign of a more advanced design (weight optimizied).

I wonder why you bought the cheapest version of this motor without hall sensors when you can get them installed for a few extra dollars...
Or is there anything wrong with the stock sensors?

The revolt E versions don''t look bad!
- 10kW belt drive with Neumotor 8057: [url]viewtopic.php?
- KTM Hardtail Pedelec / eZee V2 6T / 27,5" / Kelly KBSX @ 1,5kW / Torque PAS / CA-V3 / 13s4p Sanyo GA in Shark case

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 05 2018 10:42am

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spinningmagnets   100 GW

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Re: Revolt RV-series motor review and comparisons

Post by spinningmagnets » Jul 05 2018 11:22am

The faces of the rotor teeth are curved, and the back-iron can is also curved. Many believe there is a small benefit to using curved magnets instead of flat pieces. Then tightening up the air-gap...

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 05 2018 1:00pm

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Re: Revolt RV-series motor review and comparisons

Post by thepronghorn » Jul 05 2018 3:26pm

Like madin88 said, measure the Rm, Kv, and no load losses at two different voltages, and then we will be able to compare these two motors performance wise (inductance would be nice as well for an indicator of the "controllability" of the motor). You have already covered their mechanical design fairly well. One measurement that would also be nice is the stator lamination thickness (careful inspection of the stator photo you posted indicates 0.5mm lams, but the picture quality wasn't high enough to easily count laminations).

Like others have said, some of your electrical design comments need a little clarification.

You mentioned that you liked the 100% magnet coverage, but usually a motor's torque/weight ratio is optimized somewhere closer to 80% coverage. The 80100 motor was designed with the intention of optimizing power/weight for model airplane use. For our applications, weight may be a smaller factor, but optimal magnet coverage still varies from motor to motor and user to user, so it is hard to say that the Revolt motor is definitively better than the 80100 in this category.

Spinningmagnets wasn't quite correct. What madin88 was pointing out is that the flat magnets cover 360/14=26 degrees of the rotor each which results in a maximum gap to their back iron (the rotor steel) of 2.6% of the motor's radius (exact solution is 1-sqrt(1-pi^2/14^2)). For a 80mm diameter motor, this results in a 1mm air (plus some epoxy) gap from the flat magnet to the curved back iron which means the back iron is much less effective at linking the magnet flux since the flux must jump across the 1mm gap.

Thicker stator teeth means less space for wire. This improves peak power capability but decreases continuous power handling. Again, specific motor design parameters are not necessarily good or bad, they are all varied by the motor designer in order to optimize for the motor's performance targets and constraints (speed, torque, power, weight, cost, size, etc.).

Thanks for the motor review. Others have posted varying reviews of Revolt motors in the past, but your in depth analysis is good content.

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Re: Revolt RV-series motor review and comparisons

Post by spinningmagnets » Jul 05 2018 4:48pm

Justin had a long thread a while back where he was developing his ideal small direct drive hubmotor. During that discussion, he compared magnets that touched side-to-side, against magnets that had some gap between them...

Like almost all things concerning motors, there were benefits and drawbacks to each approach. I seem to remember that having a small gap reduced cogging, while only losing a small amount of torque-per-watt.

Of course, I could be wrong, that thread is from quite a while ago...

As far as the curved magnets go...I seem to remember that the curved magnets had only a small benefit. The MXUS turbo series hubmotors tauted their curved magnets and the resulting thinner air-gap, but the consensus at the time was that...it was only worth it if the planned production numbers were high enough that the curved variety were close to the same price as flat.

Narrow magnets (in the shoulder to shoulder axis) can use a thinner and lighter back-iron. Wider magnets would result in fewer poles? per the same diameter motor...which would be good for reducing the electrical switching frequency. That used to be an issue, but I think controllers are available now that handle high Hertz...

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 05 2018 4:50pm

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Re: Revolt RV-series motor review and comparisons

Post by thepronghorn » Jul 05 2018 5:30pm

Generally it's easiest to measure the width of 10 or 20 lams.

The specs we need to characterize the performance of a motor are phase resistance, speed constant (aka Kv, rpm/volt is a common unit), and losses at no load at two different voltages. The page below discusses how to measure them all.

http://www.bavaria-direct.co.za/constants/

If you don't have a way of measuring rpm, you can scope two motor leads as you spin the motor and get the voltage and angular velocity from the bemf waveform.

Two no load points are useful so we can approximate the 1st and 2nd order losses as explained by crossbreak here.

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 05 2018 5:46pm

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 07 2018 9:48pm

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Re: Revolt RV-series motor review and comparisons

Post by larsb » Jul 08 2018 7:49am

Please, don't start a second wave of hype on the revolt motors. i was on the first and got burnt

The first lineup of revolt motors are crap, read my posts, there's plenty more reviewers here with issues.
Flawed design, poor quality control. Good at inflating specs.
They have a new lineup that could be better but since the first motors were so bad i wouldn't buy from them again.
Ride on!

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Re: Revolt RV-series motor review and comparisons

Post by John in CR » Jul 08 2018 9:16am

EG,

Great job on the physical review of the motor. Pick up a cheap inductance meter on ebay. It's good to check inductance and resistance phase-to-phase each way to make sure there's no mistakes in the winding (impossible to check visually), and the resistance is a critical measurement in understanding how much current it can handle.

To me the real test is no load current at 2 different voltages. With that, measured Kv and the physical attributes you have all the info for it to be put into Miles motor performance spreadsheet. Then we know efficiency at any current and voltage combination, which to me is the true measure of how good a motor is.

Why are you playing around with the little toy motor anyway when you have the best highest efficiency hubbie ever made? Get that HubMonster up and running pushing less than a 400lb all up load with the smallest tire that will fit. Feed it 100A battery side per controller X 2, and you'll be in electric transportation heaven, while you work on something lighter.

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Re: Revolt RV-series motor review and comparisons

Post by madin88 » Jul 08 2018 11:38am

ElectricGod wrote:
Jul 05 2018 1:00pm
Revolt claims the Pro and E are more powerful motors. I don't think the stators are larger or longer. Revolt presents very few details for the "regular" motors on their web site. It's hard to compare specs when they are not listed!

2-5kw for the RV-100-regular
3-6kw for the RV-100-Pro
6-11kw for the RV-100E


Whether those numbers are exaggerations or not is a guess right now, but 2kw continuous vs 6kw continuous out of the same size stator is impressive...if it's real. Honestly though, I already get about 4800 watts max out of a C80100. How could a larger stator with more copper do worse than that? IE: the "regular" motor ought to realistically be about 5kw continuous.
For the "regular" motors there are no specs, but for the "pro" and "E" versions almost everything is specified :wink:
The RV-100E has 84x60mm stator VS the the RV-100 Pro (and regular i guess) which is 84x45mm. Thats the reason for the huge difference in power between those two.
Even the thickness of the laminations and tghe phase-to-phase resistance of any available kV is listed, but only for the pro and E versions.

One really annoying thing are the performance graphs with logarithmic scale.
It makes the motors look really good on the first sight, but it is impossible to find out if peak ETA is more like 85% or 90%.
You only do this if you want to hide details on purpose. It's not much useful.
John in CR wrote:
Jul 08 2018 9:16am
To me the real test is no load current at 2 different voltages. With that, measured Kv and the physical attributes you have all the info for it to be put into Miles motor performance spreadsheet. Then we know efficiency at any current and voltage combination, which to me is the true measure of how good a motor is.
I found out that this is only one part you like to know for comparing different motors.
The problem is saturation which makes it hard to tell how much torque you really can get out of one motor at given current.
- 10kW belt drive with Neumotor 8057: [url]viewtopic.php?
- KTM Hardtail Pedelec / eZee V2 6T / 27,5" / Kelly KBSX @ 1,5kW / Torque PAS / CA-V3 / 13s4p Sanyo GA in Shark case

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Re: Revolt RV-series motor review and comparisons

Post by John in CR » Jul 08 2018 12:51pm

madin88 wrote:
Jul 08 2018 11:38am
John in CR wrote:
Jul 08 2018 9:16am
To me the real test is no load current at 2 different voltages. With that, measured Kv and the physical attributes you have all the info for it to be put into Miles motor performance spreadsheet. Then we know efficiency at any current and voltage combination, which to me is the true measure of how good a motor is.
I found out that this is only one part you like to know for comparing different motors.
The problem is saturation which makes it hard to tell how much torque you really can get out of one motor at given current.
Phase-to-phase resistance gives you a better idea about current limits than saturation. Running anywhere near saturation is only useful for drag races, because getting near saturation creates too much heat. Knowing Kv gives you the torque number, just not the torque limit. No load current lets you know the voltage limit unless the Kv is so high the physical rpm limits come into play. Efficiency trumps all because heat is our limitation, and the Revolt motors others have tested failed in efficiency and couldn't be run at near the power claimed. The telltale sign was the high no-load current. I bought one of their original 120's when they first came out, and it still sits in a box because I know it won't do what I was sold it could. Look at all the time Larsb invested trying to improve one. Sure saturation is good to know, but it's not so easy to measure. No load current tells so much more and is super easy to obtain.

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 09 2018 3:17pm

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 09 2018 6:00pm

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Re: Revolt RV-series motor review and comparisons

Post by ElectricGod » Jul 09 2018 11:35pm

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