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Mar 03, 2017, 01:21 PM
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Build Log

FMS 80mm 12-blade Inrunner Motor EDF fan


I just got this new FMS 80mm inrunner motor plastic fan from China,

https://www.rc-castle.com/index.php?...roduct_id=6674

http://www.banggood.com/FMS-80mm-12-...p-1125125.html

http://www.fmsmodel.com/fms-80mm-duc...0-kv2000-motor

http://hobby-paradise.com/en/product...ct_detail.html

For $76 it includes (what looks like) a nice inrunner motor, and that was the main reason for buying it. Many of these chinese fans nowadays include some $10 junk outrunner motor that I really don't care about

I am not familiar with that particular motor brand ("Predator") ... we shall see

So far it seems from the FMS and Bangood sites, there is only one version of this fan with a 3270 2000kv motor.

Different measurements that people might or might not get could depend on a weak battery, incorrect transmitter endpoints, free-standing vs. installed in edf jet, and wrong esc setup (wrong timing not suited to a 4-pole inrunner) etc.

EDIT : Now there is also a softer 1930kv inrunner motor version (see later below).

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Last edited by Herb; Apr 24, 2019 at 01:09 PM.
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Mar 03, 2017, 01:29 PM
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The fan design seems well executed, interestingly they use a 32mm diameter inrunner motor, which was one of he reasons I got interested in this fan.

Most quality 80mm EDF fans (WeMoTec, JetFan, Schuebelr etc.) use a large (90mm-size) 40mm diam commodity motor (eg HET), which provides good electrical efficiency - but ends up clogging the duct quite a bit with that big chunk of metal.

Here the 32mm inrunner motor is an intermediate size between the common 70mm fan motors (29mm diam) and the common 90mm fan motors (36-40mm).

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Last edited by Herb; Mar 24, 2017 at 03:14 PM.
Mar 03, 2017, 01:33 PM
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The weight is pretty good, coming in fully assembled with motor at ~ 289g.

Given the larger fan size, this compares well with the weight of a significantly smaller, complete WeMoTec 70mm MiniFan EVO with 29mm inrunner motor.

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Last edited by Herb; Mar 30, 2017 at 12:35 PM.
Mar 03, 2017, 01:43 PM
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The plastic spinner is not the greatest design, not sure what they were thinking. A bit more rounded would have been aerodynamically better.

I suppose the reason for the "straight cone" design is that the spinner (and the screw that comes with it) is the only thing that keeps that plastic rotor on .

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Mar 03, 2017, 01:46 PM
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Once the spinner is off, the rotor just comes out by pulling on it ... Behind it is what looks like a nicely machined aluminum adapter.

The adapter has two set screws, but to get to those you first have to pull out the motor by removing four phillips screws.

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Last edited by Herb; Mar 03, 2017 at 01:55 PM.
Mar 03, 2017, 01:49 PM
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The lightweight one-piece plastic rotor seems to have been statically balanced with some material that looks like chewing gum or possibly epoxy.

I tested it for balance on a precision magnetic balancer (the same way I have tested fan rotors for 15+ years) and it seems a bit off.

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Last edited by Herb; Mar 03, 2017 at 01:54 PM.
Mar 03, 2017, 01:54 PM
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Another rather minor issue is that the fan shroud, and specifically the plastic stator blades, are supposed to support the back of the outrunner motor can.

Nevertheless - for whatever reason (motor mounted crooked, misalignment in the fan firewall, or large toterances in the stator molds) - there's still a small residual gap between the motor support plastic parts and the motor can.

This could - or could not - lead to extra vibrations at high power.

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Mar 08, 2017, 01:18 PM
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Thanks for posting Herb.
Looking forward to see what your experience will be with this unit.
Mar 09, 2017, 11:39 AM
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Thanks ... might go in a twin F/A-18 or in a Freewing MiG-21 ... still have to decide.
Mar 13, 2017, 01:05 AM
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Was thinking about dropping this in my 80mm super scorpion which has freewings 80mm inrunner setup. Been hearing good things about FMS edf units lately, best bang for you buck.
Mar 20, 2017, 05:51 PM
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I replaced that cone-shaped odd looking spinner with a WeMoTec MiniFan aluminum spinner (the older plastic one, on the left, fits as well),

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Mar 30, 2017, 12:31 PM
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I ran up the fan at full power and it seems pretty smooth.

I did statically re-balance the fan a second time, using a better rotor balancing setup (those notches in the aluminum fan hub make it difficult to center the rotor, so this time I used a different method).

When all mounted together, the spinner only needed one tiny weight one one side to run smoothly.

After setting up the correct timing and PWM for this motor, I ran it up and it's quite smooth and runs pretty cool too.

The motor has large front and back ventilation holes, and the rotor seems well designed for efficiency, with a reasonably small gap.

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Last edited by Herb; Mar 30, 2017 at 12:38 PM.
Mar 30, 2017, 12:37 PM
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Generous cooling holes should help with efficiency and longevity. NMB bearings are made in Japan.

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Apr 06, 2017, 12:06 PM
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Nice writeup Herb. I'm interested in the higher FSA on this 80mm fan as a potential candidate for a re fanned airliner project I've had for a long time. It has not flown in a couple seasons due to the re fan project that I abandoned due to too many other planes I had flying and a regrettably short attention span for older projects. It flies really nice so it deserves another power setup. Was thinking two fans for the inner pods and the outer two of the four pods, being dummy pods.

Was considering running it on reduced voltage as I don't need 2000 watts per fan (!), more like 700 would be good, per fan, for my project. What sort of power are you planning to run through this fan and what are the numbers? Do they compare well with the stated numbers on the web site as far as amp draws, etc? I do not trust market advertised thrust, I'd have to see it myself or see what you get. Thanks Herb, have fun flying!
Ed
Apr 07, 2017, 10:17 AM
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Hi Eddie, Thanks ...

It seems overall a decently made fan, at a good price. And for once with a decent quality inrunner, as opposed to some junk $10 out-of-balance horribly inefficient outrunner.

Mine seems to run well out of the box, cool and quite smooth with the correct ESC setup.

I am not overly impressed by the plastic fan and shroud, but it seems acceptable for $80 free shipping (from bangood).

The numbers seem in the ballpark of what they claim, so no issue there.

It would seem to me like a good match for your project, but keep in mind that if you run this fan at ~700W instead of 2000W then your efflux will be (7/20)^(1/3) =0.7, or only 70% of the ~130mph air out the back you get at 2000W. Depending on how slow or fast your jet might fly, this could be adequate, or not.

For one thing, they are definitely light weight for a mass produced (ie not carbon) 80mm fan & motor.

Also, you don't get that intake (the FSA) half plugged up by a huge 39mm diam motor. Here the motor is relatively thin (as it should be) at 32mm diam, and the blockage is much less ... it runs cool so mine to does not need cooling fins to plug up the shroud, that would defeat the purpose of having a smaller diam motor.


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