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Hoffman magnetics composite motors

Old 11-15-2008, 06:29 AM
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Chuck George
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Default Hoffman magnetics composite motors

HOFFMAN MAGNETICS COMPOSITE MOTORS IN STOCK

Check these motors out in action in 6 videos...

Video

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Old 11-15-2008, 06:30 PM
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There were photos of the thing in **groups that illustrated V poor winding /stator coverage (easy to see the the stator thru the 4 wires loosely draped (?) on it and IMO way too many,, plastic bits. Not good for heat conduction and v inexpensive in appearance. Which seems, to me at least, to be Surprisingly Pricey for that kind of mass production product. Even United Hobby motors are of all metal fabrications.
Ohh boy! here come da flames
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Old 11-16-2008, 02:22 AM
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The Don
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I have tested the "Mighty Mite" 60mm EDF motor and found it to be no better than what is currently available in its class.

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Old 11-18-2008, 05:42 AM
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We'll you can't really hold them to the specs, as there is not much to call them on. This is all it says: "Raw power is the only way to describe this new powerful EDF outrunner"

There are too many proven, low cost motors out there, to buy something new and more costly without extensive evidence from other flyers that they are really better. Better means at least as reliable with more power than others, or more reliable with at least the same power as others. For example, what I really like about the Dons outrunners I have is not their power, but the 3mm shafts and apparent durability. I can get good performance from a 2025-5300 also, but they tend to break the small shafts, and blow up rotor magnets.
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Old 11-18-2008, 05:52 AM
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Lack of data is one of the reasons why I bought one. I was quite suprised to find the Alfa 5 blade fan test on 3S and 4S I did that that the Wicked 4800 tested basically identical. The Hoffman motors are very nice looking, I just figured for the price tag there would be some resonable performance gain over current EDF outrunners.

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Old 11-18-2008, 11:29 PM
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Hmmmm ... I hope more get out for testing, and maybe some revisions can be made down the road. I was hoping for higher quality magnets in these for the price. I was most interested in the 70mm EDF motors. Was hoping there would be a good alternative to the JS-1400 motor. I need to start diversifying and trying out some 28mm inrunners on the market, too. Are there any 28mm inrunners that can get up in the 1000W+ range? I've got a twin F-15 that runs off Midi Fans and Mega 22/20/3 motors that I have yet to run. Guy who built it said it was pulling 2800W total on 6S, which is quite a bit over spec per motor (I'm assuming the Mega 22/20/3 is the same thing as the Mega ACn 22/20/3?). But those are a whole lot bigger than the motor choices for 70mm Mini Fans and such.

I'm still hopeful for Hoffman. First runs are always tough. If the price goes down, or the quality goes up, I'll be willing to give them a shot or two.
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Old 11-19-2008, 05:44 AM
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Originally Posted by PerlAddict View Post
Hmmmm ... I hope more get out for testing, and maybe some revisions can be made down the road. I was hoping for higher quality magnets in these for the price. I was most interested in the 70mm EDF motors. Was hoping there would be a good alternative to the JS-1400 motor. I need to start diversifying and trying out some 28mm inrunners on the market, too. Are there any 28mm inrunners that can get up in the 1000W+ range? I've got a twin F-15 that runs off Midi Fans and Mega 22/20/3 motors that I have yet to run. Guy who built it said it was pulling 2800W total on 6S, which is quite a bit over spec per motor (I'm assuming the Mega 22/20/3 is the same thing as the Mega ACn 22/20/3?). But those are a whole lot bigger than the motor choices for 70mm Mini Fans and such.

I'm still hopeful for Hoffman. First runs are always tough. If the price goes down, or the quality goes up, I'll be willing to give them a shot or two.
If you hurry up, there's that new JS for 90mm fans for $79 bucks intro price at HL. On the other hand, I impulse bought the JS1400 at that price, have it in a really nice A4 with retracts, and still haven't flown it yet.
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Old 11-19-2008, 05:59 AM
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Originally Posted by PerlAddict View Post
HAre there any 28mm inrunners that can get up in the 1000W+ range?
Well they are going 160mph on the HP F-16 with the ARC motors from LightflightRC and are over 1000 watts and the Ritewing guys use them as well in the 1200 watt range.

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Old 11-19-2008, 05:33 PM
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No kidding. That's pretty impressive. Maybe I'll check some of those out for my Mini Fans. The SF fan is built for a 28mm motor, too, isn't it? I've got two of your first batch of 4000kv's I still have yet to install in that plane (seeing as I still have yet to take that plane out of the box. ), but I had toyed around with the idea of using them in smoe 64mm EDO fans instead, and then going with ARC motors for the SF fan.

As for that JS-1490 motor for 90mm fans, I'll let someone else do the testing before I plunk down any money. I only have one 90mm plane, and it's supposedly pushing the Mega 22/20/3 motors at 1400W each (twin). I doubt the JS-1490 is going to outperform that, so no point in spend more money at the moment. Though I wouldn't mind knowing how it does for that day I finally break down and buy a FlyFly F-86 Sabre.

I really do need to start looking at inrunners more now that I'm getting into 70mm EDF's. I really like Dave and Sara over at LightFlightRC, and I'd like to give some of their ARC motors a try.
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Old 11-19-2008, 11:55 PM
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Originally Posted by PerlAddict View Post
No kidding. That's pretty impressive. Maybe I'll check some of those out for my Mini Fans. The SF fan is built for a 28mm motor, too, isn't it? I've got two of your first batch of 4000kv's I still have yet to install in that plane (seeing as I still have yet to take that plane out of the box. ), but I had toyed around with the idea of using them in smoe 64mm EDO fans instead, and then going with ARC motors for the SF fan.

As for that JS-1490 motor for 90mm fans, I'll let someone else do the testing before I plunk down any money. I only have one 90mm plane, and it's supposedly pushing the Mega 22/20/3 motors at 1400W each (twin). I doubt the JS-1490 is going to outperform that, so no point in spend more money at the moment. Though I wouldn't mind knowing how it does for that day I finally break down and buy a FlyFly F-86 Sabre.

I really do need to start looking at inrunners more now that I'm getting into 70mm EDF's. I really like Dave and Sara over at LightFlightRC, and I'd like to give some of their ARC motors a try.
The JS1400 is a sick mod for the SF fan. I ran mine up to around 425W if I remember correctly (not full throttle) but changed the rotor to an HW505, as I don't trust the SF rotor at those levels.
I still have the SF rotor with 3mm adapter on it, sitting in the drawer.
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Old 11-20-2008, 01:03 AM
  #11  
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Once you get to the 70mm fan/28mm motor size it starts to make more sence to go inrunner over outrunner. The inrunner will give you more rpm/watt. You can move the same amount of air for less power or more air for the same power.

Once you hit the 90mm fan sizes and 36mm motors, its a definite loosing game to go with an outrunner. You're just heating air instead of blowing it

The only reason for going outrunner on the smaller ones is that - with the extension mounts - they can survive at grossly inefficient power levels out in the airflow where a small 20mm inrunner cant. So you can run an outrunner at the 50% efficiency point just to get that little bit of extra speed.

If you notice, all the fastest motors in the F16 speed contests have been inrunners in 70mm fans

The other reason to go with a outrunner is still cost. The LSJS on sale is a bit cheeper than a quality 28mm motor that could be pushed that hard - but not by much. In the smaller sizes, Dons motors win on the cost/performance basis easily.
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Old 11-20-2008, 12:59 PM
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Originally Posted by Larry3215 View Post
Once you get to the 70mm fan/28mm motor size it starts to make more sence to go inrunner over outrunner. The inrunner will give you more rpm/watt. You can move the same amount of air for less power or more air for the same power.

Once you hit the 90mm fan sizes and 36mm motors, its a definite loosing game to go with an outrunner. You're just heating air instead of blowing it

The only reason for going outrunner on the smaller ones is that - with the extension mounts - they can survive at grossly inefficient power levels out in the airflow where a small 20mm inrunner cant. So you can run an outrunner at the 50% efficiency point just to get that little bit of extra speed.

If you notice, all the fastest motors in the F16 speed contests have been inrunners in 70mm fans

The other reason to go with a outrunner is still cost. The LSJS on sale is a bit cheeper than a quality 28mm motor that could be pushed that hard - but not by much. In the smaller sizes, Dons motors win on the cost/performance basis easily.
I never really looked at it that way, but it makes sense in the fact that the larger inrunner 90mm fans usually are low kv and high cell count, taking advantage of the higher torque and efficiency of the low kv motor, since high kv inrunners have lower torque. I imagine the main app selling point for the larger fan outrunners out now, like the JS motors, is that you can use a lower cell count, since the outrunner has the torque to run a high kv and large rotor. This allows folks to use their larger 3 and 4 cells, without having to invest in high cell count lipos, although not saying the outrunner is any better, but just uses the lower cell count.
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Old 11-20-2008, 03:56 PM
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You know, I'd never thought of that. Until I read that, Bill, I was thinking, "Why WOULD anyone want to use an Outrunner on a 90mm fan?" Makes sense ... a lot of EDF guys already have 4S packs they can chain together in parallel without having to fork over more money for 5S - 8S packs.

When I finally break down and buy that Fly Fly F-86 Sabre, I'll definitely be getting an inrunner for that baby. Got a couple of 6S packs sitting around and a bunch of 3300mah 3S packs I can daisy chain together.

Now all I need is a wonderful, patentable invention to make me my first million so that I can accord everything I want and need for a fleet of big ol' EDF's.
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Old 11-20-2008, 08:13 PM
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I dissagree on that part to some degree. A higher kV inrunner is still going to be more efficient than an equivilant outrunner.

Becides - to get the 1200-2500 watts you need to properly feed a 90mm fan would take a minimum of 117 amps on 3S just to get the 1200 watts. 88 amps or so on 4S. If you want serious performance you must go higher cell counts or the amps are just stupid. Not very practical

Take those 2 4S packs and run them in series. Your better off all the way around.

The JS motor is designed to run on 5S or 6S in the big fan. There are several good inrunners that will beet it easily in the rpm/watt battle even at that low a cell count - many of them for less money and more at only slightly more $$. You dont need a Neu inrunner to beet out an outrunner once you get over a few hundred watts.
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Old 11-21-2008, 04:14 AM
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Got to run my hoffman 70mm beast today for the first time. The numbers that I pulled from my watt meter with the motor mounted in a HET6904 were:

16.6v start
91.15 amps peak after 5-10 seconds
1244.1 watts peak, didn't catch what it settled to
13.46 volts at WOT after 5-10 seconds

using a TP 3850 4 cell 25c battery.
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Old 11-21-2008, 04:23 AM
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What rpms were you getting?
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Old 11-21-2008, 05:36 AM
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I don't have an eagletree so I don't have a clue what kind of rpm's I was gettin. One of these days maybe I'll get one. (in case my wife is reading this a subtle HINT HINT) lol.
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Old 11-21-2008, 07:13 AM
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Originally Posted by Larry3215 View Post
I dissagree on that part to some degree. A higher kV inrunner is still going to be more efficient than an equivilant outrunner.

Becides - to get the 1200-2500 watts you need to properly feed a 90mm fan would take a minimum of 117 amps on 3S just to get the 1200 watts. 88 amps or so on 4S. If you want serious performance you must go higher cell counts or the amps are just stupid. Not very practical

Take those 2 4S packs and run them in series. Your better off all the way around.

The JS motor is designed to run on 5S or 6S in the big fan. There are several good inrunners that will beet it easily in the rpm/watt battle even at that low a cell count - many of them for less money and more at only slightly more $$. You dont need a Neu inrunner to beet out an outrunner once you get over a few hundred watts.
That's what I was saying, although maybe not worded clearly. From my understanding the inrunners are more efficient motors by design. I was just getting at the point that a low kv inrunner is more efficient that a high kv inrunner. Both cases were meant to be inrunners.
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Old 11-21-2008, 07:34 AM
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Ah! I had misunderstood
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Old 11-21-2008, 07:38 AM
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Originally Posted by gr8taz nitro View Post
I don't have an eagletree so I don't have a clue what kind of rpm's I was gettin. One of these days maybe I'll get one. (in case my wife is reading this a subtle HINT HINT) lol.

LOL Yeah tell her not to forget the RPM sensor for sure.

The only way to compare different motors is to look at the RPM numbers on the same exact load (fan, prop etc) at what ever power level.

One motor might be making more watts that the other one, but if you dont know the rpm then you dont know if those extra watts are going into something useful like thrust/speed or if they are just heating air
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