New FMS/Eflite Su-30 coming soon

[Hugh Wiedman]

Hugh Wiedman - Hugh, i got 2 new Freewing 2957-2210kv inrunners from Motion. Do you think these will help the SU, or should i just find the new FMS fans w/motors and go that route...? I'm about ready to do major surgery on her, but this little voice in my head is chirping in my ear for some reason... Thoughts?

Good question. According to RC Castle (one of the few places I've found that list static thrust for each motor-but not sure how accurate it is and they seem to use different voltages on some-maybe specs from the manufacturer), the FMS 12 blade 3060-1900 Kv inrunners that I used has static thrust of 2500 g but at 25 Volts (remember that number) and costs about $60. The Freewing 2957-2210kv 12 blade inrunner list static thrust at 2450 g, but at 22.2 volts and costs about $73 at MRC. So I would say try the Freewing inrunners. You already have them and I can't image they will be any less powerful than the FMS fans (which you would probably have to get from China). In fact, based on the motor size and higher Kv of the Freewing, along with the specs showing static thrust at 22.2V for the FW and at 25V for the FMS, I'm fairly certain those FW fans are more powerful than the FMS ones. So seems like a done deal! Is it probable that FMS uses a higher voltage to list their static thrust numbers than what FW uses? The fully charged 6S is at 25.2 volts, so not surprised FMS uses that number of 25 Volts, but why would FW use 22.2 Volts?

[kallend]

Good question. According to RC Castle (one of the few places I've found that list static thrust for each motor-but not sure how accurate it is and they seem to use different voltages on some-maybe specs from the manufacturer), the FMS 12 blade 3060-1900 Kv inrunners that I used has static thrust of 2500 g but at 25 Volts (remember that number) and costs about $60. The Freewing 2957-2210kv 12 blade inrunner list static thrust at 2450 g, but at 22.2 volts and costs about $73 at MRC. So I would say try the Freewing inrunners. You already have them and I can't image they will be any less powerful than the FMS fans (which you would probably have to get from China). In fact, based on the motor size and higher Kv of the Freewing, along with the specs showing static thrust at 22.2V for the FW and at 25V for the FMS, I'm fairly certain those FW fans are more powerful than the FMS ones. So seems like a done deal! Is it probable that FMS uses a higher voltage to list their static thrust numbers than what FW uses? The fully charged 6S is at 25.2 volts, so not surprised FMS uses that number of 25 Volts, but why would FW use 22.2 Volts?

I have measured INSTALLED thrust of both the FW and FMS fans in a number of models. The FMS wins in every model I've tried. It also sounds better.

[nuts-n-volts]

Another win... It's also much lighter.

[Hugh Wiedman]

kallend and nuts-n-volts so that's 2 undisputed points, 'proof is in the pudding" (whatever the heck that means). Obviously real world specs beats published specs any day. It's great to be able to get input from those that know what's what, thanks.

[kallend]

kallend and nuts-n-volts so that's 2 undisputed points, 'proof is in the pudding" (whatever the heck that means). Obviously real world specs beats published specs any day. It's great to be able to get input from those that know what's what, thanks.

Of course, one caveat is that static thrust and thrust at 120mph are not the same thing. I don't know of anyone who's put one of these in a wind tunnel to see how they compare when fed air at high speed (GPS or radar speed measurements have too many other variables to be really valid as indicators of fan performance).

[jasmith41]

Great info all - thanks for taking the time to share the data and your knowledge...

[Hugh Wiedman]

Of course, one caveat is that static thrust and thrust at 120mph are not the same thing. I don't know of anyone who's put one of these in a wind tunnel to see how they compare when fed air at high speed (GPS or radar speed measurements have too many other variables to be really valid as indicators of fan performance).

For me, the most important stat is the static thrust as I'm only interested in it's 0-60 performance to get off our grass runway. Not interested at all in high speed in flight and am only at full throttle during take-off and the occasional vertical climb, so your measurements are exactly what I'm looking for. Getting off in a shorter distance means less time at full throttle and a little more flight time. With that said, wonder if you've tested any of the following 80mm fans.

I'm thinking of upgrading the stock FW 9 blade 3658-1920Kv inrunner in the Mig 29. RC Castle shows static thrust at 3-3.1g. Although I'm fairly happy with the stock performance on our grass field of the Mig and get off in about 100' in a calm day, wouldn't mind getting off quicker and having a little extra punch if I need it in a go-around. A friend upgraded his with the FMS fans, and although I haven't seen it fly yet, he claims it was a nice upgrade. The FMS fans were the 12 blade V2 Pro 3280-2100 Kv inrunner, 3400g static thrust for about $86 (at RC Castle-discontinued at HH and out of stock with FMS). HH instead now lists a new FMS 12 blade 3280-2100kv inrunner but with metal blades for $95 but I've lost some trust with HH in the last few years. RC Castle also lists a 12 blade V3 3665-2000Kv inrunner for $105 with 3450 g thrust. The other option is the FW 12 blade 3658-1857Kv inrunner for $107 from MRC but the static thrust listed in RCC is only 3100-3200, almost the same as the stock motors. I'm kinda lost when it comes to EDF performance comparisons and I've yet to get a good handle on the motor numbers comparing one to the other (although I completely understand the size numbers and the Kv values, but those don't always lead to exact comparisons from what I've seen) so have a hard time determining what is the best value for cost. The only thing that seems to work for me is the opinions of those that have tried them out.

[jasmith41]

i can't get the FW fans apart, so the SU may just be stuck with the stock units. as i unscrew the nosecone, it unscrews quite a ways, but then stops and it seems something on the inside is turning with it stopping the screw from unscrewing completely. any thoughts...? i've tried it twice now... #frustrated...

[xviper]

i can't get the FW fans apart, so the SU may just be stuck with the stock units. as i unscrew the nosecone, it unscrews quite a ways, but then stops and it seems something on the inside is turning with it stopping the screw from unscrewing completely. any thoughts...? i've tried it twice now... #frustrated...

Have you tried holding the fan blades to prevent them from turning. Perhaps if you see how it goes together, it may help you to take it apart:
https://www.horizonhobby.com/product...FLA7012DF.html
Are you trying to get that center screw out of the fan nose cone? If there is a bit of a cross thread as you unscrew it, it will turn the fan blades. I've never had much luck replacing just the motor in any fan. Even when you get the nose cone and the fan off, getting them back on the new motor can be difficult as it's hard to keep the fan blades and/or motor shaft from turning as you try to tighten it all down, especially on an inrunner where grabbing the motor itself won't help prevent the shaft from moving.

[jasmith41]

xviper - thanks man - that's what i was afraid of - i think i'm going to return these motors and just find whole new 70mm units. Any suggestions aside from the FMS 1900kv's...? Are the Xflys any good / better than the FMS...? Was looking for more than 1900kv for some reason. Is more better, or not necessarily...?

[xviper]

KV alone doesn't always translate into thrust. When looking at other EDF units, you have to compare things like fan dimensions. It's pointless buying 2 fans that may involve some foam modifications to make them fit if that's not your thing. Look at the published static thrust of each unit. Even though they may not be accurate and considering that manufacturers can tend to exaggerate their numbers, they are at least something you can use to compare one with another. RC Castle shows you all kinds of EDFs, along with thrust numbers, dimensions and amp draw. Keep in mind that the more power you ask for, the more likely the battery drain. Now, you have to think about how long you want to fly and whether or not you want to hog out more foam to accommodate more battery.
You can also look at some shops that sell custom EDFs but now you're into some serious money. It's already and expensive model. It is worth it to spend several hundred dollars more, keeping in mind you may need upgraded ESCs as well. It can be a long, expensive, winding road.
A couple of examples:

https://www.effluxrc.com/main.sc

http://edfhobbies.com/index.php?route=common/home

[jasmith41]

I ordered the FMS fans Hugh Wiedman recommeded and i'm sending back the motors i bought to upgrade the EF fans... Seems like a more logical approach.

[radfordc]

I ordered the FMS fans Hugh Wiedman recommeded and i'm sending back the motors i bought to upgrade the EF fans... Seems like a more logical approach.

The FMS fans are an improvement...but they won't really shine unless you go to dual batteries. Two 4000 mah instead of one 6000.

[Hugh Wiedman]

The FMS fans are an improvement...but they won't really shine unless you go to dual batteries. Two 4000 mah instead of one 6000.

Ever since you first posted about this, I've been very intrigued about following your lead. One of these days soon, I will get it done! Quick question or two.

1) The Admiral 4000's I have are 43x42x142 and weigh 578 gr each (even though the MRC website lists it at 540 gr). What are you using? I'm wondering if my SMC 40C 5300's will fit at 43x43x160 weight 680 gr each. Not worried about the extra 100 gr of weight for each, but the length, only 18mm longer. If those could fit in the speed brake compartment, I think I'd be in seventh heaven. The SMC tests out at 39C, while the Admiral more like 20C so not keen on using them or buying some SMC 4000's just for this one aircraft. I've flown it with a single SMC 5300 and it's a rocket ship, but like most rockets, the brighter the burn, the less burn time and only get about 2:50 on it. With 2 of those, I have no doubt I could get at least 5:00!!

2) Assume you removed all the speed brake components and what did you do with the ESC's, just cut off at the joint where they come together and add another EC5 connector there for the 2nd battery? (sorry for such a juvenile question, but I'm not the sharpest tack in the box when it comes to electronics) Any other issues I need to be aware of before I take a chain saw to an aircraft whose parts are no longer available? And I do remember (I think it was you) that the 2nd battery needs to be strapped in in case you go inverted and that 2nd battery becomes a bomb!

[kallend]

RC Castle shows you all kinds of EDFs, along with thrust numbers, dimensions and amp draw.

I don't think these are independent measurements. Looks to me like they just reproduce the manufacturer's numbers.

[xviper]

I don't think these are independent measurements. Looks to me like they just reproduce the manufacturer's numbers.

But of course they are. RCC is a seller/distributor. They're not going to do measurements on everything they sell.

[radfordc]

Ever since you first posted about this, I've been very intrigued about following your lead. One of these days soon, I will get it done! Quick question or two.

1) The Admiral 4000's I have are 43x42x142 and weigh 578 gr each (even though the MRC website lists it at 540 gr). What are you using? I'm wondering if my SMC 40C 5300's will fit at 43x43x160 weight 680 gr each. Not worried about the extra 100 gr of weight for each, but the length, only 18mm longer. If those could fit in the speed brake compartment, I think I'd be in seventh heaven. The SMC tests out at 39C, while the Admiral more like 20C so not keen on using them or buying some SMC 4000's just for this one aircraft. I've flown it with a single SMC 5300 and it's a rocket ship, but like most rockets, the brighter the burn, the less burn time and only get about 2:50 on it. With 2 of those, I have no doubt I could get at least 5:00!!

2) Assume you removed all the speed brake components and what did you do with the ESC's, just cut off at the joint where they come together and add another EC5 connector there for the 2nd battery? (sorry for such a juvenile question, but I'm not the sharpest tack in the box when it comes to electronics) Any other issues I need to be aware of before I take a chain saw to an aircraft whose parts are no longer available? And I do remember (I think it was you) that the 2nd battery needs to be strapped in in case you go inverted and that 2nd battery becomes a bomb!

Hugh, I'm using HRB 4000s....weight 590g, 135x40x47mm The Admiral 4000s will fit for sure. The SMCs may be a little long. Using two 4000 packs I once flew for over six minutes just to prove it could be done...just flying around in level flight at half throttle.

I did remove the airbrake servo and linkage...but I saw one guy who managed to fit the battery without doing that. I cut the ESC wires where they joined and soldered on new connectors. I hindsight there isn't any good reason to run each ESC from a separate battery....just join the batts in parallel if that is simpler.

And yes, you must secure the battery with a strap or it will definitely leave the ship!

[jasmith41]

I ordered the FMS fans Hugh Wiedman recommeded and i'm sending back the motors i bought to upgrade the EF fans... Seems like a more logical approach.

does anyone know where i got the 70mm FMS fans from, because i sure as hell can't remember... 🤣🤣🤣

i think i need to cut back... on day-drinking...

[jasmith41]

Never mind - I found it. Got them from Banggood (wife sill thinks this is a porno site...)

FMS 70mm 12b 3060-1900kv's...

Hoping for the best - 2.7kg thrust est...

[jasmith41]

For a 90mm swap-out, does anyone have an opinion of this one? FMS 90mm Metal 12 Blade EDF Ducted Fan with 6S 4068-KV1850 Inrunner

I'm thinking about an upgrade for my FW F15 and / or F22....

Thoughts?