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Feb 06, 2013, 09:32 AM
Registered User
well, in the plane you are going to lose quite a lot (depending on ducting and exhautszdiameter) of those thrust "dream values" - but at least the current will be similar to the situation with inlet lip IF airflow is not obstructed. If the fan is starving and/or stalling because of exhaust below around 58mm you will have less amps - and awfully low thrust...
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Feb 06, 2013, 11:34 AM
Registered User
i will adjust the intakes and exhausts accordingly... hopefully can get good performance...

but the ducts are designed for dynamic flow, which means the performance should increase when the plane is moving right?
Feb 06, 2013, 11:37 AM
Registered User
1) will do!

2) i;m using twin fans on the tomcat, 1 a side,... so i should not be facing that problem... I;m hoping to get 2kg total thrust from the combo... 1.8 min

3) thanks for the advice, will follow this through1

Originally Posted by PeterVRC
You will strike more issues in the plane... LOL

1) No need for an inlet lip.. the plane has them - its inlets!
You want the fan 'flowing' into the fuselage ducting - no steps etc, a nice smooth blending of fan housing diameter into the ducting shape, otherwise it will be like no inlet lip.
If it is 'flowing' then the airflow path is clean, all the way up to the inlets and then those are the final 'way for air to get into the fan' item. It is like you just extened the fan housing X distance and then still had a lip at the end. Different aircraft have inlet different designs, and cross-sectional areas (to allow volume/speed of air as required for any given fan combo), so you won't know the true result until tried. A plane also moves... lol... so things can change in flight, compared to static results.

2) Exhause side of the fan..... again, on the bench it has unrestricted flow out of the housing, but might not be in the plane. Especially an F-14 which is a bifurcated exhaust ducting - it splits into two paths. This is restrictive on airflow 'ease'. You will very likely need to open them out larger.
This side of the airflow will be the biggest cause of thrust loss.

3) I expect you will find:
Test the combo on the bench with an inlet lip.. you will get your expected/hoped-for 60A 1.45Kg thrust area.
Throw it in the F-14.... I would guess you will get 700g thrust only!!!
It will largely be due to the the exhaust side. But check the look of the inlet side to see how clean that is, and improve it if you can. Modify foam etc to have the smooth flow if there are steps etc. Though the exhaust side will be the main thing to concentrate on really.
Once you see that 700g Thrust (LOL... and IF it is low like that) you wil need to sand 'open' the exhaust tubes more. Use a round 'something' with sandpaper on it..... the closer to the starting radius the better, so it can sand more accurate 'roundness'.

Pics: My F-15 with CS10... exhausts sanded out. Thrust went from 700g area to 1.1Kg.... still a bit lousy, but there was no more to sand!!
The only way left to get more thrust is throw more at it!! eg 1.7Kg bench, and lose a lot to end up with maybe 1.3Kg area.
Feb 06, 2013, 06:42 PM
Registered User
Which F-14 is that then?
Must be 1500mm (in one dimension) I would expect? If you can fit two 70mms!
Swing wing?

I have only seen one 'common' F-14 around (and it comes with the swing wing), but I forget what size that was. Stock is 2x 60mm.
Which I thought it was actually 1x 70mm - or 1x 64mm
Maybe it is at least big enough to fit two 70mm......
Probably that one best 2x 64mm though.

Oh and while on the F-14 topic....
If it IS that one I have seen (HobbyKing sells it too), is it any good??? Lots of reviews say it is a really bad kit. ???
Though I have seen some YouTube posts of it all done and flying fine.....
Last edited by PeterVRC; Feb 06, 2013 at 06:54 PM.
Feb 07, 2013, 02:08 AM
Registered User
Actually, none of the tomcats are bi-furgirated, Mine is the old EPF f-14 70mm Tomcat (fixed wing)

i also have the HK tomcat which i will mod for 64mm edfs
Feb 07, 2013, 05:32 AM
Registered User
Just wanted to say thanks again for all the information that has been contributed on this CS-10 fan, it's helped me have success with my F-18. Now I plan on putting the CS-12 in a GWS A-4!

Walts New F18 Part2 (4 min 49 sec)
Feb 07, 2013, 09:47 AM
Should've, Would've, Could've
v8truckin's Avatar
Delete wrong thread
Feb 07, 2013, 09:53 AM
Registered User


Guess I'm a bit behind..been some testing has been good and bad..big inlets sound great and make good thrust..95 percent fsa dosent..amp draw is higher ad results are with 110 fsa & long this what u guys have found also
Feb 07, 2013, 10:05 PM
other than the het 2w25, has anybody found an inrunner w/ a 4mm or larger shaft in the ~110 to 130 gram range? i am looking for a lighter setup for ~800 watts on 4's.

kinda done w/ the cheapo outrunners at this time.

1 thought was this;
in the2750kv

not sure if it will put up w/ 60 amps though even in burst? the description at at OSE
says it has vents in both bells, not sure i see them though?

any input appreciated,

Feb 07, 2013, 10:21 PM
Registered User
You should look for the 2850 Leopard

Leopard 2860-2730kv here: (these are the open end cans versions) <- this one is good value - if you are in the US.

Or: (Unfortunately RCtopshop is a bit expensive really)
2850s here:
(I would prefer a 2860, to have leeway and future higher power options - depends on the KV you grab)

Or use the CyclonePower in a CS12 instead (because it is a 29mm motor):
Feb 07, 2013, 11:55 PM
Originally Posted by PeterVRC
You should look for the 2850 Leopard

Leopard 2860-2730kv here: (these are the open end cans versions) <- this one is good value - if you are in the US.

Or: (Unfortunately RCtopshop is a bit expensive really)
2850s here:
(I would prefer a 2860, to have leeway and future higher power options - depends on the KV you grab)

Or use the CyclonePower in a CS12 instead (because it is a 29mm motor):
thanks, i was hoping to remain near the weight of the het and save a few bucks

2860's are nice but at 2oz heavier, and only 800watts to pull it around , it is a weight penalty. i have sworn off 5's for now so 800-1000w is all i can realistically see asking of the 4's. the 2850 is a bit better, but the $'s are getting up w/ the het.

so are the pics just wrong w/ regard to the vents?i dont see any in any of them.

thanks for the info ,

Feb 08, 2013, 12:19 AM
Registered User
Only Offshore says they are vented ones.
All the new Leopards are vented, so even if pics show they are 'car' type that MIGHT be wrong... unless they have older ones in stock. So it is best to ask to be sure.

I like the CP. Getting to HET like but at lower cost. Though you really want to push them to 1000W area (or more) to get your moneys worth! hehe

I have a HobbyKing 380L-2600kv and that does 800W area on 4S. $31
But that 800W (or so) is nothing exciting in the 70mm F-16.
The useful info from that is that 2600kv in a CS10 does 800W or so..... and that is probably a bit better motor than an L2855. But an L2855-2800kv only does about that area on 4S too.... suggesting to me that it can't truly do the work. Which would mean a 'good;' 2800kv should do 900W to 1000W really.
(I have to check all my CS10 record when I get home to verify the Watts that come from what motor/KV).
Feb 08, 2013, 02:33 PM
Registered User
Hi guys , need your advise here. I read in this thread that CS10 - 70mm is good for - 2800-3000kv on 4s. I just tested it with NTM 2700KV

On my WATT meter ( WHATSUP ) it shows 63-66A on 4s batt. As this motor is rated for 50A max , it seems that 2700kv is too much for that fan

On 3s it get about 45A , but I guess the thrust will be too low. I intend to use this fan/motor for my Durafly Sea Vixen.

does anyone have expirience with that motor and if not what you will sugest for 4s ?
Feb 08, 2013, 03:07 PM
Registered User
MagnusEl's Avatar
It could very well work with 4 cells. In an EDF the motor gets better cooling than with a prop. Best way is to run it , lets say 20 sec and then check temp. extend the runs with 10-20 sec and check the temp right after. Up to~ 80 Celcius should not be a problem, but take note if the temp rises after the run.
Feb 08, 2013, 03:13 PM
we can take off without that
green_flyer's Avatar
check out Tenshock as well. I discovered them recently and have a smaller one in a 50mm fan, really good thrust.
They are a bit more pricey than HET.
There are several 29mm and 28mm options, in various weights, here is one.

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