why are edfs expensive?
- Thread starter f-35lover
- Start date
The Fopster
Master member
I just built an EDF plane on the cheap. It’s made from home insulation foam - total cost about £5. The EDF is a 64mm by QX-Motor, which I ordered direct from China. Cost was just under £30 including taxes and shipping. I got a cheap ESC from my local hobby store for £30, and servos were generic 9g cheapos. It flies great off my existing 3s 2200 batteries, and if I decide to spend a bit more it can cope with 4s with no modifications. So - as long as you can wait for slow shipping from China you can do it cheaper - it’s still more than a prop plane but it doesn’t have to cost hundreds.
quorneng
Master member
F-35lover
An EDF is not just a rather high power high revving motor and thus sold in relatively small numbers but has to include two high quality injection mouldings, the fan and the body, as well as assembly and in many cases this is followed by a balancing process so it runs smoothly.
Looked at like this it is not surprising that an EDF is more expensive than a basic motor.
Most EDFs are heavy and fast and use very powerful battery setups but as Fopster points out if you build as a "light weight" there are ways to create a "jet" airframe and in certain cases without actually buying an EDF as such.
This standoff scale Douglas Skyray certainly looks like an EDF but light and built out of sheet foam.
it is powered by a readily available & cheap racing drone motor driving a 3x4.5 three blade prop inside the fuselage.
It only needs a 1500 mAh 3s LiPo. It weighs 430g (15 oz) ready to go.
Takes a bit of ingenuity but it flies. An easy hand launch and at a true scale speed too!
An EDF is not just a rather high power high revving motor and thus sold in relatively small numbers but has to include two high quality injection mouldings, the fan and the body, as well as assembly and in many cases this is followed by a balancing process so it runs smoothly.
Looked at like this it is not surprising that an EDF is more expensive than a basic motor.
Most EDFs are heavy and fast and use very powerful battery setups but as Fopster points out if you build as a "light weight" there are ways to create a "jet" airframe and in certain cases without actually buying an EDF as such.
This standoff scale Douglas Skyray certainly looks like an EDF but light and built out of sheet foam.
it is powered by a readily available & cheap racing drone motor driving a 3x4.5 three blade prop inside the fuselage.
It only needs a 1500 mAh 3s LiPo. It weighs 430g (15 oz) ready to go.
Takes a bit of ingenuity but it flies. An easy hand launch and at a true scale speed too!
f-35lover
Member
could you tell me where can i buy that cheap an edf???? how good is the performance?
The Fopster
Master member
This is what I’m using - looks to be about 30 bucks shipped to USA. Performance is very good - on a par with FMS I’d say from what I’ve seen (I have an FMS but that one is a 50mm). In my simple scratch build depron jet it will knife edge on 3s so pretty happ with that!
Link is here - Cheap EDF
I’m using the 3800kv on both 3s and 4s, with a 60a esc from the local hobby store.
And some flight footage of my simple “Easyjet“ here.
Link is here - Cheap EDF
I’m using the 3800kv on both 3s and 4s, with a 60a esc from the local hobby store.
And some flight footage of my simple “Easyjet“ here.
f-35lover
Member
Thanks!
skymaster
Elite member
I got something for you i think it's a good deal.
FT Viggen 5 Blade 70mm EDF Power Package - Base
FT Viggen 70mm EDF Power Package - Base
graysonhobby.com
I found a guy on discord that send me a 64mm edf for 25 but it was just 3s one with 5 blades but it also had the esc so you could look at used stuff too. i recently learned about value hobby and their edfs look cheap.
Powerfun 64mm 11 Blade 3500KV 4S EDF Fan Motor Combo-BFM-MT-
valuehobby.com
JustPlaneChris
Well-known member
I've got two 50mm and one 70mm (all 4s versions) from Value Hobby and they work great! Certainly a lot of bang (whoosh?) for the buck.I found a guy on discord that send me a 64mm edf for 25 but it was just 3s one with 5 blades but it also had the esc so you could look at used stuff too. i recently learned about value hobby and their edfs look cheap.
Powerfun 64mm 11 Blade 3500KV 4S EDF Fan Motor Combo-BFM-MT-
valuehobby.com
L Edge
Master member
Looking at EDF prices, it essentially goes that the larger the size, the much more expensive it is. And by exponential dollars in terms of motor and fan, escapes, and batteries.
Yet, it is possible to have fun with cheap 64mm 5 bladed 3s EDF's and don't break the bank. The only negative factor is don't go looking for high speeds with this setup.
As long as you build light and use a 1300mm battery, you can get a 3-5 min flight and have fun with EDF's.
You can build even a 2 engine transport, SR-71, A-10 Warthog and a flying wing and don't break the bank and each flies nicely. Here is an 64 EDF with a 1300 mah battery that flies nicely in the gusty winds due to a 20 degree dihedral.
Warthog:
Yet, it is possible to have fun with cheap 64mm 5 bladed 3s EDF's and don't break the bank. The only negative factor is don't go looking for high speeds with this setup.
As long as you build light and use a 1300mm battery, you can get a 3-5 min flight and have fun with EDF's.
You can build even a 2 engine transport, SR-71, A-10 Warthog and a flying wing and don't break the bank and each flies nicely. Here is an 64 EDF with a 1300 mah battery that flies nicely in the gusty winds due to a 20 degree dihedral.
Warthog:
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JustPlaneChris
Well-known member
The 50mm fan from Value Hobby combined with a bit of DTFB makes for a lot of fun! I designed and built a delta based on the FT Simple Delta plans, with my own fuselage and fin. It flies amazingly well on a 4S 1350 pack, and has more than a 1:1 thrust to weight ratio. Total investment less than $100. Here's a bit of video.
dap35
Elite member
I can attest the FT Viggen fly's great on an inexpensive 70mm 4s. I think I spent more on my unit. I have also used QX motor EDFs.
rc-castle.com is a good site, they also have good specs on the units.
:==> FT Viggen Maiden
rc-castle.com is a good site, they also have good specs on the units.
:==> FT Viggen Maiden
f-35lover
Member
That is awsome where can i find the plans?
f-35lover
Member
I was thinking of getting a 50mm and experimenting with it. then going on to 64mm. any suggestions on a 50mm plane?
JustPlaneChris
Well-known member
Thanks! There real aren’t any plans, I made it up as I went. There’s more info in this thread: https://www.rcgroups.com/forums/showthread.php?3903353-50mm-DTFB-Delta
If you want to buy a great flying 50mm EDF, I can recommend the Arrows Viper. It flies great on 3S or4S.
quorneng
Master member
f-35lover
In theory each with the appropriate kv motor there is no difference in the performance between identical 3 & 4s EDFs. The Watts will be the same but the 3s will take more amps to do it.
In practise it is normal to use the extra voltage of 4s to give it a more power but it is likely to need a bit more battery capacity and thus weight to give the same flight time.
Be aware that using 4s on a 3s EDF will likely cause it to burn out. The motors are different.
In theory each with the appropriate kv motor there is no difference in the performance between identical 3 & 4s EDFs. The Watts will be the same but the 3s will take more amps to do it.
In practise it is normal to use the extra voltage of 4s to give it a more power but it is likely to need a bit more battery capacity and thus weight to give the same flight time.
Be aware that using 4s on a 3s EDF will likely cause it to burn out. The motors are different.
JustPlaneChris
Well-known member
Given the choice (and assuming one has the correct batteries) always opt for the higher voltage system. As quorneng mentioned, lower voltage means more amps to get the same watts (power). More amps means more heat and less efficiency.
f-35lover
Member
Thanks for tthe information
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