Combatevolved
The specs on Hobby King Dr Mad thrust 50mm edf say up to 450g of thrust. This unit is rated for a maximum of 3s drawing 18a.

I made 320g at 15a which is totally under spec and exaggerated by HK.

I rigged up 4s and dropped the throttle to a max of 85% and still only managed 400g.

The housing, fan and balance is perfect but I'm guessing the motor is the weak link.



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Wildthing
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The specs on Hobby King Dr Mad thrust 50mm edf say up to 450g of thrust. This unit is rated for a maximum of 3s drawing 18a.

I made 320g at 15a which is totally under spec and exaggerated by HK.

I rigged up 4s and dropped the throttle to a max of 85% and still only managed 400g.

The housing, fan and balance is perfect but I'm guessing the motor is the weak link.




I have 2 of their Dr Lazy Thrust edf's, don't remember the kv but very disappointing.
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Sterling101
I used two of the 50mm 4s in my first Vulcan and yes they leave a lot to be desired as far as all out power goes.
I think it's one of those things that looks great on paper with the alloy housing but at anything below 64mm you need to be as light as possible otherwise you lose out on thrust massively.

And I don't trust the official specs at all - my Vulcan has just enough power with two of them to hand launch with a good throw. Anything less and it would never fly...
Whoever said nothing is impossible had obviously never tried slamming a revolving door...
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Combatevolved
Indeed the build quality is great but the motor they use is trash.

I've got a 50mm AEO which smashes the Dr poo thrust producing 480-500g. It's the fan I fitted to the mini Typhoon.



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bogusbandit56
Quote:
The specs on Hobby King Dr Mad thrust 50mm edf say up to 450g of thrust. This unit is rated for a maximum of 3s drawing 18a.

I made 320g at 15a which is totally under spec and exaggerated by HK.

I rigged up 4s and dropped the throttle to a max of 85% and still only managed 400g.

The housing, fan and balance is perfect but I'm guessing the motor is the weak link.




You can get over 450grams with a little blue wonder motor swinging a 9x3.8 prop
https://hobbyking.com/en_us/hextronik-24gram-brushless-outrunner-1300kv.html?___store=en_us
Wot, no Depron?
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Combatevolved
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I used two of the 50mm 4s in my first Vulcan and yes they leave a lot to be desired as far as all out power goes.
I think it's one of those things that looks great on paper with the alloy housing but at anything below 64mm you need to be as light as possible otherwise you lose out on thrust massively.

And I don't trust the official specs at all - my Vulcan has just enough power with two of them to hand launch with a good throw. Anything less and it would never fly...

Hi Sterling, How much did the Vulcan weigh and what sort of thrust did both units produce?
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Sterling101
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Hi Sterling, How much did the Vulcan weigh and what sort of thrust did both units produce?

I think the all up weight in the end was something like 1480g and the thrust I get is about 1200g from the two fans.

One thing I did find out both on this build and probably more on my BAe Hawk is you don't need a 1:1 ratio for an EDF plane! My Hawk on the 4S setup came in at 2044g and the fan put out 1425g and it still flew really nicely. Now that's been upgraded to the 6S setup it's closer to a 1:1 ratio but the flight characteristics are about the same.
The new Vulcan should come in just below the 4kg mark once it's painted and the thrust will be somewhere around the 3.5kg level so should fly nicely enough - just a whole lot bigger!

The other thing to remember is those figured are STATIC thrust - so with no air moving into the fan itself. Once the plane is airborne and has some air pushing its way into the fan intake the thrust improves hence you need lots of static thrust to get airborne but once you're up you can throttle back and it'll fly just fine.
Whoever said nothing is impossible had obviously never tried slamming a revolving door...
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Combatevolved
Cool when will the big V be ready? That's the plane I really want to see.
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Sterling101
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Cool when will the big V be ready? That's the plane I really want to see.

It's ready for maiden and has been since the end of October last year. Just waiting for weather and work to align correctly and I'll be able to get it in the air
Whoever said nothing is impossible had obviously never tried slamming a revolving door...
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