Knief Racer - New Product & Build

[MikeRC]

Just thinking of a light weight set up on 4s to fly at the local club , easier to land since light using this drone motor. and play with some 5" props...

F80 PRO 3-6S FPV Racing Drone Motor KV2500 | T-MOTOR®

T-Motor F80Pro 2408 fpv motors. These brushless motors are mean and put out insane power! Designed for long range, racing and freestyle builds.

store.tmotor.com

says it can do 700 watts , 47 A, Only query is will a regular airplane esc like 50 a or 55 will work on a drone motor like this?

Mike RC

 

[Jarron]

Only query is will a regular airplane esc like 50 a or 55 will work on a drone motor like this?

Mike RC

Of course! You should have no issues.

 

[JustinMader]

Love it!

More stable than the Mini-Q you made?

Flown back to back, yes, the Xray is currently more stable than the MiniQ. Made me realize I still need to do some tweaking to the MiniQ, most likely shimming the motors down further to remove that last bit of speed-induced lift. The Xray will hold it's line at any angle when I let go of the sticks, it's probably the most dialed in plane in my hangar.

Using the same powertrain (1507 2700kv + APC 4.1x4.1 + 4S 18650 P28B) as the MiniQ, the Xray is a bit slower at WOT (by about 15mph), but is easier to launch. MiniQ is more stable at lower speeds and will gently hyperstall, Xray wants to drop a wing. Xray is also 710g AUW so that's not surprising.

Just picked up some AMAX Inno 1510 2800kv motors to try. These can run APC 4.75x4.75s at the exact same efficiency (on the bench) as the above setup, so betting these will give a higher top speed.

Hoping to get the MiniQ just as dialed in, but the Xray is the current fave.

3D Files: https://www.thingiverse.com/thing:6822378

 

[Wayne]

You would probably be a bit better off with a lighter weight glass version of the X-ray. But in the end I don't know it would matter much. You would only save a little weight.

 

[JustinMader]

You would probably be a bit better off with a lighter weight glass version of the X-ray. But in the end I don't know it would matter much. You would only save a little weight.

This is the glass version

 

[Wayne]

Well, perfect!

 

[JustinMader]

This is from a month ago, first time taking the Xray to the big field. Was taking it easy, but def won't on the next trip .

 

[MikeRC]

Can you post me a link to the motor?

why is ur plane? 710 gram ...it should be less than 500 gram based on the set up weight listed here...https://www.hyperflight.co.uk/products.asp?code=KNIFE&name=knife-racer-1m

Oh... do you have FPV gear on it? how much does the FPV gear weight?

Mike RC

Flown back to back, yes, the Xray is currently more stable than the MiniQ. Made me realize I still need to do some tweaking to the MiniQ, most likely shimming the motors down further to remove that last bit of speed-induced lift. The Xray will hold it's line at any angle when I let go of the sticks, it's probably the most dialed in plane in my hangar.

Using the same powertrain (1507 2700kv + APC 4.1x4.1 + 4S 18650 P28B) as the MiniQ, the Xray is a bit slower at WOT (by about 15mph), but is easier to launch. MiniQ is more stable at lower speeds and will gently hyperstall, Xray wants to drop a wing. Xray is also 710g AUW so that's not surprising.

Just picked up some AMAX Inno 1510 2800kv motors to try. These can run APC 4.75x4.75s at the exact same efficiency (on the bench) as the above setup, so betting these will give a higher top speed.

Hoping to get the MiniQ just as dialed in, but the Xray is the current fave.

3D Files: https://www.thingiverse.com/thing:6822378

is

 

[MikeRC]

used the heat gun to remove the old motor mount to add the drone motor . the motor mount is kinda chewed up/warped ...Need a new motor mount 35mm from what i measured .

found this online , but out of stock https://alofthobbies.com/collections/motor-accessories/products/g-10-motor-mount



Any other sources for 35mm motor mount? 16 x 19" mm pattern


Mike RC

 

[MikeRC]

What size spinner does this plane take? 30 mm ??

what size is the motor mount. Trying to souce a CNC motor mount , does 35mm sounds right?

https://www.arthobby.com/index.php?p...ry=93&item=545

Mike RC

 

[Jarron]

The Knief/Xray/whatever wants a 38mm, I've got one of these in mine: https://www.hyperflight.co.uk/produ...name=universal-mount-38mm-16-19mm-motor-holes
I've taken these spinners to my lathe and turned them down to 38mm a bunch of times. : https://alofthobbies.com/products/40mm-aluminum-spinner?_pos=3&_psq=40mm&_ss=e&_v=1.0
We're..out of stock though, it's going to be a while until more arrive.

 

[Reid Williams]

Can someone measure their X-ray throws to give me a good starting point? Getting close to having mine ready to go

 

[Wayne]

@Jarron Should have some numbers for you.

 

[Jarron]

Can someone measure their X-ray throws to give me a good starting point? Getting close to having mine ready to go

Here you go:

CG: 42-47mm from wing LE at Fuselage sides.

Throws:

Ele: 3mm Up, 3mm Down
Ail: 4mm Up, 4mm Down

 

[Reid Williams]

Thank you! I'll start with that