FPV speed challenge

[g.collins]

ha Steve, check this out he has your red tape. :D

Flite Test - 100mph under $100 - CHALLENGE

[Angelos]

Here is the final layout of my FunJet....

At the nose 1000mAh/2S pack for the OSD, VTX and camera. Followed by 2x 2200mAh/3S for the motor... followed by a very small compartment for the avionics. I am still not sure where to fit the chunky DragonLink RX. I am thinking to removed the connectors and just solder directly wires for the the PPM and RSSI. The GPS module and OSD are attached on the avionics cover whist the ESC and current sensor are attached to the base of the fuselage.

With this layout the plane balances perfectly. All up weight 1.245Kg. An aerodynamically hidden hook is available in case it needs bungee launch.



-Angelos

[pk-surfing]

Certainly using every bit of space in there, I'm looking forward to seeing what it can do as I reckon you wont need to go much past tickover to log some serious speeds with it.

We should have a sweepstake going pre your speed runs to see who can guess nearest, I reckon 168mph level and 197mph with a dive !

PK

[Pasty]

Finally he shows us the goods! ;)

yeah you certainly filled every bit of space!

What C rating are those packs? nano tech 70c jobbies?

I like the idea of using the 3s in series to deal with space issues, lots of power in a slender form, you got me thinking now :D

[pk-surfing]

Steve,
go on have a guess at speeds for level and max after a dive.

[g.collins]

 I recon 115MPH level. :+
regards G

[Pasty]

ok, I cant remember the motor used but I'll go for 155 on the flat and 190 in a full power dive.

[pk-surfing]

Angelos.....

You need to chip in with your anticipated speed guess, no pressure though  ;D

[Dizzy]

Hi guys

was talking too Angelos last night apparently her maiden is today WISH I WHERE THERE  :D

[Angelos]

2720Kv * 3.7V * 6S = 60384 RPM

60384 * 4.7" * 0.0254 * 60 = 432.5Km/h (speed based on prop step of 4.7")

432.5Km/h / 1.609344 = 268.7 mph

Of course air causes drag so 268.7 mph will not be achieved but I will be very pleased with anything over 180mph level flight.

As of speed after a dive I think you should rephrase the question to "What will be the size of the bigger piece?" because I don't think the servos will be able to pull it out!

-Angelos

[pk-surfing]

180mph level.... hmmm I suppose it does look very slippery.

What have you done to the wings, are they sanded smooth and painted ?

I'm getting butterflies already

[Coyote]

This should be good ! Or very short lol

Lets hope its not too short. Are you going to get any speed readings from today Angelos ?

[Pasty]

2720Kv * 3.7V * 6S = 60384 RPM

60384 * 4.7" * 0.0254 * 60 = 432.5Km/h (speed based on prop step of 4.7")

432.5Km/h / 1.609344 = 268.7 mph

Of course air causes drag so 268.7 mph will not be achieved but I will be very pleased with anything over 180mph level flight.

As of speed after a dive I think you should rephrase the question to "What will be the size of the bigger piece?" because I don't think the servos will be able to pull it out!

-Angelos

ahh I based my calcs on 1700Kv spinning a 4x4

I dont think the servos would be the issue with a full power dive but elevon flutter or elevon flattening out will be. :D

We NEED vid of this one!

[Angelos]

A rather disappointing 120mph with the FunJet. :( Still have two major issues:

1. There is a timing issue with the ESC/motor which makes the motor kick at low RPM and particularly when the pack is charged. The kick is not present at high RPM but the bad timing may result to reduced power.

2. The prop is very small 4.75x4.75 and most of it is behind the plastic shroud funjets have around the motor. This may affect the effectiveness of the prop due to restricted airflow.

-Angelos

[g.collins]

Hi Angelos
do I get a prize for being the closest, smarty pants :laugh:
G