200mph with 70mm - Page 2 - RC Groups
Thread Tools
Oct 30, 2012, 03:31 PM
Victim of C.D.O.
murdnunoc's Avatar
Omg Steve that Speariment is gorgeous!
Are those the stock wings? Hard to tell from the angle.

Maybe I ought to just scrounge Spear airframes to suit the 70mm speed bug.
I know Joe's did 186 on around 4Kw and 64K on the Mach fan. so that's what I'm basing a lot of things on.
Sign up now
to remove ads between posts
Oct 30, 2012, 03:48 PM
Anything that gives me a High
super kupfer's Avatar
Originally Posted by Steve C
If you were flying a Spear, you shouldn't need 3500 watts to hit 200 mph.

I just put a new 6s 2800 battery in mine with ARC 28mm motor and it's going 200 now and nothing got hot. It just lands like the space shuttle! I don't know how many watts, but it can't be more than 2000 or lava would pour out of the motor.

Hack your Spear to clean up the back end. I also made the inlets a bit smaller by extending them forward a bit. Originally I cut the stock canopy down and it didn't look bad. I can post a pic of what that looked like if you want.

Cooooool, who makes this plane, I want one.
Oct 30, 2012, 04:22 PM
Registered User
Originally Posted by super kupfer
Cooooool, who makes this plane, I want one.
What i know, it once was a ultrafly spear whuch steve modified.
A few months back i went looking, there to buy a ultrafly spear, but can't find a selling point.

When wanting to see more about steves modell, search for QUEST 200 on this forum
Oct 30, 2012, 05:00 PM
Carbon fiber is our friend
Steve C's Avatar
Yes, Ultrafly made them, but I don't even know if they're around any more. There's probably still a few kits out there though.

Here you can see some of the changes. The wing is stock and a lot of the fuse is stock also. I just got rid of the center fin, did some foam glass and bondo to the back end and added the winglets, which are the tips off a sp400 racer wing. Also made the canopy from blue foam and carbon fiber, but that was more to change the look than for speed.

The rotor in this plane is the one in my Avatar. It's one piece carbon, so it can take some serious rpm!

I still need to try moving the cg back some more because it needs the elevons up all the time and that's draggy. Once I know what it needs, I have another one in the box that needs do be done up. It may end up with a new wing if I can't get the elevons trimmed out. Should just make a mold of the fuse too though. Mine is pretty heavy once all the changes were made and the wing glassed.
Last edited by Steve C; Oct 30, 2012 at 05:14 PM.
Oct 30, 2012, 06:31 PM
Registered User
the best fan for that speed is defenetly the VASAFAN 70mm! at my knowledge, i don't know any other fan who's able to produce that needs of power
with HET 2w30 on 8 s ,this is almost 3kg thrust, a lot of amps too....but if you want speed....
with a light and smooth shell like HET sniper, this would be difficult to follow in the air!!
Oct 30, 2012, 06:58 PM
High Dynamic Thrust
stoneenforcer's Avatar
Originally Posted by super kupfer
8-10cell in a 70mm EDF jet is too much weight + it would be very hard to fit in an airframe.
theres been a few guys, now retired from this limited ceiling site, that have run 10-12s in 70mm full composite frames. they were very close to 200mph but amp draw, motor rpm were an issue at the time.

the prairie is litter with the bones of pioneers
Oct 30, 2012, 07:07 PM
Ginger or MaryAnn ??
fh64_lucky's Avatar
I ran a light 10s 1100mah setup with HET motor in wemo fan in my Phoenix, and it was not very heavy. I always thought the Spear was a good platform to hit 200 with, it just needs to be cleaned up a bit in the few areas as Steve has done. Maybee thats what I will do this winter....
Oct 30, 2012, 07:45 PM
Registered User
yes! 8 cells in a small 70mm edf jet is much weight, but tons of power too!
here's my e-flite f 86 sabre with Het 2w30 on 8cells and HEt fan
should be fatser with a vasafan ,work in progress...
but already reach up to 305km/h....

high speed and low pass f 86 e-flite het 2w30 305km/H (0 min 17 sec)
Oct 30, 2012, 07:55 PM
Anything that gives me a High
super kupfer's Avatar
OK guys I'm sold "you can fly 70mm on 8-10cell".

That f86 was lightning speed.
Oct 30, 2012, 08:06 PM
Flazo's Avatar
nice 200 and 70mm wow
anybody using a JS-1400 to reach 200mph?
Oct 30, 2012, 08:49 PM
Victim of C.D.O.
murdnunoc's Avatar
I only get about 250kph (155mph) on that F-86 in the video...

A 2W-30 motor will have a hard time making anything over 2000W. It'd take a super slick airframe to do anything near 200mph with that.

I really need to get this Spear in the air for more than a second so I can see how fast I can get it with how many watts!
I'll do some good cleanup stuff as part of this repair job from the botched bungee launch. Epoxy is curing now!
Oct 30, 2012, 08:59 PM
Victim of C.D.O.
murdnunoc's Avatar
Originally Posted by frank40
I don't know if it is safe in the long term, but so far it seems ok.... It did rip the test model apart when the stick hit 25% throttle , but it is the most silence fan I ever heard. Here is a small video. note you can hear the wings break but no sound from the fan.

That Slingjet looks like a super slick bird.
When it went down, it looked like when he punched the power, the plane pitched down and then the recovery pull-up loaded the wing and it failed.
Is that what happened?

That's been my concern with pod-mounted fans that sit well above the wing. The thrust angle can be adjusted so there's no pitch change with power change, but it results in a fan that's pointed well away from the direction of flight. That hurts efficiency from what I can see.

Is a fan more efficient when it's in a pod?
Oct 30, 2012, 09:08 PM
Ginger or MaryAnn ??
fh64_lucky's Avatar
The JS1400 hit 158mph in my 1st Spear a few years ago...It was pretty maxed out with amps and batteries at the time...
Oct 30, 2012, 10:03 PM
Carbon fiber is our friend
Steve C's Avatar
There was some pretty good testing with 70mm EDF motors a few years ago. The JS could take a lot of power without melt down, but efficiency was not as good as a good inrunner like Neu and I think it was dropping quickly at 1kw+ levels. It's really not a very big motor to expect that much from it. It's a shame they never built the double length one that was apparently planned.
Oct 30, 2012, 10:54 PM
Victim of C.D.O.
murdnunoc's Avatar
We have Mega 16/45 size motors now
Still 28mm diameter, but can make way more power than any other 28mm motor. And do it efficiently.
Larger outrunners can go in the 70mm fan, like Knife Liddle did on his super 70, but I prefer to go the inrunner route to keep my hacking options under control!

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion $99 200MPH radar gun. Koo Hot Online Deals 3 Sep 21, 2012 11:19 PM
Build Log Quest for 200mph EDF carbon dart kingkyle Scratchbuilt EDFs 23 Jul 07, 2012 07:30 AM
Cool HD Video: 200mph DS Acro with Wizard at Weldon Daemon Slope 71 Feb 22, 2011 01:13 PM
Discussion My first 200mph FPV plane with video! gundamnitpete FPV Aircraft 29 Oct 14, 2009 09:44 PM
Discussion 200MPH with 200W possible? 1atlas Pusher Prop Jet Models 15 Aug 16, 2007 01:21 PM