Hi-Performance and Sailplanes RC hotliners, electric pylon racers, F5B, F5D, sailplanes and gliders

Holy Hawk foamie/delta/ powered glider - advice?

Old 05-23-2012, 04:30 PM
  #1  
Davethebluessinger
Child of the 60s
Thread Starter
 
Davethebluessinger's Avatar
 
Join Date: Sep 2010
Location: Rugeley, Staffordshire, UK
Posts: 1,082
Default Holy Hawk foamie/delta/ powered glider - advice?

Not sure which forum I should really be posting on here....
So I decided although that this question was about:
A foamie
A delta

I thought "it's really a powered glider of sorts" so here goes....

First off all I can find on this bird is here:
http://www.wattflyer.com/forums/showthread.php?t=8430
I have a few more questions!

I looked at this for ages before buying it.
I picked this up at around 50% retail as judging by the link above it's obviously old stock!

It came RTF with a very cheap and nasty 27mhz radio setup so orange receiver will be installed for Spektrum DX7.
Cheap servos were pre-installed but I plan to run with them and change them if they appear suspect.

OBJECTIVE, Lazy gliding around on Sunday afternoons but with a good rate of climb and enough capacity for several climbs per battery.

I plan to convert it to brushless, I already have 1300mah 2S batteries.
I have a few 18A ESCs kicking around that I could also use.

1. Opinions please - if I remove the 380 brushed motor that's installed and install a small (say 24 or 28mm) outrunner around 2000KV IN FRONT instead of inside the fuse will it upset the C of G too much? (will the CG be in a conventional area like 1/3rd backfrom LE?)

2. I'd like to run a folding prop, any suggestions on size/pitch given that it comes with appx 6 x 4 prop on the 380?

3. I can't believe that the 27meg system had elevon mixing maybe I'll find a V tail mixer inside when I gut it! Should I use Elevon mixing or V tail mixing? There are no tail controls whatsoever - just 2 ailerons on the main wing.

4. I have no spec on the build except it's quite nicely finished skinned foam on the wing/tail and balsa/ ply/ covering on the fuse. Just wondered if anyone can tell me any more? For instance I'm assuming theres a spar inside the foam wing, is it worth fitting a second CF spar for strength?

I know NOTHING about powered gliders (and precious little about everything else according to the wife!)

Thanks in advance!
Davethebluessinger is offline  
Old 05-23-2012, 05:11 PM
  #2  
CrimzonRider
Fastest PropHead Crasher
 
CrimzonRider's Avatar
 
Join Date: Nov 2010
Location: NW Oklahoma
Posts: 1,308
Default

Not a whole lot info out there.....hmmmm, but I did find this thread of all things rc birds, might be able to answer a few of your questions!

http://www.rcgroups.com/forums/showthread.php?t=950519

I kinda skimmed thru the thread....pretty interesting.....


cr
CrimzonRider is offline  
Old 05-23-2012, 07:07 PM
  #3  
flydiver
Super Contributor
 
flydiver's Avatar
 
Join Date: Jan 2007
Location: Seattle, WA
Posts: 2,668
Default

Treat it like a delta, it uses elevons. In this case it's a 'plank' style.
What prop depends on which motor. Chances are the motor was either a 350 or 400:
WEIGHT : 63g (2.22 oz)
WEIGHT : 95g (3.33 oz)
Weigh it and act accordingly for outrunner choice, prop selection and CG placement.

The stock prop was based on the motor/battery combo, just like any plane. I have a MUCH bigger glider with a huge brushed motor and it uses a 6x3 prop on that combo because that's what the motor could deal with direct drive-ridiculous by modern outrunner standards.

The CG is likely to be as you guess. You'll need a tad of 'reflex' (up) on the elevons most likely which is normal. Planks will be pretty CG sensitive.

Yes, some old 27MHz systems would do elevons, no problem.
That might make a fine sloper if you have the required hills, wind, and inclination.
flydiver is offline  
Old 05-25-2012, 12:26 PM
  #4  
Davethebluessinger
Child of the 60s
Thread Starter
 
Davethebluessinger's Avatar
 
Join Date: Sep 2010
Location: Rugeley, Staffordshire, UK
Posts: 1,082
Default

Thanks chaps,
I checked CG position with standard motor and NIMH in place last night then I gutted the plane of all electronics except servos and removed the 380 motor, I replaced it with an Emax BL2285 outrunner I had lying around (screwed outside the firewall on the nose not inside as per the original). I then re-installed the original battery and the CG is still pretty similar, although the new motor is further forward it's obviously lighter than the old 380 can. I don't yet have the 2S 1300mah lipos (on order from HK) so I can't tell how they will affect the CG but I suppose I can get the weight from the HK website and weigh the original battery for a comparison. I suspect the new batteries will be smaller and lighter but there's room for forward/backward adjustment so no problems forseen there. It's a nicely made little bird, small enough for the park, my only criticism is lack of a battery hatch cover, I'll probably knock one up out of thin ply or correx.
I have plans to fit an 8 x 4 folder but getting my hands on a 30mm dia spinner for the new motors 3mm shaft is proving awkward. For now I will fit a prop saver and run a conventional prop
Davethebluessinger is offline  
Old 05-26-2012, 10:27 PM
  #5  
Rockin Robbins
Super Contributor
 
Rockin Robbins's Avatar
 
Join Date: Mar 2009
Location: DeLand, FL
Posts: 1,883
Default

Dave, chances are the tail was designed to only perform the elevator function. If you hook it up as elevons you should be able to tune the flight characteristics really well with some mixing adjustments.

Sounds and looks like a ton of fun there!
Rockin Robbins is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Alabama Flying Dude
Pusher Park Jets
3
05-19-2012 05:13 PM
MarkAntony
Hi-Performance and Sailplanes
8
02-04-2012 08:41 PM
Nieuport Fly Guy
Airplanes - Electric For Sale & WTB
2
08-19-2011 12:52 AM
ehirobo.com
ParkFlyers
1
07-15-2011 12:22 PM
norcalwelder
Foamies
27
06-30-2011 10:59 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Quick Reply: Holy Hawk foamie/delta/ powered glider - advice?


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.06665 seconds with 13 queries