SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Jan 29, 2012, 07:12 AM
Registered User
domll's Avatar
Norwich.uk.
Joined Oct 2007
542 Posts
back on the build after hectic week at work. After pondering construction for the hatches i realised that i was placing them on the wrong side, need to be underneath not on top. this meant that the bearers are on the wrong side of the center line so i cut them out, new bearers will fixed to the top of stubs.

Also had to think of the motors required; to purchase the e-flite motors specified for these fans is a little over the budget i'm able to pay so new motors need to be sourced. This brought me to the next problem, motor shafts, as the adaptor is designed for 4mm shafts not the more common 3.17mm. After looking around i found a prop adaptor from OverLander in my local model shop which looked to be fine. On closer inspection the adaptor threads are the same, Overlander's being slightly longer, not an issue. Using my vernier calipers i measured the unthreaded shank, Edf adaptor measures 6.25mm and the lander part 6.35mm, 0.1mm difference. So my next thought is to mount the prop adaptor in a drill, spin it up and use wet n dry to take it down to 6.25mm.
domll is offline Find More Posts by domll
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 29, 2012, 07:35 AM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,855 Posts
awsome!
Keenan smith is online now Find More Posts by Keenan smith
Reply With Quote
Old Jan 29, 2012, 04:38 PM
Registered User
domll's Avatar
Norwich.uk.
Joined Oct 2007
542 Posts
Okay, new bearers in place and one duct complete, one to go although won't take as long due to the paper templates produced with first. I used this software to create the rear cones so shouldn't cause any problems:

http://www.pulserate.com/
domll is offline Find More Posts by domll
Reply With Quote
Old Jan 29, 2012, 04:54 PM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,855 Posts
Yikes !! thats some crazy ducting
Keenan smith is online now Find More Posts by Keenan smith
Reply With Quote
Old Jan 29, 2012, 06:11 PM
Registered User
LuvEvolution7's Avatar
St.Catharines, Ontario
Joined Jan 2009
10,377 Posts
looks pretty good to me. ever seen the ducting on an MB339? not very EDF friendly at all. LOL.
LuvEvolution7 is offline Find More Posts by LuvEvolution7
Reply With Quote
Old Jan 29, 2012, 06:26 PM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,855 Posts
Link ??
Keenan smith is online now Find More Posts by Keenan smith
Reply With Quote
Old Jan 29, 2012, 08:57 PM
Registered User
Colorado Springs, Co
Joined May 2002
97 Posts
Quote:
Originally Posted by domll View Post
Pilot colours, now just need to find a 1/12 scale pilot..
Try looking at Jet Hangar Hobbies (www.jethangar.com) and their "Castle Five" pilot busts.
They have a "Sabre Jock" bust in 1/8 and 1/2 whose helmet looks very similar to the one in your post.
They are light, nice looking and inexpensive

(if I could figure out how to attach a photo, I'd insert one of my 1/8th Sabre jock......) I hope it attached......
Greg
gbmoore is offline Find More Posts by gbmoore
Reply With Quote
Old Jan 30, 2012, 01:06 PM
Registered User
domll's Avatar
Norwich.uk.
Joined Oct 2007
542 Posts
k.smith459 - As LuvEvolution7 say's, many more complex ducts out there, although off set least its straight, would have been a lot more difficult with 'S' ducting.

Gdmoore - thanks for the link, now know were to get the pilot. I'll be doing the same as you have done with a partly sunken cockpit.
domll is offline Find More Posts by domll
Reply With Quote
Old Feb 02, 2012, 12:58 PM
Registered User
domll's Avatar
Norwich.uk.
Joined Oct 2007
542 Posts
Small amount managed during the week: Rear duct cut out, soaked in warm water, rolled and held with rubber bands until dry, helps with de-tensioning ply making fitting easier. Also final fromer cut out and laminated to depron. One rear duct fitted at the moment. As i've run out of kicker, so has the shop until tomorrow, nothing much else yet done, so will collect supplies just in time to continue at weekend.
domll is offline Find More Posts by domll
Reply With Quote
Old Feb 05, 2012, 05:31 AM
Registered User
domll's Avatar
Norwich.uk.
Joined Oct 2007
542 Posts
Ducting finally in place and started on the front section again. Side rails cut from 1/4inch balsa, need to decide if a floor is required before building up. Total airframe weight so far, 13oz.
Also started on the boons, again balsa LE added to help prevent damage and aid in keeping fins vertical. Next, add side crutches and formers. Before I can join these to the main fuselage I need also to get the elevator sorted.

Question: Not sure if to go with rudders, have heard that EDF's are better with but the original plans state these are not necessary... any thoughts?
domll is offline Find More Posts by domll
Reply With Quote
Old Feb 05, 2012, 06:42 AM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,382 Posts
Personally I build them to operate even if it says"not needed"If the thought is there now it's going to be there when you are flying.I did the same thing on a 162 ss,It gives you options.Easier to do it now than to retrofit.Just the weight to watch.
Stuart
Stupot46 is offline Find More Posts by Stupot46
Reply With Quote
Old Feb 05, 2012, 11:59 AM
Registered User
LuvEvolution7's Avatar
St.Catharines, Ontario
Joined Jan 2009
10,377 Posts
this is a boomer.................go with rudders. you'll need them.
LuvEvolution7 is offline Find More Posts by LuvEvolution7
Reply With Quote
Old Feb 05, 2012, 12:13 PM
Registered User
domll's Avatar
Norwich.uk.
Joined Oct 2007
542 Posts
thanks guys, confirms what i was thinking.

LuEvolution - Im Intrigued, is it specific that a boomer needs rudder apposed to other EDF's?
domll is offline Find More Posts by domll
Reply With Quote
Old Feb 05, 2012, 11:33 PM
Registered User
LuvEvolution7's Avatar
St.Catharines, Ontario
Joined Jan 2009
10,377 Posts
it's all about those booms. I've only ever flown one boomer and it was really bad for adverse yaw, especially in turns. I'm not sure if this is a huge problem with all boomers, but I'de be willing to bet good money that it is. I'de go with rudders no matter what. if you should ever need them and don't have them, you'll wish you did.

I think what's going on, is that there's not a lot of side area with the small booms and the plane struggles to weathervane in turns and other maneuvers. for this reason, you get some skidding in turns and gravity will always play havoc with the plane when there's not a lot of side area to counteract gravity with aerodynamics. I think this could get worse for you if you ever get a situation with a cross wind final approach. I say go with rudders.

Rich
LuvEvolution7 is offline Find More Posts by LuvEvolution7
Reply With Quote
Old Feb 05, 2012, 11:36 PM
Registered User
LuvEvolution7's Avatar
St.Catharines, Ontario
Joined Jan 2009
10,377 Posts
I think it's also important to point out that for a plane to be stable longitudally, there should be more side area towards the rear of the plane. with most planes, this isn't a problem since this is the way they are designed anyway. so, we get the advantage of the side area to help us in the yaw axis. with a boomer, there's more side area towards the nose, so it opposes stability in the yaw axis. I believe this explanation is more helpful aerodynamically speaking, which is why I'de add the rudders.
LuvEvolution7 is offline Find More Posts by LuvEvolution7
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sea Vixen fly20 Non R/C Items (FS/W) 6 Dec 12, 2011 10:54 AM
Discussion Search for help on Chris Golds DH 110 Sea Vixen jettrainer Scratchbuilt EDFs 0 Jul 18, 2011 01:12 AM
Discussion Search for Chris Golds DH 110 Sea Vixen review jettrainer Electric Ducted Fan Jet Talk 2 Jul 17, 2011 04:17 PM
de Havilland Sea Vixen FAW.2 drawings. bipeflyer Electric Ducted Fan Jet Talk 8 Sep 02, 2003 05:56 AM
Sea Vixen or vampire BruceWilkerson Electric Ducted Fan Jet Talk 15 Jun 12, 2003 05:40 PM