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RE: (Something Fast?) Delta Build Thread - 1/13/2008 3:09:50 AM   
iron eagel



Posts: 1318
Joined: 7/15/2004
From: Middleboro, MA, USA
Status: offline 		I plan to sheath it and skin the sheathing with carbon fiber veil (tissue) that weighs .2 oz per sq yrd.
I know that I am looking at a steep learning curve in building the plane, and to be honest I have yet to do any real research into all of the consideration involved in "Hyperspeed" R/C flight. I probably will not even do the maiden on it but have one of our speed guys do that, I have get to work to flying something really fast before I would feel comfortable going over 150 anyhow.
Thus far all I have really gotten into is what type of power I would need and what it is that could provide it and keep the weight down. It may well result in just finding out what the Vne is for the airframe, or what happens when a prop tip exceeds mach1, but looks like it might be able to exceed 220 at the very least.
I still think a major factor is to get the control horns and alike out of the high speed airflow. Another thing I have got to look at is fairings for the vertical stabs and blending the wing and fuselage together. I am an advocate of the BWB concept in airplane design, one of my favorites is something called the Alantica that is being pursued by the guy who use to make wings for the Velocity FS airplane.

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< Message edited by iron eagel -- 1/13/2008 3:16:40 AM >

_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to Speedy-Gonzales)
       Post #: 276

RE: (Something Fast?) Delta Build Thread - 1/13/2008 3:36:53 AM   
iron eagel



Posts: 1318
Joined: 7/15/2004
From: Middleboro, MA, USA
Status: offline 		CP,
I had meant to comment earlier how that thing looks fast even with you holding on to it!
Nice!!!

_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to combatpigg)
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RE: (Something Fast?) Delta Build Thread - 1/13/2008 3:46:33 AM   
Speedy-Gonzales


 

Posts: 304
Joined: 3/7/2004
From: Bryan, OH, USA
Status: offline 		You are about to find out that there is a BIG difference between theory and reality. I do not mean this sarcastically either. It is just the plain truth. One other thing to remember is that weight can also work to your advantage. Weight of a speeding object adds stability. Too light and you may be very eratic at these speeds. There is a happy medium that can only be found with trial and error. Best of luck to you. I hope you achieve your goal. Speedy

(in reply to iron eagel)
       Post #: 278

RE: (Something Fast?) Delta Build Thread - 1/13/2008 4:00:10 AM   
iron eagel



Posts: 1318
Joined: 7/15/2004
From: Middleboro, MA, USA
Status: offline 		What is the saying “a airplane is just a bunch of compromises” or something along those lines.
I feel Mikes design can really push the envelope as it is. But where I would be moving up to the far edge of the envelope I know it is going to at least get interesting.
Yes I am going to learn “that there is a BIG difference between theory and reality” but that is the coolest part of the hobby for me. Hopefully I can get input from the guys in the know on here and actually get close to the target I have set.
But even if it fails I know it will be an education in aerodynamics, as well as a possible waste of balsa….
I had not really given consideration to the stability issue yet just the power plant and keeping the weight to a minimum. One thing I have decided on is that all of the control surfaces will need to be set up using pull/pull in order to minimize flutter, perhaps some beefy servos as well!


_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to Speedy-Gonzales)
       Post #: 279

RE: (Something Fast?) Delta Build Thread - 1/13/2008 4:35:39 AM   
Speedy-Gonzales


 

Posts: 304
Joined: 3/7/2004
From: Bryan, OH, USA
Status: offline 		I would consult with Kurt Bozarth or Paul Bradley . They write PYLON speed columns for Model Aviation magazine. Dave Shadel at Performance Specialties would also be a good source of info. Don't leave out Terry Nitsch. These guys will suprise you with their willingness to share tried and true secrets to achieve speed. Acheiving a laminar airflow through proper control surface hinging is very important. At 200 mph you do not get the chance to hear control surface flutter. Always remember to keep it safe. I always try to never test fly a model of this calibre with a crowd around. Never fly alone. Always have an experienced helper and a second set of eyes on your model. Work the bugs out of it and get some flight time on the model before showing it off. Speedy

Kurt Bozarth's email: kurt@bozarthhomes.com
Paul Bradley's email: bradleyp@ix.netcom.com

< Message edited by Speedy-Gonzales -- 1/13/2008 5:33:18 PM >

(in reply to iron eagel)
       Post #: 280

RE: (Something Fast?) Delta Build Thread - 1/13/2008 5:01:07 AM   
iron eagel



Posts: 1318
Joined: 7/15/2004
From: Middleboro, MA, USA
Status: offline 		Will do, saved the info in a word doc and will keep a print out.
Thanks Speedy!!!

And yea this thing will not be flown with any crowds around until proven airworthy, I would do that even with an lt 40, we are still dealing with aircraft albeit a bit smaller than FS. As far as hinging I want to do it pretty much the same as FS, hopefully Robart hinge points are up to the task. There is only a small group in my club that are into speed and it is that group that I will enlist both to maiden and test. Like I said right now I would not feel that comfortable at 150 that would have a very sever "pucker factor" for me right now. But I feel comfortable enough with my building skills to build a plane that is a lot faster than that, even though I might not fly it myself for awhile.

_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to Speedy-Gonzales)
       Post #: 281

RE: (Something Fast?) Delta Build Thread - 1/13/2008 5:16:30 AM   
HaveBlue



Posts: 852
Joined: 1/3/2005
From: Sydney, AUSTRALIA
Status: offline 		I've got to get some pics of the finished product( I lent my friend my camera , it must of dropped somewhere, as all photos turn out blurry now), but I think the biggest gains come from proper cowling this is where I started out with my Diamond Dust... I ended up sheeting it then I found some fiberglass matting ..dont know what it weighs but it is see thru and almost like tissue ..a bit of a pain applying /cutting it as frays easily..but very lite

when it come to cowling the engine , its fine just cowling it alone ..but it's also important to direct the airflow over the ports and the best option is to direct the flow so you get low speed but high pressure airflow through the cowl

photo 1 is how the flow is directed to the correct areas ..all this is , is a spool from a toilet paper roll cut and convered in epoxy.

photo 2 is the body cowling with fillets before shaping...it was easier to make the cowl in two pieces

photo3 is the actual engine cowl viewed from the top before glassing..I know it doesn't look symmetrical in the photo but thats camera angle...

I'll get some photos of the finished item soom... I would really like to get the eagle flight telemtry kit as I would be very keen to do speed tests cowled and not cowled..I dont think it is a huge difference but I do think it more effecient...if the airflow is directed properly you can even run a more aggresive needle valve setting without worrying to much of over heating..

even though I think its a modest improvement in speed I still think it's worth going through all the trouble to do this


cheers
HB

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< Message edited by HaveBlue -- 1/13/2008 5:28:20 AM >

_____________________________

if your still in control....you aint goin fast enough
**Revver Bro 95**

(in reply to iron eagel)
       Post #: 282

RE: (Something Fast?) Delta Build Thread - 1/13/2008 5:41:56 AM   
Mike Connor



Posts: 1416
Joined: 1/10/2002
From: Tulsa, OK, USA
Status: offline
quote:

ORIGINAL: Speedy-Gonzales

I'll stick with GLOW! I like things that are noisy...

You have to admit that electric has come a long way in a short time. The power goes up and the price comes down and even the noise at well over 30,000 rpm sounds good.


_____________________________

Mike
http://www.mikesrc.us/

(in reply to Speedy-Gonzales)
       Post #: 283

RE: (Something Fast?) Delta Build Thread - 1/13/2008 6:04:56 AM   
Mike Connor



Posts: 1416
Joined: 1/10/2002
From: Tulsa, OK, USA
Status: offline
quote:

ORIGINAL: iron eagel

I plan to sheath it and skin the sheathing with carbon fiber veil (tissue) that weighs .2 oz per sq yrd.
...I probably will not even do the maiden on it but have one of our speed guys do that, I have get to work to flying something really fast before I would feel comfortable going over 150 anyhow....It may well result in just finding out what the Vne is for the airframe, or what happens when a prop tip exceeds mach1, but looks like it might be able to exceed 220 at the very least.
....one of my favorites is something called the Alantica that is being pursued by the guy who use to make wings for the Velocity FS airplane.

Paul,
.2 oz per sq yrd is light. Is it flexible or fairly rigid? It may take a few flights but you should do fine with speeds of 150 mph. Not sure about 200+ though as I have not experienced that yet. To me the airframe is not much harder to see, because of size, then my Q-500, F1 and other 40 size airframes. I suspect that Vne is up to the builder and you and Speedy are well above average builders and understand some of the problems you could face. That "Alantica" looks neat and I like the winglets.

What is the size of the battery you will be using? Just wondering how it will fit in the fuse.


_____________________________

Mike
http://www.mikesrc.us/

(in reply to iron eagel)
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RE: (Something Fast?) Delta Build Thread - 1/13/2008 6:18:29 AM   
Mike Connor



Posts: 1416
Joined: 1/10/2002
From: Tulsa, OK, USA
Status: offline
quote:

ORIGINAL: HaveBlue

even though I think its a modest improvement in speed I still think it's worth going through all the trouble to do this
cheers
HB

Back in the 20's NACA determined a properly cowled engine alone could add 12-13% to the speed. That was on a radial engine so a single cylinder will be different. The NASA site shows a high drag coefficient for the round shape and Speedy's cowl design may cut down engine drag by 500%. Show us some pics when you get finished.

_____________________________

Mike
http://www.mikesrc.us/

(in reply to HaveBlue)
       Post #: 285

RE: (Something Fast?) Delta Build Thread - 1/13/2008 5:48:11 PM   
Speedy-Gonzales


 

Posts: 304
Joined: 3/7/2004
From: Bryan, OH, USA
Status: offline 		Iron Eagle, Believe it or not I actually trust the wick type super hinges over the Robart hinge points. I just use more of them and space them at about every 3-4" apart. The ones I use are heavy duty for 1/4 scale. They are made by Radio South and are called "Pro Hinges". I have never had a failure using these hinges. I use a knife for making slots. The hinge cutting machines seem to make the slot too wide for the hinge to get full contact with the wood. The hinge must fit snug in the slot. This is very important. You also need to cut the covering away from the immediate area around the slot in the wood. This helps the thin Cya to flow into the hinge material and surrounding wood with complete saturation. Use what you think is best. I am not trying to persuade you to use this method. This is a discussion forum and not a matter of absolute law! Speedy

< Message edited by Speedy-Gonzales -- 1/13/2008 5:52:35 PM >

(in reply to Mike Connor)
       Post #: 286

RE: (Something Fast?) Delta Build Thread - 1/13/2008 7:31:49 PM   
Mike Connor



Posts: 1416
Joined: 1/10/2002
From: Tulsa, OK, USA
Status: offline 		I like the Radio South hinges also and use an exacto knife for a tight fit. I then squeeze the hinge area top to bottom as I apply thin CA. I do this before any covering is put on and cover the airframe and elevon with one piece of covering. I find it easier, faster, better looking, stronger hinge line and it is already sealed. Three pics attached of my last hinge covering job.

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_____________________________

Mike
http://www.mikesrc.us/

(in reply to Speedy-Gonzales)
       Post #: 287

RE: (Something Fast?) Delta Build Thread - 1/13/2008 7:44:19 PM   
Speedy-Gonzales


 

Posts: 304
Joined: 3/7/2004
From: Bryan, OH, USA
Status: offline 		AMEN BROTHER on the hinges! Hey Mike, Could I get you to slip a couple of those nice decals from WWW.MikesRC-US in an envelope to me? I would like to put them on my Demon. I think they will add some speed to the model and make it sexier to boot! You could also just email me a WORD document file to copy and download. I can print out clear vinyl decals with my printer. I just need the fonts so decals will be the same as yours. Whaddayahsay? I think you should have my email address. Speedy.

(in reply to Mike Connor)
       Post #: 288

RE: (Something Fast?) Delta Build Thread - 1/13/2008 8:36:31 PM   
Mike Connor



Posts: 1416
Joined: 1/10/2002
From: Tulsa, OK, USA
Status: offline
quote:

ORIGINAL: Speedy-Gonzales

I think they will add some speed to the model and make it sexier to boot!


Yep, the decals should put you over 200 mph for sure. I emailed the Lucida Handwriting TTF font. My clear labels do OK over yellow and some other colors but looked terrible over red. If I could figure out how to keep ink jet color from fading I could print the background of the decal the same color as the plane. maybe a Screamin Demon or Mutant Demon decal would look good across the wing. Post a pic so we can see what you do. Randy Racer has some nice vinal decals availabel that I may need to look into.


_____________________________

Mike
http://www.mikesrc.us/

(in reply to Speedy-Gonzales)
       Post #: 289

RE: (Something Fast?) Delta Build Thread - 1/14/2008 12:41:48 AM