Cheap speed
11-20-2003, 06:29 PM
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Cheap speed
For those of you in between Whiplashes or Magnums, here is an alternative to keep your speed demon paritally fed while your saving your pennies.
The one on the left is the Spad Sickle, designed by Tim Tong, aka "Grim". Yes it looks pretty much like a coro version of the combat Gremlin with a shorter wing. This one weighs 2.5 lbs. on the nose with a Norvel .25 with Kentucky MCP turning an 8X7APC. In a dive, probably around 110mph. It's a responsive beast, it loses almost no speed in high g turns. The needle has to be just right to avoid flameouts in the turns. Roll rate about 3-4 second ( due to speed of the hopped up Norvel, 8X7 and MCP, I trimmed the elevons down to avoid flutter, a standard .25 with 9X5 APC prop can have larger elevons, so the roll rate goes up to 5-6 rolls/sec, but top speed will be a little under 100mph). You can get plans on tims web site, [link=http://home.earthlink.net/~tnttong]here[/link] .
The one on the right is the DDust, patterened after the Diamond Dust but smaller, also made of coroplast with a wood substructure (lite ply ribs with two 1/4" dowels running through them spanwise). This one is powered by 25fx, also an 8X7APC prop, 2 lbs. exactly. It also has an MCP on it, but that was after the pic. A bit faster than the Sickle, probably 120mph or so. I hear with a tt36 it goes around 130+. It is not as responsive as the Sickle, you need to keep the turns and loops larger (sweeping). The roll rate however is out of this world, it's basically a drill bit. Expo helps ease it up around the center. It gets small fast, but it's quite stable and floats in amazingly well for such a fast plane. You can find build pics and plans at Chris Jumper's website, [link=http://users3.ev1.net/%7Ecdjump/main/mydesigns/index.html]here[/link]
I don't know how either of these would handle Nelsons and Jetts, it might be too much to ask...or maybe not. With some modifications to make the elevons stiff I bet it would work just fine. These are a far cry from the 200mph speeds you fellas get, but you can't beat the price!
The one on the left is the Spad Sickle, designed by Tim Tong, aka "Grim". Yes it looks pretty much like a coro version of the combat Gremlin with a shorter wing. This one weighs 2.5 lbs. on the nose with a Norvel .25 with Kentucky MCP turning an 8X7APC. In a dive, probably around 110mph. It's a responsive beast, it loses almost no speed in high g turns. The needle has to be just right to avoid flameouts in the turns. Roll rate about 3-4 second ( due to speed of the hopped up Norvel, 8X7 and MCP, I trimmed the elevons down to avoid flutter, a standard .25 with 9X5 APC prop can have larger elevons, so the roll rate goes up to 5-6 rolls/sec, but top speed will be a little under 100mph). You can get plans on tims web site, [link=http://home.earthlink.net/~tnttong]here[/link] .
The one on the right is the DDust, patterened after the Diamond Dust but smaller, also made of coroplast with a wood substructure (lite ply ribs with two 1/4" dowels running through them spanwise). This one is powered by 25fx, also an 8X7APC prop, 2 lbs. exactly. It also has an MCP on it, but that was after the pic. A bit faster than the Sickle, probably 120mph or so. I hear with a tt36 it goes around 130+. It is not as responsive as the Sickle, you need to keep the turns and loops larger (sweeping). The roll rate however is out of this world, it's basically a drill bit. Expo helps ease it up around the center. It gets small fast, but it's quite stable and floats in amazingly well for such a fast plane. You can find build pics and plans at Chris Jumper's website, [link=http://users3.ev1.net/%7Ecdjump/main/mydesigns/index.html]here[/link]
I don't know how either of these would handle Nelsons and Jetts, it might be too much to ask...or maybe not. With some modifications to make the elevons stiff I bet it would work just fine. These are a far cry from the 200mph speeds you fellas get, but you can't beat the price!
11-20-2003, 10:33 PM
#2
RE: Cheap speed
LOOKS LIKE THE COMBAT GREMLIN....
HAS ANY OF THE SPEED CLAIMS BEEN VERIFIED BY GPS OR RADAR???
From Nnorvel's webpage:
Specifications for AME .25 BB R/C Revlite
Spec Name Description
1 Displacement .25 cu in (4.1 cc)
7 RPM w/ 9 x 4 APC 3,000-16,000
8 Bore .68 in. (17.3 mm)
9 Horsepower 0.91 at 16,000 rpm
I doubt it would turn a 7x6 at 16000 you be lucky toget 80mph out of it
HAS ANY OF THE SPEED CLAIMS BEEN VERIFIED BY GPS OR RADAR???
From Nnorvel's webpage:
Specifications for AME .25 BB R/C Revlite
Spec Name Description
1 Displacement .25 cu in (4.1 cc)
7 RPM w/ 9 x 4 APC 3,000-16,000
8 Bore .68 in. (17.3 mm)
9 Horsepower 0.91 at 16,000 rpm
I doubt it would turn a 7x6 at 16000 you be lucky toget 80mph out of it
11-21-2003, 12:11 AM
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RE: Cheap speed
I did mention the similarity to a combat gremlin. The Norvel BigMig is turning an 8X7, not a 7X6. It also has the Kentucky MCP on it, which gives a big boost in RPM. Why the instant pessimism? I was merely pointing out fun, cheap, easy to build fast Spads. Was this a naughty thing I did?
11-21-2003, 02:03 PM
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RE: Cheap speed
Those look great Frank, but I have a question.
Do you experience any flexing at high speeds? I have several "rail" spads, which I realize were not designed for speed, that flex really bad at full power. My .46 pqhor has to have the throttle retarded at full speed dives just to regain straight control. I know I probably answered my own question in that my only SPADS were not speed planes, but the flexing issue still makes me wonder?
Do you experience any flexing at high speeds? I have several "rail" spads, which I realize were not designed for speed, that flex really bad at full power. My .46 pqhor has to have the throttle retarded at full speed dives just to regain straight control. I know I probably answered my own question in that my only SPADS were not speed planes, but the flexing issue still makes me wonder?
11-21-2003, 02:19 PM
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RE: Cheap speed
These are very short coupled Spads, flying wing types, so there is no flex issue. With the aluminum fuses, you might want to try "box" or "tubular" aluminum rail. It comes in 3/4" and 1", and this stuff is amazingly strong and doesn't flex at all, and the fuse will only weigh a couple ounces more (you could drill holes in it to overcome the weight penalty). I have a large model powered by an O.S. 1.60fx with tubular rail fuse and it flies great without flex. The U-channel, as you've discovered, can exhibit flex especially when you use .46 engines and above. Take a look at the SPA3DT.
On my webiste (look at my sig) there is a video of a previous Sickle of mine in action. That one was powered by a TT36. That day all I had was a very lousy 10X4MAS, so it was all noise and no go, and it was only moving around at 70mph or so. It usually flew with a 9.5X6APC which REALLY made it haul. BUT, the video does give you a good idea of it's responsiveness and maneuverability, and this one was a good deal heavier than my new one, which performs much better. These Norvels weigh very little and give you a lot...and they're still cheap. They can be finicky though.
On my webiste (look at my sig) there is a video of a previous Sickle of mine in action. That one was powered by a TT36. That day all I had was a very lousy 10X4MAS, so it was all noise and no go, and it was only moving around at 70mph or so. It usually flew with a 9.5X6APC which REALLY made it haul. BUT, the video does give you a good idea of it's responsiveness and maneuverability, and this one was a good deal heavier than my new one, which performs much better. These Norvels weigh very little and give you a lot...and they're still cheap. They can be finicky though.
11-22-2003, 11:38 AM
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RE: Cheap speed
our version of cheap speed here is a Mini Rapier ( or funfighter! ) with a LEO 37 "rpm" the frames about 50 ( hardly anything if you self build ), the engine 60ish
for 140-160 what more can you ask?
for 140-160 what more can you ask?
11-22-2003, 01:38 PM
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RE: Cheap speed
lots of pics on your club site, it's only a club design tho bassed on the Rapier ( delta, with a bit of a fuz and two fins ) , can't remember what we've called it.
it's a bit smaller than the Dust and Whipps.
it's a bit smaller than the Dust and Whipps.
11-22-2003, 05:45 PM
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RE: Cheap speed
Frank does that sickle have a gutter fuse or is that coro or coro wrapped.
I dont understand why someone feels like they need to Slam someone here.He must have crashed his last plane. lately.
I dont understand why someone feels like they need to Slam someone here.He must have crashed his last plane. lately.
11-23-2003, 01:24 AM
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RE: Cheap speed
It's a corofuse, basically 4mm coro wrapped and glued around two 1 1/2" PVC pipe formers front and rear. It saved an ounce or two over a PVC fuse, plus it looks nicer. I took some rpm readings on these two today, the Norvel spins the 8X7 @ 16,100 rpm and the O.S. turns the same prop @ 15,600 rpm. Both unload quite a bit once in the air. I've never radared these planes, I base my mph figures on those who have radared these designs, and also on a gent who evaluates sound files for me.
