phase5

My Feedback: (2)

I have found a new in box kit I can get for $215.00 to the door, would I be better off to try to find plans and build it from scratch, I have only built 1 kit an uproar it turned out ok. They seem to be simple and straight foward or am i missing something thinking that way, Thanks Daniel

combatpigg

My Feedback: (3)

Dude..!
If you pay that much, then see how little goes into building the airframe..you'll feel pretty silly if you value a dollar the same as I do.
The ribs can be cut very easily out of 3/16" or 1/4" thick balsa.
The center rib doublers can also be cut very easily with a #11 Xacto blade out of 1/32" plywood.
All you need are the basic dimensions to build it from scratch.
All I needed was to research some old build threads, use some common sense and do it my way for about $20 worth of materials.

carider67

If you're not married to the idea of it being a Diamond Dust, I have an Extreme Flight RC Outlaw (not for sale) that is crazy fast, 150 mph +, with just an OS .32 or similar sized power/weight .32 or .36 2 stroke. You should at least read up on it, the complete (built straight) ARF is only $150! Thats $1 per mph lol.......... The last pic is of a GMS .32 mounted, it should be fast enough and only costs about fifty bucks brand new....... comes with sort of mini pipe muffler.

http://www.google.com/url?sa=t&rct=j...vVfvUXckv4MJfA

phase5

My Feedback: (2)

Thanks for  the input, I don't mind spending money when needed but if I can save money and end up with quailty product, I'm all for it. I bought a jett 50 and can't wait to get it on something and in the air, not stuck on a diamond dust but want to stay with some type of delta wing. Ifanyone has plans for sell or can let me know what would be good to buy please let me know. Thanks for all the help I have learned alot from all the post and input from all on RCU

iron eagel

I have heard the kit for this one may be back out soon, I beta Jett 50 would be real nice on one.
http://images.rcuniverse.com/forum/u...95/Mk27253.pdf

scotty302

Just came across this thread and they can definitely be constructed for alot cheaper and much stronger than what is supplied in the kit, built 2 of them this way. Used 5 ply 1/8" birch and carbon 3/16" kite tubes with Easton carbon arrow shafts for the main structure, shaped aileron stock medium to hard balsa to make sure there wasn't any flutter. I used an OS 40 vrp motor in mine till i wore it out and no replacement parts, a Jett 50 would pull it around like a homesick angel. I'm working on converting mine over to electric and hope to get the same results. Just purchased a combo motor setup for the Zephyr II - 500W motor and a 65amp speed control for a start to see if it even comes close, then move up to a 4400watt 750 align motor with a 100 amp speed control. As long as it is well built, 200+ mph flights are possible on a consistent basis. With the installation of an EZosd with the gps, this should give exact speed alot more accurately than someone trying to follow it with a radar gun.

iron eagel

It is my hope to get a modified Screaming Demon (based on a diamond dust type of airframe) to the 200 mark using on the order of 1500 watts with a HET 2W-23 pushed by a CC 100 Amp ESC. (pdf plans in my earlier post)
Right now I know of only one airplane based on the dust type of design that hit 200 using a Nelson RE engine and pipe developing about 4.5 hp or 3500 watts of power. With the reduced frontal area of an electric I hope that about 2hp or 1500 watts should work if it is kept clean and lightweight enough.
this is my version of the above plane.

phase5

My Feedback: (2)

I have started working with some plans I came across, I have carbon arrow shaft that are slightly out of spline tolerance that I will not hunt with that I'm using for the leading egde and through for support. I will post photos when I get the airframe together before I cover it.

combatpigg

My Feedback: (3)

Phase5..I'm glad to hear that you are going to build your own. Build it on top of a pair of scraps of lumber that lay down level with each other and check all of your rib centers with whatever dimension you come up with from the surface of your work table.
If needed, a sloppy fit where the spar passes through the rib can be packed with saw dust and zapped with thin CA. These planes are fun to build because you can see a lot of progress in a hurry plus you have the anticipation of what it will be like seeing it in the sky.

phase5

My Feedback: (2)

Combat, Thanks for the tips and also telling me not to be lazy and build it myself LOL instead of wasting money, after reading on RCU past threads I'm glad I decided to go this way if the first dosn't turn out well I will keep trying until I get it right. I can buid at least 8 fopr the cost of the over priced kit. Also when it buzzing by at 150 I will be able to say " I did That "

combatpigg

My Feedback: (3)

One more thing comes to mind...those "very fine line" marking pens work great for marking centerlines on the ribs. I can't start a build session without a fresh one on hand.
Look up "Da Screw" for his delta build threads. He keeps his simple and light. His planes are covered in Super Hero schemes that look pretty sharp.

times2

Awesome.  I've got a diamond dust that's clocked at 212 mph.  OS 46 ducted fan with custom piston/sleeve/crank/head.  It's a rush to fly for sure, but the take-offs are hairy as hell.  Good luck w/ the build!

evan-RCU

What prop?

times2

I think it's a 9 3/8" x 8.5. It likes pitch.

evan-RCU

Sorry, not even a F3D Nelson will do what you say your OS will and not even close with that size prop.... And on a Dust... Any proof? Pics, video?

times2

Hey look, it happend. I was just making comment on the cool OP plane, not looking to get into a bragging match with you. I wasn't running the radar, but won the speed competition with that setup. I'll tell you that the piston sleeve setup was made by Henry. I have a pin for breaking the 200mph mark, will it make you feel better if I send you a picture of it?

combatpigg

My Feedback: (3)

What makes the Nelson .40 capable of 200+ mph is the huge crankshaft that has the huge air passage inside. The FAI version uses a 13mm intake.
You can try every "trick" in the world with the "normal" sized crankshafts on other .40 to .50 sized [non racing] engines and never get past the 170-180 mph range on a Diamond Dust. Those engines just do not have the air handling capability of the F3D types.
The Nelson .36 combat engine uses the same design principal and it made all other engines in it's class obsolete over night. Years later a few clones were made by other companies.

Does the OS.46DF share this feature....?
Any .46 that can turn a 9.375 x 8.5 can't possibly be a "high timed" DF engine....?
I would expect to hear that it could turn a 7.375 x 8.5 ......fast enough to make some serious power.

evan-RCU

Exactly... The Dust is very draggy compared to my F3D ships. Or my F5D's, hot liners, etc... Plus the F3D FIRE Nelson makes huge power and even it won't pull that 9 3/8 X 8.5... But on a more appropriate 8x8 (or smaller) I would think the .46 DF would be able to get on pipe but still not be anywhere near 200, at least not in MILES per hour...

But hey he says he did it and radar never lies... Either way I'm not going to Reno to check out this wonderful machine.

combatpigg

My Feedback: (3)

If the OS.46DF has a lower end to match the Nelson engine, then it would be [potentially] one hot tamale.
I've never laid eyes on one of [any of] these OS DF engines, but I'd like to know more about them.

iron eagel

Cp they would be a perfect engine for you to re-work, stock they spin up around 20k rpm. I have never tried one with a prop yet but have a .91 with pipe and rnv I'd like to try with a prop like MTD did on his plane.

I have a dumb question about these engines.
Where the intake is on the rear plate does the air still pass through the crank?

Pylonracr

EVAN
I live in Reno and I have never seen that thing fly. That being said, I rarely fly at the crouded club field. I fly with a couple of friends at a private spot. Reno is at almost 5000' altitude also, so engines do not make as much power up here. The problem with the OS ducted fan engine is the high powerband limits prop selection and it will destroy nylon props.

Freakingfast did a thread on this engine on his clipped wing dust. He runs 7.4 x 8.25 carbon props at about 24,000 on the ground. Trying to get one to turn a 9 3/8 x 8 1/2 would bog the engine down so low it would not hit the pipe.

CP, The OS ducted fan engine is a rear intake, so id does not suffer the crank diameter limit of front intake engines, but it is still limited by carburetor diameter. I have not run a 46, but I have a 91 ducted fan engine in a pretty fast Little Tony. It is a little cranky to tune and prop, but it moves pretty well. I have not been able to clock it, but we estimate it at about 150 or so.

combatpigg

My Feedback: (3)

With a rear intake engine you should be able to get away with a smaller diameter crank that is easier to spin [than a front intake type]. Checking the disk valve timing from a known world class rear intake engine like the OPS .60 series ought to get a OS.46DF right up there with the best...especially if Nelson made upgraded parts for this engine.
The one comment that Dave Shadel made that sticks with me is that the "modular / bolt together" case design seems less trustworthy than the one piece type.

A big obstacle for me would be to learn how to service [or modify] the rear intake valve.
A bigger question would be why MB/Profi decided to use front intake when they decided how to build the most powerful .40 in the World.

Pylonracr

The one thing I noticed when I put the 91 DF engine in my Little Toni was the rear carb made installation harder. I had to cut a hole in the firewall and duct air behind it to feed the carb. I do not know how easy that would be in a QM40 where the front of the plane is no bigger than the engine. Just a guess, but it could have had something to do with it.

combatpigg

My Feedback: (3)

Maybe someday I'd like to try the OS91DF in a 36-38 inch span Diamond Dust. I see these engines for sale at good prices every time I take the time to look. I can mix 80/20 fuel for about $5 or $6 a gallon, so owning an alky guzzlin' .90 wouldn't bother me too much...just as long as it didn't eat glow plugs every run.

iron eagel

The cost of fuel is a big consideration with the big block engines.
If you keep the nitro content down they are not too bad on plugs they do like lots of oil.
Instead of a dust with the pipe alone is 18 inches long add the 4 inches or so for the engine. You could hang the pipe out of the back if you had something like a 22 inch cord if you did something more along the lines of your Komet .
Come up with a way to put it between two bays in a sidewinder configuration like you did your 1.2 A one...
Northrop buried the engines in his XB35 with a center section that was a shell with hatches you could probably pull it off with a composite top and bottom spar arrangement.