fireman7875

My Feedback: (7)

I found a plan for an F-84 Thunderstreak in MAN recently that looks interesting. Only problem is that it calls for a Midwest RK-049 fan unit which, as I understand, they haven't made in years. Does anyone know who makes these now if anyone does? Also, could a Norvel 061 be used as well as an 049. Anybody out there do any 1/2a ducted fans? What are some product sources?

thanks

blvdbuzzard

I have not heard of any fans being made for the 0.049-0.051 size engines in along time. I have an RK 0.049 fan setting on the shelf.

I did read an article about putting a glow engine in place of an electric on on one of these fans.

http://www.hobby-lobby.com/ductfan.htm


Hope this helps.


Dru.

SRA Foam Flyer

My Feedback: (11)

I read somebody is getting good results from a convert kyosho fan. I also asked the electric jet factory in Tucson if they had anything that could handle a 1/2A motor, they suggested the mini 480 I think.

2fast4u

My Feedback: (5)

Ok, with all the SMALL stuff out there, why are there no fan units ready for the task? Paul Willinborge designed the "Fan Jet" which was 1/2A powered and turned a cut down 3 blade prop. That thing would move out!! It ran an exposed .051 and shrouded blade. Very close to a "DUCTED FAN" but not really.

Anyway, does Kress not sell something like that?

Duane-RCU

My Feedback: (5)

Check out the Clancy Turbo-Bee, not sure but it uses a big prop cut down to like 4"....Can use s400, or .061? Maybe you can use the idea and make something work.

EASYTIGER

My Feedback: (119)

That's the old Musciano F84. It flew, but it did not perform like a jet.
1/2a glow DF is something of a blind alley. Many, including myself, have travelled up that road, and found out that the performance is very limited. You can have some success, yes, but you won't get really jet-like results. Just not enough power. Maybe if you wanted to lay out for something like a Shuriken 049, something that could turn the fan at over 30k, you might be able to get a pound of thrust out of the RK049 rotor. I got less than 12 ounces out of mine, with a SCREAMING TD 051. I don't mean to be pessimistic, just realistic.
A really hot 09 is a much better bet. I have had two of the RK709 units. While the fan unit itself was terrible, there was nothing wrong with the rotor, and with a TD09 going full tilt, it did put out some useful thrust.
If somebody could come up with a really honking 061, and a proper fan for it, tweaked for the right size engine, with all the proper refinements, like area ruled ducting, streamlining for the head, a tuned pipe, etc., maybe things would be different...

EASYTIGER

My Feedback: (119)

Kress Jets makes the 049 fan that is shown on the plans. Not sure of a current contact number.

Mark Turner

My Feedback: (29)

Kress contact # is [email protected] or phone #845.336.8149

phuffstatler

My Feedback: (20)

Interesting Topic. I just this very day's lunch hour bought a Wattage F-86 and a Norvel .049 engine, just to see if I can make
it work. A guy at the field had the electric powered one yesterday, with the recommended battery, equipment, etc. and I just couldn't call that fun. Just kind of slid around slowly. I had one of the first Kyosho T-33's that came out, and although it did great and was a real breakthrough, still I think it needs to fly more like a jet! And, I want more then 4 minutes of fly time, without having to sump $100 into high-end batteries and controllers.

I figure about 12-15 oz. ready to fly, if I do it right, and I certainly will re-design the servo layout, etc. and the way they want you to operate the surfaces. Gonna spar up the wing a bit, and open up the duct to the front, since there will be no big battery up there. I'll leave the cheater hole on the bottom, for now, and will make a hatch on top for engine access. I'm ready to adapt props, mold blades, what-have-you, to make it work. I'm going to get all of the radio in the cockpit area, hopefully. if the speed I'm looking for starts coming on, I'll probably replace those little foamy tail surfaces with some balsa, too.

While the electric fans work pretty well, the weight and cost penalties ($200 for an Astroflight 020 brushless!) rob the small jets of most of the 'fun' factor, at least for me.

I refuse to believe (yeah, I'm stubborn, too ) that the only inexpensive jets are electric. Maybe I'm chasing up an old and tired tree here, but I'm willing to climb up some different limbs this time, and see what I come up with.

Some long nights ahead, but I'm enthusiastic about it.


Phil in Austin

EASYTIGER

My Feedback: (119)

I think the wattage sabre could be a good choice. Smaller than most of the 1/2a fan jobs. IF you can keep the weight down to what you are proposing, I think half the battle will be won.
I would skip that norvel, firstup, though.
I would get the hottest 1/2a I could find. At least the norvel 06. I would probably skip the throttle, too. It's just one more thing in the airstream, cutting down the thrust, and you probably won't be throttling down very much!
Maybe the wattage rotor can be used, and you can roll your own shroud?
The Marcel Lahaie Mirage uses the Kress RK720 rotor, with a simple homemade shroud, and from what I have heard, works very well.
You should also look at the Wemotec electrics for a rotor.
I think cutting down props to make a rotor is probably a bad idea, just not efficient enough.
I would just replace the tail now. It'll break, I'm sure you are right.
I know what you mean about the EDF stuff. I bought the Wemotec/Astro 01 unit for $140, it worked very well, but electric, well, it just does not float my boat.
Same thing with the Kyosho T33. I had fun with it, it was very novel when it came out, but now, I want more performance.
Go explore the outer edge of the envelope, and let us know how it works out!
Remember this, the biggest lesson Bob Violett taught us...stuff the smallest airframe around the HOTTEST engine you can find.

phuffstatler

My Feedback: (20)

Thanks for the reply, Easy-Tiger. I think you're right about the hotter motor, so I'm going to search some for that. I did some piddling last night, and I think I can use the Wattage rotor. The strength, pitch, etc. of the 6 blades seems about right (Total TLAR). They claim 12+ ounces of thrust @ 24.5K RPM, and I've gotten Norvels to exceed that and hold together, though that was with 4.5x4 props. I will have to machine a small adapter to fill in the space around the crankshaft and rotor, but it shouldn't be too hard. I think I can modify the current shroud, too, at least I'm going to try first. The design is not far off of the Turbax 1, which had to be cut up on top to fit the K&B motors. I'm going to try and mold a little fiberglass piece to fit over the shroud and engine top, ala BVM, allowing for an igniter hole. I'm going to run the needle valve right out the side of the fuselage. Will have to drill a hole in the shroud for that, too. And, I'm coming up with a beam mounting system to center the engine, and extend on back to hold a 1-2 oz. tank centered in the airstream.

And to top it off, I'm hoping to get a test flight or three in before the Greater Southwest, in two weeks! Oh boy! Nothing like a little pressure to make one perform.... Gosh, I hope all of this works...

Phil in Austin

SigKavalier

Hi I'm new here but I've had some thoughts on that very same idea for the very same reasons. The problem with electrics is that they are capable of turning very high RPM's but they don't produce a lot of power. The problem with gas motors is that they produce plenty of power but lack the ability to produce extreme RPM's. The solution I think is not in the motor but in the fan. I think that if you sqeeze in a big fan into a light model then you don't need to RPM's to produce the same amount of thrust as with a smaller fan. It seems to me that a gas engine will run longer off less fuel if you compare the battery weight to the fuel weight. My stopping point is whats a good high rpm .049? I've had little experience with small gas motors. Except for a few u-control planes when I was younger. I know that some like the Black Widow have a fuel tank mounted behind the motor I think 8cc's. How long will a engine run off that? I recall my old u-controls flying for several minutes. Seems a 1-2 ounce tank would make for good duration flights with a lot less weight than the batteries for an electric. I've thought about how to mount a tank, and get a glow plug to it but I still don't know how you'd go about starting it. You can't flip start it so the only other option I can think of is by using a adapter like the big DF's. Or maybe a weed blower lol. Anyone know how many RPM's a Black Widow puts out? Also Kyosho makes some mid sized ducted fans and use car engines with pull starts for power.
As far as the wattage rotor it should hold out as the guys over in the electric forum are running it brushless and haven't had it decentigrate yet.

phuffstatler

My Feedback: (20)

There are several higher performance engines that will run the socks off of the Cox motors. The best Cox motor that I ever had was a Venom, and while it was fun, the Norvels will run circles around them with few to no modifications. I think even the VA engines, and the Fora motors are screamers, too. I may have missed a few. I'm working on a fan 'design' right now to fit the little Wattage F86. Turns out the best way I can seem to fit everything in there, is to run a Pusher setup, ala Byron style. This gets the fuel tank up by the CG, get's the engine easily accessed through the big cheater hole in the bottom, and a straight run if you want to throttle it. Still dabbling with the fan rotor itself...

I'm putting all of the radio (except the elevator servo, down in the lower compartment that was meant for that 10 oz. battery. The duct is going to get cleaned up as much as I can, and I'm sealing the entire plane in clear epoxy paint to fuel-proof it...

I'm also doing some other mods to change up the plane and make it tougher, too. I'm taking pictures of the whole process, and will put it on my website when it all happens...

Stay tuned,
Phil in Austin

SRA Foam Flyer

My Feedback: (11)

This will prove useful, I have a flying styro F-16 not sure if I will use a teedee .020 or an .049. It's a ducted fan model, but slated for free flight or micro electric RC.

LoneRanger

My Feedback: (1)

What do you plan to do to the exhaust for the norvel that you are using? I am interested.... I also agree that a larger fan is probably the way to go (keep the RPM's down) and try to push more air...


good luck and keep us posted

LoneRanger

SigKavalier

I've heard a lot about Norvels but have no clue which one and what would need to be done to get the RPM's up high enough. I have a test bed ready to go I just need some motor help. Would a BigMig Norvel work? I see the horsepower ratings on all of them are at 17,000 RPM's but thats not enough. It needs to be up in the 20's. My test bed is a foam glider from wal mart. It's a Ultra Flyer. I've hacked the rear of the fuselage off and installed a ply mount for the motor in a pusher configuration. With mounts for the shroud around it. Two aluminum arrow shafts for tail booms and a elevator and rudder made from DOW Blucor foam. The problem is how to run the motor backwards? Because simply reversing the rotor will give poor effeciency.

phuffstatler

My Feedback: (20)

The Big Mig puts out .19 hp at 17K, the AME Norvel puts out .36 at 25K, quite a bit of difference when turning fans....


LoneRanger, to reply to your exhaust location, because I'm mounting the engine in a pusher arranagement in the cheater hole area, and I'm also mounting it inverted (keeps the tall head down in the main airstream), the exhaust will go straight out the bottom of the plane through the cheater hole. I thought seriously of going straight out exhaust (from the side), but thought it would just be too much heat in the little all-foam ducting. The Norvel exhaust outlet is rotatable, so I just turned it to go out the bottom of the plane, right by the head itself. The only 'Trick' to this is keeping the hands clear of it when removing the igniter setup.
With an all fiberglass duct, the exhaust temps wouldn't matter as much, I don't think... ;P But since this one is foam, I'll be more careful.


I will be using a homemade probe to start it, made from music wire with a brass sleeve over it, with some custom bits for and aft to mate to the starter and engine hub.

I am proceeding carefully, as I really do want this to work. We'll see. I haven't broken any rules as yet....

phil

SigKavalier

Hey I was surfing around for info on Norvel engines and found some interesting stuff. First with the right fuel and prop they'll all turn upwards of 24,000 RPM's. Give an oversized fan this should produce a lot more static thrust with less weight although the efflux velocity will suffer. Also I found some very interesting tuned pipes for Norvel .049's. Well priced and weigh under an ounce. Supposed to reduce the sound quiet a bi, improve performance "Test showed a 1,200 increase in RPM's" and will make it easy to run the exhaust to the back of the ducting. Also anyone who's flown a electric DF can appreciate the whistling sound on a low pass vs. screaming like a banshee. But sound aside if it up performance and lets me rout it out the back for $12 I'm all for it. It's also supposed to reduce exhaust temperatures or pipe temperatures so thats a plus if working with foam. So looks like I'm gonna order me a BigMig .049 I know the bigmig isn't the performance model but I'm on a budget and it should work fine. You can barely get a cheap cobalt motor for the price of one which if it all works should leave the electric DF guys in denial. I'm reversing my idea and I'm gonna put the motor and fan on top of the fuselage over the wing in a tractor configuration. That gives me less problems to work out.

f_o_r_d_man

I don't know of a 1/2A ducted fan but that sound like a nic elittel plane I would love to hear from you if you do find a 1/2A ducted fan for it I wouln't mind makeing an Avero Arrow in 1/2A

Troy-RCU

My Feedback: (1)

I have a suggestion for getting a little more thrust for the Wattage F-86. A guy I fly with flew it stock (S400 motor on 10 cells) with the included fan unit. He upgraded to a brushless motor but tossed the stock rotor away and used a cut down kyosho rotor (from the T-33 and F-16 kits). This provided a lot more power and all-in-all a more efficient fan unit. You might give it a go. The kyosho fan units are readily available and even the Wemotec 480 fan blade may work too. You can purchase it individually from www.electricjetfactory.com or more directly at:
http://www.electricjetfactory.com/itemmf480rot.html
The e-flux velocity is a little higher for the Wemotec 480 fan but if the plane is under 14oz it shouldn't make much difference for launching and the top speed should be higher.
I fly gas and electric stuff and I see a lot of people say how they can't get performance out of the small electric planes. That is usually more a problem of the wrong set up than the fact that it is electric. I have small electric planes that are powered by $10 S400 motors that top 100mph and brushless powered pylon planes that top 180+mph. The expense is generally higher than a 1/2A motor when you add up batteries and a decent charger but to say the performance isn't there is not necessarily true. Plus, if you take the cost of a couple batteries vs how many bottles of 25% 1/2A fuel you use over the course of a year you'd find it evens out quickly.
For the Wattage F-86 there are batteries available that can boost flight times up to 8+ minutes with no weight gain or loss of power. It's all there, you just have to look for it and apply the technology available. Remember when our 1/2A's weighed 20+ ounces, used full size radio gear, and people laughed at their performance? Things change over time
If you guys do some 1/2A ducted fan conversions, don't forget the pics

phuffstatler

My Feedback: (20)

Troy said " for the Wemotec 480 fan but if the plane is under 14oz it shouldn't make much difference for launching and the top speed should be higher. "

Troy, a 10 cell battery alone weighs 10 ounces. Doesn't leave much left for airframe and gear. A wattage charger is about $50, the battery packs are $35-$50, and I know from experience they don't last very long, especially when pushed like a ducted fan will certainly do. A brushless motor starts at about $90. Add another $35 for the Kyosho fan, or more for the Wemotec, you have to cut them down anyway to make them work, you still end up with a plane that weighs at least 20+ ounces, with a 29" swept wingspan on a plane that is already minimally built. It HAS to have some spars put in it for any kind of speed. With all of that, plus one extra battery pack, you can buy 5 or 6 Norvels, or maybe more, for the price of that one electric setup.

Truly, I've almost given up on the Wattage F86, as it's just too lightly designed/built for anything but flying in slow circles. Once I get the fan situation figured out with the 1/2A engine, it will probably be just as easy to build up a plane from scratch, rather than modify the Wattage plane. It's got be fuel-proofed throughout, the tail section re-worked/replaced, plus other mods to the wing attachment, and that totally ridiculous servo layout UNDER the wing of a belly flopper airplane.

I'm glad you've got SP400 airplanes that can do 100 mph. Sounds fun. The Wattage plane could not begin to approach half that speed without disintegrating, unless all those mods happen.

Troy-RCU

My Feedback: (1)

Re reading my first post I left something out. I was referring to a 1/2A conversion; a 1/2A being under 14oz (which should be no problem) and using a Wemotec 480 fan BLADE $19, it's on the link. There are Kyosho fans or rotors available for cheap in the classifieds on the Ezone. Lots of people have broken T-33s and a perfect fan with no home. One could make an adapter to make the rotor fit to a Norvel or Cox. Just a suggestion
If your 10 cell pack weighs 10 ounces and the plane weighs over 20 oz it's no wonder it won't fly. A 10 cell 600AE or 1100 2/3A Nimh pack should weigh just a tad over 7oz. The wattage F-86's that I have seen and flown do not weigh over 18-19oz. It definately does need a spar. Some carbon top and bottom would stiffen it up and not add but a few grams.
They are not blistering speed demons (it is sold as a park flyer DF) but with a decent set up it is quick enough for flying foam and scale like. On a hot set up one was recently clocked at 68mph. The Wattage reccommended set up for elevon-ish control is a waste of time. Anybody who tried that around here tore it apart and put conventional ailerons and elevator. There is great info on mods to make it fly well on the Ezone
http://www.rcgroups.com/forums/showt...threadid=52237
Unfortunately with the rapid marketing of ARFs, there seems to be more emphasis on keeping the kit cheap so someone will buy it rather than making it fly well with the stock gear. Most of those Wattage ARFs need a few tweaks here and there to get them to fly well but you have to search for the info. Many people have had problems getting it to fly well but many more are happily flying theirs every weekend.
On another note, I have battery packs that I have been abusing for 4 years and they are still going strong. The amp draw of the Wattage ducted fan set up is about 12 amps which is not that hard on the cells. Over charging and improper discharging practices degrade a batteries life more than anything.
I'm not trying to convince you to stick it out if you really are sick of looking at it. I just want you to know that there is a lot of info for this stuff available and there are guys happy to help. I love small planes no matter what the power plant is. Heck, I like anything that flies

phuffstatler

My Feedback: (20)

Great info, Troy. Thanks a million!

WINANS

I have tried the .049 in the Wemotec minifan 480. It works pretty well. I set up a Cox reed valve .049 to test the lower end of the power range. Dropped it onto a 2 meter glider on a pod above the wing. Don't recall the total output but it was not bad. A TD would do well, especially souped up a little. I even have some thrust data off of a load cell somewhere.

The electric fans are great; easy operation, relatively cheap. Glow is fun though. I believe that .049 DF is definitely not a dead end street.

Scott

SRA Foam Flyer

My Feedback: (11)

Yes, Electric Jet Factory sugested that same fan to me for 1/2A so the might be the one to use. Looks like the best direction so far. No problems with the fan flying apart or shattering, how many run cycles, is it still working?