PilotSmith

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Nothing to be sorry about. I've enjoyed the chat. It was therapeutic to keep me motivated to finish the project.

oz Row

Well it wouldn't be BS if it was all Foamy F/A-18!!!!!!
I saw the thread as a great discussion on putting a fan in a propped plane and the issues involved. I learnt a lot. I thought 'how could i contribute?', and decided to build one myself just to see how the whole foamy thing worked, considering I wanted a small elec df jet. Then when I got going i started to think about making it look good and not just std fleet grey and the Aniversary hornet came out and i thought 'ok thread, take this- I'm gunna make mine look damn good!' and worry about the fan after Pilot Smith got it all sussed...... sorta worked.

The thread may have changed direction a bit, but it has kept me happy and amused! Alot of fun! don't stop now!!!!!!!!

PilotSmith

My Feedback: (1)

Glad it has helped despite my propensity to BS too much. Hoping someone else also builds an EDF version so we can learn from that too. The 3D Foamy seems like a good platform to work from. A bit hard for me given I've never had an EDF plane before. So I probably reinvented the wheel a few times in building this one.

X-spec

BUMP.......................................[&:]


X-spec TKs!

[/quote]

PilotSmith

My Feedback: (1)

Bump?

X-spec

Bump! Mean to cut in or as the post mention.

X-spec

stirlo

nice work Pilot smith, taken me a few nights to read this whole thread and a few others.
as you just said I am 90% built with the following.
3d Foamy FA18, built to 90% size (full plans fit on A0 paper)
Power =
- 2 x EDF 55 (25,400rpm with b,less motors)
- 2 x Brushless 5000kv motors
- 2 x 20P controllers.
- 1 x PN - N2600 2s Lipo.

The 3dfoamy plan asked for 14-24 Oz thrust and the stock fan unit motors just weren't going to give me enough.
it came to about 12-14, I wanted 26+.. and thats what the power plant has been designed around.
I will get some photos and post them soon, no digi atm.

interested to hear how your third attemp goes....

Cheers,

Stirlo - Australia

PilotSmith

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Thanks. Your setup sounds very cool Stirlo! I like the idea of twin turbines in it. Please post more info and photos when you get a chance. What is your weight looking like so far? After the last repairs, repaint and adding the heavier ESC mine is now up to 27oz dry and 32oz with battery. But the weight didn't seem to be a problem with the soft throw hand launch on the last flight. The original plans call for 11.5-18.5oz so I am well over that now. If I built another one I think I could make it 3-4 ounces lighter. I have 10 sheets of Depron on order so who knows what is next...

stirlo

Will keep you informed, I plan to do a write up on the plan and changes for EZONE, Aircraft-world and 3d foamy.

I had to make to make modifications to the plan to make the twin units fit. They are mounted just infront of the stab Bar+servo. I had to twist the intake walls from the front of the stab forward so the intakes are bigger due to the angle, this was to fit the units in the space.
I will keep you up dated...

Cheers,
Stirlo

PilotSmith

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Three flights and 3 crashes. [] At least I'm being consistent. Flight #1 ESC fried using 4 cell LiPo - front end wasted. Flight #2 throttle glitching and I got nervous and brought her down messy and bumped a pole - minimal wing damage. Flight #3 today: Range check fine. Flying in the middle of a dry lake in the middle of a desert, in the middle of nowhere so there was no interference. Take off is a little hairy as I still have the controls a bit too sensitive. Was messing with the dual rate switches on take off to see which mode felt better - one not enough and the other too much. Few seconds later after turning around and on the way back for a straight pass she becomes demon possed and does a sharp dive and a flip up. I also hear the throttle change in pitch. I decided to cut back throttle as at that point she is doing her own thing. I walk out to the plane and it is glitching real bad. Motor is turning on and off despite throttle being at zero and servos jittering. Damage is moderate. Have crack in rear fuse, one broker vertcal stabilizer, and cracked up cockpit area.

I was also going to take out my F22 today that I just finished up. But when I plugged all the electronics in it was glitching a whole bunch, so I figured something was wrong with the receiver so I left it at home. Now what is interesting is that the FA18 after the crash had the same glitches going throught it (throttle going on and off, servos jittering) that the F22 had at home. So I figure my radio may be having some intermittent problems. When I got back I tried the radio with the F22 again and it didn't have a single glitch. So now I wonder if it is an intermittent problem, how the heck will they fix it if it is not acting up when it goes in for warranty work?!?[:@]

If you guys want to see crash #3, here is the link: www.smithland.com/FA18-3.wmv . My son did a little better job on the video this time. 5MB file. I'm going to take a break for a few weeks before I start any repairs. This is getting too frustrating right now.

stirlo

Sad to hear, but get back on the bike!!! or put all your gear in something new, dont let it beat you...

Oh and I would say it sounds like a broken RX arial, only if its happening to your another RX that would be very sus and I would decide that the TX is faulty!

Also send the company (waranty) the bill for your $5000 F18 scale Turbine plane that it destroyed ...

Chin up a sheet of depron is only a couple of bucks!

Hey you have kids why aren't they in a production line makeing kits ???

stirlo

on an up note!

I have nearly completed my Twin DF project.
I have the twin QWS EDF55's monuted just infront of the carbon stab tube, I am not worried about a pan pipe as its only 3-4" to the exhaust, I have shortend the tail to increase the size of the outlet.

As I posted earlier I have twisted the sides of the air intake walls to open up the fuse a take to fit the 55's and to open up the intake for more air.

Still working on pics but its nearly there and I ... WILL .. take pics before its maiden..

lotek8404

just asking question, where did you buy this kit? I been flying heli but I wanted to get into planes
is there a a site where you bought this kit.

JohnVH

My Feedback: (38)

www.3dfoamy.com

vicman

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Tilden, I haven't forgotten about you. I have just been way overloaded with school the last few weeks. [8D]

PilotSmith

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Not to worry Vic. I've had my planes mothballed for a bit. Got real busy and also dealing with a very ill family member which is leaving no hobby time. Hoping in a month or so to be back to flying and repairing again.

PilotSmith

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Bet you guys all thought I was gone for good huh? Finally some time to start repairing and building again. Just spliced together the nose of the EDF F18 conversion. Need to sand, fill and quicky paint. She is starting to look a bit beat and hasn't even had a real landing yet... Ordered a new battery as the original battery I had is only putting out about 22 amps and that probably is not enough. Hoping the next flight will be good as all the others have been plagued by stupid mishaps! Won't have the battery until late part of this month so it will be a couple 2-3 weeks before I get her up in the air again. I'll report back how it goes. The stock pusher F18 is next on the build table Vic! Heard so many good things about the stock one I am anxious to try that out too! While I was gone anyone know if anybody else got a converted foamy going EDF?

vicman

My Feedback: (10)

Heya Tilden! Great to have you back!
Check out wattage.com its a new lekky only site from mark. If you look around in there I belive the guy who assisted Levi with this one has done the DF thang.

Ed Waldrep

I converted a 100% Super Bandit kit from 6mmflyrc.com to MF480, Mega 16/15/2, 3S2P Thunder Power prolite lipos. Flies great, lots of power (probably about 400 to 450 watts but I haven't measured it yet myself). Weight is around 31 to 32 oz with paint.

Here's a thread on the Ezone:
http://www.rcgroups.com/forums/showthread.php?t=462338

Nice work Pilotsmith, adding the extra depth to the rear fuselage is to me (and you!) an obvious mod that most people who try conversions don't think of. You also skipped the GWS underpowered trap. I guess maybe if you put enough power in them with brushless you can get decent performance but I don't know. One fan in this model is easier than two due to the clearance issues in the back.

One question, what is the diameter of your exhausts? Each one I mean. Have you calculated the area? I don't know if it was mentioned in the thread, I only read a couple of pages. The FSA (fan swept area) of the Minifan 480 is about 4.5 square inches. Your exhaust should be about 95 to 85% of that area. If you make the exhaust too big (bigger than 100% FSA), the flying speed will drop. The smaller the exhaust, the higher the efflux speed and the lower the thrust, up to a point. If you have enough power to hand launch or more so, then restricting the exhaust can lead to higher top speeds. Some airframes though if large and draggy, will not see much advantage to this as they can only go so fast. Sorry if I'm preaching to the quior, maybe you already know this.

I missed this thread last year as I don't normally surf here much, I mostly stay at the Ezone (I waste enough time browsing instead of building as it is). Nice work! Good luck on resuming flights. Hope you avoid further glitching. If you get more, twist the servo wires, keep them away from the power wires (which you can twist as well to prevent 'crosstalk'), and also you can wrap the wires and receiver in aluminum tape. I've done this alot in the past and it prevented glitching, but on some airplanes with the electron 6 receiver I got lazy and didn't do that, and they were glitch free, so who knows!

PilotSmith

My Feedback: (1)

Hello Vic and Ed,

Vic, I didn't understand the wattage.com web site. It is a music site now?

Ed, that Super Bandit of yours looks fast! I punched your motor info with 3s2p Lipo into MotoCalc and it comes up with 55.4amps / 544 watts! With single 3 cell pack 48.8amps / 444 watts. Too much juice for my budget! Post some video if you get a chance. While I don't know yet if it was worth my effort, I tend to enjoy things have been modifed and not stock. Sounds like your conversion was a success!

The exhausts on my F18 are each aprox 38-39mm diameter measuring them with a ruler. I was fortunate enough to exchange a few emails with the owner of Wemotec and he gave me info for optimal intake and exhaust sizes for the MiniFan480. Per Oliver the exhaust should be 56mm for a single or about 40mm for each dual exhaust to correspond to 24.63sqcm total area. (This was a bit diffent than the info that came with the fan as far as the optimal size.) The intakes he said should be 90-100% of the FSA. I'm going from bad memory here now but I think the intake area of the stock 3D foamy was less than ideal. My intakes were enlarged in the process of enlarging the fuse to fit the fan unit. Coincidently, I think the intake size ended up corresponding to about 100% of the FSA. As far as the motor I'm using a brushless Typhoon 3 turn which is similar in performace to a Mega 16-15-3. I am also using a 4 cell LiPo to make the 3 turn spin about 6-8,000RPM faster than running it with a 3 cell but it is still about 6K RPM less than the 2 turn Mega on a 3 cell pack. I didn't go with a 2 turn as that would have used more amps than I wanted to put into this thing to try to keep cost down. According to MotoCalc this setup pulls 28amps / 371watts. In the short flights I had there was adequate speed but I didn't fly it long enough to get a feel for performance. By the time I trimmed it out and was ready to start to do some maneuvers problems happened. (Fried ESC and later glitch problems.) Recently I tested my 4 cell 10C 2100 battery and noticed it was not really putting out much more than 22 amps and falling to 20 amps pretty quick. It didn't have the burst reserve I thought it did. The new battery I am putting in is a 20-30C 4 cell LiPo that is lighter and will put out 36amps continuous. So it should be able to supply all the amps the motor is drawing while also being lighter. The total flying weight with battery is now 32 ounces. Per MotoCalc it should have close to 79MPH top speed. I'll be happy with less than that. Forgot what the static thrust was using a postal scale to get a rough measurement but it had adequate power for hand launching and normal flying. Hoping to fly it long enough to see what type of performance it will have. I relocated the receiver antenna wire away from the motor and ESC which likely was the problem on earlier flights. I also built a voltage regulator so I could bypass the battery eliminator on the ESC as it can't handle 4 cell LiPos as I learned the hard way melting 2 brushless controllers in the process.

babflyer

My Feedback: (2)

Mine is finally done. Its not a df but I am going to read up more and possibly try it out. I have had 3 flights but with very slow setups, axi 2212-34 with a 10x? prop and a park 400 inrunner geared at 6-1 with a cut stock eflight 12x6 prop. Had to cut it down to the point that myold tp 10c 1320 battery could handle it. I now have a align 1400kv outrunner and a 8x6 apc drawing around 18.5 amps and 185 watts. running a cc25 contoller and a align 13c 1900 mah 3cell pack. From what I understand this should give a good combo of thrust and speed. I may want to go faster but will give this a try first. I am so used to GS planes that this thing seems like watching an arrow fly and trying to see if its right side up or not. lol Paint messed up so had to redo some of it and it now weighs 21 ozs. With a 7x7 prop I can run a tp 13c 1320 mah battery and get my wight down, I think that was about 14 amp draw. Im not a electric expert yet so if anyone can tell me anything that I am overlooking such as Im not pushing my equipment to the max yet or if I am going to burn something up let me know.

babflyer

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pic

PilotSmith

My Feedback: (1)

Ok, my F18 EDF Foamy must be jinxed. I got it fixed up and ready for flight just waiting for the new battery that I will have this weekend. I decided to move her from the garage to a room in the house where it would be safer from getting banged or bumped. In the process of moving it slips from my hand and lands on an elevator messing it up. [:@] I've never been happy with my elevator setup as it has more slop than I'd like and I wonder if that could cause flutter and a failure down the line. I could not use a rod thought the rear due to the exhause tube. So I had to come up with something that would fit in a tight spot. If anyone can come up with a better solution please let me know. I figure I might as well redo both sides now that I have to fix one side. Here is an early photo that shows how I set up the elevators. http://image.rcuniverse.com/forum/up...73/Lg16930.jpg Thanks for any tips.
By the way, the current setup has a piece of hardwood about 5 mm thick with an aluminum rod in it that is used as a bushing for the brass rod that goes into the elevator. In the photo you can only see the part of the wood that is 5mm thick. Closer to the rod the wood is doubled up and flush to the outside of the fuse making it 10 mm thick at that point. But is still has a moderate amount of play in all directions.

cadetman

PilotSmith

wow that is tight !

a couple of linear servos may help to increase the travel and get a better tolerance between servo and horn

but linears are expensive [&o]

just an idea [8D]

i hope this helps your quest

Ray

PilotSmith

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Hey Ray! I want to keep the cost down so I was thinking more along the line of a simple mechanical solution. I was toying with the idea of moving the servos further forward and using a semi-flexible pushrod as there is so little room back there to do anything. Maybe put the horns on the outside of the fuse so I can beef up the "bearing" area inside and have the pushrods exit near the rear??? I don't build very much so I'm counting on the builders here to come up with a creative idea.