whissel_blowa

The exhaust duct should be trimmed to the length of the tailcone, once ducts go over 6 inches long they really should not taper at all until the last 2 inches or so of pipe. Even under 6 inches the most correct nozzle is straight out from the fan then tapering down 10% of the fans swept area. Have a look at this pic of my current F16 on the bench, the exhaust is a genuine wemotec part that fits the back of the fan like a glove!

Aussie Damo

just a little thing on converging nozzles, if u make the exhaust area smaller you get a higher specific thrust output (eg you will go faster) but your thrust effeciency will go do (ie more energy is needed to create same thrust)

main point, wana go fast make nozzle converge, wanna fly longer leave it as big as possible

cheers

whissel_blowa

It doesnt quite work that way, all fans require a reduction in outlet diameter in order to maximise their efficiency. Going past the sweet spot in outlet size will raise your eflux speed a certain degree but will lose you sometimes considerable thrust.
If the outlet is over the FSA of the fan you will experience a reduction in thrust in flight, we have proven this with the large 90mm mirage, stock exhaust is oversize at around 95mm and the model suffers from less than 1:1 thrust to weight and a good but not great performance. Bringing the nozzle down to the correct 78mm sees a big increase in thrust as well as eflux velocity "in the air" and the model picks up almost 20mph in speed and climbs much stronger.

As for amp draw, I have recorded minimal changes between a bench tested fan with no exhaust duct at all and the same fan inside a model with ducts varying from 4-6 inches long to 15+ inches long (all with the correct outlet size or within a mm of it). Its only when you go seriously past the optimum nozzle diameter that your amp draw rises noticeably. Graph below shows our 90mm F86 Sabre in flight, pulling 49A constant with a 16 inch almost straight duct. On the bench the same fan pulled the exact same figures with open back.

skrez

My Feedback: (15)

Hi Guys,
I don`t like the color decals that comes with the kit so I want to repaint it. Where can I buy decals for this scale size plane?Regards,
Frank

MerlinFan

My Feedback: (27)

You just have to shop around some to find decals. I was lucky to score an Ultrafly F16 that I am robbing the Thunderbirds decals from and giving the plane to my grandson to build with a brushed pusher prop setup. I see you are from IL. Slot and Wing in Champaign has the biggest decal and sticker collection I've ever seen.
On a similar subject, as I remember, water based spraypaint used to be easy to find, however I can't find it anywhere now. I have heard about Krylon H2O but nobody around here carries it. Does anybody know...........

dinoatwoodys

michaels crafts carries the h2o paints

crashcrash

I print my own and use quality packing tape to affix. My first F-16 crashed too, but I think it was a BAD servo that got me. I bought the bare bones from hobby people, and re-installed the original fan unit and replaced the bad servo...the new one flies fine. I did READ the ESC's are becomming a problem in burning up. I use a 2200mAh 20C, I keep the flights to 7-8 minuets, no probs so far (knock on wood).

crashcrash

Use MS paint to increase or decrease size, print and cut it out...they're OK from 10ft and out.

gooseF22

I saw one fly the other day with an upgraded 40 amp controller and the stock fan on a evo lite 2500 4S. then he flew it on a 2500 3S. he flew pretty hard on 3s and it did pretty good about 70mph or so. With the 4S, the thing was ballistic and fast, but he limited his full throttle to 10 seconds and then let it cool. It is the most impressive foamie I have seen. A bunch of us jet guys saw it and we all ordered one the next day.

crashcrash

I've flown mine 5-6 times now....I'm finally getting used to it. Even as stock....it'll eat up 500yds QUICK.

crashcrash

Been flying mine almost every day when wind permits. Can't say enough good about it. The supposed prob with the ESC.....I haven't even had mine to offer to get warm while running 2200mAh 20C's. I run it full power on takeoff, and run it normally a little below half throttle which would get me 15-20 minuets per flight, but I don't keep it up longer than 10 minuets. I got the servo throws at 45% and expo dialed down to make it fly more stable and less quick reactions. At full speed at 100% throw...this would be a monster to fly. My first one crashed because of a bad servo....all the guts were good so I transferred it to a bare bones, added new servos....been flying my butt off since. This is a very impressive foamie.

gooseF22

Hey guys, I have a 30 amp ESC that is good for 4S out of my wrecked Trojan. Do you think that will handle the stock motor on a 4S 2500? I will take it easy on it of course, just dont want to smoke it.

assembling it now

crashcrash

Ooooooohhhhhh....I'd be careful[X(]

Squirrlybird

http://donsrc.com/cart/index.php?act...d&productId=52

If you want 4s, the motor above is a good choice on this (XF) fan. It is also a good 3s motor as well. This seems to be a common motor that wont break the bank. Just dont run the stock esc on it.

Some people are also using the little screamer motor from HL, but it is pretty pricey.

Every report that I have heard of using the stock motor on 4s shows that it will burn out fairly quickly.

crashcrash

I agree. AFter the stock one I got is done being battle tested (I'm having a ball with it), I may opt for a more powerful fan unit having more blades. Had a MINOR mishap tonight. I come into a slow turn at about 4ft up, I seen the nose drop (knew I had a stall going on), I gunned it, but it wasn't enough to pull it out. It impacted nose and right wing tip causing a slight bend in the right wing, popped the air intake plastic loose, and the right side of the lower fuse come loose as well. Had it repaired and flying in 20 minuets with no problems.

gooseF22

OK guys,

Im going to order Dons wicked extreme and run my stock fan. I have a dualsky 40 amp ESC on the way. I want to run both 3S 2200's and 4S 2500 EVO LItes. They are the 20C 2500's.

I dont know what wicked extreme option to order. One says standoff alone fits XF, and another says XF/Eflite.

Can you tell me which one to get?

For those running the bigger batts, I know to mount the motor aft, where did your battery end up. Do I have room to stuff a little spektrum receiver at the back of the canopy?

Im putting HS-65HB's in it too.

hairlip

My Feedback: (65)

Did you know that the 5400 wiked motor is only 300 KV more than the stock motor ?The shaft on the motor is 3mm the same as the stock.Don said that the stand off was there because the motor would not fit back in the housing.

gooseF22

Ya I saw that, the housing is bigger and it will handle more amperage than the stock motor. Im going to try the stock fan, and then maybe later the alpha 3 with the extreme.

Next one will go with 70mm fan set and glassed intake and a 3000 4S 25C Kokam batt pack.

I just dont know which pull down option to order on Dons website. the XF/Eflite one or the standard one. both have the standoff. The standoff is ok for me as it shifts weight rearward too. I have a large pack going in, as well as a larger controller.

hairlip

My Feedback: (65)

I flew my #2 plane today for the first time.I moved the fan assembly back about one inch from the recomended position.I still ran the stock motor on 3cell 2200 pack. The only difference was the seven bladed fan.

crashcrash

How did the 7 bladed fan work out? Where'd you get it (I'm new at this EDF stuff)...link?

hairlip

My Feedback: (65)

I'm new to this also.
The fan blade worked OK, but I didnt notice a major difference.
I have not been able to find the fan by it's self yet,and the motor that comes with this is not very strong.

crashcrash

So where did you get that outfit (seller/part number, all info)? Does it all fit in the F-16?
I had a minor crash because I went into a stall, and the stock outfit didn't have enough to recover/pull me out of it (slow speed turn...about 5ft up). Damage was light and I had it back flying in 20 minuets. Had the motor/fan been more powerful, I could have prevented the crash completely. Sometimes, raw power can save your butt. This plane lacks vertical raw power as stock....I agree.

hairlip

My Feedback: (65)

http://www.rc-warbirds.com/product_i...roducts_id/440

This is the link to the fan set up. Like I said the motor is not as strong as the stock one.

If you choose to go with the wicked 5400 ,it should fit.

crashcrash

Thanks

gooseF22

So for those that ordered the Dons wicked.

Which plug do I order, the one that says XF/Eflite?

Its an option on the bottom of the page when ordering