54" F4D-1 Skyray

[Corsair nut]

Just checked. 80mm is about 5.5 sq in for fsa. 90 is about 7.5 iirc. Ive flown edfs sucessfully down to 65% on the inlet side, with properly designed ducts. My lil 28" 70mm skyray had plenty of inlet and they were maybe a lil bit oversized. Id be more than willing to bet a 80 would work just fine wothout a cheater..and a 90 would even work awesome, especially if you have anywhere near 10 sq in.

[Corsair nut]

Infact a 80 might be clpser to 6 than 7. Id need to look it up

[Corsair nut]

.a 80mm only needs about 6 or 7 sq in. I think a 90 is around 8 or 9 sq in

[Kloverzero]

80mm would fly this thing awesome, and you womt need a lame cheater hole! :p

The inlets are not going to be very big, probably 5 square inches each. It will need a cheater either way. It has plenty of duct space, but to keep the scale lines, I am going to have to go with the cheater.

[Corsair nut]

80mm would fly this thing awesome, and you womt need a lame cheater hole! :p

[Kloverzero]

I missed that one Boots.........how about a refresher for us memory challenged Squawkers :P

https://www.hobbysquawk.com/forum/rc-airplanes/the-hangar/55047-the-sig-king-kobra-batplane

He is just making fun of me and my 18 pound King Kobra....

[OV10]

You may have to Fiberglas this one! Reminds me of an funny story I read on the squawk....
LOL

I missed that one Boots.........how about a refresher for us memory challenged Squawkers :P

[Kloverzero]

You may have to Fiberglas this one! Reminds me of an funny story I read on the squawk....
LOL

You are not amusing...:Crying::Crying::Crying:LOLLOL

[Boots Whirlygig]

You may have to Fiberglas this one! Reminds me of an funny story I read on the squawk....
LOL

[Kloverzero]

This is really cool! Same materials as the Bronco, half inch blue with 3/16 sheathing and epoxy? Brilliant! I might build one as a belly lander, and power it with a 80mm 6 blade on 4s. Probably make a great edf trainer.

Yup, same material as the Bronco!! After getting it off the bench last night, I am seriously thinking about shrinking the fan mount section and putting the 80mm fan in it. The top of the fuse doesn't even weigh 6 oz, I think the empty weight for this one is going to come in about 24 oz or so. That will put it all up minus the battery at about 4 lbs. There will be three servos (No rudder or flaps. Nose wheel steering and elevons), three retracts, receiver, ESC and fan. I am afraid that 90mm inrunner will tear it to pieces, because you know, if I have the power, I am going to use it!! I am taking a short stay home vacation, so today is my last day at work until Wednesday, so maybe, I can have it pretty close to finished by then, and get a maiden next weekend!!

Here she is with the posterboard wing and tail templates!!

[Boots Whirlygig]

This is really cool! Same materials as the Bronco, half inch blue with 3/16 sheathing and epoxy? Brilliant! I might build one as a belly lander, and power it with a 80mm 6 blade on 4s. Probably make a great edf trainer.

[Kloverzero]

Progress from last night. I finally got her off the board!! Wow, super light and super strong!! She is straight as an arrow and very rigid. Tonight, I will get the upper ducting in and the fan mounts, get the top sheeting filled and sanded, and start working on drawing the bottom formers. I also went ahead last night and made the templates for the tail and the wing, so maybe I can get a few snapshots of what the whole picture will look like!!

[Kloverzero]

Last nights progress...

[Kloverzero]

Remember the throttle is not boolean (off or on); you can fly at something less than full. Ha ha, just yanking your chain. I'm looking forward to seeing the completed plane and a flight video. This is very cool!

I do not use the throttle stick for throttle, I assign the throttle channel to a two way switch;)

[dkalwishky]

I think I might should have stuck with the 80. I think the 90 is gonna put this thing into orbit. I already have all of ducting sized for the 90 though, so no turning back now!! To the moon Alice!!!

Remember the throttle is not boolean (off or on); you can fly at something less than full. Ha ha, just yanking your chain. I'm looking forward to seeing the completed plane and a flight video. This is very cool!

[Kloverzero]

I have already determined that I am going to need a cheater due to the small inlets, but that is okay. Rather have the air and not need it, than need it and not have it!!! The way that I have the ducting worked out, I think I am going to add two louvers, one aft of each inlet, and I am thinking I may put one just forward of the fan as well. I don't want to compromise the duct too much though. I will have to do some wattage and thrust tests once everything has come together.

[Corsair nut]

90 will be awesome. If it has the inlet area, why not :) my 28" wingspan depron version was 70mm amd it flew saweet. It is a skyray afterall..performance should be pretty spirited :) they set some records thats for sure. Such a cool subject.

[Kloverzero]

I told ya a long time ago....freewing 80mm...cmon! :p ill settle for 90mm though....lolol

That's pretty funny. My original intent was 80mm in this one, but once I got the drawings finished, and was looking at it, I thought an 80 might not have as much a$$ as I was hoping for. Now that construction has started, and I am seeing exactly what it will be, I think I might should have stuck with the 80. I think the 90 is gonna put this thing into orbit. I already have all of ducting sized for the 90 though, so no turning back now!! To the moon Alice!!!

[Corsair nut]

WANT!

I told ya a long time ago....freewing 80mm...cmon! :p ill settle for 90mm though....lolol

[Alpha]

WANT!