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FT Cruiser (Finally)

#1
Hello everyone,
I've been away from my computer lately, and I just wanted to catch up with everyone. I've had a few projects that distracted me from this one, but I'm finally where I need to be to start on the Cruiser. I've even got my bench cleaned off!
I've been flying for decades, but I'm just now really getting into FPV. I picked up an old 3dr ccd with a budget 5.8 transmitter and I must say I'm very impressed with this setup. I destroyed a 120% sparrow (I've come to hate that design) breaking this system in. It took several lack of altitude mistakes including burying the camera in the pasture. All of this I managed from a POS 7" backup camera TFT mounted to my transmitter. I've got a pair of Eachine goggles 2 on the way so I need to get a new FPV rig built before they arrive.
I've been putting this one off for a month or so just to get my gear ready. Here's what I'm putting it together with:

110% scratch build FT Cruiser (nose mod) using Adams black on black foam-board
SunnySky 2216 1400 KV 2 (black ones not the sweet blue ones)
8x5 (4s) or 9x5 (3s) Chinese carbon fiber props or 10.47/8x4.7 apc style if over amping is a problem. I'll amp test all 4 styles loaded on the bench first.
Generic Simonk 30a esc with 3a BEC (not mounting permanent, probably won't hold up)
Sunfounder SG90 digital clutch servos (LOVE these servos)
Flysky FS-ia10 10 ch receiver
Generic servo-less retracts with up/down mag lock
Jumper T8SG v1 transmitter
Sony Super HAD CCD 520TVL
200mw Generic 5.8 transmitter
2200mah 3s or 1300mah 4s (45c)

This is my "Plan"
Independent ailerons
Retracts mounted in nacelles
Bomb drop on bottom of fuse (maybe in the nacelles if I have room)
LEDs

With the 2216s and retracts, my wings will need a little extra sparing. I haven't decided on what to use at the moment but it'll either be a basswood 3mmx12mm bar or a 3/8" fiberglass tube. I need to weigh them both and see who's lighter.

I've built a backpack with my camera/transmitter on an old 3dr carbon fiber quad camera mount. I don't care much for the amount of space lost when using the "FPV nose" from Flitetest, so I'm hoping to mount the backpack to bottom of the standard nose and routing the antenna up through the fuse. This way even if I have to leave the antenna in the nose, I should be able to move the backpack between models without too much fuss. If it doesn't work out, I'll mount the FPV gear permanent and pick up another pair (been looking at integrated camera/transmitters anyway for my smaller planes). I'm not going to worry about a HD camera mount at this time, but I may try to find a spot fore of the canopy to mount my Goproa later on (I love the way this plane looks from the cockpit POV).
I'm starting on my cutouts today which always takes me WAY too long. I'll post up a shot of all my gear tonight before I get started. Happy Friday!!!
 

Hondo76251

Well-known member
#2
That'll be a fun one for sure!

I finally had to break down and fix the spar in my old FT Cruiser. It was broken in a few places, I could still make it fly but it was iffy. I need to do a parachute drop over the 4th here so I Frankensteined the old girl!

The original cruiser spar is 1/2" so I used two 1/4" square balsa sticks glued together and slid them in behind the original foam spar. It seems to be quite strong. If I were doing it from scratch I'd do the same thing but sandwich the balsa in between the foam spars rather than next to it...

 
#3
Too awesome Hondo! Too bad about your cruiser, but I'll keep that spar idea in mind. I think I've got some balsa stock floating around somewhere. I couldn't tell from the video, how did you rig the parachute drop?
 

Hondo76251

Well-known member
#4
I've got another speed build cruiser on the way! Lol can't be without the DH.88! Going to do a few mods to it this time around (like real spars!)

Looking forward to seeing your "Black Majic" !
 
#5
Man I tell ya, after 3 hours of taping, cutting, and cussing I sure see the beauty of the speed builds. I'll prolly go that way when I run out of this black foam. Wings really eat up a big board. I'd hate to do this with dollar store board. 15623722559191359168822.jpg
 

Hondo76251

Well-known member
#8
Man I tell ya, after 3 hours of taping, cutting, and cussing I sure see the beauty of the speed builds....
Its probably a good idea to do at least one custom build to actually appreciate how well they've fit great number of their speed builds into just a few sheets of foam! I've had some scratch build's that ate up 6 or 7 full sheets of foam and ended up being no larger than a Tiny Trainer! :ROFLMAO:
 
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#10
Helps keep a steady hand hahaha. She's bit bigger than I expected at 110%. Tip to tip I'm 54 1/2". I've also cut the nose off my mini (it was held together by hope alone) and I'll use it as a prototype for the 3d nose. I might have to add a 1/2" or so if I loose too much battery space. The mini really sucks for room. Got the swing shift tonight so I'll try and get more knocked out tomorrow. Still sorting out a bomb drop.....
 

Hondo76251

Well-known member
#11
I figured you'd be about the size my Franken Cruiser at 110% I think she's right at 57" tip to tip now... wish I hadn't been in such a hurry and could've made the wings removable! Definitely making them removable on my next full size cruiser...

This is by far the best bomb drop setup I've come up with... very simple and works great. I usually use a little zip tie rather than putting the rubber band directly on the servo horn. On my beaver I actually bent a wire hook on the end and glued a little 1/4" of dowel to the servo horn to prevent it from slipping too far down the horn and getting stuck...

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#13
I've got some metal gear 9s that'll be perfect with that setup. I wonder if a long servo arm would allow you to mount inside the fuse with a slot for the arm... Not sure how much space I'll have but it looks promising so far.
I see you took some surface to air over the holiday :D My umx sport cub has a smoke bomb streak down her belly now lol.
 

Hondo76251

Well-known member
#14
That's actually battle damage from last year on the old ascent 🤣 I've got better planes now days! Lol (not to encourage irresponsible behavior, but rumor has it she can also launch bottle rockets 😁)

I'm sure you can mount them inside, only trick is that the rubber band has to be pretty close to the pivot point or the servo doesn't like it much... they'll start to howl on me if the rubber band is too far out on the servo horn (depending on the tension) I'd do a wire hook (like the beaver) that could slip inside the slot and hook low on the servo horn...
 
#15
Good point there... I've come to use a lot of gift card material for stress points. I could even shape a porthole for the hook to fit through, glue it to the outside of the fuse skin, and try to prevent wearing the foam out from hooking/releasing. I don't know why I always go overboard making foamies look good. They only ever get one good picture, then it's all bailing wire and duct tape from there lol.

I did pick up some cheapo clear laminate at DG today. I'm going to try wrapping the mini cruiser nose with it to add some duriblity (it literally disintegrated on me). If It's not too much of a booger putting on I might try wrapping the big cruiser with it. I think it was a buck fifty a roll so it's not much of a loss if it's crap.

Thanks for all the tips Hondo! Keep em level!
 
#16
Ok, I've finally got all of my cutting done. I'm about half way done with my power pods (still working on the retracts). I've got my wing spar glued together and I've added some 2mm and 4mm carbon to the tail feathers I changed course with my nose mod. I've cut everything out to spec, but I'll trim and fit as I go along to get the look I'm going for. I'm really not changing much, just adding a bevel to the vertical walls of the nose. Hopefully I can get close to symmetrical where the nose comes together in a 1/2" square. I'll add some pics of my idea when I get the wing done.
I've also got a problem I'm hoping some minor mods will fix. These Sunny Skys are rated at 32amps with a 9x64s. My cheapo Simonks are 30amp with a 10 sec 40 amp burst. I know i shouldn't ever get close to the 32amps running slow flys or my 8x6s but I do have some mean 9x6 CF props I want to throw on to scare myself with. The problem is, the nacelle design encapsulates the esc and provides little to no airflow. I've already cut away the heat shrink from around the heat sinks, but I'm going to add a "chin" to the bottom of the power pods to direct some air from the prop wash into the nacelles via a breather hole. This will also add a more "comet" look as their nacelles hung very low beneath the wing. Hopefully it won't just look like some hillbilly glued some balsa to some foamboard and called it good. But that tends to happen with me lol. And of course if I smoke these escs, it'll be a good excuse to move up to a 40amp.

So tonight I'll be finishing up the pods, get my motors wired up. And start on the wing.

I have to say again, these SunnySkys are the BEST motors I've ever bought. I love just sitting at the bench and spinning them by hand. I know there are millions of other awesome brands out there. But I'm cheap, and I've always bought cheap motors until now. It'll be hard to buy any racerstars after this...
 

Hondo76251

Well-known member
#17
I'm still toying with a simple way to do a flitetest style build on the wing but alter the shape to look more like DH.88 myself. Had some success but it looks like I might just end up doing the whole wing from scratch rather than trying to modify the FT plans/kit...

I'm also thinking I need to do something with the nacelles... for starters I'm not going to have them sticking out behind the wing... also thinking of modifying the FT power pod with a big rounded bottom, that could add airflow and looks. Something similar to what I did on my Lidl Blackbird...
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#18
That's exactly what I was going for too, except I hit a snag. My retracts ate up more real estate than I wanted. So now I've got a facade around the motor, and a "scoop" to drive air into the nacelle. I'm not exactly happy with the look, but it was this or retracts and I REALLY wanted gear. I'm working on some home built wheels that'll allow me to run a very narrow slot in the power pod. It's just a doped up 3" cd with some foam board on the front. I'll put some hub-caps on them when I'm happy with the retract throw (the factory lg wire is very short). I'll have a lot of wheel sticking out but so does my mini and it doesn't look too bad. They actually help save the belly when doing tall grass landings.
Since I spent all night on the power pods, I think I'll finally get to start on the wing tonight. I can't wait to see how these sunnyskys run! KIMG0096[1].jpg
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Hondo76251

Well-known member
#19
That's exactly what I was going for too, except I hit a snag. My retracts ate up more real estate than I wanted. So now I've got a facade around the motor, and a "scoop" to drive air into the nacelle. I'm not exactly happy with the look...
Nah man, that looks great! Worth it for the retracts for sure!

Did you go 110% on the whole build or just wings?
 
#20
110% on everything. I have to watch the gaps on some of my cutouts (nacelles for sure) as it widened everything. I ran into this on the sparrow I did, but as long as you plan ahead it's not too bad. Does suck to get everything glued just to realize the power pod is 1/4" too narrow lol.
Thanks for the encouragement! There was more than once I almost trashed these things last night.... I don't think the scoops should adversely affect the flight characteristics, but I won't know until I get it in the air. Should definitely move some air through the power pod now tho.

I did find out something that I wasn't aware of until yesterday. These servo-less retracts do NOT like servo testers. I don't know if it's because they only want to be ON or OFF or if they're just cheap. But after an hour of testing, I managed to fry both of them. I had to physically take them apart to wind the retracts back to the "down" position" I can't say for sure it was the servo tester that did it, but I can't think of anything else that would have affected them both at the same time. I wound up ordering another pair just like mine so they'll interchange. And i'll only be testing with a transmitter switch from now on...