FT Cruiser - BUILD

OutcastZeroOne

Fly, yes... Land, no
I seem to recall in at least one video (Maybe the Bloody Wonder...it was one of the first folded foam wings they did a video for) Josh B specifically mentions that the ridges are intentional in his designs and are meant to perform as turbolators.

It's been years since I did anything close to a serious study of aerodynamics and even then it was really limited. But I can see the possibility of the ridges being beneficial after doing a bit of reading on turbolators.

It would be interesting to see someone build a small wind tunnel and do some head to head tests to see if they are actually effective in that way or not. I'll try and talk my daughter into it when she's ready for a science fair project...but I'd say someone's got about 7 or 8 years to beat her to it :) Probably another 5 star article waiting for someone who's got more time than me :D

Then again summer is starting. Which means I won't be getting to fly as much (not a lot of fun flying when it's over 100 before the sun is fully up!) so maybe building a small wind tunnel and doing some airfoil comparisons should go on my list....

Be sure to have some way of cooling the air, since you know, air is cooler the higher you go ;)
 

Gyoenastaader

Junior Member
I seem to recall in at least one video (Maybe the Bloody Wonder...it was one of the first folded foam wings they did a video for) Josh B specifically mentions that the ridges are intentional in his designs and are meant to perform as turbolators.

It's been years since I did anything close to a serious study of aerodynamics and even then it was really limited. But I can see the possibility of the ridges being beneficial after doing a bit of reading on turbolators.

It would be interesting to see someone build a small wind tunnel and do some head to head tests to see if they are actually effective in that way or not. I'll try and talk my daughter into it when she's ready for a science fair project...but I'd say someone's got about 7 or 8 years to beat her to it :) Probably another 5 star article waiting for someone who's got more time than me :D

Then again summer is starting. Which means I won't be getting to fly as much (not a lot of fun flying when it's over 100 before the sun is fully up!) so maybe building a small wind tunnel and doing some airfoil comparisons should go on my list....

I actually do CFD work (computational fluid dynamics) for a living, think virtual wind tunnel. I tested a KF2, 3, and 4 (I believe) to a baseline SD7003 airfoil. Why SD7003? It is the prefered "Low Reynolds Number" airfoil for research. The KFs actually did compare well in terms of lift and viscous drag, but suffered higher pressure drag. While I only tested angles of attack of 4-8 degrees, SD7003 still came out on top. It terms of construction out of foam board, the KFs are not a bad option at all.

But just finished my Cruiser, and I can't wait to fly! Definitely was a challenging scratch build.

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Liemavick

Member
Mentor
Unlucky Gy, I bet if you tried to hit the flag pole it wouldnt have happened :) Thanks for sharing your virtual wind tunnel experience, interesting stuff on the wing comparison
 

neusse

Junior Member
After seeing the FT Spitfire removable wing, has anyone else thought it might be a good mod for the FT Cruiser?
I am not sure it is possible, Any thoughts?

Regards,
 

Gyoenastaader

Junior Member
Ok, where's the damage assessment pictures?

Damage is not terrible. Not sure whether to amputate the wing at the engine pod and build a new section, or attempt a repair. Either way, tape, glue, and skewers will be involved. I am extremely surprised I didn't lose a propeller. Everything else is still flyable.

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Liemavick

Member
Mentor
Perhaps a little foam trimming at the crack to where wing can return to level. Add hot glue, and tape her up and fly! :) Not as bad as it looked from the video, I figured you lost a wing and one pod at least.
 

Gyoenastaader

Junior Member
Yeah I believe it's still flyable. The damage is far worse on the bottom, the rip runs from leading to trailing edge. But hey, its foam!
 

rallyman

Junior Member
FLAMES CRUZR is finally done and set up. With my reputation at the club - nickname " Lawn Dart " I am almost afraid to fly it. I hope you enjoy - and even better if you are a hockey fan. Dollar store sells sticker sets real cheap......
June2013PlanesCruszrFrontBest.JPG June2013PlanesFlamesCruszrFrontBest.JPG June2013PlanesCruszrPilots.JPG June2013PlanesFlamesCruszrSide.JPG
 

Shylow

Junior Member
I love the FT builds!

We have had a lot of rain here this winter, so have had lots of time on my hands to get some building done.
I am very new to the hobby and have loved both of the FT builds that I have done. (The FT Cruiser and Spitfire).
I may have jumped the gun on these builds and should have probably started with building the FT Flyer, FT Nutball or FT Delta...
...But I just couldn't help myself! The Cruiser and Spity just look so good on the site and the videos!
So I just had to give them a go!

Over the past two weeks, and when ever time has allowed. I have been cutting and building. A Big Thank You to the FliteTest team for making all of the plans freely available. I would have loved to have been able to buy a speed build or two off of the site, but the shipping costs to far off Cape Town are just a little too steep for my Rand/Dollar exchange :(
None the less! I was able to source a local supply of Dolartree/Foamcore and after a quick trip to the print shop. I was ready to get going.
I found the scratch build very enjoyable and had to stop myself tinkering well into the night.

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So this past weekend I spent Saturday morning finishing up the electrics and gave both models a bit of colour. I was a bit worried that the poster board would not handle moisture very well. So thought that a light coating of spray paint would do the trick. The down side is that I think I may have added a bit too much weight in trying to even out the colour...
They both look great, pre-flight. I even splashed out on counter rotating props! :D
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So Sunday past was the maiden of the FT Cruiser. I had dulled down my rates and checked my CG... Kinda... I am still learning the functionality of My Spectrum DX6i. My CG did seem to show that I was very tail heavy. I added 45grams of balast to the nose and got ready to launch! (in front of most of my local flying club members and their running commentary... so my nervs were all over the place!)
The take off was good and very short! But as soon as I was in the air I realized that the tail was still too heavy! So I got her back on the ground as quickly and as safely as possible, with only minimal nose foam compression.
After adding another 35grams to the nose, (80grams total), I was ready for flight number 2!
In a few short metres she was back up in the air, but still twitchy as heck in pitch! So with a little help from my father, managed to get her trimmed. But nowhere near where I would like it. I had to trim full forward on the elevator just to get to level flight, so I think I may need to add even more weight to the nose, (Not good), or I would it be better to move the rear two servos further forward instead?
I kept the flight short after I had her trimmed as I was also concerned as to how long a flight time I would have on my 3cell 2200 battery.
The Cruiser came in true and straight on my approach to land, I could feel that I had this landing in the bag! I would just softly set her down on our make shift runway and all would be well. What I had not remembered to account for on my landing, was the fact that our runway is frequently trampled by our local farmers cows... I touched down perfectly! ...perfectly square into a hoof print...
The landing gear snagged, and she went nose over tail with a bit of a crunch...

I expected the worst, as I walked my walk of shame, over to the runway... But to my great surprise, the only damage was a little squished foam in the nose, some scratched paint on the wing tips and some very bent undercarriage.

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I did not maiden the Spitty. I need to do some soldering and get the right motor and prop. The one I had used just doesn't have the umph. But still looked good with the spinner on. :)
I plan on making some new landing gear this week as the wire that I had used on the Cruiser seems to be a little too forgiving and needs some stiffening up.

I think in future builds I might avoid spray painting and go even easier on the hot glue, but If any one has any tips or advice on CG and weight reduction, I would greatly appreciate the input.

A BIG Thank You to the Flite Test crew! Keep up the good work and great builds!
 

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Davec921

Junior Member
I just downloaded the plans and printed them off at college. Love computer tech labs. Any ways I got two counter rotating 6X4 3blade props. Would you think this will work for this plane. I know the recommended is a 8X4. With the one I have being a 3 Blade it equals out to one extra inch of prop compared to a 2 blade.
Thanks
Dave
 

Galand

New member
P1050205 (Medium).JPG Finished the Cruiser. First time I used hotglue. Not easy to work with. Difficult to control dosage. It squirts either too much or not enough. I guess I am not good with the trigger. But it sets fast, thats good.
I covered the wing in very thin laminate ironed on at low temp. Works well and allows to stick on tape colors without ripping off the paper and it strenghtens the board a lot. I like it so much that I plan to coat both sides of the foamboard before cutting out the shapes.
I also added some aeration in the fuse and the pods.
Downloading pictures is way too complicated on this site. See RCGroups for how it should be done!
 
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uavwriter

Junior Member
Do they have a wiring schematic? Since there are two wires coming from the ailerons and only one pin in one pin in the receiver to plug your runs into in the receiver, do I need another Y splitter? Yes if you haven't guessed I'm a newbie.:black_eyed:
 

splitwindow63

Junior Member
NEED help what esc do i need if im not going for diff thrust and im getting the 1450 turnigy motors, and second how do i wire the leads that go to the esc can i just wire them to a y harness and plug them into the throttle slot on my rx thx