FT Sparrow Builders'/Owners' Thread

[SP0NZ]

Sorry for not seeing this thread sooner and being a little more prompt with some responses here. I'll try my best to answer all the questions that I can.

CG
There was a little bit of a miscommunication on this, and I take full responsibility for that. Originally Josh told me the CG was 1.75 inches from the leading edge. I got the specs from Alex on release day and noticed that the CG was listed as 2.75 inches. Alex told me to use the 2.75 inches but that didn't seem right based on the glider version that I built so I left it at 1.75 inches on the plans. I have since built a second glider (such a fast build, so why not) and balanced it at 2.75 inches. If you watch the build video, Josh puts in some up elevator with the CG at 2.75. They probably did a lot of testing to find the sweet spot for the glider. I can say that without the up elevator (I did not cut in control surfaces for my gliders) 2.75 is a little tail-heavy. I think the glider is slightly nose-heavy with the CG at 1.75 inches, but it's definitely flyable.

AILERONS
The feedback that I got from Josh was that the ailerons are not needed and the Sparrow flew much better without them.

PLANS
@localfeind - I am not seeing what you are referring to with the score and cut lines not being correct. If possible can you take some screen caps of your plans and markup where you think the errors are?

 

[Jimmyp]

I only did one test flight in the back yard and so I don't really know how it flies. Now it is really windy so no more testing until it calms down. But I went ahead and cut in the ailerons anyway. If I don't need them I can just leave them alone and fly with the rudders. I went really quick and cheap on this build. All used parts kicking around. I even cheaped out on the control horns and used Popsicle sticks.
I really wish the beak on this little sparrow was about an inch longer and will be if I build another. I want more room to adjust the CG. Right now I have a 1300 3s in there jammed right to the front.

 

[slyke]

I can say that without the up elevator (I did not cut in control surfaces for my gliders) 2.75 is a little tail-heavy.

Thanks for the update!
I wish there was an 'official' thread for the build in the All Articles forum to keep all the build discussions in the same place.

Quick question - If it is already tail heavy at 2.75 then wouldn't the up elevator make it fly worse?

Stephen

 

[localfiend]

Don't think it was your fault Sponz. Sounds like there are two CG's for two different things.

Sorry for not seeing this thread sooner and being a little more prompt with some responses here. I'll try my best to answer all the questions that I can.

CG
There was a little bit of a miscommunication on this, and I take full responsibility for that. Originally Josh told me the CG was 1.75 inches from the leading edge. I got the specs from Alex on release day and noticed that the CG was listed as 2.75 inches. Alex told me to use the 2.75 inches but that didn't seem right based on the glider version that I built so I left it at 1.75 inches on the plans. I have since built a second glider (such a fast build, so why not) and balanced it at 2.75 inches. If you watch the build video, Josh puts in some up elevator with the CG at 2.75. They probably did a lot of testing to find the sweet spot for the glider. I can say that without the up elevator (I did not cut in control surfaces for my gliders) 2.75 is a little tail-heavy. I think the glider is slightly nose-heavy with the CG at 1.75 inches, but it's definitely flyable.

That makes sense. If you're going for glider range from a toss, it could make sense to have a different CG and elevator adjustment to get the optimal arc.

I can attest to 2.75 being too far back to be flyable with a motor. You have very little control at that CG, and it's almost impossible to get the nose down. 1.75" Flies very well with a motor. I tried slightly further back than 1.75 inches and it was less stable. If you're putting a motor on your plane, I'd reccomend starting at the 1.75" mark like it's written on the plans.

PLANS
@localfeind - I am not seeing what you are referring to with the score and cut lines not being correct. If possible can you take some screen caps of your plans and markup where you think the errors are?

Here you go.

Number 1: The outside line between the fuse sides and bottom plate. It's a cut through line and I think it should be a score cut there so you don't make three pieces out of your fuse.

Number 2: It looks like on the speedbuild kit there is another score cut line here that matches up with the point of the fuse. The other score cut line that's further up on the center plate isn't the center line, it's the hatch bend point.

 

[localfiend]

Thanks for the update!
I wish there was an 'official' thread for the build in the All Articles forum to keep all the build discussions in the same place.

Are there any active moderators who have the power to move threads around and combine them? On other forums I frequent and moderate, it's common practice to combine threads with the same topic into one. Seems that as time goes on here information gets more and more scattered and I get lost.

 

[Craftydan]

Active? You mean as in exercise?!?

Clearly you don't know me sir!

 

[localfiend]

Active? You mean as in exercise?!?

Clearly you don't know me sir!

Uh oh, don't make me run any laps!

Wasn't sure if anybody on the board had the power to move anything, as I never saw it done. FT is an unusual board. It really doesn't seem to need much if any moderating. We seem to be a pretty laid back bunch.

 

[kacknor]

No, I'm using an F pack, which is why I want to make changes. I'm not saying anything is wrong with the design if you build it the way FT recommends, my woes are self inflicted. I've overpowered mine and am using a 6" prop, both of which throw the CG out of wack.

Thanks. I did noticed in the video Josh said A pack or 1806 motor while clearly holding up a 2204. From my experience (limited as it is) the FT planes fly quite well on much less motor then recommended. Not saying fast isn't fun!! But slower is a lot easier to control for newer flyers. I'm betting the Sparrow is the same.

I had no intention of building one of these things. The pre-release promotion did little for me. But I see that great video they did for the release and dang! I want one!

JD

 

[localfiend]

Thanks. I did noticed in the video Josh said A pack or 1806 motor while clearly holding up a 2204. From my experience (limited as it is) the FT planes fly quite well on much less motor then recommended. Not saying fast isn't fun!! But slower is a lot easier to control for newer flyers. I'm better the Sparrow is the same.

I had no intention of building one of these things. The pre-release promotion did little for me. But I see that great video they did for the release and dang! I want one!

JD

If you decide to scratch build one I finished a modified set of plans that will be a better fit for the F pack. It's essentially the same but with a longer nose, a bit wider fuse, and a slightly different pod arrangement. The wing is the same, except I added option cutouts for ailerons, which may be a bad idea.

I have some micro FPV gear I need to finish soldering then I think I'll build the longer fuselage.

Thread:

http://forum.flitetest.com/showthread.php?25342-F-Pack-Sparrow-Swappable-Build-Thread



F Pack Sparrow - Swappable Beta v.1 - Tiled

F Pack Sparrow - Swappable Beta v.1 - Full

 

[SP0NZ]

Don't think it was your fault Sponz. Sounds like there are two CG's for two different things.



That makes sense. If you're going for glider range from a toss, it could make sense to have a different CG and elevator adjustment to get the optimal arc.

I can attest to 2.75 being too far back to be flyable with a motor. You have very little control at that CG, and it's almost impossible to get the nose down. 1.75" Flies very well with a motor. I tried slightly further back than 1.75 inches and it was less stable. If you're putting a motor on your plane, I'd reccomend starting at the 1.75" mark like it's written on the plans.




Here you go.

Number 1: The outside line between the fuse sides and bottom plate. It's a cut through line and I think it should be a score cut there so you don't make three pieces out of your fuse.

Number 2: It looks like on the speedbuild kit there is another score cut line here that matches up with the point of the fuse. The other score cut line that's further up on the center plate isn't the center line, it's the hatch bend point.

localfeind, great feedback as usual man. I fixed #1 for the v1.1 update. I went back and watched the video to check for issue #2. There was no line in the laser files I received to make the plans with, nor is there any that I can see in the build video? Go to 14:50 in the video and look at the piece that folds over, I only see 1 score cut for the battery hatch. Am I missing something?

 

[DumbThumbsRC]

Okay so I just finished building mine and I am thinking it is to heavy. What is the auw you guys are seeing.
5gm motors
2204 emax motor
326 grams balances it at the cg location.

I did cover it in packing tape.

 

[localfiend]

localfeind, great feedback as usual man. I fixed #1 for the v1.1 update. I went back and watched the video to check for issue #2. There was no line in the laser files I received to make the plans with, nor is there any that I can see in the build video? Go to 14:50 in the video and look at the piece that folds over, I only see 1 score cut for the battery hatch. Am I missing something?

Nope, I probably just manufactured that line in my head. When I was building mine I couldn't get the nose to form well without a line there and assumed there must have been one in the build video as it went smoothly for Josh.

Okay so I just finished building mine and I am thinking it is to heavy. What is the auw you guys are seeing.
5gm motors
2204 emax motor
326 grams balances it at the cg location.

I did cover it in packing tape.

Mine was just a bit over 300 to balance with the same electronics. The packing tape is probably the only difference. Wing loading at that weight is still perfectly flyable, but it will be fast. If it's too fast for you and you crash it, build a new fuse with my plans. That should let you balance the plane without so much extra weight.

 

[kacknor]

If you decide to scratch build one I finished a modified set of plans that will be a better fit for the F pack. It's essentially the same but with a longer nose, a bit wider fuse, and a slightly different pod arrangement. The wing is the same, except I added option cutouts for ailerons, which may be a bad idea.

I have some micro FPV gear I need to finish soldering then I think I'll build the longer fuselage.

Thread:

http://forum.flitetest.com/showthread.php?25342-F-Pack-Sparrow-Swappable-Build-Thread



F Pack Sparrow - Swappable Beta v.1 - Tiled

F Pack Sparrow - Swappable Beta v.1 - Full

You are with the quickness. I have been busy and 'spare time' was used here:

http://forum.flitetest.com/showthread.php?25031-Windfall-Super-Cub-LP&p=265619#post265619

Ready to go now however. Still planing on building that mini Gloster Gladiator of yours, and now a Sparrow. So little time!

JD

 

[Jimmyp]

Here is my maiden flight with ailerons cut in. It worked out really well. Sorry about the video which is a raw upload from my iPhone. I forgot to take my head mount GoPro.

 

[GremlinRC]

As soon as I saw the FT sparrow, I saw an opportunity to do exactly what most people would not want to do. Downsize it!! I have a couple of NTM 13-12 motors and 6a escs which needed a bit of inspiration and the FT sparrow was just that. I scaled it to 70% so the wingspan is 512mm. Straight away I had a problem. In order to get the CG anywhere near where it needed I was going to have to put an awful lot of weight in the nose. I figured the AUW would end up being in the order of 130g. Using that 13-12 outrunner and a 5x2.75 prop gets me just under 30W. It *Might* just fly, but probably just about. So after a little rethink I decided to make it a puller instead of a pusher. So here its is;



I havent got to maiden this yet. Now without all of that extra weight and including an 850mah 2s is 105g. I calculated that based on a rough 100w/lb rule then approx 25W should be enough, so it still wont be a flier but should be ok.



I had to do a reasonable amount of modification uncluding changing the location of the servos and have the push rods totally on the outside.



Hope to get to maiden on Wednesday. Fingers crossed.

 

[sveininge]

Here is my build, waiting for the motor in the Mail 2204 2300kv.
Used 6mm depron,

 

[Jimmyp]

Here is my build, waiting for the motor in the Mail 2204 2300kv.
Used 6mm depron,

View attachment 64757 View attachment 64757 View attachment 64757

Very nice

 

[Just add foam]

Jimmy P, saw your maiden video. Is that Blue Mountain in the back ground ? I see your from Ontario, and I was almost positive that was Blue. Either way good job on the build and maiden. I'll look up the next time I'm visiting the in laws in Collingwood.

My sparrow is ready just waiting for some good weather and luck. Balancing was a problem, but I think she is over powered. I did a glide test and it landed a little nose heavy, but I feel wing loading is fine.

 

[geduxk]

my frend doit from deprom 5mm

 

[Jimmyp]

Jimmy P, saw your maiden video. Is that Blue Mountain in the back ground ? I see your from Ontario, and I was almost positive that was Blue. Either way good job on the build and maiden. I'll look up the next time I'm visiting the in laws in Collingwood.

My sparrow is ready just waiting for some good weather and luck. Balancing was a problem, but I think she is over powered. I did a glide test and it landed a little nose heavy, but I feel wing loading is fine.

You are are right it is blue mountain in the background. I would love to meet next time you come up to the C-Wood area.
I also get down to Elora once in awhile. I like to camp at the gorge. My brother also lives is Elora. Last time I flew in town I tossed up a plane from the far end of the slots parking lot and flew over the open field at the end of the horse track.
Send me an email if you would like connect and fly. jimnottawa1@gmail.com

If I build a second sparrow I will make the nose a bit longer for more room to balance. As it is I have a 1300mAh 3s jammed up as far as it can go. I didn't even check the cg point. Just chucked it up and it worked out ok.