FT Mini Arrow

thearne3

New member
Hey Guys,

Built my Arrow with Elmer's foam and it requires massive weight in the nose to balance at the CG. Is there any way to take weight off from behind the CG? For example, move the motor, etc forward by say 1/2" by cutting a deeper 'indent' slot between the elevons?

Thanks...
 

Ricci

Posted a thousand or more times
I placed 2 850mah lipos to get the cg. After repairing i modified the centerpart by make it longee about 10 mm
 

adamooo

New member
Hey Guys,

Built my Arrow with Elmer's foam and it requires massive weight in the nose to balance at the CG. Is there any way to take weight off from behind the CG? For example, move the motor, etc forward by say 1/2" by cutting a deeper 'indent' slot between the elevons?

Just because I haven't seen anyone else respond - Elmer's foamboard is known to be significantly heavier than Adams / Flite Test / Dollar Tree stuff. Using it will definitely change the CG compared to the design based on the lighter material. I haven't used it, let alone on an Arrow in particular, but you'll likely need either artificial weight in the nose, bigger/more batteries, or to change the design to allow pushing the weight further forward. I think it would be hard to push the motor forward without weakening the wing, although maybe the Elmer's board would allow that.

If you look back in this thread, I've posted about my tweaks to the Arrow center pod. I've built a couple with the pod both widened (which lots of people have done) and extended forward past the "leading edge" of the wing sections. I kinda like the hawk-nosed look this gives anyway. I have done standard-size Arrows with a the pod poking out 1-2" in front, which lets you push battery weight further forward. You can use much bigger batteries if you make it wider as well, but that is harder if you're building from a speedbuild kit. If you're cutting your own, just add "width" to the bottom panel of the wing as well as to the pod top pieces.

Adam
 

FlyingScotsman

New member
Hi folks , started building my arrow about 2 weeks ago then set aside waiting for a motor and pushrods which arrived yesterday so finished it off and maidened it. Everything went really well the cg seems spot on with a 5g weight on the front. This is using ft water resistant foamboard , 2 9g servos , an emax 2204 with 12a esc , 6045 prop and 800mah 2s battery.i tried 6030 first it flew but was very lethargic. I decided to add tape after the build to help with rigidity and to be able to tell top from bottom. Its nothing fancy just black with red wing tips and red centre pod with the opposite on bottom. I got 4 batteries through her yesterday , got it home then noticed the poor jst connectors (esc end) had melted together. I plan on changing over to es3 as thats also what my 3s sport cub s2 uses. I'll probably stick a 20a esc on to test out 3s at some point but 2s was not slow by any means. Its too much fun dive bombing at full throttle and she has displayed no bad manners. She does fly as straight as an arrow. Just wondering what connector type you guys are running (2s) it seems crazy to supply a battery with a connector that is not capable of the amps it will run.

Forgot to add - she is my 4th flite test scratch build starting with mini sportster , mini speedster , mini mustang (flew very poor and did not withstand crashes well atall , stole wing and threw on top of a mini scout frame , tried once actually flew pretty well but ive since moved the wing forward. Okay thats 5 but the scout/mustang aka stout doesnt count. Cheers
 
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nevenelestate

No Agenda FPV
Hi folks , started building my arrow about 2 weeks ago then set aside waiting for a motor and pushrods which arrived yesterday so finished it off and maidened it. Everything went really well the cg seems spot on with a 5g weight on the front. This is using ft water resistant foamboard , 2 9g servos , an emax 2204 with 12a esc , 6045 prop and 800mah 2s battery.i tried 6030 first it flew but was very lethargic. I decided to add tape after the build to help with rigidity and to be able to tell top from bottom. Its nothing fancy just black with red wing tips and red centre pod with the opposite on bottom. I got 4 batteries through her yesterday , got it home then noticed the poor jst connectors (esc end) had melted together. I plan on changing over to es3 as thats also what my 3s sport cub s2 uses. I'll probably stick a 20a esc on to test out 3s at some point but 2s was not slow by any means. Its too much fun dive bombing at full throttle and she has displayed no bad manners. She does fly as straight as an arrow. Just wondering what connector type you guys are running (2s) it seems crazy to supply a battery with a connector that is not capable of the amps it will run.

Forgot to add - she is my 4th flite test scratch build starting with mini sportster , mini speedster , mini mustang (flew very poor and did not withstand crashes well atall , stole wing and threw on top of a mini scout frame , tried once actually flew pretty well but ive since moved the wing forward. Okay thats 5 but the scout/mustang aka stout doesnt count. Cheers
I would throw an XT30 on there if you are not planning on going to 3S. If you are then you might want to go XT60 since that is what most 3S batteries use. I had trouble fitting a 3S 1000mAh battery with XT60 in the Arrows I built though.
 

FlyingScotsman

New member
I would throw an XT30 on there if you are not planning on going to 3S. If you are then you might want to go XT60 since that is what most 3S batteries use. I had trouble fitting a 3S 1000mAh battery with XT60 in the Arrows I built though.

Thanksfor your reply , i did decide to try out 3s so changed over to ec3 connectors with a 20a esc and heavier wire. The batteries connectors are ec3 and ive changed the 2s over to this aswell. I put the reciever in left hatch and esc in the right which has left enough room for me to be able to squeeze my 1300 mah batteries in the centre pod. Ive still to fly it on this set up. I will be trying it out in the next hour if the wind stays calm but wont be able to put many 3s batteries through her as i will be re-maidening my sport cub s2 ( first time was in an area much too small so got scared and landed , rough)
 

mikej997

New member
Crashed it!

HAHAHA!!! Be a noob and have your CG too far back! If you get it to stall and dive straight into the ground from 2 mistakes high you should have no problem getting it to rip in half;):black_eyed::p I've torn 2 in half now:D

I get the speed build kits from FT and it takes me about 1hr to 1 1/2hr to build and maiden providing I'm not peeling the paper/adding LED's etc....

I haven't built one from the plans yet but it seems like a lot of the guys that do make templates to help speed up the process. If you wanted a perfect start you could order one of the speed build kits for $15 and use it for templates instead of building it. Pin it down to your foam board and trace maybe? Like I said I have no scratch build experience so not sure if this would work but it seems easier than gluing sheets of paper down.......

Ok, so I guess I need to eat a little crow here. I was teaching my son to fly line-of-sight using trainer cables and we managed to break one in half. Apparently a vertical, full power dive into the ground is what it takes. LOL! I was nowhere close to being fast enough to recover from the snap roll and dive.... Anyway, a little (OK, a lot) hot glue and tape and it was flying again in 30 minutes. It is now fairly "squishy" in the center section allowing the wings to flap a little. It flies OK but has pretty much been retired since I have several others ready to go. We are waiting for good weather to continue training, except this time with a Tiny Trainer - slower and easier.

On another note regarding build times. I've got a system where I can build from blank DTFB and be ready to add electronics in about 90 minutes and fly in 2 hours. It is a way of doing the plans that allow them to be very quick to transfer to the DTFB and be supremely reusable. You don't need to glue them or pin them, you simply trace them. It takes me 10 to 15 minutes to transfer the complete Mini Arrow plan to the foam. They are fast but also very accurate, the builds fit very well. My question is, how much interest do you all think there would be in something like this?
 

Dgreco63

Multirotor Enthusiast
My question is, how much interest do you all think there would be in something like this?

Are you kidding? :)

As a person who is just getting into scratch building I find the bulk of my time is spent cutting out the parts. I'd LOVE to hear of a system that will make this more efficient/faster!!
 

mikej997

New member
That is good to hear! Kind of what I was thinking.

This system primarily speeds the transfer of the plans to the blank foam board. The cutting seems a little faster due to better markings on the foam.

I am putting the finishing touches on this thing for the Mini Arrow, when I'm done I might need a volunteer or two to test it out. It would probably be good to get feedback before I put a bunch of work in something everyone else thinks is dumb or redundant.
 
Thanksfor your reply , i did decide to try out 3s so changed over to ec3 connectors with a 20a esc and heavier wire. The batteries connectors are ec3 and ive changed the 2s over to this aswell. I put the reciever in left hatch and esc in the right which has left enough room for me to be able to squeeze my 1300 mah batteries in the centre pod. Ive still to fly it on this set up. I will be trying it out in the next hour if the wind stays calm but wont be able to put many 3s batteries through her as i will be re-maidening my sport cub s2 ( first time was in an area much too small so got scared and landed , rough)

I built mine with foamboard from hobbycraft (west foamboard) which is said to be 50% heavier than FT stuff. I thought i was gonna have issues balancing mine, Especially since i was using a heavier 30A ESC in the powerpod. But surprisingly CG was very close with an 850mah 3s battery as far forward as possible. First flights i was having to always give up elevator to stop it nosing into the ground, dialed in quite a bit of trim (maybe im nose heavy?>) but it flew great.

It was lathargic though... but it turns out i had the prop on backwords! And i think that says how well this wing flies even with it being 325g including battery.

Im runing the 6x4 prop thinking i needed to change motor and prop size but no just put the thing on the right way!

Im also running the old school jst connections!!! didnt even get warm despite a backwords prop and running full throttle most of the flight. btw i run those batteries on my trex 250 and they are barely warm, however i do agree with using better connectors and thicker wires its just what was on them.

now question.... when i had my first few flights i found that the rols were super slow!!! i was able to fly around well, but it would take so long to roll i would almost crash, i thought wings were supposed to roll fast, i tried increasing servo travel and also going out on both the servo arm and also control horn on the control surface. im sure im now going over 12 degrees of throw.

Would this also be an effect of a backwords prop?
 

mikej997

New member
The first flights I had with my Arrow had an underpowered motor. The plane flew, but slow and the motor got hot. Response to controls was slow and it took a lot of nose up input to keep it level. Since then, I installed a 2205 2300KV motor running 5x4.5x3 bull nose props on a 3S battery. This thing really tears around! The controls are very snappy now and it will climb vertically. It is super fun to fly. I think your problems with slow control response could be from slow flight speeds, mine definitely improved with a little more speed.
 
The first flights I had with my Arrow had an underpowered motor. The plane flew, but slow and the motor got hot. Response to controls was slow and it took a lot of nose up input to keep it level. Since then, I installed a 2205 2300KV motor running 5x4.5x3 bull nose props on a 3S battery. This thing really tears around! The controls are very snappy now and it will climb vertically. It is super fun to fly. I think your problems with slow control response could be from slow flight speeds, mine definitely improved with a little more speed.

Ill hopefully get to test today as it looks like the wind is somewhat calmer! Yes it wasnt very fast but still surprisingly fun to fly. When i swapped the prop i held it vertical and it gave a good push at full throttle, so it looks like it may eve be able to take off vertically
 

Dgreco63

Multirotor Enthusiast
just say the word

That is good to hear! Kind of what I was thinking.

This system primarily speeds the transfer of the plans to the blank foam board. The cutting seems a little faster due to better markings on the foam.

I am putting the finishing touches on this thing for the Mini Arrow, when I'm done I might need a volunteer or two to test it out. It would probably be good to get feedback before I put a bunch of work in something everyone else thinks is dumb or redundant.

Count me in! ;) Just drop me a line and I'll use your system on the next plane I scratch build
 
Im still struggling with mine.

flying weight is 325g. Its better witht he prop on the right way but it still rolls very slowly.

I readjusted the cg to close to the plans, i had marked the wing at 1.7 inches added weight to the nose and got it to say 1.5 inches. It flew like crap and would just want to nose dive into the ground without full trim and some holding the stick. so i ditched the weights and went back to where i was before which was just under an inch infront of the firewall. It flew much better, but rolls were still slow however i was able to yank and bank fine. I am however feel like im using alot of stick with no expo.

What i found with the CG close to the 1.7 was that in slow flight the wing would yaw left right.. and was quite a handfull. with it at 1" it was so much easier to fly.

Now from reading a few pages back theres recomendations for gett it at 1.75 and then trimming it for level flight, then adjusting your linkages for the amount of reflex needed . im guessing i was using maybe 30% up elevator....
 
Solved. i reset the arrow up. Think my reflex gauge was cut wrong because i found the original one which i used a straight edge with, it had slightly more angle on it.

Also decided to balance it as per the plan with 15g in the nose got it almost dead on. And well it launched with ease, no diving or any other funny stuff making you scramble for the controls. just left my hand straight and at a shallow angle climbing.

2 batteries with no dramma. roll rate still isnt great but it will turn on a dime.
 
frustration, broke my getting there setup mini arrow, build a new one saving 50g of weight (removing paper and using coloured packing tape on outside) broke that one on the 2nd flight.

Anyway, has anyone made the mini arrow as a whole wing instead of in 2 piecs. Im pretty sure my foamboard i big enough.

Im having issues with breaking the wing front to back. mine never folds bit instead breaks 1 wing. The first wing broke in line with the servo, straight trhough the wing spare. Almost clean in 2.

The 2nd wing broke just before the electroins pod from an inch infront of the leading edge right through to the back. Again not worth repairing.

it takes me 6 hours to build these.. to have it suddenly go nose down on me and hit the ground, the last crash wasnt even under power and only from about 15 feet onto soft grass.
 

raneous

New member
frustration, broke my getting there setup mini arrow, build a new one saving 50g of weight (removing paper and using coloured packing tape on outside) broke that one on the 2nd flight.

Anyway, has anyone made the mini arrow as a whole wing instead of in 2 piecs. Im pretty sure my foamboard i big enough.

Im having issues with breaking the wing front to back. mine never folds bit instead breaks 1 wing. The first wing broke in line with the servo, straight trhough the wing spare. Almost clean in 2.

The 2nd wing broke just before the electroins pod from an inch infront of the leading edge right through to the back. Again not worth repairing.

it takes me 6 hours to build these.. to have it suddenly go nose down on me and hit the ground, the last crash wasnt even under power and only from about 15 feet onto soft grass.

Unfortunately this is the weak point on the FT mini arrow. There are several users who have used a variety of clever methods to strengthen that area but when it comes down to if it's going to break when you crash it will most likely to be there. At least all of mine;)

I used spars for some of my earlier builds which seemed to help a little. Then I came to the realization that with the way I crash I was only adding weight to the wing and time to my build. I don't mind building new ones. In fact I enjoy it just as much as flying them. But I do understand your frustration. My first few didn't stay in the air very long. I've seen plenty of posts about how strong it is then I realized that most of them were veteran pilots and probably not crashing nearly as hard as a noob like me. I ended up spending around $40 on an EPP wing. They take a beating and gave me enough flights to dial in my wing flying skills so my Arrows last multiple packs before meeting their impending doom. I'll always build Arrows, I love the little bugger. I just do it knowing it probably won't survive my crash but for the $ it doesn't bother me a bit. And the knowledge gained from the build process and maidening is invaluable$$$$

On a side note about your previous post, all of my best flying Arrows have been based off of the recommended CG no matter what the weight needed in the nose to get it there. Every build has varied in the amount of weight needed. On my last build (I purchase the speed build kits from FT) I did what your about to do and stripped all the paper replacing the outside with colored packing tape and it ended up requiring 0g of weight. Final build balanced perfectly on the recommended CG:D
 
Yep ive reinforced mine with filament tape so theres minimal weight gain, strip along the leadnig edge and then at the back of the U section to help stop it tearing in a nose crash.

Although im not flown wings before, and only flown fixed wing tainer many years ago im pretty sure my flying is good enough to keep it in the air doing simple circuits and figure 8's i was flying really well on the original once i got the CG right when suddenly it goes weird pulling a tight turn. Same thing happens twice. Whcih makes me thing something went wrong, supect control surface. after the crash i did notice 1 control horn loose in the elevon but then that could have just been the crash but it is suspect.

My 3rd wing the horns are in solid.

the other issue i had was that it would need aileron corrections in flight, it wasnt trim it would randomly twitch and need a bump to level it back out. I put it down to slop (cheap servos and horns with holes that are too big) ive taken care of teh horn slop so only the servo slop remains.

Hopefully this 3rd wing will fly a bit better.

I need to make templates whichw ill cut the build time down by anout an hour (it takes me an hour to trim the tiles down and tape them together) im also going to be getting foam from hobbyking which will eliminate remvoing the paper o another 20-30 minutes saved,

Need to make another 2 next week as im going on a sort of holiday for a week and wont have anything with me.
 
OK here are my 3 new wings. only 1 has electronics in it, the other 2 are backups. Unless i dont break it then maybe ill put electronics in 1 of the 2 new ones as that is made of the lighter foam.

IMG_20171018_130212.jpg IMG-20171012-WA0004.jpeg

The one that is setup ready for maiden is made from west foambnoard with the paper removed and 1 side done with packing tape. this saved 50g. Although my original was heavy it flew fairly well and flew pretty slow.

The lighter version didnt last long enough to be able to say if lighter made it fly bettter, infact its flight was pretty horrible before it crashed and broke 1 wing in half....

Hopefully ill get a decent patch of weather with little wind to test fly the new one out. Balanced it the other day ponly needed a medium sized coin in the nose. 1000mah battery balances it with the battery moved back slightly. Need to change the ESC out for a lighter one, which will hoefpully make it easier to balance.\

the lighter wings are coming in at 100g before electronics are added.
 
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