Helicopter Flight Times

[Bob Miller]

I think it is because of how many winds you are using. We have reached 2:10 solidly with 1 bonus and we are still trying to optimize. We have been using around 130 winds with a rubber that is 1.2 to 1.3 times the size of my motor stick without constant breaking. We have also been using FF motor sticks, though I think they are flimsy XD. Try to up your winds and the size of your rubber with rubber that is slightly less thick.
On another not, what rotors are you using? Carbon fiber FF, balsa FF, or your own design?

[dhdarren]

I've only been in competing in Helicopters for about three weeks so far, and my partner and I have been struggling a bit with figuring out how to optimize our helicopter. We built a simple helicopter by basing the rotors off of the paper template from the Ward's SciOly practice kit. For our motor stick, we cut our own out of a sheet of 1/16" balsa to resemble the FFM laser cut model, however we shortened it to about 13". We did notice that this may have been slightly more dense than the laser cut motor stick.

Our rubber motors are currently approximately 2/3 the length of the motor stick (relaxed, after being knotted), and we have been going at about 40 winds with a 15:1 winder. Unfortunately, we have been unable to break past a time of 32 seconds. One of the main problems we think may contribute to this is mass, as our helicopter weighs approximately 3.3 g. However, we are not sure about what more we can do to lower that mass, and if that is ultimately our major problem.

Does anyone have any suggestions on how to increase flight times? How does the size of the motor stick influence flight time? And what about the length/width of the rubber motor? Any help or advice would be greatly appreciated!

I think first step is to change up your motors. They should be much longer than you have them now; from my experience, just a bit longer than the length of the motor stick (maybe 2" ish longer) works best. You'll be able to put an a lot more winds this way; how many total depends on the thickness of your rubber. Speaking of the number of winds, you should be able to aim for a heck lot more winds. Lubrication + good winding technique + a properly chosen rubber width/length will get you very far (you can probably get 3x the number of winds you're getting now. Your helicopter is a little on the heavy side, but if you are doing the motors part right, I think you'll be able to get to a semi-decent time.

[kaziscioly]

I think it is because of how many winds you are using. We have reached 2:10 solidly with 1 bonus and we are still trying to optimize. We have been using around 130 winds with a rubber that is 1.2 to 1.3 times the size of my motor stick without constant breaking. We have also been using FF motor sticks, though I think they are flimsy XD. Try to up your winds and the size of your rubber with rubber that is slightly less thick.
On another not, what rotors are you using? Carbon fiber FF, balsa FF, or your own design?

We used our own balsa rotors (2 blades on top and bottom), with the bottom being able to rotate freely (not fixed). We were being conservative with our winds because one of our teammates actually used too many winds on a motor and caused their entire motor stick to bend back and snap. However, our balsa is a little sturdier than the FFM one which is lighter, and we reinforced it with Kevlar too. We thought that a shorter motor might help because more tension would give more power, but the only thing it has done is cause the helicopter to accelerate faster. I will try a longer rubber band on more winds!

I think first step is to change up your motors. They should be much longer than you have them now; from my experience, just a bit longer than the length of the motor stick (maybe 2" ish longer) works best. You'll be able to put an a lot more winds this way; how many total depends on the thickness of your rubber. Speaking of the number of winds, you should be able to aim for a heck lot more winds. Lubrication + good winding technique + a properly chosen rubber width/length will get you very far (you can probably get 3x the number of winds you're getting now. Your helicopter is a little on the heavy side, but if you are doing the motors part right, I think you'll be able to get to a semi-decent time.

Does vaseline do any good as a lubricant? Or am I better off getting ArmourAll
Also, we have been winding our rubber band off of the helicopter in order to avoid damage to the motor stick in the case of an accident. Instead we have a wooden block with a hook on it which we wind our motor up on, and then we remove that and place it on to the helicopter. Is this ok or are there better winding techniques?

[dhdarren]

I think first step is to change up your motors. They should be much longer than you have them now; from my experience, just a bit longer than the length of the motor stick (maybe 2" ish longer) works best. You'll be able to put an a lot more winds this way; how many total depends on the thickness of your rubber. Speaking of the number of winds, you should be able to aim for a heck lot more winds. Lubrication + good winding technique + a properly chosen rubber width/length will get you very far (you can probably get 3x the number of winds you're getting now. Your helicopter is a little on the heavy side, but if you are doing the motors part right, I think you'll be able to get to a semi-decent time.

Does vaseline do any good as a lubricant? Or am I better off getting ArmourAll
Also, we have been winding our rubber band off of the helicopter in order to avoid damage to the motor stick in the case of an accident. Instead we have a wooden block with a hook on it which we wind our motor up on, and then we remove that and place it on to the helicopter. Is this ok or are there better winding techniques?

Don't know if vaseline would work as a lubricant, but if it does, I'd imagine that it's heavier and is terribly messy. It'll probably get all over your hands and the helicopter and just make it pretty annoying to fly. Armor all is most commonly used, and probably for good reason. If you don't have a bottle, they're not too hard to find in random stores. For winding, I think you're doing it right. We do the same technique for the same reasons, and it probably works better than just winding it on the helicopter.

[Bob Miller]

We used our own balsa rotors (2 blades on top and bottom), with the bottom being able to rotate freely (not fixed). We were being conservative with our winds because one of our teammates actually used too many winds on a motor and caused their entire motor stick to bend back and snap. However, our balsa is a little sturdier than the FFM one which is lighter, and we reinforced it with Kevlar too. We thought that a shorter motor might help because more tension would give more power, but the only thing it has done is cause the helicopter to accelerate faster. I will try a longer rubber band on more winds!

How much does your heli mass? Also, what is the gauge of the rubber you are using, try using thin rubber if it keeps breaking. I haven't had trouble with the FF motor sticks at 110 winds with 0.95 gauge rubber(comes with the kit). Try using better glue for the motor stick (I use CA glue)? Always incorporate the Kevlar string with the kit, and try making it very tight, that way, the motor stick wont collapse in the direction of the rubber band.

Does vaseline do any good as a lubricant? Or am I better off getting ArmourAll
Also, we have been winding our rubber band off of the helicopter in order to avoid damage to the motor stick in the case of an accident. Instead we have a wooden block with a hook on it which we wind our motor up on, and then we remove that and place it on to the helicopter. Is this ok or are there better winding techniques?

No Vaseline wont work XD. Too sticky. Try WD-40, after 2 runs it gets sticky though, so always re-lube after 2 runs.

[dhdarren]

Oh yeah, to keep it on topic, at our Regionals this past Saturday, I got a time of 2:19 for first place! It was at a ceiling about 20 feet high, and I built basically straight from this year's FFM kit.

[jander14indoor]

Avoid petroleum based lubricants (vaseline and WD40 are both petroleum based), they will degrade the rubber over time.
Use silicone based lubricants, Armorall and Son of a Gun vinyl protectants work well.

Jeff Anderson
Livonia, MI

[Krypton]

Oh yeah, to keep it on topic, at our Regionals this past Saturday, I got a time of 2:19 for first place! It was at a ceiling about 20 feet high, and I built basically straight from this year's FFM kit.

Good job! What was the configuration of your FFM copter? We've been getting around 1:45 w/ 2top 2bottom

[dhdarren]

Oh yeah, to keep it on topic, at our Regionals this past Saturday, I got a time of 2:19 for first place! It was at a ceiling about 20 feet high, and I built basically straight from this year's FFM kit.

Good job! What was the configuration of your FFM copter? We've been getting around 1:45 w/ 2top 2bottom

Through experimentation and discussion with some other teams, I've found that 4 top and 2 bottom works best for us! With this config, we reach 2.51g with just a tiny little bit of clay, and we've found that it flies relatively stable as well. Best of luck to you!

[ckssv07]

Is there anyone who's breaking into the 2:20ish area with a device sizably over the minimum weight? Also for those of you at 2.5g, what are your component weights. I can hit 2 minutes with a 3.5g helicopter and from what I've seen here cutting down the weight to 2.5 would help a ton but I'm weighing using thinner rubber to accommodate a lighter motor stick which is currently 1.6g. Thanks.