Seeking BIPE Setup Advice

[dah1202]

I flew my bipe for the first time yesterday. (3 flights) I flew with the CG at the midpoint of the recommended range and thought the plane behaved like it was tail-heavy.

The plane went together great and requires virtually no trim for straight flight. Guys at the field said "sweet". It looked to spectators like it was flying great, however, as the pilot, I had my hands full. Perhaps I could get an actual CG measurement from a BIPE owner whose plane is behaving well.

[paulg]

Just keep moving it 1/4" at a time, til you get that sweet spot, that is the best way to do it. If you fly a KE and it tuck to the canopy your nose heavy.

[dah1202]

Thank you for the tip paulg! I moved the battery forward to get the CG at 2 9/16" behind the leading edge of the top wing. I may tinker with the space between 2 9/16" and 2 3/4" (the front side of the recommended range), however, I think the plane is just right for now. It's a joy to fly - a very capable airplane! After a flight a couple weeks ago, a fellow pilot insisted that I write down the web address for Airfoilz so he would know where to get a Bipe. (My Airfoilz YAK also gets great remarks from fellow pilots.)

[Ryguy]

The way I set my CG is to find the spot where it's hands off both upright and inverted. If it still feels tailheavy there, then just adjust to whateve feels right for you.

[Jimv]

One thing about the bipe is that with full (45 degree) throw on the control surfaces it is VERY responsive. The best setup is to use dual rates and only use the high rates for the full on 3D moves.

[msprygada]

Thank you for the tip paulg! I moved the battery forward to get the CG at 2 9/16" behind the leading edge of the top wing. I may tinker with the space between 2 9/16" and 2 3/4" (the front side of the recommended range), however, I think the plane is just right for now. It's a joy to fly - a very capable airplane! After a flight a couple weeks ago, a fellow pilot insisted that I write down the web address for Airfoilz so he would know where to get a Bipe. (My Airfoilz YAK also gets great remarks from fellow pilots.)
So where do you balance the bipe for GC? Using the upper wing or the lower wing?

If you were using the upper wing it would be exectly as it is stated in the manual but if you were using the lower wing, then you would need to add the difference between the upper and lower wings which is about 1/2 to 3/4 of an inch if I measured it correctly. The problem is my GC machine cannot get in between the wings to work correctly.

Thanks,

[msprygada]

Well, finally got the bipe together. It came out real nice. I took my time and did a good job. Now I just need to balance it out and wait for calm weather and take her out.

I put strips on the bottom so I can see it better and makes it easier to see which is top and bottom. I did this on my Yak and it made it much easier to know which end was up. This was my first shot at fillets and I thought they came out excellent. Coonak's suggestions made them easy to do. Thanks Coonak!

I will let you know how the maiden turns out.

Thanks for all the assembly tips.

[bighead93]

Well, finally got the bipe together. It came out real nice. I took my time and did a good job. Now I just need to balance it out and wait for calm weather and take her out.

I put strips on the bottom so I can see it better and makes it easier to see which is top and bottom. I did this on my Yak and it made it much easier to know which end was up. This was my first shot at fillets and I thought they came out excellent. Coonak's suggestions made them easy to do. Thanks Coonak!

I will let you know how the maiden turns out.

Thanks for all the assembly tips.

Looks Great!!:D I should have mine in the next few days...what type of material did you use on the strips?

[njfsu2]

if you are flying inverted, and the plane tends to climb up, that means it is too tail heavy? thank you

[Mikey]

if you are flying inverted, and the plane tends to climb up, that means it is too tail heavy? thank you

Yes trim it to were you have to hold a touch of up when upright and a touch of down inverted.

[bighead93]

Where should the ailerons sit at the neutral position?

[msprygada]

Where should the ailerons sit at the neutral position?I was told, and it make sense, that if you looked at the end of the wing and you cut that profile in half horizontally, that the aileron should follow this line. This is because the wings of the Airfoilz line are asymmetrical so that it produces the same lift whether or not the wing is right side up or up side down. So if you cut the wing and the aileron down the middle, each side would be exactly the same. Where if you did this with non aerobatic planes, you would have two different profiles. They are designed to create their max lift when upright as they are not expected to fly inverted.

If you don't have them neutral, it will be hard to get the plane to fly level right side up and inverted at the same time without a lot of stick input in one of the attitudes and not the other.

My Superfly has a non-asymmetrical wing and the ailerons move the same up and down and I can do a inside loop very easily but it is very hard to do a outside loop as there is not as much lift being generated. So if I wanted it to loop the same both ways, I would need to make the ailerons move more down than up to equal it out.

[bighead93]

I was told, and it make sense, that if you looked at the end of the wing and you cut that profile in half horizontally, that the aileron should follow this line. This is because the wings of the Airfoilz line are asymmetrical so that it produces the same lift whether or not the wing is right side up or up side down. So if you cut the wing and the aileron down the middle, each side would be exactly the same. Where if you did this with non aerobatic planes, you would have two different profiles. They are designed to create their max lift when upright as they are not expected to fly inverted.

If you don't have them neutral, it will be hard to get the plane to fly level right side up and inverted at the same time without a lot of stick input in one of the attitudes and not the other.

My Superfly has a non-asymmetrical wing and the ailerons move the same up and down and I can do a inside loop very easily but it is very hard to do a outside loop as there is not as much lift being generated. So if I wanted it to loop the same both ways, I would need to make the ailerons move more down than up to equal it out.

I understand...I think...so the natural curve of the airfoil should contiune all the way down to the end of the aileron? I will get some pics when I get home...I am trying to figure out what was causing the plane to feel so tail heavy...even with the battery moved up almost 3/4" it still felt heavy. I will power it up and take pics of the wings and elevator...still flew great...and the knife edge is crazy!! I need to get a few more flights and see how it does...I balanced everything at the 3" mark...CG is perfect all around at the 3" mark. Could you post some pics of your ailerons in the neutral position?

Also...how has your landing gear block held up?

[msprygada]

I understand...I think...so the natural curve of the airfoil should contiune all the way down to the end of the aileron? I will get some pics when I get home...I am trying to figure out what was causing the plane to feel so tail heavy...even with the battery moved up almost 3/4" it still felt heavy. I will power it up and take pics of the wings and elevator...still flew great...and the knife edge is crazy!! I need to get a few more flights and see how it does...I balanced everything at the 3" mark...CG is perfect all around at the 3" mark. Could you post some pics of your ailerons in the neutral position?

Also...how has your landing gear block held up?Well, if I read your comment correctly, the aileron will not follow the curve. I have attached some pictures of my aileron aligning jig. I just cut this out of paperboard (cereal box from recycle bin actually). I cut it to match the wing and the cut it out so that it only touches the wing at the LE and TE. I leave some extended down so that it hooks on the front of the wing so it is easy to put it in the exact position fore and aft every time. Then measure the distance at the back of the jig to the aileron. Do this on the top of the wing and then move it to the bottom and the gap should be the same with the jig at the bottom. If not then use the adjustment in your control arms to make that gap the same on both sides. Now your aileron will be centered. I find it hard to do any other way. You do not want to use your sub trim in the radio to make this adjustment as you want your servo arms perpendicular to your control rods (or parallel to the trailing edge) so when it pushes or pulls on the aileron it moves it the same distance.

I have attached a picture of my ailerons in their neutral position. Your mileage may vary. But if you look at the picture of my ailerons with my jig on, that gap is the same top and bottom. My rudder and elevator are exactly in line with the adjoining surfaces so I am pretty happy with the plane and how I built it.

I checked my CG and it is at 2.75". I have attached a picture of the Bipe on the GC jig. Notice where my battery is? I initially had problems with my maiden flight being way tail heavy (flew like I was hovering) as I had the battery where most others had it which in this picture, the back of my current battery position was the front of their battery position. I must have put too much weight in the back of the plane. The only thing that I can think I did to add weight to the back of the plane was I did fillet joints on the horizontal stab and I filled in the open spot on the top of the fuse in front of the rudder with epoxy with micro balloons but that should not have added much weight? What is the weight of your Bipe minus battery? Mine is 21.75 oz. But the location of battery is irrelevant as it flies right side up and inverted without any elevator needed.

How does your plane fly inverted? Does it fly right side up and inverted with very little or no stick input? That is more important than where your CG actually is. The suggested CG is just to get you close and the way if flies is how you determine its exact position. If not move battery accordingly (assuming you have the ailerons set correctly). If you invert and it dives to the ground, then move the battery back. If it gains altitude when you invert, then move it forward. According to you saying it is flying tail heavy you should find that the battery needs to go forward and it climbs on inverted.

My landing gear block is doing fine, but the landing gear gets bent on almost every landing. It should either be made of heavier wire or made of spring steel. It is the same gear as the Yak but the Bipe is much heavier so it should be designed accordingly.

I got a few more flights on her tonight and I am liking it more and more. Or maybe I am getting better with each flight and that is why I am enjoying it more. I put a wing tip down hard on the tarmac tonight and part of my zip tie come loose but no damage to the strut so that idea has been well worth it. Came home and just reglued it on. Good as new.

[msprygada]

Looks Great!!:D I should have mine in the next few days...what type of material did you use on the strips?Big, I know I answered this post of yours and now it is gone. This is the second post that I have had disappear from this forum. :confused:

Anyway, I just used vinyl graphic material that is just like the decals that comes with the plane. I have a friend in the sign business and just bought some red material from him and cut it into 1.5" strips.

[bighead93]

Well, if I read your comment correctly, the aileron will not follow the curve. I have attached some pictures of my aileron aligning jig. I just cut this out of paperboard (cereal box from recycle bin actually). I cut it to match the wing and the cut it out so that it only touches the wing at the LE and TE. I leave some extended down so that it hooks on the front of the wing so it is easy to put it in the exact position fore and aft every time. Then measure the distance at the back of the jig to the aileron. Do this on the top of the wing and then move it to the bottom and the gap should be the same with the jig at the bottom. If not then use the adjustment in your control arms to make that gap the same on both sides. Now your aileron will be centered. I find it hard to do any other way. You do not want to use your sub trim in the radio to make this adjustment as you want your servo arms perpendicular to your control rods (or parallel to the trailing edge) so when it pushes or pulls on the aileron it moves it the same distance.

I have attached a picture of my ailerons in their neutral position. Your mileage may vary. But if you look at the picture of my ailerons with my jig on, that gap is the same top and bottom. My rudder and elevator are exactly in line with the adjoining surfaces so I am pretty happy with the plane and how I built it.

I checked my CG and it is at 2.75". I have attached a picture of the Bipe on the GC jig. Notice where my battery is? I initially had problems with my maiden flight being way tail heavy (flew like I was hovering) as I had the battery where most others had it which in this picture, the back of my current battery position was the front of their battery position. I must have put too much weight in the back of the plane. The only thing that I can think I did to add weight to the back of the plane was I did fillet joints on the horizontal stab and I filled in the open spot on the top of the fuse in front of the rudder with epoxy with micro balloons but that should not have added much weight? What is the weight of your Bipe minus battery? Mine is 21.75 oz. But the location of battery is irrelevant as it flies right side up and inverted without any elevator needed.

How does your plane fly inverted? Does it fly right side up and inverted with very little or no stick input? That is more important than where your CG actually is. The suggested CG is just to get you close and the way if flies is how you determine its exact position. If not move battery accordingly (assuming you have the ailerons set correctly). If you invert and it dives to the ground, then move the battery back. If it gains altitude when you invert, then move it forward. According to you saying it is flying tail heavy you should find that the battery needs to go forward and it climbs on inverted.

My landing gear block is doing fine, but the landing gear gets bent on almost every landing. It should either be made of heavier wire or made of spring steel. It is the same gear as the Yak but the Bipe is much heavier so it should be designed accordingly.

I got a few more flights on her tonight and I am liking it more and more. Or maybe I am getting better with each flight and that is why I am enjoying it more. I put a wing tip down hard on the tarmac tonight and part of my zip tie come loose but no damage to the strut so that idea has been well worth it. Came home and just reglued it on. Good as new.

Good to hear...I really couldn't find what the neutral position should look like! I just posted the pics on the build thread...and I will give that a try tomorrow...flew 2 packs today...before I changed the ailerons...and although it was flying tail heavy...it still flies great! I have really only been doing slow flying...just getting the hang of it...I love the harrier landings...I can't do those with the Edge;) Knife edge is crazy...I did 2 laps around the park...without more than light adjustments with the rudder...hammerheads are insane...I could see how this baby will pull off a knife loop at will! My landing gear block has a small crack...even though I wrapped it tight with spiderwire...and my landings are very easy and light...I put a small amount of epoxy on the crack...and it didn't crack on both flights today. The landing gear does bend...but it is easy enough to bend back. Can't wait to try it with the aileron adjustments. Thanks again for all the help and tips! I need to get some of the strips...I might do mine in blue...:confused:

[bighead93]

Flying weight is between 24.5-26.8 oz. (Depending on what battery) Dry weight is 20.6 oz. I used microballons on just about everything!

[msprygada]

Good to hear...I really couldn't find what the neutral position should look like! I just posted the pics on the build thread...and I will give that a try tomorrow...flew 2 packs today...before I changed the ailerons...and although it was flying tail heavy...it still flies great! I have really only been doing slow flying...just getting the hang of it...I love the harrier landings...I can't do those with the Edge;) Knife edge is crazy...I did 2 laps around the park...without more than light adjustments with the rudder...hammerheads are insane...I could see how this baby will pull off a knife loop at will! My landing gear block has a small crack...even though I wrapped it tight with spiderwire...and my landings are very easy and light...I put a small amount of epoxy on the crack...and it didn't crack on both flights today. The landing gear does bend...but it is easy enough to bend back. Can't wait to try it with the aileron adjustments. Thanks again for all the help and tips! I need to get some of the strips...I might do mine in blue...:confused:Yes the Bipe does slow down real good for landings but I think when you get the plane set up correctly, the harrier landings will go away unless you intentionally do them. Yes you can bend the landing gear wire back but every time you do that, you weaken the metal to some degree. If it were made out of say spring steel, it would flex end spring back. But maybe that might spring the plane up into the air.....:eek:

I have only heard of a few people that had cracked landing gear blocks. Do you have the thin piece of wood facing forward or backward. I have it facing forward. Not sure if it makes any difference. I did it that way figuring that the gear would be pushing back more than forward and it would be pushing on the thick part. If this was made out of plastic or nylon that would be virtually unbreakable, that would be the ideal material. The problem is that if it breaks, you have to hack it out of the fuse. I am sure that is not a clean process.

Hope the tips help. That is what makes these forums great. I learned almost all I know from them. Just passing along the good word.:)

[bighead93]

Yes the Bipe does slow down real good for landings but I think when you get the plane set up correctly, the harrier landings will go away unless you intentionally do them. Yes you can bend the landing gear wire back but every time you do that, you weaken the metal to some degree. If it were made out of say spring steel, it would flex end spring back. But maybe that might spring the plane up into the air.....:eek:

I have only heard of a few people that had cracked landing gear blocks. Do you have the thin piece of wood facing forward or backward. I have it facing forward. Not sure if it makes any difference. I did it that way figuring that the gear would be pushing back more than forward and it would be pushing on the thick part. If this was made out of plastic or nylon that would be virtually unbreakable, that would be the ideal material. The problem is that if it breaks, you have to hack it out of the fuse. I am sure that is not a clean process.

Hope the tips help. That is what makes these forums great. I learned almost all I know from them. Just passing along the good word.:)

I have the thin part facing the rear...I pulled the landing gear block out of my Edge...but that was because I broke the block and fuse:o This time...on the Bipe it is just a crack! I can't wait to fly today! It is always tricky flying a plane that is tail heavy;)

[msprygada]

I can't wait to fly today! It is always tricky flying a plane that is tail heavy;) You should have seen my first flight. I was flying at a 45 degree angle. I was freaking right out inside. :eek: I am thinking "I am going to total this new plane on my very first flight". I managed to get it down without damaging anything. If I would have been green, I would have put her in for sure. Then for some reason, I think I moved the battery as far forward as I could (but not nearly as much as I needed) I put it right back up where I should have taken it home and found out what the problem was (GC was wayyyyy off) and then try the maiden again. It was flying around again at nearly a 45 degree angle. Needless to say when I went home that day I was not very happy with how it flew. But then I got the correct CG and went out on my second flight, and it flow perfectly. I even inverted it and it flew level and I have not changed the battery location since. Now I just love the way it flies. I am getting braver and lower as the flights progress.:D

[bighead93]

You should have seen my first flight. I was flying at a 45 degree angle. I was freaking right out inside. :eek: I am thinking "I am going to total this new plane on my very first flight". I managed to get it down without damaging anything. If I would have been green, I would have put her in for sure. Then for some reason, I think I moved the battery as far forward as I could (but not nearly as much as I needed) I put it right back up where I should have taken it home and found out what the problem was (GC was wayyyyy off) and then try the maiden again. It was flying around again at nearly a 45 degree angle. Needless to say when I went home that day I was not very happy with how it flew. But then I got the correct CG and went out on my second flight, and it flow perfectly. I even inverted it and it flew level and I have not changed the battery location since. Now I just love the way it flies. I am getting braver and lower as the flights progress.:D

I know what you mean!! I was freaking out too:eek: I really can't believe how far your battery placement is...I guess I will know later today. Like I said I have the CG at the 3" mark and she sits perfect. With the adjustments that I made last night I hope it isn't still tail heavy! I will let you know how she does!

[msprygada]

I know what you mean!! I was freaking out too:eek: I really can't believe how far your battery placement is...I guess I will know later today. Like I said I have the CG at the 3" mark and she sits perfect. With the adjustments that I made last night I hope it isn't still tail heavy! I will let you know how she does!Just be careful. Once you have it dialed in, it will be great. But the unknown flights are where scary things happen.

Good luck.