Kitbasher twinrotor winged autogyro adventures

[iter]

As I mentioned (342046), I recently acquired some Penni blades from Ackus (http://www.ackus.com/) of Sweden. Penni is a rubber-powered, FF helicopter designed by John Burkam that Ackus manufacture as a kit; Peck Polymers are US distributors. The blades are machined from balsa, are 20mm wide and have a Clark-Y-type, 11% airfoil.

I am experimenting with different setups with these blades and yesterday had my first success. I used a stock GWS Pico Stick fuselage, complete with IPS-A and standard rudder/elevator controls. On it I mounted a short wing made from a $5 foam glider http://www.lifelikeproducts.com/lifoam/gliders.htm cut down to just over 2' span. I tested several rotor head designs, including three and four-bladed ones in the photo. Don't laugh :=) I actually flew it with two dissimilar rotors to see which one performed better. It seems that the 4-bladed one works better and I now have two of those on it. More photos coming.

The wing has enough area to lift it without rotors, but just about. Stall speed is very close to maximum speed, and is pretty high for a pico stick :=) (the cambered wing produces less drag). With the rotors, it flies very slowly, and at very high angles of attack, at which point the wing is completely stalled. It can also descend almost vertically and hovers in light breeze. However, I am now building a new, smaller wing to prove to myself that the rotors work :=) It will be more of a brace than a wing, 2" chord.

Comments and suggestions welcome.

Ari.

[mnowell129]

Congratulations!. Looks like great fun.

[iter]

Removed lifting wing and replaced it with aerodynamically-insignificant brace. Maidened it this morning, need to get someone to take flying pictures

The "wing" is a piece of 1/4" x 2" aileron stock. Pylons made from the same material.

Ari.

[iter]

AUW is 160g/5.6oz with TunderPower 730 mAh 2-cell LiPoli.

[iter]

Here are some videos my coworker shot tonight. We'll get better quality over the weekend.
http://www.lib.aero/~ari/autogyros/

I need to work on my landings :=) Sloppy as it was, no damage occurred.

Ari.

[iter]

I've been flying the basher every day now, and here some lessons I learned so far.

1. Rudders and elevators are not effective with no forward speed. This one should have been obvious, and has been mentioned so many times, but I had to learn the hard way.

2. Twin-rotor autogyros are extremely sensitive to differences in mast tilts because the rotors will spin at different RPM and consequently develop different amounts of lift. One mast leaning back as much as 1.5 degree more than the other will make it completely unflyable. As much as .5 degree difference will make for a noticeable differential in lift.

3. No crosswind takeoffs. On takeoff run, the model will attempt to weathervane itself into the wind... Let it. Any significant crosswind component and it will flip over.


1 and 2 above lead me think that if you could control mast tilt directly, it would be much more controllable. Have two servos each tilting one rotor back and forth and have them set up as elevons on the transmitter. One difficulty I see there, except for the added weight of servos and linkages is that normal servos rotate through about 60 degrees, while I only need about 6. I could limit ATV, but then, if my understanding is correct, I'll get very poor resolution. I could use very short control horns and very long servo arms, but that would introduce non-linearities in the linkage.

What I really need is a servo with an extra gear in it to further reduce its travel, raise the torque and improve resolution. Anyone heard of a servo like that?

Ari.

[mnowell129]

Stuff to gear down servos:

http://www.lynxmotion.com/Product.aspx?productID=332&CategoryID=75
http://www.e-clec-tech.com/standard51.html
http://www.robotzone.com/customer/product.php?productid=185&cat=51&page=1

http://www.robotzone.com/customer/home_options.php?cat=184
combined with
http://www.robotzone.com/customer/home_options.php?cat=171

or
http://www.robotzone.com/customer/home_options.php?cat=157
combined with
http://www.robotzone.com/customer/product.php?productid=655&cat=53&page=1

[iter]

Wow! Thanks, Mickey. All I need to do is ask, eh? :=)

Do you know if anyone has had success with this kind of differential tilting?


Ari.

[mnowell129]

Wow! Thanks, Mickey. All I need to do is ask, eh? :=)

Do you know if anyone has had success with this kind of differential tilting?


Ari.
That, I don't know.

[dougmontgomery]

I don't know if this will help but I once built a airplane where I could adjust the aoa with a servo attached to the fuse that with the gear dial, I could adjust it being hinged off of the leading edge.

If you used carbon fiber hollow tube as your mast supports, you could pivot each individual support on a commmon shaft through the fuse, with one servo like ailerons, or the duals for elevons.

Above you stated making your control horns short and servo arms long, that will give you too much throw.

You will need to make your control horns long and your servo arms short, and throw say 30% dual rate until you achieve your goal.

Nice ingenuity, keep up the good Work Iter.
Doug

[iter]

I once built a airplane where I could adjust the aoa with a servo attached to the fuse that with the gear dial, I could adjust it being hinged off of the leading edge.How did it work for you?

Above you stated making your control horns short and servo arms long, that will give you too much throw.Doug, you're right of course, I meant it the other way around. But I will still get non-linear behavior where it's much more sensitive near the center than at the extremes (or did I get it revesed again? :=))

and throw say 30% dual rate until you achieve your goal.Dual rates have the same problem as ATV - you lose resolution. So in effect you leave yourself only a few discrete positions for each channel.

But I've had another idea. I could leave the masts fixed, but what if I added collective? I could use tail rotor hubs from a helicopter, each with its own servo again, mixed as elevons or maybe flaperons. Hm... That way I could even fly inverted... And adding pre-spin would be a breeze... Need to stop right there...

I can't think of a model helicopter that uses more than two blades on the tail though. Do you guys think that would be a problem?

Ari.

[David A Ramsey]

Hey Ari; You could do it, just need to do some machine work. What tickles me is you've got your gyro flying on an IPS A drive on 2 cells. Perhaps when the weather gets better I'll get a chance to see if my 5.5 oz. gyro will do the same.

David

[dougmontgomery]

Ari,
On My 9 oz airplane, the in flight adjustable wing worked great in testing out Aoa but once it is dialed in per -plane it is really is not necessary to change during flight. It was easier to figure out with some push pins.

In your ideas, it can save a lot of tear aparts, due to small changes you need to gain your best efficiency. You cant just move the battery because of your horizontal surface now changes either positive or negative.

Full flying elevator could alleviate this problem if you could adjust the cg in flight by a battery anchored on a slider, or screw assembly.

Just some ideas, keep us posted. Doug

[iter]

Hey Ari; You could do it, just need to do some machine work.Man, I can't even find a drill press to use, you're talking to me about machine work :=( But I think I could do it with no machinning if I used helicopter tail rotor assemblies, all that is standing between me and that experiment is $160 worth of Shogun parts. I even know which parts I'd need - anyone with too much cash on their hands, PM me and I'll send you the list of part numbers :=)

What tickles me is you've got your gyro flying on an IPS A drive on 2 cells. Perhaps when the weather gets better I'll get a chance to see if my 5.5 oz. gyro will do the same.
Like the man says, build it light :=) I've got 4.22 sq.ft. of rotors there for a 1.33 oz/fq.ft disk loading. You can see why it doesn't handle wind well. I should note though that it does take almost WOT to fly. I need to experiment with other props. So far I've been flying with 9x7. 10x4.7 would probably work better, but the pico stick landing gear is too short to allow safe ROG. What motor do you have in yours? Is it gas or electric? Have we seen pictures of it?

Full flying elevator could alleviate this problem if you could adjust the cg in flight by a battery anchored on a slider, or screw assembly.I think my problem is slightly different from what you were trying to solve. I'm not trying to find optimal CG location or AoA, I've got those pretty much figured out for this model. What I want to do is change the relative angles between the masts so I could modulate the amount of lift each rotor generates /in flight/. Differentail collective would do the same thing.


I broke a blade on takeoff today (http://www.lib.aero/~ari/autogyros/hos/rsa.avi). It looks bad, but the damage was limited to one broken blade. Being light has its advantages :=) It was quite embarrassing though because I went to a field I hadn't been to in a year, and people I hadn't seen in as long all gathered to look at it... First flight, I flew it into the sun (http://www.lib.aero/~ari/autogyros/rancho_san_antonio.avi) and struggled to bring it back. Second flight, broke a blade. I had dual rates set for a hot 4-channel airplane and forgot to turn them off... Was pretty embarrasing.

[JWarren]

Great stuff Ari! Congrats on how far you have gotten! Great thread! Thanks for sharing!

John

[iter]

Thank you John.

Everything I read on autogyros (especially by Jim Baxter :)) made it look like designing them was ridiculously complex. But Mickey says he only flew one 'gyro before he designed his masterpiece, and I've never even seen a flying model 'gyro in person until I designed this one (not counting my abortive 20 gram attempt). Mine is much simpler than Mickey's, of course, but considering that my knowledge of aerodynamics is limited to what I remember from my fixed-wing private pilot training, I can state with authority that (at least twin-rotor) autogyros are things mortals can design and build.

But - I would never have attempted this design if it weren't for the information and support in this forum. Thank you all who post here, and thank you for encouragement!

Ari.

[JWarren]

I've never seen one live either and still havent, other than the one I built. I went stickly from what information I was able to gather from Baxters site and used a basic design from plans that I got from RCM on the Gyro Shtick. I totally redesigned it for electric and almost have all the bugs worked out. It's been a challange to say the least, especially with the 62" rotor span and almost 5 lb weight!

The build thread is here in this forum. Just search for "The Heat".

I'm really thrilled everytime someone gets one flying!

Talk to ya later!

John

[iter]

Ackus, the Swedish company that manufactures the blades I used in my basher, got so encouraged with my success that they are thinking of making it as a kit. Do you guys think there could be a market for it? they are thinking about $35 street price. This is a conversion kit for Pico Stick / Pico Cub. No modifications needed to the GWS kit. You can go back and forth between airplane and autogyro configuration in about two minutes. The rotor brace is held in place with rubber bands and CG stays the same for both configurations.

Ari.

[JWarren]

I think there is a big market for Gyro kits, as long as the kit itself is not too difficult for people to assymble and get airborne! Not everyone is a hardcore builder or have the patience to put up with too much grief to get something to fly. So, whatever you and your co horts come up with, it must be well thought out and tested or I don't think you will get very far. I wish you luck with your project if you decide to go forth with it!

$35.00 certainly sounds resonable to me! I'll give it a shot at that price!

John

[iter]

I think there is a big market for Gyro kits, as long as the kit itself is not too difficult for people to assymble and get airborne! Not everyone is a hardcore builder or have the patience to put up with too much grief to get something to fly.I'll pass your comments to Ackus. If they decide to kit it, pretty much the only things you'd need to do would be glue blades to hubs and glue wing halves together. Think builders will handle that? Keep in mind that it's a conversion for a GWS plane, so the fuselage, control surfaces, etc., are as simple as they come.

$35.00 certainly sounds resonable to me! I'll give it a shot at that price!Careful, they could hold you to your word in about a month :=)

"GWS kit sold separately"

Ari.

[imsofaman]

Hey guys...I have just skimmed thru here and have not read everything yet....but I understand that the rudder does not have a lot of effect? I had a thought on this problem and twin rotors in general. If you slow one of the rotors down....like the left one if you are making a left turn and apply left rudder at the same time...this should do the trick....just like aileron control. I know it sound easy as 1,2,3 :rolleyes: ....but I belive it would not be too difficult to do ;) .

A servo in the middle of the fuselge plugged into the aileron spot on the reciever. Two control rods...one per rotor on a control horn. When the control horn rotates on the servo....they move oposite. The shaft on the left and right rotors....glue a cork on the shaft towards the bottom. I am invisioning the whole shaft is spinning...not just the head. A control arm at each shaft hooked up to the control rods via the aileron servo.....will move the pivot control arms pulling the arm onto the cork and slowing down the shaft. So one control arm is pulling against the cork on one of the rotors....and moving away from the cork on the opposite side. Does this make sense? If not...I will illustrate it later.

[iter]

So essentially, you're talking about putting brakes on rotors? It could work, if you can come up with fine control over rotor speed. Even a small drop in rotor RPM will cause a significant loss of lift, so you need to slow them down just a tad. Whatever you do, make sure you don't stop one of the rotors; respinning it in flight could be difficult. The difference between this and ailerons is that you are subtracting lift on one side, but not adding lift on the other. Some airplanes (B-52 comes to mind) have spoilers instead of ailerons, so it could work.

Now as far as rudder effectiveness, I've been very happy with a conventional rudder. The basher has plenty of rudder authority as long as it has some forward airspeed. Differential breaking could make it more maneuverable in vertical descent.

Let us know if you build it!

Ari.

[imsofaman]

That is correct! I had been thinking about this for a while...even before I had read this post. I thought it would be awesome for tight turns!!!! :eek:

[iter]

I have commitment from a mail-order supplier who will carry kits when they are ready. What needs figuring is the price point at which it would be worthwhile. I need your guys' input here.

There are two versions that could be produced. Both will have blades with the airfoil machined in, so the difficult part is taken care of in both cases. The rest of the kit could come as completely assembled as its shipping box will allow, which will decrease building time and effort but will drive the price up. Alternatively, it could come with all materials needed to finish it included, but the builder will have to do all of the glueing and some of the cutting - this will naturally be cheaper. If you were going to buy a kit like this, which would you prefer?

Ari.

[imsofaman]

For me....gluing and cutting would be the answer to keep the cost down. I am a builder and I get more satisfaction from a plane by building it myself. I have only two ARFs in my little hanger.

I want a kit!!!!! :p

[iter]

I hear you. I'll post in this forum when I'll have a schedule for kit release.

Ari.

[iter]

What tickles me is you've got your gyro flying on an IPS A drive on 2 cells.
I'm not the first one by far. This guy flies a direct-control-head autogyro on an IPS-A and two cells, although he says he swithced to dual IPS eventually.
http://www.aerocompositedesign.com/Products/RC_Electric_Airplane/Cap_232/indoor_gyro.html
http://www.autogyro.com/models/boren/boren.gyro.htm
His is a bit heavier than mine though - 9oz. Looks like it might have stated from a P-stick as well. I like the way he put downthrust on the stick fuselage... I might do the same.

Ari.

[iter]

Following flight testing and many repairs of the basher, and the arrival from Sweden of a large shipment of blades, I've built and flown a second version of the basher.

Changes include heavier (stronger) blades, quad ball bearings (two in each rotor head), enlarged control surfaces, geared speed 300 motor and a Slow Stick fuselage. AUW ballooned to 280g / 9.8oz for 2.32 oz/sq.ft. Hopefully, the higher disk loading will make it less sensitive to wind.

The city decided to turn on the lights in my local park/baseball field, so now I can fly at night. The flying is limited to the lit area which isn't huge, so I'll be here tomorrow during the day with a more detailed flight report and photos.

Ari.

[iter]

Here are some photos of the new configuration. It needs more tilt-back and more aft CG, but in general, I am very happy with its flying characteristics. Except for a different donor fuse and powerplant, all other equipment is identical to the original basher.

Current 5 degrees' tilt-back, coupled with too-forward CG and 0-degree downthrust (an artifact of the Slow Stick fuselage) are sufficient for stable powered flight, but insufficient to flare on a deadstick landing. I /have/ landed it safely with no power on a hard surface, but would probably have ended with a broken prop if it weren't for a prop saver. Landings under power are graceful and uneventful. I will report here on (hopefully improved) flight characteristics when I change these.

The last photo is a comparison between v1 and v2 wings. While rotors are virtually identical, the new wing has about 60mm or 2.5" shorter wingspan and increased dihedral. Because the new fuselage is longer, and the propeller consequently farther in front, I was able to move the rotors closer together to improve roll response. Previously, the distance between rotors was influenced by considerations of rotor-to-propeller clearance.

You'll note that the fuselage looks well-worn. This airframe has seen a lot of abuse when I used it to re-learn R/C flying after a long hiatus from the hobby, and then from extended disuse and storage after I outgrew its capabilities. I hear about many similar airframes lying around in people's garages; perhaps this design will give some of them a new lease on life.

The fuselage is longer than needed, and could probably stand about a 4" chop at the front. I'm reluctant to do that, however, because so far it is possible to go back to original SS airplane configuration by simply undoing a rubber band.

Ari.

[iter]

On the heels of Mickey's success, I used GWS ball-bearing gearboxes for rotor masts. I used the lighter, smaller LPS items. These come with 2mm shafts as opposed to 3mm ones in IPS and (G3PO) EPS. My apologies for poor image quality. I was using a friend's camera who needed it back in a hurry.

Numbers on blade roots are individual blade weights. Ackus mark their blades in 1/100th of a gram, making it easier to match blades by weight for simplified rotor balancing. In v1, I used very light blades (in the 1.2g range) that proved fragile for prototype work. The heavier blades have so far stood to much more abuse, and the overall added weight is not prohibitive (the 10 added grams are 3.5% AUW). Interestingly, Ackus consider these blades too heavy for their primary product (the 12g Penni helicopter kit) and used to discard them. Recycling is fun!

Ari.

[imsofaman]

Please let us know when the kit is available!!!! I want one!!!! :p :p :p

[iter]

Well, I have the blades, I have commitment from a mail-order distributor and a design I'm happy with. Now I need to get some balsa and plywood laser-cut, and we'll start shipping them out.

I'm looking at a couple of laser cutter businesses. Anybody has experience with any of them, let me know. Anyone has a laser cutter in the basement and wants to give me a quote, let me know.

Ari.

[mnowell129]

Jesse Wilkins [laserlizard@laserlizard.com]

[imsofaman]

Oh man....we are getting close!!!! :D :D :D :D

[iter]

I had my gyro get away from me this evening and land behind a fence. I thought the fence belonged to the local school, but turns out the city is leasing part of the school property to some inline skating place. So you can't get there from the street, and you can't get there from the school. The fences they put in are twice as tall as the school's, no one at the school has keys, no one knows who to call, and the phone number that's on the fence is dead.

It's sitting there in a puddle right now yanking itself to pieces with no signal, and there's nothing I can do about it.

Edit: So I got it back after 4 hours of walking around in circles and cursing in the rain. The fence was too tall for me to scale (what a wimp, I know). But let's just say, I fished it out with some, erm, creative engineering.

Normal programming will now resume.

Ari.

[iter]

I had two wonderful days of flying the basher and showing it to other people. Yesterday, at Rancho San Antonio; today, at Baylands Park. A number of people took stills and video and I expect that they will either post them here or email them to me so I could post them. Brian Chan (bhchan) was kind enough to send me these videos:

http://www.lib.aero/~ari/autogyros/baylands.avi (6.10 MB)
http://www.lib.aero/~ari/autogyros/baylands-almost-hover.avi (7.99 MB)
http://www.lib.aero/~ari/autogyros/baylands-handlaunch.avi (4.66 MB)

Everyone seemed surprised at how little runway it needs to take off. I also tried hand-launching it today for the first time - you can see that in the last video.

On two of the flights that Brian captured, as well as on a subsequent flight, I lost power to the motor without warning or good cause. The pack was fresh, and there had been no sign of dropping voltage before power cut. Unlike normal BEC activation, retarding the throttle to 0 and advancing it again had no effect. As you can see in the videos, landing without power is still problematic. It lands OK, but you can't flare and landings look bad. Interestingly, there was no damage to the rotors at all. When I was flying v1, landings like that meant 2-3 new blades. With the new stronger blades, no damage is done.

Ari.

[bhchan]

http://www.lib.aero/~ari/autogyros/baylands.avi (6.10 MB)
http://www.lib.aero/~ari/autogyros/baylands-almost-hover.avi (7.99 MB)
http://www.lib.aero/~ari/autogyros/baylands-handlaunch.avi (4.66 MB)

Ari.

Ari,

The second video link should be http://www.lib.aero/~ari/autogyros/baylands-hover.avi

It was a treat for me to see the AGSS(auto-gyro-slow-stick) flys.

Brian, an EAJ :)

[iter]

The second video link should be http://www.lib.aero/~ari/autogyros/baylands-hover.avi

It only appeared to hover because I had it pointed into the wind, but if you insist, I'll make a symlink :=)

I don't know why I never came to Baylands before. It's the closest field to my home, and the crowd was great. I'm glad you liked my contraption. I hope more people will try to build gyros, they are real fun! I'm still looking for a good name for my gyro BTW, so keep them coming :=)

Ari.

[imsofaman]

Ari....this on the large slow stick ...right?

[mnowell129]

Looks like you are having a great time. Congratulations.

You will probably improve the power off performance by moving the CG back, looks like you are probably nose heavy. Once you move the CG back, go up high and take the power away and it should descend near vertically. If you add a touch of down elevator you should get a little forward speed that you can use to flare with.
You would also benefit from an elevator that is 50-60% of the stab or an all flying stab. At low airspeeds the small elevator quits working.
Ditto on the rudder.

Loss of flight controls at low speed is why the early autogyro designers went to cyclic pitch on the head because it works at zero airspeed...

[iter]

imsofaman: yes, v2 is built on a standard Slow Stick, http://www.gws.com.tw/english/product/airfly/slow%20stick.htm There are close-up photos of it a couple posts back. It has bigger control surfaces and a stronger fuselage, so it seems to work better than the pico stick v1.

Mickey: I'll try to move the CG back. I've been moving it back little by little, but it goes so much against all my airplane experience to have to CG so far back :=) I've also been slowly adding back-tilt. Because of how the fuselage is, I can't add any downthrust, though it would really help.

Re elevator size, you are right about effectiveness and size. One of the reasons I went to a Slow Stick from a Pico was to get bigger surfaces. I'm trying to see how few modifications to GWS gear I get away with though. I'll try to play with back-tilt and CG, and will change the elevator if all else fails.

Ari.

[bhchan]

Ari,

I am making couple bearing blocks to see if it will work.

Brian, an EAJ.

[iter]

Photos by Jeff Mate

[iter]

More photos

[imsofaman]

My latest autogyro attemp was successful...but ended in desaster!!!! I love Clancy Aviaiton. I made an autogyro for the Baby bee. It flew today!!! man it was so cool. Had a hard tome trimmin it out. It was getting dark and lost my orientation...splat! :eek: What the Hell...I panicked! Anyway....i got a good feel for how it is supposed to fly. looking forward to making another Baby bee and going for it one more time!!!! ;)

Oh...by the way, I modified the airfoil today and made the rotors 1 1/2" wide with an undercambered foil to it. Added more pitch and it would go into auto rotation by just walking!!!! :)

[iter]

imsofaman, sorry to hear about your loss. You'll rebuild it, right? With my 'gyros, every time I crash, I feel I've learned something about their handling. Well, almost every time :=)

Everyone: I've observed that my models tend to roll right on takeoff. You can clearly see that in many videos. I am speculating that this is because of how the propeller slipstream, assymetric as it is, interferes with the rotors. To test this theory, I need a pusher 10x8 prop that I could run CCW. Where do I find one that would work with an EPS?

Ari.

[imsofaman]

Hey Ari,
Oh yes...she will fly again!!! This time i will pay more attention to the landing gear. it was fragile to begin with. Yes I learned a couple things...more throttle...more climb. I think i was nose heavey...when i killed the trottle...it would nose down. It is supposed to float down...right? My blade rotate clock wise. Min kept vering to the right.

Once i modified that rotpr blade...it was all over!!!!! I knew it was going to fly. Now...all the things i have learned...will be applied to the next one!!!!

[imsofaman]

I am almost ready to get her in the air again. I have to cover all the blasa first and then let her rip!!! I will keep it close and not fly at dusk....that was dumb...right? :o


Dave

[iter]

I've got a pre-production run of laser-cut parts done. Now I need to put together a manual and package all the pieces, and kits will be good to go.

Ari.

[quailbird]

Try a pinion gear on the servo and a larger gear on the other part. then it could turn slow and not so far.

[iter]

Kits are now available - see this thread - http://www.rcgroups.com/forums/showthread.php?t=364269

Ari.

[bhchan]

Ari,

Here is my Slow-G,

[bhchan]

.....more photos of the power plant and the blade stop.


Brian, an EAJ

[bhchan]

...here is another view of the home made bearing holder and the blade stop.

Brian, an EAJ

[imsofaman]

I like the bearing holders!!!!

[quailbird]

Just curious, is it stable enough to be a camera plane? I know that folks say they can be a little tricky.

[Don Sims]

Great photos Brian and I like the blade stop idea! :D

[bhchan]

The bearing holders were a quick and dirty way to get it flying before Ari get all the parts he needed for the "kit". When I saw Ari put a loop of tape to hold the blades from spinning while the plane is sitting on the ground every times he lands, and that was too much work for me( I am lazy!) This is the outcome from a lazy man point of view :).

quailbird,

I think the Slow-G can probably carry a light camera, like the Aiptek. But the Aiptek requires absolutely no vibration to record the images. The Slow-G will not provide that, even you balanced the blades carefully. Plus Ari's original Slow-G required less runway than mine. He ran a 700 mah Lipo pack and I use a 1500mah Lipo pack. So I think the little weigh differentce made a bit difference in the performance. So I am not sure if the weight of the camera will affect what percentage of performance. Also the Slow-G glide ratio is a bit shorter than the Slow Stick. You have to be careful on how far you can fly and able to come back.

Brian, an EAJ

[iter]

Brian, very cool photos! I'm happy to see your Slow-G fliying. I haven't been able to get out to Baylands in a while now because of an extended family visit. :rolleyes: It has cut into many things for me, including flying - which I haven't done any of in the last 4 weeks. Having family over is good, but very tiring after a while. I really want to see your model "in person", but I won't make it to the park until the 28th.

I see you've increased the elevator area. How does it work for you?

It looks like you're using some sort of brushless? What is it and what prop are you swinging? Props make a big difference on this model. You want the largest, slowest prop you can turn with your motor/gearbox. It flies very slowly, so you want to optimize for static thrust.

What's your AUW?

I love the "rotor brake" idea. I'm not sure how to work it into the kit without drilling the wing panels (which will drive costs up), but I'll certainly mention it in the manual as an optional improvement the builder can make. May I use your photos?

Ari.

[iter]

A single rubber band across the rotor, both ends sitting on the shaft.

[bhchan]

Ari,

The motor is a Razor motor(not sure what model it is, as it is one of the preproduction motor I got from Matt Orme) with the 6.6:1 reduction. The prop is a APC SF 11x8 on 2S 1500 kokam LiPo battery. The fully charged pack will last about 15 minutes. I land when I need full throttle to maintain flight.

I increased the elevator area because I read you need large control surfaces during slow flights, and full flying tail is better. On the SlowStick, it is not easy to put on a full flying elevator, so I did the next best thing. So far i did not find I need that much elevator but I think a larger rudder might be helpful. The side benefit is the white elevator is it really shows up as the Sun hit it. That is the most visible thing of the whole plane. It gets a little hard to see the plane when it get some altitude.

Attached is another photo of the blade stop, without the rubber band. It is just a short lenght of a bamboo skewer about 2 inches long, I just glue it in the end of the "wing". Yes, you can use the photos for the manual. I have the higher resolution originals (2.5mb) if you want them.

Brian, an EAJ

[iter]

Brian, thanks for the photos. I would be in your debt if you emaled me the higher-res versions -- I'll include both versions of blade stops in the manual for builders to choose from.

You may want to try a larger prop. I use an 11x8 on an EPS-300, so you should be able to use at least a 12x8 on yours, maybe even larger. It really makes a difference.

Ari.

[bhchan]

Ari,

I need higher reduction ratio, I am pulling about 9.5 amp on 2 cells. I am try to reduce the amp draw. I used a lower pitch rop and found out there is not enough power when you get into trouble.

I like your blade stopper better, simplier than mine. Just make sure the rubberband is not too tight. Otherwise it will have the problem I mentioned to you before.

Brian, an EAJ

[iter]

Maybe I can sneak out to Baylands at lunchtime some day this week and we can fly formation to measure relative perfomance :=) Funny thing is, you're reporting same or inferior performance with brushless to what I'm getting on a brushed motor. That can't be right!

Your battery should be about an oz heavier than mine, I'd guess? I use JST connectors on my low-capacity cells - if you use those as well, I'd be glad to lend you my 730 TP and see if it flies any better.

Let me know if you can do lunch this week.

Ari.

[bhchan]

Ari,

I am pulling over 9.5 amp. The 730 mah pack is not going to able to supply current to run it.

Brian, an EAJ

[iter]

It's not on his website yet, but I have an official dealer now. AeroMicro (http://www.aeromicro.com/contactus.htm) is now sipping Slow-G kits with printed manuals and fancy packaging. Until it's on the website, you have to call AeroMicro and order by phone; number is on the website.

I'll put a link to Slow-G order page as soon as it appears on AM site.

I've had a surge in requests for kits over the last few days (just after I sold the entire batch to Perry - I'm sure he'll be happy) and I've been redirecting thest to him. Anybody know what happened? Did Slow-G get posted in another forum?

Ari.

[iter]

I put together a modest website for the Slow-G kit at http://www.slow-g.com.

Ari.

[rcnerd]

updates?

[iter]

How do you mean?

Ari.

[Tram]

Any videos out there of the Slow-G?

[gpw]

Do Both sets of blades rotate in the same direction , or is one CW and the other CCW...????

[bhchan]

left one goes counter-clockwise(from top), the right side is clockwise.

Brian, an EAJ