spad autogyro
 

http://spadworld.net/viewtopic.php?t...light=autogyro

Thats not my gyro in the link but i am trying to built a gyro out of coroplast. I have built 4 sets of blades which are all broken now and have achived only 2 flights in a 3week period. i am frustrated now!

My current plane which is much better than the other attempts is made out of coroplat fence post peices and 3/4 aluminum U channel. The mast is a peice of 1/4 inch music wire. rotor hub is a 2 blade desing made out of 1/4 inch plywood and 1.5x.25 inch lattice blade mounts. Hinges are american gutter pipe which is flexable and durable for about 35 hard impacts with the ground. My blade were set to flap to 45 degrees both ways wiht blade stops. The blades were 2mm coroplat flat bottom airfoil with a5.5 inch chord and a .5 inch tall spar and a 48 inch rotor span.
I also tryed a twin gyro with two 30 inch counter rotatiing rigid rotors.

Now my problems are not consistant at all. The single hinged rotor gyro wanted to roll over into the asending blade for so reason unknow. But i did it it to fly once wich lasted about 2 mins when the plane all of a sudden decided to nose straight up and then lose control from about 100 feet up. my models are rudder elevator type with a small 20 inch flat stab behing the mast fixed with alierons. After this flight i couldnt get it to fly again. it kept rolling over into the acending blade. One time it lifted straight but it nosed straight up and fell back down hard onto the ground. i have a 10 degree mastangle 10 degree downthrust in my saito 91 and about a 15 degree hang angle. The blades spin easily once the ground roll starts but i just cant get consistant results.

The twin rotor version fly once also but the plane ran out of fuel after takeoff and autoed down. it didnt fly again either due to a roll to the left on take off. It always rolled left but so how i managed to kick in enough right rudder to roll it straight on takeoff. It also has 10 degrees of mast tilt and 10 downthrust. The rotors were set about 7 inches above the fuselage. No diheadral in the rotor boom. I tryed one simlar to the one in the link above but it was over weight but lifted rolling over to the left ripping one of the rotor blades off the bottom rotor.

For my desings i used the average spec from www.autogyro.com to figure all of the measurements. I have been building spad fixed wings for about 3 years with great success but this gyro experiment has me really confused because every little adjustment never leads to a consistant result like dealing with a fixed wing.

Anyone have any ideas to why my gyro attempts are failing?

RE: spad autogyro
 

I'm no expert, but it seems the consensus is that two bladed rotors just don't work very well. I'd redo your hub and make it a three bladed rotor.
I too was considering a SPAD gyro. I was planning on just using spad material for the fuse and a conventional setup for the rotor. I might try the 2mil coro for the rotor, though. That's the easiest method I've seen yet.

RE: spad autogyro
 

I too have been working on a SPAD (SPAG DC) Gyro for a while now. I've been trying to collect ideas and specifications that will help me build. What I have so far is a Gyro with a three bladed rotor (10 degrees on the blade holders...though I've since read 20 degrees is preferred...ideas?) The finished weight should be 4 pounds if I add it all up without fuel. I'm for sure going to have questions such as servo direction for roll (rotor tilts right looking from behind to make a right turn?) and such. I've hopefully included a picture so you can see my progress. With a little more time I'll get to the radio install and make some blades (balsa and maple covered with Monokote to start....no Coro for the time being).

Splinter Wood.

RE: spad autogyro
 

I noticed a spinner on top of your hub. Are you planning on using an electric starter as a pre-rotater? That is what I'm planning on, but I think I'll need a cordless starter. I don't know if I can get the cord out of the rotor path. The craft looks good. Let us know how it turns out.

RE: spad autogyro
 

Man thats neat! What did you use for the rotor hub, hub shaft and the mast?

RE: spad autogyro
 

Thanks for the interest....glad to see others are interested in SPAD's and GYRO's at the same time. :)

The hub I machined from a plastic called "Black Delrin". We commonly use it for low speed bearings or grippers for handling machine parts etc. It machines dimensionly very accurate with a great finish while having good strength to weight ratio (perfect for SPAD's). I have used it in the past for my firewall's on my Dogfighter and DasPlastic. I'd say it's heavier than a wood/ply rotor...but is way more robust (crash survivability!!!). I hope to pre-spin the rotor for ROG using a cordless drill (I hear 400-600) should be right). The cone is store bought and adapted to my bearing retainer. I had to raise it above the flapping stops for clearance. This rotor is a near copy of Emilo Cabezas DC Gyro published by RCM (plan 1244). All I've done is convert wood to plastic (the SPAD way).

I figure the plans might be a bit old and things have progressed some since. My question was about the rotor design and the flapping range of motion. The drawing called for -1 to +10 dergess of travel. I read a post that up to +20 is better. Also there is talk of +15 degrees of blade advancement at the tips....was wondering if the blades set square to the root will be fine as well for know?

I've included a picture (a little blurry...sorry) of the rotor. Let me know if you'd like any others.


Splinter.

RE: spad autogyro
 

Forgot to reply to the last question. The mast is only made of 1/4 sheet balsa with 3/32 light ply on either side for ridgidity. Not exactly great SPAD material....but I feel it's the best and quickest material for the job. Nothing fancy here. The hub shaft is machined from aluminum and press fitted to the inner ID of the bearing (1/4 ID x 5/8 OD).


Splinter.

RE: spad autogyro
 

I am really glad to see that you fellas are giving the autogyro a shot. Gyros are very complex and require a lot of time. Don't get frustated and give up. Walk away if you need to and come back with a new purspective. There is plenty of help here in the gyro forum. It may take a little time for someone to get back to you with some info, just don't give up on your efforts! One thing is for sure, if you get your gyro flying, you will be the envy of the flight field!

I am recovering from hurricane no. 2 and will get back in touch with you as soon as I have more time!

your RC friend

John

RE: spad autogyro
 

http://rcgroups.com/gallery/data/500...030229-med.JPG
http://rcgroups.com/gallery/data/500...030235-med.JPG
http://rcgroups.com/gallery/data/500...030234-med.JPG
http://rcgroups.com/gallery/data/500...030230-med.JPG

Specs wing scrap 60 inch wing cut down to 42 inches. rotors 2 25 inch 2mm coro rotors attached to the wing with long 1/4 inch steel bolts. fuse coro/ fencepost and alumin u channel. H stab20x11 V stab half that. saito 91 for power.

Flight report= great This gyroplane flew very well with some right trim needed but its a very stable slow flying gyro. it lands almost vertical like a parachute. Finally i have one that flys and flys great. Now my rotor hubs need to be reworked and it will be a better flying machine. Sorry for lack of spec but this was throw together rather quickly. :grin:

RE: spad autogyro
 

Love those in flight pictures! You have truley created one of the most unusual SPAG's I've seen to date. Sure hope my project goes as well....we'll see shortly. I made a bit more progress this weekend by building a rotor blade sanding fixture (no coro blades yet). I was able to produce 3 blades this moring. Things are looking good.

Splinter. :D

RE: spad autogyro
 

Balsa blades are too darn aggrevating! I like your design but its way too much work for me. the hub at least. I am trying to keep the S in spad LOL plus i counldnt get the single gyro to fly or none of them without wings. Well i did make one flight with the single gyro but it lost control and crashed. Anyway i made me some ball bearing hubs for my rotors and plan to test this afternoon. The gyro is cool tough and stands still in a stiff breeze!

RE: spad autogyro
 

Golly wheeze!

RE: spad autogyro
 

i got around to weighing my plane and its a wopping 8.8lbs! MAn thats heavy for somthing that flys so light. my scales are right because i checked them. The wing on the plane is 44x13 so its not near big enough to fly it without the rotors.
I also straped the gyro wing onto a standard DPS spad design and it flew with the small tail feather to my amazment. The short 30 inch pvc fuse was too short though as yaw was a problem. it was powered by a TT pro 46. Landed it vertical. weight was 6.6 lbs on it.

Also one of my rotors is not spining as fast as the other during normal foward flight however when i auto down for a landing both spin equally. Why is this?
I tell you what this is darn fun!