In flight problems

airfan · Post by **airfan** » Thu Jun 25, 2009 11:13 am

Hey there! I'm a newbie to this forum and have just finished building the Guillows 600 series Cessna 180. It test glides okay but in powered flight (I'm using rubber power), sometimes it goes straight, but slowly goes down instead of climbing up. Sometimes it stalls, too. Its entire weight is 30 grams. This is my first plane and I followed the plans exactly. I also used the kit wood which seemed very light. I am using some lubricated rubber band gun rubber. Thanks in advance for help!

cliffm · Post by **cliffm** » Thu Jun 25, 2009 12:26 pm

Finding your question unanswered I feel obligated to extend to you a welcome to the forum and hope you receive as much enjoyment as I have over the past few months. Everybody must be outdoors enjoying. In answer to your quary if you have done your basics in the trim and balance of your craft I would suggest the evidence of a thrust vectoring solution. This involves the fabrication of some type of adjustable nose block to varie the incidence of your propeller in relation to angle of attack,compensation for torque to assist in straight flight or formulating trim for manuevering. If you search this forum I'm quite sure there is some material on this topic. Hope this helps and good flying.

airfan · Post by **airfan** » Thu Jun 25, 2009 1:47 pm

Thanks! But I have already put in a down thrust shim,if thats what you mean. Also,as far as I can see it has no warps. Is 30 grams too much?

Anybody have any suggestions?

Thanks,airfan

airfan · Post by **airfan** » Thu Jun 25, 2009 6:47 pm

Oh,sorry I forgot to mention that it sometimes tries to bank left very sharp then flips over backwards. I am flying it when its perfectly still!

Whats wrong?

cliffm · Post by **cliffm** » Thu Jun 25, 2009 7:04 pm

Have you put it to full revolutions of wind and held it for its full run to observe any irregularities as it runs through fully?

scigs30 · Post by **scigs30** » Fri Jun 26, 2009 7:25 am

Post a picture of the plane from the side view and front view. Also show the down thrust. What prop are you using?

airfan · Post by **airfan** » Fri Jun 26, 2009 1:36 pm

Cliffm,yes I have tried that but cant find anything wrong. Scigs30, I'm using the kit prop which seems big enough. Anyway,heres the pics link:

Thanks for any help!

scigs30 · Post by **scigs30** » Fri Jun 26, 2009 2:17 pm

1. Stabilizer looks warped.
2. Not enough dihedral for a stabilizer of this size. This will explain lack of stability.

airfan · Post by **airfan** » Fri Jun 26, 2009 3:53 pm

Okay,but how do I fix the stabalizer if it's warped?

More braces? Steam it? Should I cut the wing struts loose at the base and then pick up the wing a little bit and reglue it for more dihedral? Never built one like this before. Guess I don't entirely know what I'm doing. Thanks for more help!!!

dbcisco · Post by **dbcisco** » Fri Jun 26, 2009 8:34 pm

scigs30 wrote:1. Stabilizer looks warped.
2. Not enough dihedral for a stabilizer of this size. This will explain lack of stability.

Ditto

Do these planes use any kind use rigging? I only do WWI planes and the rigging can trim them up well including dihedral.

scigs30 · Post by **scigs30** » Fri Jun 26, 2009 9:06 pm

You can try steaming the stab to straighten it out. The wings might be a problem, but yes you can remove the struts to increase the dihedral.

airfan · Post by **airfan** » Sat Jun 27, 2009 4:46 pm

Hey dbcisco! Nope,the cessna don't have any rigging,but I think I got the right dihedral now. Scigs30,I steamed the rudder and it worked awesome!

However,I'm not flying it until I get some FIA rubber. Would you look at that link again? I posted more pictures of the new dihedral. Thanks, all of you for all your help and I might need more when I start flying it! Much thanks,Airfan

scigs30 · Post by **scigs30** » Sun Jun 28, 2009 6:06 pm

Airfan, The stab and dihedral looks better. The right trailing edge of the wind also looks a little warped. The best thing to do is pin the parts to the building board after spraying the tissue with water. This should help prevent warps.

airfan · Post by **airfan** » Mon Jun 29, 2009 12:09 pm

Hey,Scigs30,thanks for all the help you have given me!

I looked at the wing though and it isn't warped although it kinda looks that way in the picture. I flew it with some cheap rubber today just for a test and it flew 58 feet! That's the best flight I've ever had yet!

But it'll probably fly alot longer after I get some good rubber! I'll try to post some pictures on that site of it flying! Thanks to all for your help!!!!!!!

dbcisco · Post by **dbcisco** » Mon Jun 29, 2009 1:51 pm

Congrats Airfan! Nice to hear a happy ending! Hope the new rubber helps.