Author Topic: Sig Skyray landing gear (Read 3227 times)

Larry Renger · « **on:** July 20, 2009, 06:06:39 PM »

I am building a Sig 1/2A Skyray and want to put LG on it. I have several methods in mind, but wanted to see if you guys have done it, and how it worked out. What was the wheel position compared to, say, the leading edge, and 1 wheel, 2, 3? How was it mounted? What was the weight penalty? I don't need ideas, just solid facts from the giants upon whose shoulders I may stand.

(bet I get a bunch of ideas anyway......pbttttt!)

kenneth cook · « **Reply #1 on:** July 20, 2009, 07:36:32 PM »

In my opinion Larry, the Skyray would benefit significantly from landing gear. I've built six of them and all have built tail heavy. After you crashed it the nose would break off just in front of the leading edge. After about 6 crashes and repairs, the plane would always fly better. I always wanted to install a 1/32 piece of ply from nose to midwing prior to the install of the triangular blocks. I always wanted to go with a Sure Start set up with a good size tank. All of mine were built with a black widow and were great fliers on 35' lines. So in regards to your question I think a single wheel would surely suffice. One problem I had with the last few I built was trying to keep the kit supplied wood from warping. Ken Cook

don Burke · « **Reply #2 on:** July 21, 2009, 10:57:33 AM »

I've tried twice to post a pic, doesn't want to.

Anyhow I used a 3/32 wire single strut, captured by a slotted plywood piece between the engine and firewall. Ply has a hold for the air intake. Also used a plastic r/c horn for a tail skid.

don Burke · « **Reply #3 on:** July 21, 2009, 11:03:50 AM »

try again!

don Burke · « **Reply #4 on:** July 21, 2009, 11:05:59 AM »

Note the 3/4 oz of lead, re: Ken's reply.

Mark Misegadis · « **Reply #5 on:** July 21, 2009, 11:18:00 AM »

Hi,

My flying partner is flying a Skyray with the single wheel landing gear after we had a horrible time hand launching last summer. It was my suggestion and I have two Skyrays that are near completion. One is slated to get the single wheel set up and the other will have a Brodak wire setup for two wheels on the front and tailwheel out back.

So far the single wheel with nylon skids in the wing and elevator tip work great and we are off the ground in about 8 feet. If you want a photo I can take and post one.

Mark

minnesotamodeler · « **Reply #6 on:** July 21, 2009, 03:31:03 PM »

Quote from: don Burke on July 21, 2009, 11:05:59 AM

Note the 3/4 oz of lead, re: Ken's reply.

Two pennies do not equal 3/4 oz., at least in American money. Maybe you meant 1/4 oz.? Closer.

Ooooops, you meant the lead under the nose, not the tip weights...never mind.

corey mckenzie · « **Reply #7 on:** July 27, 2009, 07:55:55 AM »

i used the gear from a brodak .049 basic trainer simply sandwiched between the firewall and motor and it worked great for parking lot flying but useless on grass

LARRY RICE · « **Reply #8 on:** July 27, 2009, 09:03:24 AM »

First off I want to say that I am not belittling anyone or looking for a fight but there many people who do not understand 1/2A models and how to hand launch them. There are also a lot who do not know how to land them either but that is another matter.
Believe that your model WILL fly without your assistance, that's important. If your model will not fly on it's own you can not throw it into the air or run fast enough with it to make it fly. Okay, that said let us direct our attention to the launch person. Position yourself facing the pilot, plane in right hand held by wing tip, lines taunt, engine running. At a signal from the pilot that he is ready, sweep the plane across in front of you at waist level, much like a backhand tennis stroke , and let go. The plane will fly.
Pilot, be prepared to step back should the lines slacken and keep the controls in neutral for take off. Giving controls to soon will slow the plane, so wait until the plane has reached flying speed.
Landing: Most 1/2a planes do not float around after the engines quits so nose down to maintain flying speed and pull out just above the ground (hot landing).
Larry

George · « **Reply #9 on:** July 27, 2009, 09:33:04 AM »

Hmmm. I prefer flying 1/2A over grass so my landings with wheeled aircraft consists of bringing it in fast to prevent stall until the wheel(s) touch the grass, then watch it flip to a complete stop.

George

Russ Danneman · « **Reply #10 on:** July 27, 2009, 01:25:58 PM »

i have 3 sig skyray's .all fly great w/o landing gear. nice easy hand launch & their off.

Alan Hahn · « **Reply #11 on:** July 27, 2009, 01:40:05 PM »

If you have a reasonable running engine, I find that simply dropping the plane is a great way to launch. For our Coxy Hazel 100 lap "Cox Sig Skyray" race, it works really well.

A detail on how to minimize the dreaded fuse break at the wing leading edge, glue on some thin (1/32) ply doubles that go roughly 1/3 of way of the wing span. This is before you glue on the motor braces of course.

Now the wing will break at the trailing edge!

I built one that had the ply running all the way back to the elevator. That worked well (hasn't broken yet!), but I should have used "door skin" (1/64" I think) ply to keep the plane lighter.

Mark Misegadis · « **Reply #12 on:** July 27, 2009, 10:29:24 PM »

Here are some pics that I took of my buddies short nosed modified Skyray. It has a single nose wheel and with a Goldberg nylon skid on the wing tip as well as another on the tib of the stab. This works well and is the difference that helped get him in the air as we could never get him hand launched.

I am going to add a set of gear to the one that I have between the firewall and tank on the motor. I will make a groove for the piano wire so they sit flush in the firewall with a small tailwheel out back.

Mark

Robert McHam · « **Reply #13 on:** July 28, 2009, 12:38:22 AM »

I think I know why you cannot get a hand launch! It looks way over propped. Try a 6D 2P prop, or maybe a 5.25 X4!

Robert

Mark Misegadis · « **Reply #14 on:** July 28, 2009, 07:13:04 AM »

Hi Robert,

This Prop is a 6x3. Overpropped would be... a larger diameter right?

This combo works pretty good. Last summer when we started down this path Rich was running a stock build Cox powered Sky Ray and we could never get a good hand launch. I chalk alot of that up to our being rookies. We may have to try it again in the future with Larrys suggestions.

Mark

don Burke · « **Reply #15 on:** July 28, 2009, 11:03:28 AM »

Those little dudes like to rev, try a smaller dia.

When you make the wire gear just use a firewall shaped piece of ply the same thickness as the gear. Capturing the wire betwen the engine and the firewall. Makes it easy to make changes or mods to the installation. Or to remove it if wanted.

minnesotamodeler · « **Reply #16 on:** July 28, 2009, 08:03:55 PM »

Is that one of those Wasp .061s? If so, a 6x3 is not overpropping. 6x2 might hold down the speed to something reasonable however.

George · « **Reply #17 on:** July 29, 2009, 06:51:21 AM »

Quote from: Mark Misegadis on July 28, 2009, 07:13:04 AM

...This Prop is a 6x3. Overpropped would be... a larger diameter right?

Mark,

Overpropped can be too large a diameter, too large a pitch, inefficient airfoil on the prop...whatever causes it to not reach its peak performance RPM.

I tend to use a 6x3 also, but if you are having trouble getting enough initial thrust for hand launch you might want to try hotter fuel or a smaller prop. The NORVELs that the AP was designed after liked to rev and many preferred an APC 6x2 or 5.73 prop. Yours may be unloading in the air for proper performance but could be down on its power curve at take off.

Be aware that this is just speculation on my part. I have some NORVELs but not a Wasp, so I will defer to minnesotamodeler's experience.

George

john e. holliday · « **Reply #18 on:** July 29, 2009, 08:55:13 AM »

Been watching and reading this thread. The biggest thing about planes without landing gear is the hand launching procedure. I still remember the little booklet about flying u-control stated that on hand launch the person launching the plane should take a couple of steps forward as he/she releases the plane. Do not throw it. Also the pilot should be taking a step backward while leading the airplane with neutral or slight up on the controls. Most pilots I have helped usually stand flat footed with full up on the controls until I give them some instructions. I do get loud once in a while depending on the individual. Remember flaying over grass is much easier on the planes and no landing gear makes landings easier also. Have fun, DOC Holliday

Mark Misegadis · « **Reply #19 on:** July 30, 2009, 09:09:00 AM »

Yes the photo of that Skyray is with a AP Wasp .061 with an old Top Flight prop. It zips pretty good with that so it appears to work okay.

We have not experimented yet with others on that plane but can. On my PT-19 that I am flying I dont get full R's running a Gray Cox 6x4. I did however put a Black Cox 6x3 on it and (forgive the car ref) it was like I had a clutch slipping. I ran a Master Airscrew 5.5x4.5 and that was also decent. I just dont like how sharp they are.

I am sure that if we werent at 6000' this would all change in a hurry.

Mark

minnesotamodeler · « **Reply #20 on:** July 31, 2009, 03:33:08 PM »

6000'!!! I know nothing about that kind of elevation except that it makes a dramatic difference in everything--fuel, engine run, airfoil performance, prop efficiency, pilot respiration, etc., etc., etc.

Disregard anything I have said heretofore, I'm at 1000' and have always lived/flown at this height, + or - a few hundred feet. What any of my setups would do on your mountain is anyone's guess, but it I'm sure it wouldn't be good.

Bill Adair · « **Reply #21 on:** August 01, 2009, 12:44:43 AM »

Ray,

I built a Ringmaster in 59, while on temp assignment to the Martin Aircraft plant in Baltimore MD. Flew great at sea level, with a stock Fox 35, on 60' lines.

Brought it back to mile high Denver, and with the same set up, it didn't fly very well at all.

Bill

minnesotamodeler · « **Reply #22 on:** August 01, 2009, 06:01:21 AM »

I do remember from my combat competition days, when I was young and stupid (no remarks please), noting a difference in my planes' (and engines') performance from one contest to another. Didn't know why, never occurred to me at the time that elevation was the culprit. I don't think there was more than a couple thousand feet difference in the locations I visited, but that was enough. Less speed, less jump, bigger turning radius, etc.

So I carried two different types of planes with me everywhere: Small wing, thin airfoil, low pitch props (Big Iron, Voodoo types, my own Beelzebub designs, etc.) and big wing, fat airfoil, higher pitch (Equalizer, Combat Cat, etc.). Also a couple cans of Fox "Blast" for fuel doctoring. Then I'd test fly and use whatever was working best that day. Sorta like solving a problem by brute force or a million experiments rather than analysis. By the time I figured out to check altitude for each contest and just bring the appropriate equipment, I was done competing anyhow.

Now I hear high/low pressure systems, heat (or lack of), humidity, all make similar changes in performance. Way too complicated for my simple mind.

So now I just stay home and fly within my temperature limits (say, 55 to 85 d.) on dry calm days only. With a hat and a water bottle. And a time limit of, say, 2 hours.

Can't be gtting old can I?

john e. holliday · « **Reply #23 on:** August 02, 2009, 07:46:14 AM »

I am not going to say you are getting old. Maybe wiser. Took a couple of planes to my sister and brother-in-law's place to fly yesterday. Even got him up on the Bi-Slob. May have to build him one minus the landing gear. Flew the Doodle Bug once and until that back/hip decides they are not there I may be done with flying the pattern. Doctor has me on a couple of pills that don't seem to be working. DOC Holliday

Mark Misegadis · « **Reply #24 on:** August 03, 2009, 06:38:06 PM »

Hey Guys,

Pictures will be posted in the near future of some further Sky Ray landing gear versions.

As far as Altitude here is what we are working with:

Colorado Springs is located just east of the geographic center of the state and 61 miles (98 km) south of the Colorado State Capitol in Denver. At 6,035 feet (1839 meters) Colorado Springs sits over one mile above sea level, though some areas of the city are significantly higher. The city is situated near the base of one of the most famous American mountains, Pikes Peak, at the eastern edge of the southern Rocky Mountains. Colorado Springs was selected as the No. 1 Best Big City in "Best Places to Live" by Money magazine in 2006,[7] and placed number one in Outside Magazine's 2009 list of America's Best Cities.

A little off topic but.. I am a racecar guy so I have had to deal with altitude there as well. We just held a race that has occured annually since 1916 that deals heavily with altitude. Although the wings are all for downforce.

Search on YouTube for these words for some recent fun. 2009 Pikes Peak Hillclimb

Mark

PS: These rear wing mounts are my handy work http://www.tuningnews.net/event_gallery/66/080717/goodwood-festival-of-speed-2008/

Author Topic: Sig Skyray landing gear (Read 3227 times)

Alan Hahn