Activity Stream
Activity Stream
-
C5Engineer added a post in a topic Let's talk gear geometry
DB thanks for sharing your information. This is the type of conversation I was hoping this thread would generate. I think the reoccuring theme here is don't make poor landings....I know mine would still be on there if I would have said naw....I better not land that spot that's at 6000ft on the side of mountain that's full of rocks and gopher holes, 20 miles from the nearest road, with all my camping gear on board, by myself......I made a laundry list of screw ups that day...I survived, damage was minimal, it makes a good story, and I learned alot so about all you can do is press on and try to not do it again.....
-
0
-
-
C5Engineer added a topic in Files and Forms
Avid Wing technical dataPlease place everything wing related in this thread. The following is from Doug Holly.
I built a custom hybrid 'long heavy hauler speedwing' for my Avid+, hoping to have the best of both worlds. I used and followed the Mk-IV Heavy Hauler material and construction method (see both Leni's .pdf drawings and the wing difference explanation below), however, I substituted the flat-bottom Speedwing ribs instead of the under-cambered Heavy Hauler/STOL ribs. The root rib on Avid Speedwing/Aerobat planes is a special 'transitional' rib that matches up to the butt rib (which was always HH/STOL shaped to allow folding wing clearance). In the attached pictures, you can clearly see the differences between the speed and under-cambered rib profiles both on and off my wing.
Also keep in mind, 'Heavy Hauler' was the name attached to several Avid models. A Heavy Hauler B or C model was 1050lbs M.T.O.W. A Heavy Hauler MkIV was originally 1150lbs and then, to compete with the Kitfox 1200, "re-marketed" as 1200lbs. This is the reason one has to be careful around Avid gross weights and wings. In addition to wing length, material and construction differences, the under-cambered HH rib profile was very different from the flat-bottomed Speed rib profile.
In general, Avid Flyer wing differences extend to spar thickness, spar length, lift strut o.d. diameter, airfoil, rib spacing and drag tubes. All wings called for (2) nose ribs between wing ribs, though an additional nose rib per bay is often added on the Speed and STOL wings due to their wider rib spacing. Here are the basic differences between the (4) Avid Flyer wings explained:
Speedwing: .065" thick 2-1/2" o.d. spars; 108-1/2" spar length; 3/4" dia. lift struts; Avid flat bottom airfoil; (7) ribs ~ 18" o.c.; (3) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71" and 106-1/2" o.c. from tip rib
Mk-IV HH: .083" thick 2-1/2" o.d. spars; 144" spar length; 7/8" dia. lift struts; Avid undercamber airfoil; (13) ribs ~ 12" o.c.; (1) 1/2" dia. W-2A steel drag tube; (3) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2A, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", 106-1/2" and 142" o.c. from tip rib
STOL: .065" thick 2-1/2" o.d. spars; 144" spar length; 3/4" dia. lift struts; Avid undercamber airfoil; (9) ribs ~ 18" o.c.; (4) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", 106-1/2" and 142" o.c. from tip rib
Mk-IV Aerobat: .083" thick 2-1/2" o.d. spars; 108-1/2" spar length; 7/8" dia. lift struts; Avid flat bottom airfoil; (10) ribs ~ 12" o.c.; (1) 1/2" dia. W-2A steel drag tube; (2) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2A, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", and 106-1/2" o.c. from tip rib
* Applies to wings with wire trailing edge only, not required with metal trailing edge.
Be aware that wings with the exact same descriptors, ie., STOL wings, may have different Gross ratings depending on when they were sold/built. One thing is certain, there were so many combination of fuselages and wing components bought, built, or cobbed together over the years it can be very difficult to determine exactly what Gross you have unless you physically measure spar thickness, tubing diameter, or even cut a tube to verify wall thickness.
Wing contruction.pdf
- 4 replies
- 4,492 views
-
C5Engineer added a post in a topic Different wings
That's why te forum took a dump a few weeks back. Doug I'm going to move the wing info into the files and forms area. Sure there's lots of folks who have needed access to that data at some point.
-
0
-
-
FoxDB added a post in a topic Let's talk gear geometry
SkyPirate,
I believe it defintely would have gone slack at the outside. There is a bending moment on the axle which would transfer to the gear leg. This is a big contributor to bucking of the gear leg as shown in the picture posted by C5enginger. The best defence is to increase the diameter of the gear leg as I don't believe the tire could be any closer to the leg.
Dave
-
0
-
-
FoxDB added a post in a topic Let's talk gear geometry
SkyPirate,
Are you refering to the drop test?
Dave
-
0
-
-
SkyPirate added a post in a topic Let's talk gear geometry
Fox if you could have put a couple points about 3 inches long ,,1 at top of forward gear leg 90 degrees to leg and one at the bottom and then put a string between them so you could see it parallel with the forward gear leg from the front,..I wonder how much it would have slacked at impact
-
0
-
-
FoxDB added a post in a topic Let's talk gear geometry
Av8r3400 That is not what caused the fuse failure. It was the compressive load of the gear leg not being directed to the center of the longeron due to the lug hole being directly below the longeron.
Dave
-
0
-
-
akflyer added a post in a topic My new ride
Damn... That's 2 weeks hangar rent here.. Hence 90% of the planes live outside
-
0
-
-
Av8r3400 added a post in a topic Let's talk gear geometry
Dave, your gear, just like the Airdale and Highwing gear have the spring strut linkage making a strait line from the tire to the opposite side longeron. This directs the force from the tire to the opposite side longeron.
If you look at the Rans or Piper gear the link is not a strait line. By breaking the plane of force it splits the force. In this case to both longeron sides.
IMO this is the first design flaw.
-
0
-
-
FoxDB added a post in a topic Let's talk gear geometry
BTW This is what happened to the fuselage with the hard landing;
-
0
-
-
FoxDB added a post in a topic Let's talk gear geometry
Just thought I would put in my 2 bits. I built a Bush gear for my Mod 1 Kitfox. I used die springs in a housing similar to the bearhawk gear. Designed it to take 3 G's before spring would go solid. I did a very poor landing. The gear held up fine but the fuselage failed. I don't believe the springs went solid because the safety cable cable ties were unbroken. I have considered building new tension members with bungees. I believe an Aluminum Spring Gear or bungees are the more forgiving as they provide the most flex (not including the new Highlander gas strut gear). Here is a link to the drop test video I did on my gear; http://www.youtube.com/watch?v=fvQtKQ5gHVY
Dave
-
0
-
-
SkyPirate added a post in a topic Let's talk gear geometry
if a person could incorporate the shocks that are used in a soft tail Harley, they are designed for extraction loads not compression,..at the bottom of the stroke the oil works as a damper versus when you bottom out the spring it's solid,..the solid "Bang" of bottoming out is what instigates the deformation of the tubes, sending a ripple down the shock rod to the axle weldment at the wheel back up the forward gear leg,..take the "Shock or Bang" and add the fulcrum of the wheel center being close to 8 inches outward of the axle weldment junction,..which adds warpage to the forward gear leag like a bow,..bendind inward,..there is allot going on at once and the weakest link will deform and sometimes to the point of failure.
is anyone familiar with Challenger's fiber glass upgrade on the mains? if you could replace the front gear leg with a similar round fiberglass rod,..when the coil spring bottomed out,..this would transfer the "Shock" to the forward gear leg which would then dampen the forces that would be normally put on a tube,..yes it adds weight,..,..but now you have also added flex for when the spring gets compressed completely
-
0
-
-
Av8r3400 added a post in a topic Different wings
I didn't think that Google would land that many hits without some sort of wierd porn being involved...
-
0
-
-
dynomike added a post in a topic Favorite pics of your plane thread
as much as I enjoy my avid I also love this little plane ,so I put it on amphibs .its not so little anymore
-
1
-
-
Chewie added a post in a topic Different wings
Wow, this thread has had over 9.3 MILLION views? You guys are rock stars!
-
0
-
-
Bandit added a post in a topic Different wings
I have STOL wings with .083 spars and 7/8" lift struts.
-
0
-
-
no1son38 added a post in a topic Different wings
my wing spars are .83 and has HH ribs and total wing is 12 ft. and have 10 ribs with 2 false ribs and has alum raps about 12 in. HH wings are supposed to be 14ft. has anyone have any experience with this set up? thanks Randy in tn. also looking for someone close to dyersburg tn with experience with the avid .cell 731 589 1330 email no1son38@aol.com
-
0
-
-
Bandit added a post in a topic My new ride
Holy shit Leni, thats over 6 months of my hanger rent!
-
0
-
-
Bandit added a post in a topic Let's talk gear geometry
I took a close look at the black Highlander at Oshkosh this summer. It looked like to me the fuselage ahead of the verticle fin and the gear attach points had been repaired. The fabric had been patched and the black paint wasn't as glossy. I think those airplanes bend to.
-
0
-
-
Trackwelder added a post in a topic Need folded wing struts
Manual part3 page 35 I believe shows the part at the length of the Horizontal stabilizer being attatched to the frame with an AN3-4 Bolt
-
0
-
-
Trackwelder added a post in a topic Yahoo Group
No you came across with a correct and proper answer, but I was the one who probably was a bit out of line, But 6 months and enough money to have gotten my plane in the air and you think I could get a Biannual done or at least have the instructor at the community college stay awake while I am Flying.
If you want to add some good information, Steve Winder gave a lot of information giving tubing sizes and wall thicknesses of the different models, It was interesting reading, but he deserves his own slot over here, I would put down the tubing sizes of the ModelIV and where they are since that was the ultimate of the Avids when He was there, the Pursang was probably a bit better but Larson is putting those down in an interesting manner, If people could look at one place and see what size tubing was used in each location it would be of advantage to the people who are rebuilding their planes. Some of the information about how the stretch was a matter of taking out 75 feet of tubing and adding back, I'll let you find that answer.
-
0
-
-
Trackwelder added a post in a topic Let's talk gear geometry
I don't think or at least didn't mean to say the airshock wouldn't work, but my math was in the ball park, I believe the next point of failure is the V at the top of the struts, if a person were to put a cross member through there it would triangulate it and take the seat truss out of the equation. Like I said the troubles seem to occur with the 1 % ers and then only when they have reached beyond the limit, If you can build it I can break it, the only thing I had to really say about the airshock is that the patent won't hold up. I will never build a part to sell if someone else is making a living at it but someone will. I think the ultimate for now is the Highlander Superstohl with 18 inches of travel, other than the wings coming off I don't know how you could break it without trying.
-
0
-
-
Trackwelder added a post in a topic Avid visability
There is something about a tripacer that I just like, If I buy a certified plane that would be the one, I have been finding some around me that the old guys are finally letting go of with 400 hours on the engines and they are only asking $14000 give or take for. I just consider it to be the big overgrown Avid. Both my wife and Daughter want to get their pilots licenses and with 2 to have trained the rental cost would be about the same price as buying a Tri Pacer, everyone has to have a goal, planes aren't real active around here and it seems that every third farmer is an A&P but nobody flies anymore, they do work on the planes fairly cheap with annuals costing under a grand for a fairly simple plane. It goes up if you have IFR but still stays reasonable. I have hangar costs that a lot of people would dream of a nested T hangar on the end so I have an extra half hangar so I spend the extra money for it I pay $600 a year, mechanics that are cheap and available planes that are reasonable but flight instructors trying to make there annual salary off of one student while I am on a fixed income.
I wish I was still working there would be flying planes in my hangar instead of half finished proects.
I understand what you are talking about with the cost of parts, I started building a Lycoming 235 and when I got to the piston rings it was cheaper to machine the pistons and run ford Big Block rings instead of buying one ring I got a complete set for less.
When it comes to the Good old boys Club, I have worked in my hangar most days for the past year, and other than the occaissional person stopping for fuel, I have the airport to myself
-
0
-
-
C5Engineer added a post in a topic machining a prov 8 case
Leni is enjoying his new baby during his break from the rock so I'll link to this. He's been working a similar project for a long time now with the 800.
http://www.avidfoxflyers.com/index.php?/topic/77-my-new-power-plant/
-
0
-
-
C5Engineer added a post in a topic Need folded wing struts
Just make sure you do it right. A guy just posted this week on the other forum who totalled his plane while towing after a wing swung out going down the highway and I know of a few others who have done the same thing. I'd post pics of mine if I was home. Are they in the manual anyplace? A full manual is posted in the Files and Forms area on here.
-
0
-