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Post by Supervee on Oct 12, 2016 4:30:33 GMT -6
Very Good!..'Need to humidify a work area'....You don't hear that too much down here in South Carolina!!! I have been DE-Humidifying my work area this week...... Nice to hear your progress, Dave.
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Post by dmar836 on Oct 17, 2016 4:51:26 GMT -6
My plywood arrived the other day. Been sizing the rib spar openings. Built a quick jig with cleats to hold each rib to the basic plan form despite the very slight variances in length. This allows me to visualize spar markings for filing(always too tight) while the datum is the airfoil itself. It will also allow me to trim them all to the exact length without shifting the airfoil back and forth on each. Dave
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Post by dmar836 on Oct 25, 2016 9:16:18 GMT -6
Been gluing the plywood doublers on the spars. Made the attach hardware last week and tig'd the wire attach plate doublers. Found one of the rear spar attach holes(in the fuse) was drilled at an angle AND the front and back plates forming the mount are not parallel. This either places bending force on the bolt or loads only one attach strap, or both! Reamed it to AN5 and am waiting to mock up the partially assembled wing before deciding how to continue. Still a little angle but only in one plane now. I will likely use shim stock or make a tapered washer. I hate to make a one-off wing attach but I am of the belief that there are no interchangeable V Witt wings out there anyway - too many variables and plan interpretations for everyone to build them identically. 4130 material is no longer commonly available in .080 plate, for example and the rear spar attach straps are not really serviceable once closed up in the wing. Plan says that's where you adjusts incidence but only with major repair. Did mock up the spars to the fuse the other day to measure the tie rod c-c lengths. Called then emailed Steen about the flying wires this am. I'll make sure I'm sitting down before I open the quote! FYI, 12wks is the lead time! Do something! Dave
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Post by dmar836 on Nov 3, 2016 7:46:49 GMT -6
Started gluing ribs this week. No turning back! T-88 was my glue choice. A buddy loaned me his Senco staple gun- very smooth gun that doesn't countersink the staple. I'd rather use no fasteners but that just isn't practical. Ordered the tie rods(flying wires) last week. About $1700 but that's not a part I would want to skimp on! Dave
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Post by dmar836 on Dec 16, 2016 13:50:52 GMT -6
The wing tip bows took a lot longer than thought to rig and attach. .028 is tough to weld. Tig helps but I'm lousy unless with a perfectly positioned piece(then I'm just really bad). Brought the wings home for that challenge (also it's too cold in the hangar). I'm now amidst the laborious process of cutting, fitting, and gluing the spar filler strips between each rib. Get movin'! Dave
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Post by Supervee on Dec 17, 2016 10:00:52 GMT -6
Thanks for the update. You are making steady progress, glad to see it !!
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Post by dmar836 on Jan 22, 2017 16:37:05 GMT -6
Tried to mock up the wings yesterday. The clevis pin heads holding the tie rod ends to the attach bracket were too thick and rubbed the spars. 1/8" thick! They are stainless from Burton. AN pins have only a 1/16" thick head. I turned two down to .038 and they still rubbed. That would put a side load on the bracket. I'll turn them even further down as they are only in shear. The other option is an additional doubler on the spar which would set the bracket further from the spar. A big no no IMO. Fun, Dave
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Post by Supervee on Jan 23, 2017 9:08:03 GMT -6
True,,,what if the clevis pin was put in the other direction?..cotter pin towards spar?
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Post by dmar836 on Jan 23, 2017 11:39:08 GMT -6
I'm about to head out there so I'll check. I'm thinking that will require even more space. Will advise, Dave
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Post by dmar836 on Apr 17, 2017 10:12:04 GMT -6
Progress? The ailerons and flaps are primed and I'm about to cover those and the wings with fabric and start on the engine. Fabricating the control horns was fun but makes me question my welding! How anyone made these Dutchman clamps without tig I don't know. I started one with a torch and it looked like charcoal and the tiny 1/4" .028 tubing warped so bad it was useless. I think I put a drill bit in there as a heat sinc and it broke with removal. Tig'n it was clean and fun - hopefully strong too! Found a guy locally who can balance my engine parts and the extension shaft(though neither of us know how to correct the shaft if it's out). I do think one could do better than his 1gm tolerance on rods but.... I might just do those myself. I learned the crank on a VW doesn't require bob weights(to mimic rod and piston weight) to balance since its a flat crank. Saves some math and setup. That prop extension shaft is a beast - from 4140 billet and had to start from 5" round or so. There is some corrosion on mine where the prop hub once resided. It will likely be under the hub and forward of any gyro created moment BUT I'm not at all happy that the pilot bearing is as easy slip fit either. I won't tell the numbers but the "critical dimension" on the plans, well, isn't. I think the potential harmonics issues caused wear at the pilot bearing as plans call for 36C and that's nothing to a bearing race. I could machine a new one but do I want to? That's big $$$ just for the materials. My AI thinks it will likely be fine as-is and says build it as it was and if I like the way it flies remake it or whatever when I tear down and inspect after break-in/testing. I would likely change to a slightly smaller bearing(metric if needed) but don't tell Steve! Prop hub is next as I need to lap it, etc. before getting the shaft and engine parts balanced. I talked to Great Plains about a hub but fear ordering as "just send us a drawing" usually means I get the wrong thing. I must not communicate well. That's holding me up on the engine so.... Dave
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Post by Supervee on Apr 18, 2017 4:31:21 GMT -6
Dave...Glad to see your progress. Supervee needs to clone you!! Having an engine helper is huge. Every team owner needs to have an engine guru of sorts in his team.
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Post by swiofmh on Aug 1, 2017 18:48:35 GMT -6
Howdy, wanting to build a v-whit from plans, any photos tips tech is greatly appreciated! Thanks
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Post by dmar836 on Aug 1, 2017 20:16:58 GMT -6
Great! Plans are available from Aircraft Spruce for cheap. I have some pics on the Facebook page. Quit Photobucket so can't post pics here anymore. I should ask your background. It's not a difficult build but it's no RV. You have to source parts yourself and make some parts based only on researched pics and aircraft building standards. Plastic and balsa model building as a child helps a lot. These are certainly cheaper than an RV and you learn steel, aluminum, wood, and fabric. Wings could be built for about $2000 Fuse about $1000 Flying wires are $1800 Landing gear, wheels, brakes can find all or part used. I planned around $10K and might go over just a bit. The extension drive,cone, and prop hub would require some good fab skills or about every favor owed you. Those are the difficult parts to find and are unique to the VWitt. My guess is there would be a project come up for sale saving some of this sourcing. A Lasher Renegade is simpler but similar and would add variety to the group. No plans but some projects out there. Dave
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Post by swiofmh on Aug 2, 2017 17:11:27 GMT -6
Got the plans, will check out FB, am an A & P/IA, FCC 3rd class, Private Pilot, restoring a W-8/0-200 and a MXL II sport 503 DCDI, can make just about any part, done lots of steel, sheet metal, wood and fabric work. Not much experience with composites but need to hammer down on it! what's up with the flying wires? Seems high? Having good photos of the extension drive and how it looks in 3D would be a big help. If a project pops up I would be interested! It would be a big help if someone has a v-whit with the extended wing tips to measure and look at. Thanks!
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Post by jvliet on Aug 2, 2017 18:57:24 GMT -6
To the best of my knowledge, no one has flown a V-Witt with the extended tips except for Steve's prototype. Before I sold off the project, I was in process of adding the extended tips to my #33, using wood ribs instead of steel tube. If you can find the Tailwind 'extra' plans sheet for the extended tips, the photo on that sheet is actually Wittman's V-Witt wing. By the way, Wittman's prototype in the EAA Museum is incorrectly rigged, when they reassembled it after trucking it up from Florida, they added several degrees of dihedral which is WRONG - it should be zero dihedral.
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