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Engine Mount, Gear Legs |
Edge Trimming What's the best way to get a smooth straight edge when trimming the HS & VS trailing and outboard edges? Anything better that hand shear, file, and grind? Thanks Do not hand shear as it leaves ripples. I use a sabre saw after first drawing a line. Then I use a right angle die grinder with a two inch abrasive pad to go up to the line and finish off with a file. Be sure to lay two inch masking tape along the line to protect the surface. It works for me. Bob W I use this Shop Trick: Trim to within 1/16" of the line first, then come back & cut to the line as accurately as possible. The waste from the cut is smaller that way, and produces less rippling of the part. The big shears I use are sold by Home Depot Aircraft Tools -- the big aluminum jobs made by Malco. They appear to have replaceable blades. These do not cut a circle easily... Cheers Mark Mark is right, get a pair of big-a$$ metal shears with 4-5 inch blades. They will make nice smooth cuts without ripples. Any ripples you do have can be sanded or filed out then. Eric Elevator Bell Crank Hi Fellas: Please have a look at your ships to make sure the bellcrank is installed per the plans Mark the following from Jeff Deuchar: When I took the elevator bell crank apart to install the auto pilot servo, I discovered that there was only a 970 washer on each side of the bearing instead of a 960 then a 970. When I put it back together with the 960 and 970 sandwich it operated much more smoothly. My aileron bellcranks look good. Thought you might want to pass this on to others to check (easy to do, and easy to fix)? I'm a little stumped and could use some help. I'm trying to fit the inside rib to the elevator spar. The rib has this little flange with a #12 hole in it and no instructions on how to fit it or attach it. I ASSUME that I am supposed to bend the flange back and run it along the backside of the spar and attach it somehow. Is this right? What do I attach the rib with? a -3 flathead screw? That doesn't make sense. I know that this attachment is just to hold it in place until I can fit it to the horizontal stabilizer in order to fit and drill the control horns. Did I miss something in the plans/instructions? HELP! Randy Pflanzer It's a little tooling piece or something. I asked the same question of Mark, and he said it needs to be included in the next revision. Just cut it off, and proceed. Scott Roth Randy I just cut the tab off. you need to align the rib to the spars using your jig to make sure that the rib centre line is in the same plane as the centre line of the main spar. The rivets that hold the elevator control arm on will secure the rib to the spar. Tip, When you get the one frame fitted/riveted lay it on a flat table with the control arm pointed up. Now fit your other elevator skeleton togther so that the elevator horns "match" back to back. This will ensure that every thing lines up when you go to fit the finished elevators to the horizontal stab. Check this out at fly ins, gently (while no one is looking) put one of the elevator counter balances on a RV in trail with the horizontal stab. Now look to the other side and see if the counter balance is in trail. If it is not then the elevator control horns were not properly attached. This happens on a lot of Rvs. Most of the elevator horns that were shipped from Van's were not mirror images of each other so this was a common gotcha. The good news is that they still fly great. Tom Martin
Elevator Leading Edge Clearance I'm having a heck of a time getting the leading edges of the elevators to stop rubbing on the rear spar of the HS. Mark said to flatten the LE but I don't want to deform the LE shape or push to hard and get an uneven appearance. Also, the gap between the top skin of the HS and the elevator is not even all the way across. Any suggestions would be appreciated from anyone that has tackled this.!! REED SOMBERG #88 Reed, The solution is simple. Drill out the pop rivets in the leading edge and re-roll it tighter. Re-drill the holes, and fugetaboutit. Randy #95 Mark - Pardon my ignorance but i've never ballanced an elivator before. > Right now it's just a little heavy on the back side, a 6" 2X2 block on > top of the weights will balance it. Does it have to be perfect? > Jack #70 Hey Jack: You want the elevs balanced 100% AFTER paint...which would indicate that they need to be a bit nose heavy without paint....seems a couple of ounces would be enough, as you can drill material from the inner weights after painting to acheive 100%. OK! Mark I've done these bloody counterweights several times (on different RVs) and I think that it is 1000x easier to make a quick mold out of several layers of aluminum foil and cast the weights on the workbench. Make them however thick you need and then bandsaw them to shape. The biggest advantage is that you can reduce the weight easily by sawing the ends off. When you get to the right weight, just bolt 'em back on. No more screwing around with drilling holes in them to reduce the weight. BTW, I thought that since I am a MASTER BUILDER (LOL!) that I'd just pour them in place on the Rocket. I knew better, but I was in a hurry. I SHOULD HAVE JUST CAST THE BLOODY THINGS. I may even remove them as they look like crap. The ones that I cast for Gene's RV, the next day, turned out PERFECT! Doh! After all, you don't think Van changed to the pre-cast weights for no reason, Do you? Vince F-1H, at the QB stage or close to it. I ordered my last ones from the Vans people. Then drilled to get the proper balance.. Larry # I have tried the Van's weights -- the rudder weight is OK (830 G or so). The elevs seem to need some additional weight -- maybe up to 250G more. I prefer a shot/resin/flox slurry instead of the melted lead procedure -- imagining a spot of mealted lead hitting me (or you) doesn't make me grin much! Use small shot -- #7 I think -- slightly bigger than bird shot. In any case, pour the weight over double-nutted 1/4" hardware store bolts with fender washers between the nuts. Make sure the weights stay in place! Cheers Hi Gang, > What is this "flox" you speak of when mixing resin/lead/flox > combination > for the control counterweights? Where do you get it? Has > anyone had any > long term experience with this type of counterweight vs. poured lead? > Thanks, > Scott Roth Flox is a composite filler. It can be made of a number of materials and is very light. See www.aircraftspruce.com -> on-line catalog -> composites -> Thickning agents. Quoting from above: A structural resin filler. The mixture of cotton fiber and epoxy is referred to as "flox". The mixture is used in structural joints and in areas where a very hard, durable buildup is required. Flox is mixed in much the same way as dry micro but only about two parts flock to one part epoxy is required. Mix in just enough flock to make the mixture stand up. If "wet flox" is called out, mix it so it will sag or run. Flox is often used to reinforce a sharp corner. Paint a light coat of pure epoxy inside the corner, trowel flox in to make a triangular support. The flox corner is done just before one glass surface is applied for a wet bond to one surface. Some how, hot lead doesn't excite me. And you thought you were building an all metal aircraft! --Thomas Flox is a composite filler. It can be made of a number of materials and is > very light. See www.aircraftspruce.com -> on-line catalog -> composites -> > Thickning agents. > milled fibers will also work -- get the stuff that's like powder (Wick's supply has it). Mark Flox is ground cotton used with composite resins to thicken them. It also adds a lot of strength to composite joints (as in gear leg fairings). You can find it in the composite section of Aircraft Spruce & Specialties catalog. Loren Harmon s/n 76 Do you recommend epoxy resin (or standard polyester) for the counterweights? I know I'll need epoxy later for the canopy, so that seems to be the way to go. Thanks, Scott Epoxy, please... Mark SNIP Some how, hot lead doesn't excite me. SNIP Depends on whether you're at the target range. LOL I can add 2 quick thoughts. 1) I didn't have any flox or resin on hand when I did the tail weights. But I did have a propane torch, a tin can, and lots of lead on hand. 2) Making the counterweights is easy. Just DON'T cast them into the counterbalance arm. Make a mold and cast them on the bench. A mold can be a piece of tin foil stuffed down into a box made from wood scraps lying on the bench. You don't even have to screw the wood together. After the lead block hardens, shape it on your band saw and bolt it on. If the weight is too heavy, just unbolt and saw. Too light.. melt it again. You can't do that if it's cast in place. That's why you see cast-in-place counterweights that look like somebody used a chainsaw on them. Yuck. Ask me how I know. I've done it both ways and one is easy, the other #$%&*@!! I would expect that changing the weight of a flox/resin/lead cast-in-place counterweight would be a pain in the @ss, though I've not done it. Vince I'm just going to weigh in here and probably get myself flamed but I just have to shoot my mouth off. If you are going to pour resin and shot into the counterbalance arms please think about some things. Resin of any type offers very little strength. In fact, it is extremely brittle. A boat hull made from resin would not last any time at all. In adittion, with heat and UV beating on it, it gets even more brittle and shrinks, if there are voids in the resin they will increase in size and severity over time. Now where do you think it is that these things will break. I won't venture a guess as to what would happen if a piece of counterbalance came off between the HS and the arm. I'll leave that to your imagination but I sure as hell don't want it happening to me. Just know, that what makes a fiberglass layup strong is the cloth or reinforcing fibers. In fact, the less resin (assuming its still properly whetted out) the stronger and more duable the layup. The reason for this rant is to goad you guys to go to every length possible to reinforce you layup. The Gougeon Brothers fiberglass manuals don't cover adhesion to lead shot so you are winging it here. The lead content in the layup is a wildcard, so to contend with it you really need to lean on the reinforcement issue. I mean, you are building this plane to fly for an indefinite number of years, right? Who knows what this layup will be in 40 years. The discussion of using flox or milled fibers is right on. In deciding which reinforcing material to use, think about this. In the event that the worst case does occur, and the lead layup does crack, the last thing you want is for it to break free from the rest of the layup. In other words, you want to provide enough long fibers in the layup to hold a cracked assembly in place so it does not jam your elevator, then, hopefully you will notice it on preflight inspection. This is just my take on it, I could be wrong, but, if I was going to do it this way, I would use a combination of cotton flox for strength and rigidity and milled glass, also called glass kitty-hair. This is not the bondo replacement kitty hair. They are 1/2" milled fibers that will provide extremely good tensile strength throughout the layup. I would also be tempted to lay along the longitudinal axis, strips of 10oz cloth. In other words pour a little of the shot/flox slurry and lay in some strips. Am I paraniod or what? This will not yield a brittle mixture as long as the resin content is not too high. Or, you can just get some really big lead weights, grab em with plyers and just melt them into a pool around some bolts with a torch. Its quick and easy and does not get brittle. But please don't just pour lead and epoxy resin. Flame away Eric I agree with Vince with the exception of casting them in-place. I did so with the rudder and it turned out perfect. You can see pictures of how I did this on my website. Just look in the F1 Rocket section under Assemply Pictures for the Rudder. Randy Pflanzer BTW...re elev counterweights flox vs epoxy...me 'n Ken Fowler poured my weights directly into the arm, using old lead wheel weights melted down on a camp stove retained by -3 bolt (2 of them). You can create slight undercuts that ensure the weight won't be released. Same method used on his a/c. 500+ hrs of kick ass acro on his HR2, still ok. I have 37 hrs now, easy to check each preflight. seems ok. Why not make it simple? I don't think it is that critical in this particular design. seems like most Van's based designs don't have flutter problems...just make sure it can't come loose, and check them each flight. Beep, beep Other than the obvious ED clearances, is there any wisdom or pitfalls in locating the hole in the elevator horns for attaching the elevator push tube. I assume centered in the fwd/aft dimension is preferred, if that will allow acceptable CS deflection. Tom #15 I do not have my plans here but the hole goes in a more forward location in the elevator horns. If it were further back the rod end bearing will contact the horns in the up elevator position. Tom martin Yep, The hole has to go more fwd than center to keep a collision from happening there. Regards, That's what it looked like to me, but I'm often wrong. It would appear that length of eyebolt exposed will determine leeway. i.e. more threads, more room before interference. Naturally there must be a safe margin of threads engaged. Thanks for the input, Tom Hall What configuration does the down elevator stop take? I relieved the rear cross Bob I used the heads of the bolts that hold the rear spar of the horizontal spar to the fuselage. The bolts are the lower two of four. If your horns are not quite even you can place or remove a washers to get both horns to contact at the same time. You should be able to get at least 23 degrees of down travel. The last time I spoke with Mark he was going to rewrite the manual to give a range of 21 or 22 to 25 degrees down. It is highly unlikely that you will ever use this much down elevator in this airplane. The "up" travel is 30 degrees. Tom Martin Tom Those are the bolts that hold the center bearing and gave me 23.9 down which as you say is plenty. Thanks Bob W I'm rigging the elevators. When I measure the down travel, I only get 22 degrees (instead of 25) before the elevator horns hit the second-to-the-last bulkhead. Is it worth carving out the bulkhead to get the remaining 3 degrees or should I leave it as it is? I have to guess that others have run into this. On the up elevator travel, I get 30 degrees by mounting a 1/4" bar stock across the rear bulkhead on the inside and letting the horns hit it. Is there a better way of setting the up stop? Suggestions and comments most welcome. Randy #95 Randy, I get 22 deg as well when the elev horns hit the HS attach bolt heads. No more throw will ever be available. I built a massive bracket to replace the little one that goes at the base of the VS (the anti-lawn dart bracket). This new bracket was fitted to also act as an up elevator stop. Works fine. Made it from 1.5" X 2" X.125" angle cut down to fit. You cans see the bracket in this picture. As for Mark F. I had some difficulty early on with the whole Scott "bulllshit artist extraordinaire" Brown thing as well ("it only takes 800 hours to build..."). When I came to the realization the F1 really wasn't a kit, but a fantastic assortment of parts that I must "build into what ever kind of airplane I want", I found peace with Mark. He helped me build these parts into the airplane I wanted. He has become a good friend whom I've spent many hours sharing ideas with. His service has been impeccable, his enthusiasm unbridled. Sure there have been frustrating times, but Mark ALWAYS fixed it. Period. Warmest regards, Bob Gross Thanks Bob. I'm not hitting the bolts yet so it is "technically" possible to get the additional down elevator travel, but I think I'll leave it as it is. I did notice in your recent pictures the larger "anti lawn dart bracket". I am considering remaking this bracket to also act as the down stop primarily because I trimmed the bottom flange back per the pictures in the manual and now it looks like that was unnecessary. I think I'd like the extra strength back there. BTW, it looks like you are hiding part of your paint scheme underneath he blanket covering your cowl. Looks like some fancy graphics, but can't tell. Is there more to show us? Randy #95 This will work fine for both the attach bracket and the elev stop. I'd keep an eye on the bracket to make sure the elev horns don't nick the bracket and give a stress point where one is not needed. I doubt that a larger bracket would cause any additional stress at the fin aft spar -- but sometimes adding a larger part in an assembly can do just that, by making a local point less flexible than it should be, causing a stress point. My intention for the elev stops is to put 'em on the torque tube: a pair of double nutted 1/4" hardware store bolts would do the job -- one on the front horn, one on the aft, adjusted so the stick pivot hits them at the desired travel limits. Kind of like the aileron stops in a J3, if you have ever seen those. Cheers Mark Q: are there any rivets outboard of the Hi Dave I don't have two AN3 dies so I tried using an AN4 on the manufactured head and the AN3 on the Danny Melnik in Florida did a wonderful job with flush rivets and bonding. Maybe we could get him to describe RE: Rudder/Elevator TE rivetingIt sounds like flush rivets is the wayto go. Otherwise set them first with a flat Horizontal Stabilizer Mounting I'm in the process of mounting the H Stab and am wondering about what approaches have been successfully used for placing the 4 AN-3 nuts under the fwd spar. Mark F suggests using 4 nut plates to ease the installation as opposed to making access holes in F-19 in front of the fwd spar. Is there another/better way than the nut plates that seem rather flimsy compared to using AN-3 elastic nuts? Thanks, Mark Yelich, Custom Aircraft Builders #86 Mark It is possible to reach down, up and around with one arm, and put these nuts in place. This has to be done before the vertical stab is installed. I have found that foul language helps the process greatly. Tom Martin Mark, I used the nuts, and after experimenting for the first 100 flying hours added a 1/8'' shim elevating the leading edge of the horizontal stablizer. This was done to offset a down elevator condition at cruise. To get to the nuts I had to crawl thru the fuselage, and hold the nuts while someone else removed the bolts and added the shims---quite uncomfortable, but possible.(HA) I'm not suggesting you add shims now. Fly the airplane first and check the elevator. I started with a 1/16'' shim and that was not enough. Mark had commented earlier that he had done the same to a HR ll and it added several MPH to cruise. It did help mine, and I'm still working on how much. It is not uncommon to have this down elevator condition at cruise, and it gets worse as you add weight to the rear of the airplane, i.e., passengers and baggage. Jim Cash Tom the answer is no. I tried to figure a way when adding the shim. It's not made like an RV-6 or 4. After assembly, you will have to crawl down the fuselage to remove/add the nuts, which isn't that bad. Jim Hey Jim: I hear you had some comments used on TV the other nite -- tell 'em like it is!! At any rate, I suspect your emp was set up like the RV-4, which isn't quite right for this ship. The fellas setting up per the assy manual are reporting elevs in trail with a med load in the rear seat, but that is also affected by the equipment up front (YMMV). Sounds like a good compromise -- tweaking for all conditions is not possible, considering our wide CG range. I'll be interested in any speed gains you see after changing the emp setting. I also noticed differences in full fuel speeds vs 1/4 tanks when flying solo X/CY -- this is supposed to be negligible if it's a simple gross wt change, but it isn't (4-6MPH difference, faster with less fuel, likely due to the rearward CG shift). As for using platenuts instead of nylocks, there isn't supposed to be any pull-thru difference in strength. Keep Cool up there in Montana! Mark If you have apprehensons about using nutplates you can always use more nutplates and bolts than is called out in the manual...maybe three per side. Most of the stresses of the HS are absorbed at the rear spar. Bob #80 G'day gents, Mark is correct regarding plate nuts, they have the same rating as a normal self-locking nut. The only consideration is the additional holes for the plate nut retaining rivets, but in this case, it's not an issue. If you're concerned about it, take a look at the single engine Cessna fwd. stab. attachment sometime, it's scary. BTW, for you guys freezing over there, it was 44.8C here at BK airport today!! Regards, Ron Graham (Oz, #106) Just started mounting horizontal stab and can't believe what I am seeing. Looks like I will need a .63 shim under the front left to level and I will need a .80 shim behind the right F-011 attach bar to hold the horizontal square to the plane. Wonder if I have the most crooked bird in the lot. Very disappointing. #96 John Wach John Overall the kit quality is outstanding. Don't get discouraged by something that is easily fixed with shims, etc. Having built an RV6, Stewart 51D and Pitts Model 12 I can tell you that with the exception of the Model 12 the F1 is by far the finest kit I have seen. Mine needed a few shims on the left also. Suck it up and move on. Blue skies Bob W I'm up in the air between popping them on using the small stainless screws that you get in the Clevland wing tip attach kit. If you are going to paint them attached to the control surface, I'd just pop em and use the old drop of epoxy in the pop hole trick. Makes the popper look like a normal rivet. Pretty anal huh? Is there any secret to where the holes go in the lower rudder horns for the torque tube? I was planning to locate them as low and forward as possible while still maintaining proper edge clearance. I had a slight problem in this area on my RV-6 and would like very much to drill the holes in the proper location the first time. Any advice would be appreciated. BTW, I couldn't find a word about this important connection anywhere in the plans. It is possible that I missed it somewhere so if I did, could someone please point me to the right chapter in the Manual? Thanks a bunch. Randy #95 Randy I placed this hole as you suggested. On the two planes that we had here there was about 1/4" gap when the rod end bearing was placed between the horns. I riveted a 1/8" spacer to the inside of both elevator horns. This eliminates the need for washers and at the same time gives the bolt more surface area. The spacers are about an inch and a half to two inches long. Tom Martin
Hi Folks, Does someone know the distance the rudder pedals travels from neutral to full rudder throw?? This might not be exactly correct for those using an F-1 tail, but my RV-4 rudder swings just under 2 1/4" from neutral to the stop when I measure the movement of the cable. I installed these things yesterday so it's still fresh in my mind. So, that would be about 4 1/2" total travel. I had to make my own rudder cables since I have a hybrid. I ran the entire rudder cable through some polyethylene tubing, same as I did on my RV-4 years ago. The tubing makes it a snap to feed the cable through the fuselage, but you do have to install your own cable eyes on one end. I put mine up front and have the usual factory swaged fitting on the aft end. The tubing should keep the cable from wearing a groove in the snap bushings for a loooooong time. I don't get any of that "sawing" noise that some rudder cables make when moved. When installing the adjustable links between the cable and the pedals, I left about 1/2" of space between the firewall and the depressed pedal. When I stomp on the pedal the slack in the cable eats up that 1/2" but the pedal doesn't hit the firewall. I also cut off the lower forward corners of my (Van's supplied) rudder arms so that I had a bit more legroom. YMMV, remember I have a hybrid RV/Harmon/F-1 and none of my parts like each other! Vince Mark or anyone ? On the Empanage plan it shows adding an addition attach angle to hold the R-003/031 rib to the 002 spar. I don't see it actually listed as a part number and didn't find a part in my kit that looks like it. Is this something we are supposed to make and if so out of what material and to what size ? Make this little part from some .032 angle if you have any. If not then just bend a scrap of .032 to do the job. Make sure that the radius of the bend is not too tight, use the bend on the spar to give you an idea regarding what the proper bend radius should be. Tom Martin Make it from .032 material, as would be used on the floor panels.... Cheers Mark Vincent, The part you are referring to is just a short piece of those long 3/4" x 3/4" x .032 alum angles. It is an additional reinforcement. Just eyeball the length (about an inch or so). I found a 12" drill bit to be really handy when match drilling the angle to the spar. Check and stabilize the rib to spar angle (90 degrees), drill, and rivet ! I have pictures, if you need 'em, contact me directly. Brian #28
I've just completed drilling the HS skins and it would apprear that countersinking with a microstop mightwork just as well as dimpling. Tests on scraps suggest that microstop/countersinking with skins still attached to skeleton is straight forward. Sounds like a good way to ruin a HS skin. I never countersink unless absolutely needed and then never use a microstop device. It seems way to inconsistent. I'd stick with the proven dimpling method. Just my $.02 ... Bob Gross Bill - I had some friends in a professional repair station helping me and we countersunk the eponage skins and used 1097 revits. Mark kind of wrinkled his nose at this but these guys work on every thing from B17s to business jets. Of course I'm not flying yet so it's yet to be determined if we were wrong. Jack #70 I agree with Bob. I is too easy to make a mistake and ruin an otherwise perfectly good skin. I also believe they are a little on the thin side, and you will get a perfectly good look result from dimpling. Now that's my 2 cents. Good luck, Jon Wood #73 Hi Bill, Don't do it. Dimple wherever you can, only countersink when necessary (i.e., metal too thick, etc.) The 1097 rivets are the exception. The reason why you don't want c/s is you will eventually get "smoking" rivets where they are working loose because the metal is too thin and vibration will easily work the rivets loose. If you go look on a high-time RV most likely you'll see a lot of replaced rivets or black streaks on the tail areas that were countersunk. My HS is dimpled and have had no problems. However, on my VS I countersunk and I have rivets working loose. Bob Japundza RV-6 300+ hours F1 #80 Kokomo, IN If I can shoot my mouth off here. I just finished a late model emp kit (#71). The cuts Mark calls out for the trailing edge cuts (along the rear spar) on the HS skins were dead nuts. That is exactly what the skins needed to be cut to to allow the elevators to swing correctly. I would make these cuts before riveting on the skins. Now, a lesson (golden rule) I have learned building things out of aluminum and rivets says to never cut anything until you have to. I recomend riveting the HS skin on with no cuts at the outboard skins, this of course assumes you will be as concerned with the gaps between elev and hs as most builders are. When your elevators are done, you can wedge the counterbalance arm in between the overhanging skins of the HS and pin them in place with the bearings. But first, make a line on the elev counter balance 1.5 " from the inside edge of the counterbalance skin. Run this line the length of the counter balance arm. Do the same on the leading edge of the counter bal arm using a block to square the rounded radius. Now cram the elev in the skin over hang and pin it with the bearings, you may have to do a prelim cut of the hs skin to see the marks. Just measure from the 1.5 mark now and that will show you exactly where you need to make the cuts on the hs skins and the gaps will be perfect to elevator counterbalance arms. You of course will want to add whatever gap you want to the 1.5 measurement. Cut a small gap first and then open it up slowly as you prove to yourself you are screwing the pooch. You will have perfect gaps from this. As far as how the hs skins fit the frame, the rivets will take care of tendency to wanting to open up. I put a board on the LE of the hs skins with my fat butt on it and could not change the bend enough to mention. My skins never were even close to laying on the skeleton. I made wood clamps that fit the ribs of the skeleton to clamp the skin down while drilling. Don't sweat this, the rivs are the cure for this problem. It will come out fine. As for the rest of it, just make it work, its a pretty low tech assembly. Hope it helps Eric #71 While the manual gives you the option of using blind rivets in some of the more difficult areas, I found them unnecessary. I used AN426AD3's for all of the skin. It wasn't that hard and IMHO they look better. Danny Melnik F1 #25 Melbourne (FL) Rocket Factory I did not find it necessary to use blind rivets on the HS skins. The only hard place is the center tip rib. Take your time and you can get a bucking bar in there. You may have to make a bar that will fit. In my case I have had to make a couple of "non-standard" bars. I did end up using AN426AD3-3.5 rivets for the skin. I think they give a better, stronger shop head. Jim #60 When riveting the forward spar in my HS, the bucking bar (all by itself without an help from me, don't I wish) made a small raised dent in the HS skin -- Only visible in reflecting light from an angle. I've heard that supercooling with dry ice can sometimes shrink these things. Any hints on how to smooth it out? Sometimes if you take/borrow a tablespoon from the house it can be used to "rub" marks out. Place your thumb in the spoon and firmly rub over the dent. Make sure that you have some solid backing behind the metal, a large bucking bar, or back rivet plate. Try it on a sample dent and see how it works. A small amount of lubricant may be needed to minimize marking of the skin. This will work on small marks. Have fun. Tom Martin It takes a lot of patience, but using a piece of wood (like a those free paddles they give you free at Home Depot to stir the paint) rub/massage the skin back and forward with the side of the paddle over the affected area. If the dent is deep, you might need to tap it with wood several times (not hard). Takes time and patience, but it works and you will never be able to tell it was there. I showed this method to Mark and at the end it was perfect. Saludos, Luis 21 Used a wooden kitchen spoon -rubbed it back and forth over the bump - worked like a charm!! The drawings that I have show the trim tab hinge mounted to the underside of I'm ready to rivet the horizontal stab skins, but before I do, I want to Hey Ron: All OK at my lace, but some other aren't that lucky. Geez -- no rain for too long, and too much all The problem is the skin on the tab is too thin to countersink. It must be dimpled. Which means something Hey Scott: We talked on the phone. I told Danny that I'd prefer that he machine the hinge material, which will I don't see how you guys are dimpling the hinge material, every time I've tried dimpling it will stretch the soft With Marks OK I went ahead and sandwiched the hinge between the skin and spar. I dimpled the skin, machine Before I trim the skin on the vertical fin I'd like to make sure I've got the The primary dwg to observe is on P59. You will trim the TE after drilling the skin to the skeleton, using the
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