#31
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Hi Mark. Yes! I'm willing to share the "corners" I got myself into and hope you and others can help guide me out of them. I'm a big admirer of your Daytona project and mention you often to people who ask me if car bodies can be build with a minimum of tooling. You focus on getting panels built rather than building a tool collection.
Okay, here's the story: I began the first panel yesterday by first making a Flexible Shape Pattern and then shaping the .063 alum. to it. The blue tape lines show my proposed panel join lines. I like the Ron Fournier (and others) technique of blocking out the panel with a blocking hammer and then smoothing it on the English wheel. I did some rapid shrinking of the front edge on my Mechammer. In a few minutes had the basic shape. A couple of things surprised me, however. Firstly, although I measured from blue line to blue line and allowed a 1/2" border all around, the panel itself barely reached each blue line as I laid it on the buck. I used a tipping die on my bead roller to bring over the front edge flange, but the curve of the panel is so acute that the panel edge hit the bead roller frame after about 80% around the part, and so I had to use a hammer and dolly to rough in the last 20% of the flange. I did not get that crisp enough, but would have done had I not then realized another problem. The nose buck does not "fair" properly into the subsequent buck stations. I believe this is because the nose was made last summer, and in the intervening 9 months as I tweaked the buck, I lost the original line. Upon finding out that I had to re-fair the buck, I learned that I must not shape just to the buck, but consider the next few stations. Because of that, I English wheeled intensively the very top of the panel so that it would fair into the next station, but as I did that, I got too much shape into the "2 o'clock" position (if looking straight on) of the panel and it has a bubble. From the "2 o'clock" position on down the buck shape is actually quite complex. It flattens out near the back edge, but folds inwards and around at the front. Trying to get that front edge to hug the buck proved nearly impossible despite the various shrinking methods I employed. MY CONCLUSION IS THIS: (Comments welcome) I believe that there is too much going on in this shape for it to be made by someone with my limited skill set. I think I should break the panel into two pieces. 1) The 10 o'clock to 2 o'clock piece, and 2) The 2 o'clock down to the bottom side piece. I also learned to be gentle with this foam and Bondo buck. I did some slapping with my spring steel (old Austin-Healey Sprite leaf spring) slapper, and got some cracks in the buck. I learned a lot from this first attempt, and am eager to get back to work on it tomorrow. COMMENTS WELCOME!
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Bill Longyard Winston-Salem, NC |
#32
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Bill how much time do you have in that part above the headlight? As you know my buck stations are much further apart than yours are. I think you can now see why I filled in some of my buck to get the lines to flow. See how the strip of metal is off the back edge of your stations? On mine where I did not fill it in, I cut pieces of metal Ruffly the shape of the station but larger and clamped then on to each side of each station and fill it in with fiber glass reinforced bondo to build it up . I then sanded it to shape so the metal strip touched all the way accross each station. Then when you use your strip of metal to see the flow you get a better idea of how it will look.
Some of my parts were not working good and I was going to start over. I put them down for an hour or two or three or maybe a week. Come back and try again and things work out. I may have more time in the part this way but I learn something from it. Mark
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Mark Last edited by mastuart; 06-04-2017 at 10:08 PM. |
#33
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Bill
I'm pretty sure that headlight surround needs to be three pieces all of about 120° around the headlight. And I feel your pain about fairing into the buck stations. You may know I chopped up my first buck and then completely wired over my second one. Now I am working on my fourth front fascia. This time I made it out of 1/2" and 1/4" MDF. It is layered so the parts that I plan on pounding on and into are solid MDF. It looks good but it weighs a ton. I will post a foto when the epoxy I coated it with kicks off. Tim
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Tim Freeman |
#34
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Tim, Thanks for sharing your process. I have now remade the part in two pieces and the fit and flow are excellent. I'll send pictures when I weld them together, hopefully by Friday.
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Bill Longyard Winston-Salem, NC |
#35
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The epoxy coating seems to be very tough and resistant to hammering. It has cured now so wish me luck.
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Tim Freeman Last edited by Steve Hamilton; 06-08-2017 at 02:19 PM. |
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In a previous post I said I was going to remake the outer headlight pod in two pieces. I did that and the fit is darn close to what John Glover would call a "vacuum" fit. I'm pointing to the weld seam. Silver tape on the buck was behind weld seam to prevent burning the buck as I TIG tacked the two pieces together.
I made a one-piece Flexible Shape Pattern for the panel immediately to the left of the headlight pod, but after three failed attempts to make the part... ...decided to make it in two pieces. The first piece came out very well and only took me a couple of minutes on the English wheel and Mechammer.... ...but the second piece took me four attempts, and I still have a rough surface. I consider this piece a "proof of concept" piece. I proved to myself the part can be made, but there is actually a huge amount of conflicting topography in this piece. A big reverse is next to a definite crown separated my a tight valley. It took a large amount of stretching to bring the lowest edge down into the valley that abuts the headlight bulge. Lots of English wheel, Mechammer, and hand hammering involved. Three failed attempts, and this one not pretty, but shape is correct. At the thinnest point of the lower edge in the valley the .063 aluminum is down to .025. Yikes! SO MY QUESTIONS ARE: 1. Anyone have advice on how to better form this piece? 2. Is .025 weldable to .063? 3. Other advice? Thanks!
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Bill Longyard Winston-Salem, NC Last edited by RockHillWill; 06-12-2017 at 06:53 PM. |
#37
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Hi,
I enjoy following your project, I would like to make a Maserati 300s with an all aluminum body. I looked at the panel you are making today and have you made a paper template in addition to FSP? I find more information with paper over FSP as it will show "the level" of stretch or shrink. I have welded thin aluminum .020" to .125" material in aluminum in the past. However, though it is possible, I would question if it is the right course of action for your application. I would think, if possible, not to exceed thinning material more than 25%-50% of the base material thickness due to long term cracking issues. Sometimes, when I have a problem like yours, I try to make the part with the weld seam at 90deg to my failed piece. By changing the perspective, some times it exposes the solution. Good luck with your project. Cheers, Bill
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Bill Tromblay "A sign of a good machinist, is one who can fix his F$@& Ups" My mentor and friend, Gil Zietz Micro Metric Machine. |
#38
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Paper pattern for sure so you can see where need to go.
I would try that piece in one included with the other piece you did. Due to the shape and amount of shrink needed in the centre it would be more workable in a larger area. Then you won't have to worry about welding thick to thin or vise versa. At the moment you have a piece that is being worked close to the edge, so thinning is needed to gain shape. Your progress is going well so far, I admire your challenge.
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John EK Holden V8 |
#39
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Bill,
You should be able to rough this piece to shape on sand bag & stump, then when you are close, anneal it & mallet it on the buck too shape, you don't want to be welding in the reverse.
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Cheers Martin No matter how clever you think you are, stupidity is always one step ahead!!!! |
#40
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I think I would try to make the reverse shaped valley in one piece. Sort of like a bicycle fender only with a reverse curve shape. The piece would be welded to the adjacent bulbous sections at the tangent points of the adjacent curves. This way you would be minimizing the amount of stretch at the edges. Like others have suggested, start with a paper pattern of these areas to determine where and how much stretch and shrink are involved.
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Bob Don't believe everything you think. |
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