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Discussion of various buck types pros-cons-price
I got serious about shaping metal back in 2001 when I discovered the first international event had just ended in my hometown of Huntsville, Alabama. I joined the community the next day. This was FormFest '01 held at George King's shop and facilitated by Terry Cowan's Metal Shapers Association (MSA). Wray Schelin and Dutch Comstock was the key professionals who shared vast amounts of intellectual capital, time, and skills to help a bunch of mostly low skill, high interest guys learn how to do this magic stuff.
My first event was FormFest '02 also in Huntsville. The major focus was building a wireform buck for Les Edmonson's ZM2 roadster. James Bowler had his solid wood 1/8 scale model of his early 50's Ferrari 'ish roadster. The following year, the event was in Robinson, IL under the tent James had a full size wooden buck, station buck, or sometimes called an egg crate due to the way they slide together. On the MSA forum, there was much discussion of both styles. At these same time, Wray Schelin was proposing a new idea...something called a bondo buck. Wray left the forums some years back and I understand, but have not seen, a concept based on sheet metal bucks. In addition, there are no doubt other approaches. I have made every mistake known to man on my roadster project. http://allmetalshaping.com/showthrea...highlight=Deco But the number ONE mistake was not taking the time to build a hard buck that at LEAST forced me to maintain profiles side to side. Over the course of the project which will soon be in it's second decade, I've used wire forms, foam, sheet metal, bondo bucks, and wooden stations with varying success....or the lack thereof. I was under the impression that once I had one side done to my satisfaction, it would be relatively easy to duplicate the surfaces using little more than flexible shape patterns (FSP). Boy was I wrong! The other side has been remade multiple times just to get it remotely 'right'. It's almost there...maybe. And then we get into how you create the buck that will support the desired "SURFACE". That is where 3D CAD and scanning shows great promise. Prior to recent years, many people used manual bridges to capture X,Y, Z (Cartesian Coordinates) information and transferred that to wood 'stations' Getting the lofted surface (http://en.wikipedia.org/wiki/Lofting) to be a fair curve... A "fair curve" or line is one that is as smooth as it can be as it follows the path it must take around an object. A fair line is free of extraneous bumps or hollows, and an unfair line needs to be faired, or smoothed out. Any bumps or hollows will destroy the "look" in a heartbeat. Richard Kleinschmidt started a great thread on MM about fair curves but it was unfortunately lost when they had their 'event'. Regardless, let's talk about what works, what doesn't, lessons learned....
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Kerry Pinkerton |
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this should provide some great reading!
i came across this picture last year just before i asked jeffry if he could produce a file for a wooden buck for the front of my project. the one in the picture obviously is very sturdy but also seems to have large areas to see from behind that had been said is usefull BodyBuckPM.jpg
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Neil |
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Neil, that appears to be a production buck. As you say it is sturdily made but there is lots of access to see the fit. The nose is solid and obviously intended to be used as a hammerform. Notice the stump, mallet, and piece of aluminum to the right of the photo.
One thing to notice on this buck is the edges of the stations. Notice how they are sloped to follow the surface. A MAJOR issue with station bucks is that we must consider which EDGE is the contact point. Many people will run the material (plywood, MDF, ??) through a router to round over the edges so the contact line is the center of the station. If this is not considered, the spacing has to be modified in order for the curve to be fair. For instance, if you have a simple downward then upward curved surface, on the descending side from left to right, the contact is on the right hand side of the material (typically 1/2" thick). But as the curve starts to go up, the contact is on the left hand side, and at the very bottom, it is actually at the center. I think some of the new 3D cad automatically considers this but for a backyard hack like me, it can create some really interesting challenges.
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Kerry Pinkerton |
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Clay models
CLAY MODELS
Pro- Perhaps the only way to do manual true surface development Pro- Easy to make a mold or FSPs from Pro- Relatively easy to modify by adding or removing material and resculpting. Pro- Easy to add clay to existing panels to 'develop' alternative shapes and be able to see it in full size. Refer to Mike Motage Jag project.http://allmetalshaping.com/showthread.php?t=7593 Con-Expensive Con-Big Con-Heavy Con-Easy to damage Con-Still need to capture surface information in order to create a station buck Con-Not really possible to pull a FSP Con-Largely replaced by 3D solid modeling by the large automotive manufacturing companies
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Kerry Pinkerton |
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BONDO BUCK. I'm not sure if Wray Schelin invented this or not but he certainly spread the word. A bondo buck is a combination of a wireform and short strand fiberglas reinforced body filler. A good example of the creation of one is in this thread: http://allmetalshaping.com/showthrea...ghlight=Zepher
Less durable versions can be made with casting plaster and other media over some type of reinforcement. Pro- Relatively easy to make Pro- Relatively inexpensive Pro- Can make positive or negative buck (inside or out) Pro- VERY EASY to copy existing surface Pro- Can copy existing surface without damaging paint by applying protective coverings and release agents Pro- Can be made VERY, VERY durable Pro- Easy to design for backside access to the panel Pro- Easy to capture as much of the detail areas as needed (notice grill area of the Zepher buck) Pro- Can be used as hammer form if properly designed and constructed Pro- Required little skill or specialized tools Pro- Very easy to clean up using die grinder and sander to remove excess bondo and flash. Pro- Strictly manual Con- Strictly manual Con- Nearly impossible to build freeform, must be used to COPY rather than create. Con- Nearly impossible to reverse, that is, flip to the other side. Con- Not really suited for making a FSP from it.
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Kerry Pinkerton |
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Since you mentioned it Kerry , i will post these pics i recently scanned , I built the car before i had a digital camera .
Buck 1 fixed.jpg buck 2 fixed.jpg I did not make the wheel openings , i did that by hand and i used an air file to taper the stations so it flowed right . James Last edited by James Bowler; 02-28-2015 at 11:09 AM. |
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Kerry and all
Your welcome to take a look at my adventures to date: http://www.metalmeet.com/forum/showthread.php?t=11470 I had some discussions with Richard K about lofting and had thought about doing a demo at MM Oblong but there seemed to be only minimal interest. I have a bunch of photos of bucks that I will post when I can find them. They can be a little discouraging. Either a production buck made by skilled (not me) woodworkers or wire bucks made of wire bent in 3 dimensions (magic). An important topic, essential if you want to do something of your own.
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Tim Freeman |
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Thanks Kerry, this is an important part of what we do. So many considerations involved in building bucks such as time, equipment, money, experience, capabilities and goals. To begin our projects we need the goals identified!
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Mike |
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Kabous metal cobra buck sbould be here.
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Mike |
#10
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Quote:
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Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. |
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