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1967 Moto Guzzi V700 Corsa-Record

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  • #16
    Nice work Cliff
    your cut and paste work has me thinking of trying the bring my Austin Healey fender thread over from the other forum.
    David Bradbury

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    • #17
      Fabricating the bucks for rear fender, seat and tank.

      These bucks are more complicated than the few I've made in the past. Producing properly places, well-cut & tight fitting joints while using my bandsaw was a priority. I used furniture-grade 3/4" Maple faced plywood. These three bucks required less than 1 full sheet of plywood, including a few pieces that needed to be cut again. No glue or filler was used. Hands handling metal get dirty and smudge the wood, so I apply whatever I have available for polyurethane to the bucks after completion before metal shaping begins. This keep the bucks cleaner during use and they look better later, especially as the poly yellows and honeys as time passes.


      1. Rear Fender Buck-

      This is the least complicated buck of the three. It did require the most fitted joints to be cut. Good practice.

      Some pics show a short rear fender eliminator. Some don't. It even appears and disappears from the full fairing Record bike in the MG Museum, depending upon when pictures are taken. It doesn't seem to be a cut-down OEM rear fender.

      I estimated the general shape by taking a radius from the axle, at rest, to the fender mount on battery tray and another radius from the axle to the rear frame fender mount. then I merged these two on paper by eyeballing where the transition looked appropriate.



      This pattern was transferred to plywood, sawed and sanded on the large belt sander. A decision was made about the number of stations to be produced. Placement for eight stations was laid out on the blank-



      The cross section radius of the fender was copied from the battery tray and frame fender mounts. This was used to develop the pattern for the eight buck stations. These were cut out on the bandsaw. Then these were ganged together with screws so they could be sanded together to closely match. At first I sanded 4 ganged together at a time.





      After the stations were close, I began laying out sawing parameters for fitment on both the main armature and the individual stations. Practice is important to know how your bandsaw will cut, drift, the side of the line to watch and kerf as well as what will break blades, etc. Sharp blades drift less and break less (because they require less tension) than less happy blades. It's simple to braze a broken blade back together if it's still good & sharp. Doing that is not an inconvenience- it is another chance practice to make nice viable joints in metal.

      I made a simple transfer gauge from a piece of scrap-





      Then I set up the two stacks of stations to lay out the cutting lines. The transfer gauge was clamped in the benchmate, the stacks were centered and aligned and marked for cutting.





      After marking the tops, the transfer gauge was removed from the benchmate and the cut line was transferred along the adjacent sides.



      Then to the bandsaw to SLOWLY cut along these lines. Going slow helps limit blade drift between top & bottom and subsequent crooked cuts....



      After sawing, alignment and quality of cut for a tight fit can be checked by fitting over a piece of the same plywood. All was good, so none had to be recut- very cool. The two stacks are ganged together, face to face as the cuts were laid out, and trued all together on the belt sander.



      I did tune the sawed slot while they were ganged together with an improvise sanding board. Worked slow but helped make great joints.





      You probably notice a couple of the stations are missing corners. That comes from being cheap and using scrap from the previous buck....

      Then it was a simple task to use the same transfer gauge to lay out cut lines on the main armature, go to the band saw and keep moving forward-



      I did decide to relieve the edges of all the stations for a stringer along each side. Then put it together and tuned it up a little on the belt sander. Since it all fit well, it didn't need much..

      <br />

      I decided to remove a portion of each side stringer so it would be easy to install the buck in a vise while I was using it to save workbench space





      Add some polyurethane, let dry, sand lightly, tack, repeat as couple of times and it looks like store bought. very cool.



      On to the next one..














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      • #18
        Seat and Tank Bucks-

        The seat buck was more complicated than the tank buck, so it came next. The seat buck and tank buck building process were similar to each other. I thought I had taken more pics of the seat buck in process, but apparently not so there's not much to show. It combined similar joinery of the fender buck with a less repetitive composition. Individual station patterns were developed using posterboard patterns taken directly from the clay. This was done the same way as will be shown for the tank buck. read on..

        A few pics of the seat buck-

        In process-









        Finished, less polyurethane



        The tank posed different challenges. The tunnel is a more determinant and complicated shape to produce. Too many bike projects I've studied have tunnels that are only an afterthought not well conceived imho. the pretty outside is produced and whatever will fit is hidden underneath. Not cool. If you've had a variety of cool Italian tanks, you understand that some thought went into the various cut-outs and clearance bulges that differentiate certain tanks. So I began with the tunnel considerations to incorporate the tunnel shape into the buck.

        the original Record bikes apparently used a simple bungee cord, at least on the rear, to hold the tank in place. I'll probably not do that. I do need to clear the distributor cap, ignition coil and generator (planned to be changed to alternator). As mentioned, I've always favored the black urethane tank mounting bushing like used on my V7 Sport over the typical foam & electrical tape or water pipe insulation....

        Problem was that the V7 Sport bushings won't begin to fit around the larger top frame tube of a Loop frame. I searched at length for a suitable off-the-shelf item, like a sway bar bushing, but found nothing of adequate size. So I started making them. As an experiment, I sacrificed my only hockey puck. I made a fixture to hold it, sawed the center out with a hole saw in the drill press, used the belt sander to shape it and a 1/4" wheel on a bench grinder to cut the slot around the circumference. It was too hard (around 90 durometer) and too small in both diameter and thickness, but it looked like I could do it. I sourced enough black urethane spring die stock from a local craigslist seller and made what I needed.










        I also made two 1/2" thick bumpers to match the tank bushings. I'll mount these to help keep the tank vertical-



        Bushings on the frame-



        Along with bike details like the distributor and coil, these tank bushings helped develop the pattern for the tunnel as the buck was produced. I started by standing a spare moped crate over the bike to use as a basic measuring reference. Since the clay tank model was only a half of the tank with a flat plywood backside, it was relatively simple to trace a pattern of the uppermost profile of the tank clay. Then the clay was removed, the top tube was traced onto the pattern with a 1/2" allowance for the newly-made tank mounting bushings. Now I had the basic backbone armature pattern for my tank buck.





        I had previously decided to make two of these in order to construct the buck in identical halves. the joint between them will be the centerline along the top of the frame. These pieces were marked and cut from the same 3/4" maple plywood. The were temporarily attached to each other with with screws and dressed to match on the belt sander.

        As with the fender and seat, the number of equally-spaced buck stations was determined and laid out on the two plywood pieces. Joinery for this buck was more complicated. Proportionally deep notches or dadoes in this backbone would weaken the buck. It would be even worse if the buck was not produced in halves. Instead of complicated joinery, measurements were determined & the table saw fence was set to saw several strips of plywood. Smaller pieces of these strips were cut to length and screwed to each side of the backbone halves. A piece of plywood was placed between them and a transfer guage was used to keep everything in alignment. The small overage used to help index their placement was then removed, as were the through screws as this progressed. Before the through screws were removed, the entire assembly was progressively drilled to receive more substantial bolts and t-nuts. Now I could later separate the halves as needed. this all provides a simple means to produce a well-developed and robust buck. Very cool.



        Tank backbone halves, fully assembled-



        Now it was time to pull patterns from the clay tank model. There are many ways people capture and transfer such information. I do it regularly in studio. For this, it was especially simple because I had prepared properly.

        Nearly all measurement work in granite is referenced from the bottom or joint of the stone. Since this tank is flat on the bottom I installed a properly leveled flat platform barely touching the tank and extending beyond the bottom.



        The station locations were transferred from the armature backbone (placed on top of the frame with bushings) onto the joint platform



        These locations were marked with 3/4" wide blue tape.



        The station information was then transferred onto the clay tank buck. marking them directly into the clay.





        Because I had intentionally used the "wrong" clay (too soft for typical vehicle design work) the rest was simple. I cut poster board blanks with a pair of perpendicular edges, representing the vertical center line at top and horizontal bottom, successively approximated the general shape to remove for each face of a specific buck station until it was very close and the bury the poster board into the clay so I could directly trace the shape of the clay onto the poster board.

        <

        By cutting the smaller side first, the larger face could then be quickly trimmed to approx dimension to be fine tuned into shape. Before long, I had a full set of poster board patterns for each station which could be used in reverse to produce the partnering station for the opposite side of the tank. The basic station blanks were placed before being marked to saw and roughly sand into shape.





        I was able to similarly trace end patterns for the tank. This allowed me to make a pair of end stations to properly locate the tank front to back.



        When the individual stations were produced, 3/4" was removed from both the perpendicular edges to allow for the backbone plywood element and the bottom. the general bottom exterior shape was traced from the clay, while the interior edge was developed to allow clearance for the 1/2" tank bushings and the various engine-related concerns. This was not photographed. while wrapping up the bottoms, I was rushing to have the general bucks ready for a show display.



        No matter, when tank & seat bucks were on the bike, it was looking good even if it was still kinda square.





        and finally, I had time to move things along from boxy to curvy...






        These bucks look even better when they're on the bike-









        I still have some work to do fairing the stations on the tank buck and resolving the front corners. So far only a few bolts with Tee nuts and visible screws between stations and through bottoms into stations have been used. It is very solid. I will separate the halves and add screws to the stations through the respective backbone. I =have started adding spacers between the stations along the bottom to further strengthen the assembly. Then all will be faired and sealed with polyurethane.

        The fender and seat are both shaped in metal and awaiting trimming & welding. The next several weeks are completely full with studio work so I doubt there will be much Guzzi progress for a while. Getting the pics out of bondage to get this posted over this weekend has been great. For those interested, there will be more to come...



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        • #19
          looking forward to the shaping
          thanks neil

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          • #20
            Got a few spare minutes and Looking for input-

            The original bikes were just built to use like many in-the-moment machines, including the tank. I'm not wanting to build a sloppy bike but I also don't want to make it into a pristine overbuilt machine. The original tanks were not perfectly finished and I want to achieve similar results. The concave sides are my need for input. See the attached picture.

            it looks like they were shaped and then the sides likely manipulated to turn from convex into concave. While building my buck, I've thought a lot about making convex additions (with same surface length as the current convex portion of stations) for the stations to guide shaping, weld all portions together and then simply & somewhat spontaneously reversing the sides as they were probably done back then. It would be simpler and more current to make the sides into the final shape before assembly but I'm concerned about making it too precise.

            I understand very well how a chef usually ruins a good home cooked meal by "fixing" the recipe, ingredients and the process of how it is cooked. If he cooks it exactly like his grandmother did, it is usually much more authentic and enjoyable. Doing this tank the way they did it, instead of the way current advocates would do it, is what I'm thinking.

            What do y'all think?
            Last edited by cliffrod; 09-08-2019, 10:10 PM. Reason: minor text chang

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            • #21
              Hi Cliffy
              I think the tank finish makes or breaks the look of the bike,so should be the centerpiece, The rest can be function over form.
              Regards Dennis

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              • #22
                There isn't a lot to post about making the rear fender, at least right now. With a completed buck, simple dimensions and plans to make it longer & wider than needed so it could be trimmed to size later, there wasn't much need for a paper pattern. I took it to the Redneck Roundup as a casual project. All of these pics are a couple of weeks old.

                Of the various items to be made, the rear fender needed to be produced first. I cut out a blank from some scrap .063 thick aluminum that I got for free (Guzzi content) from an old motorcycle friend years ago. It's been here waiting for just such a use. The blank was fairly long, covering the full length of the buck and approx 4" wider than the final dimension. The only pic I have of the early stages is this one, after the blank was briefly worked with an arbor press. Puckers are visible along the edge, which will be employed to shrink the edges and develop the shape. I'm on left (apparently taking a nap...), Imperial Wheeling Machine owner Pat "PatMan" Brubaker is at center holding the fender blank and Bill Tromblay is on right. some of PatMan's arbor press tooling in the foreground was being used at this point. RockHilWill gets credit for this pic-



                The rest of the RR was a blur.... Seminars, Bugattis, great food & even better friends, .. Very cool. But no more fender pics. I had time for more shaping on the fender. By the time I left, I had a well-developed semicircle of lumpy metal that approximated the buck.

                When I got home to my less-complicated shop, I spent a little time on the stump further shrinking the edges & on the English wheel smoothing things out. it progressed very quickly. As the shape was resolved, I trimmed the edges that suffered the most attention during shrinking to remove unhappy metal.



                After that, I began turning a false wire edge along each side. This will both help stiffen/strengthen the fender and give it a more professional appearance. I marked the layout for the wire edge by gently using a slapper along the buck stations. Then I began turning the edge in slow increments along the entire edge of each side using a slapper & sharp dolly plus a hammer when things got tight.



                As the edge is turned and begins to close, I used a length of gas welding rod as a mandrel to help create the false (hollow) wire edge. Some modify a set of pliers, especially on the portion that contact the outer edge to limit scarring of the metal. I simply use a pad, made froma scrap of the same parent metal as the job, to cover the potentially offending teeth while leaving the other teeth exposed for better grip. In general, like doesn't scratch like so there is no marring or damage. Very cheap, very effective.



                The pliers are used to close the false wire edge as tightly as possible while the wire can still be removed. After the wire is removed, it's tightened up a little more. I do plan to use a pair of pliers with longer handles & better leverage in the future. (edit- this pic was taken before the edge was tightened up....) These pliers did an adequate job for a first run on scrap metal.



                After all shaping was done and both sides were rolled with a false wire edge, the fender fits the buck pretty well.



                It still needs to be significantly trimmed to length once decisions are made about fender-seat-taillight arrangement.

                Seat progress pics are next.
                Last edited by cliffrod; 09-15-2019, 02:12 AM. Reason: see edit

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                • #23
                  Nice report Clint, and nice work as well.

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                  • #24
                    Getting there nicely Cliff .. the whole project is very nice good work !
                    Peter T.

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                    • #25
                      Thank you for the compliments, Will & Peter.

                      I'm saving all of them up so when I post some pics of my welds, all will still be good... Just finished making my seat into a single piece of metal.

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                      • #26
                        Top report as always from you Cliffy!

                        I have been wondering how to make a rolled-edge and your method to use wire and then remove it, may just be the solution I need,

                        Cheers Charlie

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                        • #27
                          It works fine for me, Charlie. I did debur, almost taper the trailing end of the wire. If not, it can be a bugger to remove from the rolled metal. I didn't remove the wire until nearly finished with turning the metal, probably 75%+. The wire would be really tight, almost impossible to remove. There needs to be a long piece sticking out and not too much trapped or it's impossible to just pull out the wire. There are protocols for the diameter of wire/rolled edge to be used for a given thickness of metal, but this project isn't quite that formal.. I just used what looks good.

                          Use pliers with longer handles than I did, especially to finish closing the roll.

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                          • #28
                            Another cut & paste from my WildGuzzi build thread. I thought about editing out the "how to" dialogue because most here know more about metal shaping than I do, but maybe someone someday will benefit from seeing how I did what I've done...

                            ###

                            Building the seat is more of a challenge, both with shaping the pieces and welding them together. I like to weld. Doesn't mean I'm great at it yet, especially gas welding thin aluminum.. the seat, just like the fender, were made from scrap I had for this first run. There's a lot of fitting to be done to develop the overall seat-fender-taillight assembly. The way I approached it was to make these parts, do what needs to be done to make them all work together and then remake them if necessary.

                            Not interested in CAD. I would rather make & remake parts including all welding to become better at craft than typing, For reference, this is the vast majority of my metal shaping gear- A HandBuilt cast iron English wheel by Peter Tommasini, a stump, a shot bag and a Beverly Shear plus assortment of hammers, dollies & a few other simple hand tools. I have a TIG but prefer to gas weld whenever feasible



                            Making the seat-

                            First, I used the seat buck to develop a paper pattern for the front portion of the seat.






                            The blank was marked, cut and bent.






                            I produced a false wire edge along the lower edges of the seat as well to help stiffen and strengthen it. The sidewall height of the seat is a concern, depending upon the mounting arrangement. This seat is longer than the original, with additional length added to front in area where I shortened the tank approx 4 inches. The top tube of the frame had little interaction with the seat on the original Record bikes. I may notch the front of the seat more for better frame/seat agreement or may need to do another seat pan later. We'll see. For now, the false wire edge-







                            I made paper pattern of one half of the seat hump. Folds denote areas where shrinking needs to occur and the amount of shrinking necessary can be mitigated by creating nearby areas with adequate stretch. When shaped, the two halves will be welded along the center line and then welded to the seat pan. After a pattern was in hand, both blanks were marked and cut. an ample allowance was produces around the edges, especially along the bottom where shrinking would be done. It makes shrinking a little more difficult, but will be easier to trim & clean up any defects created during the work.





                            First, I created some form in the metal by bending it to fit the buck along the center line. My plan was to not shrink this edge of the metal. since I planned to weld here, this would make a more more consistent area of metal thickness to help me produce a better weld.



                            Shrinking on the stump is done by striking the metal near the edge with a hammer over a hollow area of the stump. This raises a wrinkle or tuck along the edge, which is then hammered flat to trap & compress the metal. This shortened area causes neighboring metal to transition from flat to curved. If this curved area is them stretched by striking it with a hammer over a soft base like a shot bag, the curve is enhanced. By doing both processes in unison as needed, complex shape can be developed very quickly in aluminum.











                            After initial shaping and shrinking, the lumpy metal is rolled between the upper wheel and lower anvil of an English Wheel to smooth the surface. Additional pressure will cause additional stretching. simple contact without additional pressure (adjustment between upper & lower anvil is approx the thickness of the metal) will simply smooth out the rough surface.





                            Then, repeat until finished. Keep checking the development of form (simple bending) and shape (complex curves created by stretching and/or shrinking) by fitting the piece against the buck. Many times a piece may be shaped "incorrectly"- according to the fit on the buck- on purpose so it can be manipulated into the proper shape by another process. A good example is shrinking the sides of a motorcycle fender-shaped piece too much so that the radius is too tight. The piece is then pulled apart by the ends. this will simultaneously cause the radius to open up or increase as the sides drop down (deeper cross sectional curve) There was a lot of this done with the seat hump.















                            The first 95% happens pretty quickly. The next 4%, a little slower. The final 1% it the hard part. That's why it helps to understand how working the metal in a manner that isn't obvious will often produce the result you seek. When it actually fits the buck, it's very cool. After it fit, I turned a flange on the front of the hump half. I ended up not retaining this flange for welding as initially planned, but it was useful.











                            Then you do the other half and have two pieces to fit against each other, then trim in preparation for welding-









                            More to come..




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                            • #29
                              have you thought about trying to make that in one piece? you may find it easier than in two...
                              thanks neil

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                              • #30
                                I thought about making the hump one piece but did two pieces this time for a few reasons. When Peter was here, I asked him about a comparable seat I had been planning to make for my Harley Davidson Sportster XR750TT-themed bike. Still pending but now on hold. That one was a more complicated, but he said three pieces. So I did three pieces. I wanted to practice to make pieces that have to match, fit & weld before moving into this gas tank. It was also easier to find two pieces for the hump in my sheet of scrap than one.. i learned a lot lot with this one. The two pieces grew more than I expected in some dimension. The welds still need some repairs. Next time a one piece hump would probably be easier & faster but I really needed practice.

                                The fender made tight to the buck was too tight for the bike. I didn't marry the two radii properly. So I just pulled it open a little and it fits great at both front & rear factory mounts, so shouldn't foul the moving tire. Length has not been decided.

                                I also just played hookey from the studio for the last hour. I did a little work with the seat, planishing & filing down high spots on the welds at the false wire edge position. One side was sound and is now trimmed & rolled. It fits perfectly in relation to the fender. A little more work on the other side and I should be able to work on trimming the seat to begin taillight mounting, I'm pretty happy right now.

                                I just came up to grab this iPad for a couple more pics. Should be able to post the rest of my progress to date this weekend. There's two events on the first Weekend in Nov that are my goal for having seat/fender/taillight and hopefully tank buck finished to display. There's another one on Sept 28, but doubt all of this will be done by then.

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