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  • Making brass chassis

    Okay, I wanna try making a brass chassis. I'm gonna make a plain pan chassis using .020" sheet brass. Questions are:

    1. What do I use to cut the sheet accurately that results in a straight edge? Surely not a hacksaw!

    2. What do I use as a break (to bend the sheet) that results in a straight bend at say 90 degrees? Surely not a pliers!

    Suggestions from the experts? Maybe Chris Walker?

    1hd

  • #2
    Hi Chris
    1 A hacksaw with a fine tooth blade is good for cutting .020" sheet brass, how straight it will be depends on the skill of the man holding the saw. Mostly this is finished off with a file, although some skill is needed to get it accurately straight. To overcome inaccuracies with a hacksaw, its best to cut a bit over width and file it to the exact size needed, the less accurate the cutting the more oversize it needs to be before filing.

    A double sheer cutter can be used instead of a hacksaw for brass that thin. These leave the sheet flat. A pair of tin snips will cut it easily enough, but getting it flat afterwards is a problem. It's rare to find anybody who has the skill to get the sheet properly flat who hasn't also got the skill to cut a straight line with a hacksaw.

    2 Clamping the brass sheet in a smooth jawed vice and using a metal bar to bend the sheet works well. Depending on the amount of spring in the sheet, it may need bending some way past 90 degrees to end up with a 90 degree bend. To do this clamp the sheet against a metal strip with a bevelled edge so it can go far enough past 90 degrees.

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    • #3
      Take a look at the Micro-Mark website, they have a variety of small bending brakes, bending dies, shears and nibblers.

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      • #4
        You can also cut with an abrasive disc on a dremel with this thin material.

        When hacking with a saw, back the metal with a thin piece of wood to keep it from flexing.

        No doubt you will end up standing in front of a bench vice with a file in your hand as well. For me, there are enough options in the K&S brass rack at my LHS that it is a case of cutting tubes to length and assembling on the chassis jig to solder.

        It is addictive and fun!

        BR,

        Dave


        Originally posted by OneHotDog View Post
        Okay, I wanna try making a brass chassis. I'm gonna make a plain pan chassis using .020" sheet brass. Questions are:

        1. What do I use to cut the sheet accurately that results in a straight edge? Surely not a hacksaw!



        1hd

        Comment


        • #5
          I don't do many pan chassis as they are a bit heavy but have done a few. I sketch/etch the final chassis on the brass with a number 1 knife using a straight edge and cut it with a dremel then file it till it's sized correctly. I hope you have a motor and axle bracket as they are a pain to fabricate. I use a small hobby square and a cheap bending jig or just pliers for the front uprights and check and double check to square. Chris helped me with a design and comparing the pan chassis to one made with piano wire and then hanging bits off it I thought the piano wire chassis was easier to make. The hardest part is more than 1 bend in a piece but there are not so many in the chassis and you can design around it also. Tools are everything, a good flat tip iron, setup jig, (I have an old adjusto jig), small square, clamps and a well thought out plan. Once you've done a few you find some shortcuts that help at least in the soldering phase. These are very satisfying to build, there are a lot of great pictures on scratchbuild.com and we have some great 1/24 builders here that do it all. Good luck, looking forward to pics.

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          • #6
            When you say bend the sheet, is that for the front uprights? I would cut a slot and use piano wire bent at 90 degrees, the height and wheelbase will true up in the jig. If you're committed to bending the sheet I have ruined a lot of them trying so make that the first step.

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            • #7
              I agree with Biggy that piano wire is very useful for chassis building.
              The suitability of .020" sheet brass depends on the chassis design. It is suitable for some uses and lacks both the strength and the stiffness for other uses.

              It's very difficult to get several bends in exactly the right place in a single piece of brass or piano wire. One technique is to aim for either one or at most two bends in one piece.
              Another technique is to design 3 or more bends in one piece in such a way that they don't need to be that precise and can be adjusted slightly after initial bending so they are right where it really matters.
              Experienced builders often use both techniques on different parts of the same chassis.

              Comment


              • #8
                I build a few chassis.

                I use a variety of components....piano wire,brazing rod,brass tube and sheet brass.
                When buying the sheet brass from the K&S shop stash I select strips that are as close to the dimensions I need as possible........... so I dont have to do much cutting.

                regards

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                • #9
                  I have used .032" brass sheet, but never .020" sheet for a flat pan chassis. .020 is very flexible and I wouldn't think it would be stiff enough, unless you have additional bracing. I never tried to bend uprights and then drill axle holes, or is that drill axle holes and then bend? Too much chance for error. I solder flat strips with an angle bend, pre-drilled, for the uprights. And I use a torch to get the plate hot enough to melt solder. On some chassis, I've used HO rail for reinforcement or rails that extend beyond the plate. My latest work uses Slot Car Corner plastic uprights with set screw axle height adjusters at the front. For the rear, I usually just have a hole in the pan for a Slot.It pod! You have to get up pretty early in the morning to outbuild Slot.It.

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                  • #10
                    Here are a couple I have done and my SLOP Proxy car also. I built one for Bryan Warmack of 60's slot racing fame and another for Nesta.

                    Here is a Video of my SLOP race with the SLOP chassis as well. I use a cut of disc in a rotary tool or band saw, coping saw, hack saw etc. Bending the best way I have found is with a small vise with straight jaws and careful measuring. Good luck! It takes time to develop skills when cutting brass. Oh also I bend brass with the vise and a small hammer and a short piece of aluminum that I use to tap the bend over till its correct. I made these side pans but bought the motor and guide holders.

                    SLOP RACE CHASSIS
                    Last edited by HarVWallbanger; 07-16-2011, 02:19 PM.

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                    • #11
                      that car is very cool... love it !


                      I have a standard body on the way from another forum member and hope to pull off something nice......sometime??&^%$
                      Last edited by munter; 07-16-2011, 10:27 PM.

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                      • #12
                        Thanks guys.

                        Looks like .032" is the thickness I need. I was basing the .020" thickness on a slot car (lotus 19) that I saw in Model Car Racing mag. It was reinforced, it appears, with piano wire, and the motor itself (scuttler).

                        Mr. Wallbanger, do you think you could build a brass chassis for a strombecker lotus 19 1/32 scale? Cuz that's what I need.

                        Thanks again.

                        1hd.

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                        • #13
                          I sent you a PM. I would have to know some things like the tracks you will run on, tire you want etc... Gascarnut here also builds custom frames for people so you can contact him as well about a chassis if you like. He is one of the best.

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                          • #14
                            Originally posted by OneHotDog View Post
                            Thanks guys.

                            Looks like .032" is the thickness I need. I was basing the .020" thickness on a slot car (lotus 19) that I saw in Model Car Racing mag. It was reinforced, it appears, with piano wire, and the motor itself (scuttler).

                            Mr. Wallbanger, do you think you could build a brass chassis for a strombecker lotus 19 1/32 scale? Cuz that's what I need.

                            Thanks again.

                            1hd.
                            .032" brass plate chassis for Scuttler, with sprung motor/rear axle pod inspired by Slot.It (two coil springs at rear, one at front):







                            Front end is assorted bits of brass kit chassis from the 1960's, reshaped, cut, and soldered together.

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                            • #15
                              Very nice RL, how is the spring suspension in the rear attached to the axle bracket? I have two or three of these running, nothing so complex though but surprisingly quick. One is built as a Jag XK 120 that ran at Lime Rock and comes in at 97 grams and on a twisty course handles very well. Seems to be pretty close to an NC1.

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