Motorsport Fabrication Fundamentals: Marking Out and Measuring
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Marking Out and Measuring
04.16
| 00:00 | - Most of our projects begin with an idea sketched out on paper but to turn that sketch into reality, we need to begin adding some dimensions to work out exactly what we need to begin fabricating. |
| 00:11 | An A4 notepad, a grey led pencil, an eraser and a 300 mm rule on hand is all you need up to this point. |
| 00:20 | Once we move beyond the planning stages though, we'll also need to be able to mark out and measure the material that will form the basis of our finished part. |
| 00:28 | In terms of measuring equipment, an 8m tape measure is essential to have on hand when it comes to measuring out longer lengths of steel and tube. |
| 00:36 | Stepping down from the 8 m tape, a 1 m steel rule increases the accuracy when we need it and rulers step down in size from there to suit smaller measuring jobs from 600 mm to 300 mm and finally, 150 mm. |
| 00:51 | The technique used to mark out our measurements also differs depending on the tolerances we're working to which simply means the minimum and maximum deviation from your intended dimension that we'll tolerate. |
| 01:03 | This means that we can get away with a larger and more prominent mark on a larger length of steel that has a bigger tolerance requirement but when moving to a smaller tolerance requirement, we may need to use a thin tip marker for a sharp and defined line so we know exactly where we're working to. |
| 01:20 | These markers are available in many different tip thicknesses and can be matched to the size of the tolerance we're looking to achieve. |
| 01:26 | Another common marking out tool used in fabrication is the scriber. |
| 01:30 | This is a precision machine, hardened steel tool that's used to scratch marks into the steel or work piece. |
| 01:37 | When sharpened to a point, the scriber can give us a very clear and sharp scratch line in our work piece that gives us the best opportunity to stay tight to our desired tolerance. |
| 01:47 | A scriber will usually have a straight tip at one end and a 90° bent tip at the other, which makes marking out in tight areas a lot easier. |
| 01:55 | With the scriber covered, next we have the square which as its name suggests, can be used to scribe lines at a 90° angle to the face of our material. |
| 02:04 | This is a versatile tool that's capable of many different roles in the fabrication process. |
| 02:10 | An engineer's square has a precision ground edge with a thicker base that allows us to rest it up against the bottom face of the work piece that we're measuring. |
| 02:18 | It's available in sizes ranging from as small as 50 mm, all the way up to and over 500 mm. |
| 02:25 | As our tolerance decreases, we start to need specialised measuring equipment to ensure that we can accurately measure and check our dimensions. |
| 02:34 | Two tools worth talking about for this reason are the vernier calliper and the micrometer. |
| 02:39 | The vernier calliper is a tool that we'll be using extensively throughout all of our fabrication courses because it's the perfect tool for verifying and checking diameters of material. |
| 02:49 | You can use the vernier calliper to measure the inside diameter of a component by using the internal jaws or the outside diameter of the component by using the external jaws. |
| 02:59 | The digital version of the vernier calliper is easy to read and offers a zero function that's handy for measuring multiple items. |
| 03:07 | This tool is available in a series of different sizes, ranging from 150 mm up to 300 mm measuring capacity, with the 150 mm variant usually being sufficient for most of our purposes. |
| 03:20 | Then we move onto the micrometer which is a measuring tool that's available in many different styles for different measuring applications. |
| 03:27 | The most common one we use in fabrication however is the outside diameter micrometer. |
| 03:32 | This features two precision ground anvils, one of which can be used by the finely threaded thimble. |
| 03:39 | This spinning thimble has an index scale on it and the measurement is taken via the thimble and sleeve scale to give the exact thickness of the material between the two anvils. |
| 03:48 | The design of the micrometer means that they only span a measurement range of 25 mm which means that you may need multiple micrometers to measure the range of different diameters that you're likely to come across. |
| 03:59 | For accuracy and precision, it's hard to beat the micrometer but while they'll likely be commonplace for motorsport machining operations, it's less likely that you'll need their precision for most mainstream fabrication tasks. |
