USING LAYERS KNOWLEDGE AND UNDERSTANDING After completing this module, you will know and understand the theory regarding: layers different layer settings the use of layers in templates APPLICATION OF KNOWLEDGE After completing this module, you will be able to: create, set up and use layers effectively customise and update layers as part of templates ASSESSMENT After completion of this module, you will be assessed on: your knowledge and understanding of layers, layer settings and the use of layers in templates your ability to create, set up and use layers effectively and to customise and update layers as part of templates your saved and printed drawing (Drawing Tutorial 10K) your updated portfolio. Marks will be given for neatness, completeness, correctness and presentation. (Refer to the chapter on portfolios for further details.) Chapter 18 - Layers 117
LAYERS AND CAD CAD and layers are synonymous. Layers are used for several reasons. Firstly they help to keep the work space uncluttered as unused layers can be switched off from displaying. Secondly they allow for specific line attributes to be associated with a specific type of object. For example, all the plumbing in a drawing can be drawn in the same colour, line thickness and line type without having to adjust it each time. Layers also make it possible for selected parts of a drawing to be displayed or printed. You only want to give the wiring diagram to the electrician, not the entire house plan. You can also use this to lock the layer that contains your template against editing. It is simply bad drawing technique to draw everything on a single layer and change object properties individually for different objects. Working with layers should also encourage you to use more colour in your drawings. Drawing in colour makes for a higher visual impact and easier interpretation of drawings. You should begin by creating up to ten new layers. At least two will be for construction lines and two for your final objects. The other layers will be used for objects with unique line characteristics such as hidden and centre lines. It is a good idea to use the bolder colours such as black, red and dark blue for objects that will be printed. Construction lines can be made with colours that won t print well, such as yellow and cyan. Use your initiative and create your own style. USING LAYERS IN AUTOCAD The Properties toolbar The Properties toolbar displays the current layer settings and also contains a few layer functions. They are explained below: Make object s layer current. The current layer is the one that you are working on. If you want to work on the same layer as an existing object, select that object and click this button. Layers. This button opens the Layer Properties Manager. You can set the different layer attributes here. Previous. Restores the previous current layer. Layer properties. Shows the layer properties for the current layer. This can be changed by clicking on the down arrow and then clicking on the objects you want to change. The property symbols are explained below. Layer on/off for display in the current viewport. Freeze/thaw all viewports. AutoCAD does not display, print or regenerate objects on frozen layers. Freeze/thaw the current viewport only. Layer locked/unlocked for editing. Pen colour and name associated with the layer. Using this box to change layers is the the suggested method for changing the attributes of lines for drawing purposes. Even though it is possible to use the colour boxes shown below to change colour and line type, it is not good drawing practice. Layer colour. This box shows the pen colour setting for the current layer. The recommended setting is By Layer. Layer linetype and lineweight. These boxes show the line settings for the current layer. Linetype is for printing and Lineweight is for display. The recommended settings are By Layer. 118 CAD for EG&D - Grade 10
The Layer Properties Manager The Layer Properties Manager is opened from the Object properties toolbar with the Layers button. This is where you can create new layers and pre-set the attributes for each layer. Editing the layer name Select the layer. You can now edit the name by clicking on it. Creating layers Select the existing layer and click on Show details. To create a new layer, click on the New button. To change any properties, click on the relevant text or picture icon. Changing colour To change the colours, click on the colour box or name. You will be presented with a choice. As far as possible stick to the standard colours for easy reference. Note that the black on the standard colour box is actually a two-tone colour. It will display white on a dark background, but will print black. Changing line types If you find that you have a limited choice of line types, you must first click on the Load button to load more options. Once you have loaded, make your selection. When you have finished creating your layers, click OK. Test the different layers now to see how they display on your screen. USING LAYERS IN ALLYCAD The Properties display is part of the Command bar and displays the current layer settings. It has four display boxes. The first box is for the command line. The second box displays the pen colour of the current layer. You can change this colour by clicking on one of the colour blocks of the Color toolbar. You can also change it by clicking on the Pen box. You will be presented with a Select Color dialog box. If you want to, you can choose here to make use of AutoCAD colours. It is not recommended that you use these methods for changing pen colours. Toward the top of the Select Color box, you will find a ByLayer button. Click on it and click OK. The third box on the Command bar displays the active line type for the current layer. Click on it and select ByLayer. It is located second from the bottom. The last box displays the names of the existing layers. Using this box to change layers is the the suggested method for changing the attributes of lines for drawing purposes. Even though it is possible to use the other boxes to change colour and line type, it is bad drawing practice. To create and edit layers, select the Layer Settings option from the Settings menu. This will open the Layer Settings manager. If you want to edit your line type, click on the drop-down arrow at the right of the Linetype control box and choose Other. When the Linetype Manager opens, click on Show Details. This will allow you to apply a scale factor to your line type. You can also load more line types from here. Click on the specific line to see how it will display. When you are finished, click on OK. Chapter 18 - Using Layers 119
Creating and deleting layers Right-clicking on layer 0 will give you the option of creating a new layer. Right-clicking on any other layer also gives the options to delete the layer or make it the current layer. The name of the current layer will be displayed in a different colour. Deleting a layer does not immediately remove it from the list, but it will be removed once you have closed the Layer Settings manager and opened it again. Double-clicking on the layer name allows you to edit it. On the right hand side of the box are two arrows that can be used to change he layer sequence. Select the layer and click on the arrow as many times as you need to place the layer in the required position. Setting the current layer A layer can be made current by right-clicking on the layer name and choosing Make current layer. The current layer can also be set with the Set current layer tab on the Settings menu. Setting layer visibility Layer visibility can be changed by right-clicking on the Yes/No in the Vis column. You can also use the All layers and Current only options at the bottom of the Layer Settings window. Layer visibility can also be set from the Set visible layers tab on the Settings menu. Locking layers To change the line display or lock status, right-click on the Yes/No text box below the headings Vis and/or Lock. The current layer cannot be made invisible, but can be locked. Magnification factor The Mag column is for entering the layer magnification factor. AllyCAD can have several scales on one drawing. Each layer can be assigned a different magnification with respect to the scale of the drawing, except layer 0, even if you have renamed it. A magnification of 2 means that any drawing on that layer will be twice the size that it was drawn at. If it was created on a 1:10 scale, it will now be on a 1:5 scale. You can also change a layer s magnification using Expand from the Tools menu or Change magnify factor from the Settings menu. Changing a layer s magnification will not affect existing objects on that layer. It will only affect objects created afterwards. Pen colours Right-click on the Pen colour to change it. If you are using AllyCAD colours, you can add more colours and define custom colours by right-clicking on one of the standard colours. It is recommended, however, that as far as possible you stick to the standard colours. Highlighting layers You have three options for highlighting layers which you can select at the bottom of the dialog box. The highlighting refers to the way objects from different layers are displayed in the drawing window. No Highlight. If you check this option, no layer will be highlighted. No 8 Pen If you check this option, all the layers except the current layer are drawn in a dotted line type. This option is useful for drawing in the current layer with reference to the other layers, but without these other layers being intrusive. Rainbow If you check this option, each layer is drawn in the pen and line type associated with it, regardless of whether or not you are setting pen by layer. Rainbow is useful for isolating items that have been drawn in an incorrect layer. Saving Layers If you want to re-use your layer settings, you should save them. You can then always load them again when you need to. You can also use this to create different layer settings for different applications. A magnification of 1 is normal. 120 CAD for EG&D - Grade 10
Drawing Tutorial 10K: Layers - Perspective Prism TIME ALLOCATION: 1 HOUR 1. Load the template you created in 10A. 2. Update the template by adding at least 5 layers. (Eg. construction, center, hidden, dimension, draw.) 3. Differentiate between the layers with name, color, line-type and line thickness. 4. Set the line display thickness and save your new template. 5. Start a new drawing with your new template. 6. Name it and save it in the correct location. 7. Update your title block. 8. Choose an appropriate scale. 9. Draw the Perspective Prism shown on the next page by using 1-point projection. 10. Make fully use of all your layers. 11. Make sure that you save regularly. 12. Show all dimensions. 13. Adhere to the SANS regarding mechanical drawing. 14. Print and save the final drawing. 15. Update your portfolio. Chapter 18 - Using Layers 121
Drawing Tutorial 10K Layers Perspective Prism Name of Learner Name of FET Institution Scale Date 122 CAD for EG&D - Grade 10