pheloniusfriar | Entries tagged with software

I have spent weeks (not solid, more as a background task) trying to figure out how to produce a silkscreen for a set of front and rear panels I have been working on. As I indicated a while back, I am learning AutoDesk's Inventor 3D CAD software. In general, I have found it to be an intuitive and powerful package; however, to finish the job, I needed to produce the artwork so I could get a silkscreen done (just some basic lettering for the faceplate for some of the electronics controlling part of an experiment to go into SNOLAB). Well, whatever intuitivity (my invented word of the day) there may be in the rest of Inventor, it doesn't exist when trying to do a silkscreen. All the web pages I read talked about how to add lettering to a design, but didn't explain how to export it to what was once called "camera ready artwork" (basically the artwork needed to create the screen for the application of the ink/paint). The few web pages that went into any detail were either very old or simply indicated that it was a waste of time to even bother trying, and to use AutoCAD instead. Ultimately, that was the route I went, but I haven't used a version of that software in probably 20 years and it's not the same package at all anymore, so it was a learn-from-scratch scenario again.

I am clawing my way, millimetre by painful millimetre, to productivity.

For posterity's sake, here's the procedure I followed (I know these show up on searches of the Intertubes; and if I don't write it down, I'll forget it myself):

From Inventor, create a drawing at 1:1 scale for the 3D part's face that will be silkscreened (choose the proper sized "paper" to hold the whole drawing... C size in my case). Fill out the information box as necessary as this will be included in the output file from AutoCAD. I did this by going New->Drawing, then clicking on the Base button in the Create tools, then setting the scale to "1" and selecting the "Hidden Lines Removed" Style. I have two drawings them from the same 3D part: one that I dimensioned and gave to the machinist to make the actual part (which has different scales and such), and a new one that I created for the silkscreeen generation that just has the holes and cutouts and stuff along with the info box and page border.

Close the drawing for the silkscreen in Inventor and open the drawing in AutoCAD (if you don't close it in Inventor first, AutoCAD complains that something else has it open and offers to open it in "read only" mode).

On the Home tab in AutoCAD (we're done with Inventor), in the Layers tools, click on Layer Properties and then delete all the layers that are not going to be needed (there are a bunch). The way to do it is to turn off (the little lightbulb) all the layers and bring back the ones you need, then delete everything else you can (on this job, one layer could not be deleted or renamed for me). In my case, I kept the following layers and deleted the rest: 0 (can't delete), Border (ANSI), Title (ANSI), and Visible (ANSI). On the previous one I did, there was another layer (Defpoints) I could not delete. Furthermore, I could probably have deleted the Border (ANSI) layer in both, but I just left it hidden.

To satisfy the requirements of the company I was sending my artwork to, I had to rename Visible (ANSI) to MECH (the mechanical layer that showed the holes and such), and Title (ANSI) to PAGE (which had the identification information on it and any further instructions). I then needed to create two new layers: WHITE (one layer for each colour... I was only doing a single colour since it was basic lettering), and REGISTER (to hold registration marks to allow for alignment of the panel to the screen).

Go to the Layers tools and, using the pulldown, select WHITE (or whatever colour you are using). Changes made will go in that layer. Under the Annotation tools (in the Home tab), select Multi-Line Text (or single line if that's what floats your boat... I'm just providing my experience) and place whatever text is needed. I did not have any artwork (the logo for the project would have taken days to convert to a monochrome one and that was out of scope for me). The company I'm sending it to indicated that I should use colour #7 for all the layers. The existing layers were, thankfully, imported with that colour already.

To place text, select Multi-Line Text, one corner of the rectangle to place it in, and then the other corner of the rectangle to place it in. Type text into the box, resizing it as necessary to fit the text the way you want (one or more lines). You can use Enter to put in a line break. The key is to select the correct justification to allow the text to be positioned exactly. For instance, I wanted to place text below a cutout for an AC Power Entry Module about the allowable voltages, the maximum current draw, and what fuses to use. I put the text on two lines (voltages and current, and fuse specifications), selected the Center alignment button in the Paragraph tools, and then selected Top Center TC from the pulldown Justification list in the Paragraph tools. If you are aligning it to something below it, use Bottom Center BC (Left or Right Center to align it to the side, but then use Left/Right alignment as well for the text). That gave me centred text with a handle in the middle of the text above the text that I could choose to align with the cutout. Select Close Text Editor way over on the right to finish editing the text (it can always be opened up again by double-clicking on it).

Align and place the text where you want it... sadly, easier said than done. You will need some feature to align it to for starters. In my case, I had a rectangular cutout. In Inventor, lines have convenient middle handles that can be used for alignment, but in AutoCAD, just the ends of the lines have handles. As such, to centre my text below the cutout, I had to go to the Annotate menu and select the Centerline button from the Centerlines tools, then select the sides of the cutout to create a centreline. Once that was done, I could click on the text to select it, click on the square handle (at the top in the centre per my justification choice earlier) and then hover it over the centreline I just created to lock it on, then I could drag it down below the cutout and, as long as I didn't drag it too far off to the side, release the mouse button to drop it below the cutout along the centre line (it snaps to the feature). As you drag the text, there will be a dotted line to the feature it is locked to so you know it's aligned with the centre (or whatever). This took me a long time to figure out how to do, but it's nice and easy once I knew. You can also use the Center Mark tool from the Centerlines tools on holes and circular cutouts, which is preferable (on my previous design, I had a hole aligned above my square cutout that I used for alignment, it was a lot easier).

To set the distance between the text and the feature, you need to go to the Parametric tab and select the proper tool from the Dimensional tools. In this case, I used the pull down on the left of the tools to select Vertical. The theory is that you constrain the text to be a certain distance from an edge or a hole or something, but the reality is not quite so easy. If it is a hole, then it seems to work out fairly well, but for a rectangular cutout even, it takes some work. To set my distance on the cutout, I first had to draw lines (the Line tool from the Home->Draw tools) along the centre line from its top point to its bottom point, and along the two perpendicular lines to the centre line of the cutout. I then used the Trim tool from the Modify tools, selected the newly drawn line over the centre line, and then the top line I just drew (the two reference objects), then do a right click with the mouse to terminate object selection and put it into trim mode, then click on the part of the new centre line that is above the cutout to trim it off. It will look like the line is still there, but it is the proper centreline that was added earlier. Delete the proper centreline, and the top line that was drawn on the cutout. That will leave the rest of the new line drawn over the centreline (with its top trimmed off) and the line drawn along the bottom of the cutout. Go back to Trim, select the centre line and the remaining perpendicular line at the bottom of the cutout, right click, select the bit of the centre line sticking out. Finally, there is a handle in that can be accessed by the Vertical tool from the Parametric tool (ugh). There may be better ways of doing this, but this is what worked for me. Then... start the Vertical tool, hover over the text and you will see a red circle with an X through it for the text handle. Click on it. Hover over the intersection between the centre line and the line along the bottom of the cutout to find the next handle (red circle with X) and click on it. Slide off to the side to drag the dimension off to the side and click to place it. Double click on the dimension value and put in what you want (e.g. 0.5 inches in my case). The Parametric tool will pull or push the text to the distance you asked for. Placing other text is generally variations on this theme. Once the text is placed... delete the lines (center and bottom) used to place the text and any leftover dimensions if any (deleting the lines deleted the dimension on my drawing), otherwise these will show up on your silkscreen, which is presumably not desired! If I wasn't already bald, I would be after wrestling with AutoCAD as long as it took me to get this to work.

Rinse and repeat for any remaining text (if you figure out how to place images, maybe post below for others that might find this post... or give a link to an article on how to do it perhaps if it is detailed as what I'm doing here, no need to repeat it if it already exists). At this point, with all the text placed, it is probably a good idea to turn off all the layers except WHITE and make sure the only thing there is text (and that it is all there). If you accidentally placed text on the wrong layer, I know there is a way to move it, but I forget what I did.

Select the REGISTER layer to place registration marks (always a good idea unless the company you're sending to doesn't want them). Here, the hover/lock function I talked about is used heavily. It's quick work once you get the hang of it, but be patient until it makes sense. So... select the Line tool and hover over a corner of the faceplate (or whatever), a hollow green square will appear, move the cursor vertically from the corner and a dotted green line will appear with an X at the end, once away from the corner, click to start the line and then move the cursor up further to define the direction of the line, then enter the length of the line (I used 0.9 inches), press Enter to accept the number, press Enter again to finish the line. You should have a vertical line that isn't touching the faceplate. Do the same to place a horizontal line at the same corner. Then go to the Parametric tab and set a Vertical constraint between the bottom of the vertical line and the horizontal line (I set the constraint to 0.1 inches), and then set a Horizontal constraint between the horizontal line and the corner. Make sure to select the reference line before the line to move/constrain or the reference line will move instead (i.e. for the Vertical line, select the end of the horizontal line first before the vertical line). Repeat for the other three corners and you will have a full set of registration marks of equal length and of equal distance from the four corners. Now... delete all the constraint dimensions so they don't show up on the silkscreen! Stuff is where it is supposed to be and that's enough.

One of the last things I needed to do was to go back to the Layer Properties (under the Main tab) and change the width of the MECH, PAGE, and REGISTER lines (and your silkscreen layer lines if you added any) to values useful to the company doing the silkscreen. In my case, the default they wanted was 0.010 inches, which is about 0.25mm. As long as you didn't override the line width and left the Linetype as "by layer", this is simple from the Layer Properties list (it has a pulldown list of acceptable line widths). I then added some additional text to the PAGE layer (selecting it from the pulldown layers menu) to indicate the ink colour and the material I will be providing to silkscreen (they can acquire it themselves, but I will be giving it to them). This was according to the guidelines provided to me. Lastly, the company I was sending it to could only read AutoCAD files up to version 2007, so once I was done, I did another "Save As..." and saved it to AutoCAD 2007 format with a different name (just appended _ac2007). I send them an AutoCAD 2017 file before I realized that limitation and when they opened it, they said it was blank. When I sent them the 2007 format version, they were able to open it fine.