Model Boat Mayhem
Technical, Techniques, Hints, and Tips => 3D CAD Design & Printing => Topic started by: Gazzalene on April 20, 2019, 10:46:01 am
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While trying to find somewhere to buy building materials,no LHS, I found a place that stocks materials for students and they also offer a laser cutting service.
The guy who does the cutting showed me the machine in use. He said it's fairly cheap to have parts cut. The most expensive part is the "file" work.
So how do you get a hand drawn part to a cutting file?
Just the basic steps and software needed, not an exact description
Thanks
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it should be doable in any CAD package, draw up the part and either save as or export to the correct file type, this is how I do parts for my 3d printer.
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Is there a "norm" file type for laser cutting?
Also it was mentioned that the parts need to laid out on the correct size of "sheet" being cut,is this done in the cad programme OR separate type of programme.
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it should be part of the options when 'printing' i.e. just like any other printer the file asks what size of paper is to be printed on supported by the printer, it could be A4 (normal photocopy paper size), to A5 half that size or A3 twice the size, A2 twice that size again etc, there is also foolscrap sizes letter and other formats usually like B formats / euro etc, so just ask the assistant what is the largest size the machine can cut and go from there. If they say A0 (the largest draughting office size sheet, then any A sized sheet can be put in, your drawing at 1:1 should fit the sheet needed, if you have multiple parts correctly arranged they should fit as close as possible together and with as little wasted space between them all fit on as many sheets as necessary to get all cut, moving them around so that instead of having large gaps there is say 3mm between etc you may end up using only 2 sheets instead of 3, or all on 1, nesting the parts to keep the cost down etc., like those who cut out parts for clothes, very little waste is left after nesting.
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Warspite, thanks for info. "Nesting" was the word he used. He said you will need to nest your parts because we can only cut 12" x 48" in the machine set for wood.
Gradually getting to now the steps to take, I will look into free software and see how hard it is and have a go.
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If you search above for suitable recommendations for free cad, and show your sketches with each part labeled either 1,2,3 etc or A,b,c etc then others may give some recommendations on how to nest i.e. take 'A' put it in the bottom left corner rotated so the top is at the bottom along the straight edge, 'B' placed above 'A' rotated anticlockwise against the left edge with 3 mm between A&b, etc, draw them in the cad see if they fit and show a sketch / screen shot etc, just to give an idea of how its going.
For instance, I have in the past being toying with creating a E class container ship (of a US navy sealift type) with the internals fully open, cutting a frame, there would be a lot of material wasted in the centre cut out, so the idea was to draw the frame 3 times to be sandwiched together, but each frame would be split into 4 parts that all cut out as strips, they create the frame and the next would sit on top but the joints would be in a different locations so that a joint is not on top of another e.g. 1st layer, long horizontal strips short vertical strips, 2nd layer short horizontal strips long vertical strips, 3rd layer the same as the first.
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All this "new tech" stuff amazes me.
Watching laser cutting and 3d machines in action is amazing.
But watching a guy design using "cad" really home how far behind on the pc I am!
I even had a look about a evening course on cad with no luck .
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Draftsight is your best bet for starting out, is free and available from https://www.3ds.com/products-services/draftsight-cad-software/download-draftsight/
There's plenty of tutorials available on YouTube, I find the best way to learn is just play with it, you can't break it. For laser cutting you'll generally need to save in DXF file format
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As usual very helpful replies. This forum is great with help.
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What part do you want ? Scan your drawing and send to me in jpg format - will draw it for you if not too complex. Make sure a dxf is what they need - (most CNC machines use CAD files (dxf) ). I use Corel so can export in a very wide variety of files. In South Africa so cant offer to cut it for you. Send me a pm for my email address.
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Ah! yes dxf, we used to take the drawing for a fan casing, strip all the dimensions and notes off the drawing then all the bits that didn't relate to the body - like the outlet as it was a fabricated item added on later, if there were flanges on the outlet the lines related to that - they were removed as were flanges for stiffening and on the inlet, the rear view, we removed the pedestal where the motor would go, every thing stripped off including the centre lines, we ended up with what would be a blank with all the holes in it to make the front and back of the case,
the top view of the pedestal and its holes and two views, adjusted, of the pedestal sides as it was on an angle so its correct length shown and finally the rear of the pedestal, if all the items were made of the same thickness of steel otherwise they would be on different dxf files, this also included flanges if to be cut out of one piece, but usually these were fabricated from flat bar, all saved as a normal drawing with no border and then saved/exported again as a dxf file format, put on a 3.5 hard floppy disk and passed to the fabrication department who used it to plasma cut the parts out after rearranging the parts for nesting in a sheet of suitable steel.