I use Google SketchUp. I got the idea from an article in the NMRA Magazine. It IS addictive. I have a drafting background, that predates computers, but I did take a computer drafting class at Missouri Southern back in the 1990's. In my opinion, SketchUp is easy to learn, and they have GREAT video tutorials. All for FREE. The free version has some limitations, but I have not found anything that I could not work around. SketchUp has a help forum if you need help at any time.
Generally, I draw in full size, then shrink the item to 1/87th scale. I have drawn many thing in 1/87 scale, and personally, I like drawing in metric when I am working from a real part that I have in my hand. I find it easier to work with using a caliper.
Kent in KC
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