Excellent presentation. I was never imagined there is that much operations to draw something relativity simple like screw tread.

Using Sketch Up to model a M20x2.5 Bolt & Nut for 3D printing No plug-ins needed but solid tools are necessary. 1. Open Sketch Up and show; Entity Info, Tags and Materials. (The Tags can be used to temporarily hide objects to get them out of the way. This is not mentioned later but might come in handy. 2. Set Sketch Up units to meters. (Later the model will be resized to mm.) 3. Draw a 24 sided circle on blue plane at the centered on the central axes with radius of 10. Pull along the red axes. Find Center and make it all a group. 4. Position the circle so that the center is to the right and you can see the point where the green axes crosses the edge of the circle. 5. Draw a rectangle on the red plane starting at the point where the green axes crosses the edge of the circle. Drag toward the center of the circle. Make it exactly 1.657 wide and 2.5 high. (2.5mm is the thread pitch of an M20 bolt with coarse threads.) 6. Put a guide line horizontally along the center of the rectangle. 7. Put another guide 0.078 above the first and one 0.078 below the first. (This marks width of the crest of the thread which is the pitch divided by 8 or 0.15625. You can delete the center guide if you like. 8. From the left end of the top guide draw a angle guide 30º above horizontal toward the right. Draw another from the lower guide angled down 30º. 9. Place a vertical guide line 0.1 to the left of the right side of the rectangle. 10. Starting at the upper right corner of the rectangle draw a line to where the upper angle guide intersects the guide you just placed. 11. Continue the line along the upper angle guide to the left edge of the rectangle.. 12. Draw lines at the bottom mirroring the top. 13. Delete; the guides, the top and bottom edges of the rectangle and the left edge except the small section that forms the crest. This leaves you with the profile of a single thread. 14. Get in context of the circle and offset the edge of the circle inward to the bottom point of the thread profile and delete the original edge leaving a smaller circle. 15. Move a copy of the circle and the thread profile to the side and out of the way. 16. Select the entire thread profile and rotate a copy around the center of the circle to the next endpoint on the circle’s edge. 17. Move the new copy of the thread profile up 0.104. (This is 1/24th of the pitch.) 18. Draw lines from the first thread profile to the second at each endpoint. 19. Draw lines diagonally (one corner to another) on the sloping planes to cause them to form surfaces. You may need to reverse some of the faces to get the outside out. 20. Triple click to select all the thread section you just made and make it a group. It should be a solid group. If not. . . find and fix the problem. 21. Rotate a copy of the thread section to the left edge of the original. 22. Raise the copy up so that top left aligns with the top right if the first section. 23. Select both thread sections and use Outer Shell to make them into one solid. 24. Rotate a copy of the new larger thread section to the left edge of the original and type *2 to make a third copy. 25. Raise the second copy up to align with the previous one then do the same with the third. 26. Use Outer Shell to group all three thread sections into one solid group. 27. Rotate a copy of the new, larger, thread section around the center of the circle to the next quadrant and type *3 to make three more copies. 28. Raise each of the three new thread sections to align with the previous one. The bottom corner of the final section should just touch the top corner of the original section. 29. Use Outer Shell to group all the thread sections into a single solid. 30. Raise a copy of the now complete thread section up till it aligns with the original and type *16 (or whatever) to make copies. (Each copy will make the bolt threads 2.5mm longer in the end. It needs to be longer now than the final length to allow for head to be down on the threads and when chaffering the bottom some length can be trimmed off. 31. Get into context of the circle and pull it up to the very top of the threads making a cylinder just inside the threads. Check that it is a solid group now. 32. Select all the threads and the cylinder then use Outer Shell to make one solid. 33. To make the head and the nut we will make a hexagon that is 30 across from flat to flat. So first, starting on the blue axes at the top of the cylinder make a 96 sided circle with a radius of 15 to serve as a guide. Group the circle. 34. Starting at the same place make a 6 sided hexagon so that the flats are right on the edge of the circle. Delete the circle. 35. Pull the hex up about 10 and make it a solid group. Move a copy to the side for the nut. 36. Move the hex down over the threads some and then use Outer Shell to join the head to the threads. 37. Make a solid group of the proper shape to use it to Trim a chamfer at the bottom of the threads. Optional:[ Move a copy of the chamfer cutter to up above the bolt head, flip it over and scale it uniformly about the center until it is large enough to chamfer the corners of the top of the head.] You can put a transparent material (glass) on the trimmer so you can see what you are doing but paint it back to the default material or whatever you want the bolt to be before you use trim or the transparent surface will transfer to the trimmed areas. 38. To make a thread cutter for the nut go to the circle and thread profile put to the side earlier. Select all the thread profile and scale it along the blue axes from the center to about 1.15. Then scale it along the green axes from the opposite side outward or away from the circle by the same amount. (Scale more if you want looser threads.) 39. Move the circle down to the bottom tip of the new thread profile. 40. Do exactly as you did to make the threads earlier to form a cutter for the female threads. It only needs to be a little longer than the nut is thick. 41. Put two concentric circles centered on the top surface of the nut, one with a radius of 10 and one with a radius of 8. Move the smaller circle down into the nut about 1.5 and do the same thing on the bottom of the nut. This creates clearance for the threads to start. 42. Make sure the nut is a solid group. 55. Center the nut on the thread cutter and use Trim to cut the threads. (Use Subtract if you don’t want to keep the cutter for future use.) 43. Chamfer the top and bottom of the corners of the nut. 44. If you like, use 3D Text to put ‘ M20x2.5 ‘ on the top of the bolt head. Looks great but you may want to print the bolt with the head down in which case it is a bad move. 45. Draw a line 10 long. Measure the line with the Tape Measure and then type 10mm. When the window pops up asking if you want to resize the model click yes. 46. Use Zoom Extents to find the now very tiny bolt and nut. 47. Select the bolt and nut and export the 3D Model as an stl file and it is ready for the slicer.

Great video! Are those hummingbirds I hear in the background?

Thanks Bob.

Great video. Thanks!

Having just read a James W Hall thriller set in the Florida Keys, and partly Lake Surprise, it's fascinating to get a glimpse of the area -- especially the canals lined with homes and boat lifts. I'd also love to kayak this area. Nice filming, with stills edited into it and useful sub-titles, too. Are you guys locals in the keys or holidayers?

how far out where u??