K40 Height Adjust

prusaprinters

For those of us who cut a hole in the bottom of their K40 laser to fit a rotary tool, this may be useful to change the height of the laser. These legs replace the castor wheels which are a hazard anyway. Legs let you change the height of the laser by turning the sleeve sections. The thread is 2.5mm pitch so one turn will change the height by 5mm. The sleeve has 10 flutes so one flute of turn will change the height 0.5mm. One of the flutes has a reference mark, you may want to write on the others, 0 to 5mm in 0.5mm steps or every second one for 1mm steps The post should be firmly fastened to the laser body to prevent it turning when you adjust the sleeve. I used 3 line count for the shell and 45% infill. Uses 15g/5m of material taking almost 2 hours to print. Screw a 3/8-16 stud into the centre of the top section. It has a recess for a nut and you can tighten the steel nut down onto it, I cut about 50mm sections from a threaded bar. All 4 of the threaded top sections took about 7hrs to print. You will have to align the nut so that the stud screws into the top section without raising the nut above the level of the part, this takes trial and error and some squinting at the threads on the nuts when you find the correct position. The foot should have some anti slip material to ensure it doesn't turn as you adjust the height. The top left hand threaded post and bottom right hand threaded foot have had their diameter scaled by 96.5% so that they turn easily when printed. I added a very small amount of silicone grease to the threads, this may be a bad idea in the long run but it did turn more smoothly afterwards. Total adjustment is about 50mm, the threads are 35mm long but you need to leave about 3 threads engaged for stability. Make sure the top and bottom don't turn when adjusting or the height will be inaccurate and it may come loose at the end. Print Settings Printer Brand: Creality Printer: Ender 3 Rafts: No Supports: Yes Resolution: 0.2 Infill: 20% (45% for top LH thread part) Filament: Amz PLA Blue Notes: Use a skirt, the parts are tall and easy to knock over, the foot doesn't need a skirt. The top section is strengthened a bit by printing 3 layer shell and 45% infill. Also needs support to print upside down, use concentric pattern. Post-Printing ============= Cleanup Some elephants foot spread at the bottom will possibly affect the top post, this will make threading harder so file the bottom half of the left hand thread to a thinner diameter and make sure is turns easily. The sleeve may also have some spread, I cleaned mine with a deburring tool. Most important: My threads were slightly messy in the sleeve section, some stringing. This is not a problem but needs some cleanout. I screw the top and bottom section in and out then clean out with a toothbrush. Initially they were quite tight but after cleanout mine were quite smooth. Category: Parts