Sharp inside corners at high speed

jeepsr4ever

For those with tables and gantry kits made from august of 2013 to present can take full advantage of 400ipm cutting speed with a very high degree of accuracy on inside corners. This is done by turning off constant velocity on angles greater than a number we set into Mach 3/config general config/Stop CV on angles > 89. What this does is use the exact stop method on 90 degree and larger angles. The advantage here is to allow the ramping of motors not to make a radius in the corners but a full stop on one axis and a ramp up on another. This type of motion gives the best corners at higher speeds than 125ipm. Without going to an exact stop on corners the processor in Mach will calculate the corner based on keeping velocity up while taking in account acceleration rates of the 2 axises in motion. That equals rounding of an inside corner. If we turned on exact stop for all movements the machine would stop at ANY geometric change and the cutting would take much much longer. This is why this particular CV setting if set to 89 gives crisp corners without sacrificing toolpaths elsewhere. [video=youtube;J2G958v_C8M]http://www.youtube.com/watch?v=J2G958v_C8M[/video] [U][COLOR=#000000][B]A little note on the video. The video was taken using .9 as the rapid clearance plane and a short Z reference distance. The touch off can be tweaked to only touch off once per part and the rapid clearance plane can be set much lower. The exercise was completed using these values to show the rapid acelleration and square movements. And the part was cut at 350ipm.[/B][/COLOR][COLOR=#0066cc] [/COLOR][/U][COLOR=#0066cc] [/COLOR][B][COLOR=#008000]Here you see two identical parts. One being cut relying only on acelleration values (right). You can see the inside corners rounding. The second part was cut using the "CV off on angle" setting (left). The first part was cut at 225ipm (right) and the second part at 275ipm (left). Even with a 50ipm increase the corners sharpened drastically. [/COLOR][/B][ATTACH=CONFIG]373[/ATTACH][B][COLOR=#008000] [/COLOR][/B][U][COLOR=#0066cc] Here is where the setting is located in Mach3/config/general config [ATTACH=CONFIG]380[/ATTACH][/COLOR][/U]