ScottGus1
Tue 26 January 2010, 09:14
I don't know exactly what it is really called, but let me explain:
My boss just got majorly depressed, because the adjustable-angle aggregate he got for his 3-axis Biesse Rover is too big for the Z-axis height on his machine, despite what Biesse said. So he is looking into getting a 5-axis machine for his shop. He is put off by the for-now-prohibitive cost of such a machine, so I said, why not build one? I know that at least Shopbot and Mach3 will sell controllers and motors, all we need is a pile of thick metal to make a table and gantry...
I have a Shopbot in my garage (PRTalpha 96x60x12) and am familiar with the operation of the machine. I read up on Mach3 (including the SB vs M3 thread on this forum) and I now have a question for the Mach3 users, as well as anyone who have used both SB and M3:
Looking between the two systems, I see that Shopbot has 5-axis control, and this thing that I am calling "read-ahead travel optimziation"(see below), but no G41/42-style tool compensation (I know SB can read G-code through various means). Mach3 has 6-axis control and G41/42 tool comp, but I have read that it has a bit of a problem with "read-ahead."
By "read-ahead travel optimziation" I mean that when the controller sees a series of cut movements in the code that could be strung together in one smooth movement without slowing down (much), the controller moves the head in that smooth flow through the cuts, instead of interpreting each movement on its own, and as a result moving rheumatically through the cut. I know Shopbot has this because I have seen it work on my machine. But I have read that Mach3 may have a bit of a problem with this.
I like the 6 axes and tool comp in Mach3. But I believe that smoothness of movement is of higher importance. (BTW, I have read of chatter in the SB cuts, and it is my opinion that the chatter is from the style of rack & pinion that is used on the SB, not any inherent controller problem - I have noticed that the chatter marks are spaced the same as the rack teeth, and our Biesse, which also drives the X axis with rack & pinion, has angled teeth and no chatter.)
So, the question: Does Mach3 have this "read-ahead travel optimziation" or does it have a problem flowing through the cuts it ought to be able to flow through?
My boss just got majorly depressed, because the adjustable-angle aggregate he got for his 3-axis Biesse Rover is too big for the Z-axis height on his machine, despite what Biesse said. So he is looking into getting a 5-axis machine for his shop. He is put off by the for-now-prohibitive cost of such a machine, so I said, why not build one? I know that at least Shopbot and Mach3 will sell controllers and motors, all we need is a pile of thick metal to make a table and gantry...
I have a Shopbot in my garage (PRTalpha 96x60x12) and am familiar with the operation of the machine. I read up on Mach3 (including the SB vs M3 thread on this forum) and I now have a question for the Mach3 users, as well as anyone who have used both SB and M3:
Looking between the two systems, I see that Shopbot has 5-axis control, and this thing that I am calling "read-ahead travel optimziation"(see below), but no G41/42-style tool compensation (I know SB can read G-code through various means). Mach3 has 6-axis control and G41/42 tool comp, but I have read that it has a bit of a problem with "read-ahead."
By "read-ahead travel optimziation" I mean that when the controller sees a series of cut movements in the code that could be strung together in one smooth movement without slowing down (much), the controller moves the head in that smooth flow through the cuts, instead of interpreting each movement on its own, and as a result moving rheumatically through the cut. I know Shopbot has this because I have seen it work on my machine. But I have read that Mach3 may have a bit of a problem with this.
I like the 6 axes and tool comp in Mach3. But I believe that smoothness of movement is of higher importance. (BTW, I have read of chatter in the SB cuts, and it is my opinion that the chatter is from the style of rack & pinion that is used on the SB, not any inherent controller problem - I have noticed that the chatter marks are spaced the same as the rack teeth, and our Biesse, which also drives the X axis with rack & pinion, has angled teeth and no chatter.)
So, the question: Does Mach3 have this "read-ahead travel optimziation" or does it have a problem flowing through the cuts it ought to be able to flow through?