Quote:
Originally Posted by apples000
We discovered last night that the poor performance we had been experiencing with the tormach only happens when we travel in the y axis. It also appears that the shaft off of the motor that drives the the y axis is not concentric with the shaft coupler that drives the ball screw. Our old limit going through aluminum with a 3 flute, 3/8 roughing bit, at a depth of .080, was about 2 ipm, which is really slow.
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The Y and X axis motion control and screw design are essentially identical except for length. You should see the same performance in both, so obviously, this isn't up to spec. The shaft coupler can tolerate some misalignment but there shouldn't be much. Was the Y axis motor removed during installation (I had to pull mine off to fit through a tight door)? If so, I vaguely recall there being some wiggle room in the motor mount screws that might account for the misalignment.
There are a litany of other things that could cause poor performance in one axis- bearing preload and gib adjustments being the two big items. The manual covers checking and adjusting those. A call to Tormach would probably be a good idea.
Quote:
Originally Posted by apples000
Just making cuts in the x axis tonight, we were able to up the speed to about 8 before it started pulling the bit straight out of the (very cheap) tool holder. Once we get the y axis issue fixed, we should be all set to cut gears.
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What were the parameters of your cut? Using the 3 flute 3/8ths cutter you mentioned before, and making some broad assumptions, the limiting factor in your cut should be spindle speed. A full WOC roughing pass at .080 DOC could run at 5100 RPM, and better than 70ipm and you'd only be loaded to about .5hp. Gwizard suggests a deeper depth of cut but, depending on your priorities and tool, ~40 ipm is in the ballpark.
What kind of tool holder are you using? I've had very positive results using TTS style holders of all types. If you're using a set screw holder you
must make sure that your tool has a flat on the shank for the screw to set on. Not all tools do and a setscrew will not adequately hold a round shank. For those you must use a collet; either in the R8 spindle or in a ER collet TTS holder.