Quote:
Originally Posted by Gray Adams
Well, machining is rarely at room temperature. If it was you wouldn't really need coolant (yes I know that coolant primarily carries chips away).
But that's really impressive that you got such high precision on a machine like a Tormach with an endmill measured with calipers. The PCNC 1100 is not that precise of a machine though, and the only way you can achieve those numbers is with repeated adjustment to dial it in. The inspection sheet for this machine allows for .00118" of spindle runout alone, the axis repeatability is specced at .00078". I don't disbelieve that you got the numbers that you did, but it certainly shouldn't be expected behavior from a machine like this and a dimension like that should take numerous attempts to dial the machine in. I wouldn't think twice if you told me you got that from an Okuma or Mori Seiki.
If you have an upgraded pump that should help a lot. The one I used to work on needed to be basically full of coolant and even then the pressure was low. If your tank started to run down due to evaporation, coolant flow would be horrendous.
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Getting within a thousandth did require multiple tries and was a time consuming process which we did because we couldn't find the reamer, and is not typical normal operation, but is possible if you try really hard. We measured a slot the end mill cut with calipers, then made 5 tool paths, that were +/- .0002", measured these holes, then picked the one that appeared closest to the correct diameter. We have an end mill we use just for cutting finish passes so we don't wear it down. We can get very repeatable results, but it's difficult to get the number you want (very precise, low accuracy).
The installed coolant pump is a disaster. It's a made in China pump, complete with labeling/specs in Chinese. Be sure to keep filters in place for the pump. We dealt with coolant shortage the whole season, and the pump just doesn't run when there's less than 5 gallons in the tank, and if the tank is less than 75% full, the pressure is awful.
The Tormach Tooling system is very cool and will always get pulled in all the way to the machine. I do not recommend the set screw holders. Your tools will get sucked out of the holder if you make an aggressive cut. If possible, label tools in your tool libraries. People have a tendency to adjust stickout for a particular task without telling you.