289
« on: July 28, 2012, 05:14:14 PM »
Bob there is no need to be snide. I'm trying to help and by saying "you doing 'something' wrong" I'm meaning to imply that your results are not typical. (I was not trying to be rude.)
I do have to doubt your 20,000 hour estimate though, that would be 833 days of use 24 hours a day. So unless you have run your machine for more than 2.5 years non stop, or five years twelve hours a day then your estimate is a bit high. I think though that your point is that you run your machine a lot and judging my all the neat molds I have seen pictures of I would guess you do run it many hours.
I'm also not sure what your getting on about with your 250 IPM quip, again rudeness is not required. As is clearly stated in the video and in what I have written about it is that the point was to show big stepper motors are not required to obtain high speeds. As I said in the video it is not recommended.
For the last six months I've had my machine set for 85IPM rapids and generally cut anywhere from 4~30IPM in aluminum. I work mostly with aluminum but do plastics, steels and PCBs on occasion. Acceleration is about 10 i/s/s. Before that, for the last three years or so, it has been set to rapid around 50 IPM. I raised it to 85IPM when helping a customer tune his machine for best performance when doing lithopanes. With this machine I lube the leadscrews and ways about every 8 hours with automatic transmission fluid. On occasion I'll run an exercise program to run each axis from limit to limit to make sure the lubrication is well distributed.
I have another Taig with the MM2000 controller that is not capable of the high rapids but its cuttings speeds are similar. It is set up with flood cooling so it gets lubricated about twice as often. Both machines use the stock spindle motor and spindle. Both machines use bits from teeny-tiny sizes to 3/8"
As I recall Bob you do a lot of 3D profile work which can take many hours of continuous running. If your running these long sessions you would want to stop every now and again to lube things up or fit your machine with an automatic oiler. This is what I was getting at asking about how often you lubricate the machine and with what sort of lubrication. Lack of lubrication will wear things out in a hurry and this would be my first guess as to a cause. Cutting a small aluminum mold could take 20-30 hours and if your not stopping to relube every 4-5 hours you will wear things out quickly.
Large stepper motors can put more strain on drive components. Some folks have problems on some small machines breaking stepper couplers that were designed for 150oz-motor because they are using much larger motors. If your spindle motor is much more powerful than the stock Taig unit and your combining that with large stepper motors to get fast cutting rates with a large cutter than you could just be applying more force to the leadscrew/nut than they were designed to handle. This may be a contributing factor but I'm still guessing that it is lack of lubrication.
You could fit an automatic oiler to your machine but it is sounding like you might be growing out of it. A small Haas or similar machine might be better suited to the type of work you are doing and your need for a stronger spindle.
Good luck...
Guest
Show Posts