Messages

71

General Mach Discussion / Re: Loosing steps or backlash

« on: September 20, 2010, 03:36:20 PM »

Mine was originally running 2500mm/min with accel of 40mm/s/s so that would equate to 100IPM and 1.57inch/s/s
After a while however I was not so hell bent on rapids but looked at increasing the accel, I dropped the rapids down a bit, think to about 2200mm/min(86 IPM) and was able to get the accel up to I think 120mm/s/s (4.7 I/S/S)
But as said that is with modern steppers of 916ozin.

I havent used the Bridgeport for probably six or more months as since I finished my Beaver NC5 mill going back to the Bridgeport would make me cry

Hood

You can ship it over to me if you want, I wouldn't want you to be upset and break down in tears!

72

General Mach Discussion / Re: Loosing steps or backlash

« on: September 20, 2010, 03:35:20 PM »

No Mine is a Series I, I didn't realize that picture was a Series II. Also I have 1:1 belt drive. I removed all of my cabinets and installed a smaller cabinet to the back of the mill. I'll take some pics of it in the future, right now it's a mess and I am going to move it later this week. I am now running some test programs to see if I can replicate my problem. I really need to figure out where to concentrate my efforts. I'm getting mixed opinions about the motors, some people say replace them, others think the problem is elsewhere.

73

General Mach Discussion / Re: Loosing steps or backlash

« on: September 20, 2010, 01:18:28 PM »

Here is a picture of a similiar machine. You are right about 2:1 ratio and .200 ballscrew lead. I don't think that my machine is worn, the ways are well lubed and you can still see the scraping. I tend to agree with you that the steppers may be getting tired, but right now all I am doing is taking stabs in the dark. I really don't have any hard evidence to back any of this up. What are you using for motor tuning settings? I was using Velocity = 70, Acceleration = 4, but I spoke with Steve at PMDX and he thought that my Acceleration was a bit too fast. I am now trying my Acceleration = 2. I'll see what time difference this makes.

74

General Mach Discussion / Re: Loosing steps or backlash

« on: September 20, 2010, 12:45:05 PM »

Hi Hood, my machine is a BP Series I CNC, I am using a PMDX-122 BOB, Gecko 203s and the original BP motors. The axis are belt driven. The pulleys are held by a key and taperlock pulleys. I checked and my lube pump is lubing the ways. I am going to try and reduce my acceleration and see how that affects my overall cut times and if there is a difference in the finished part. I will check to see what my backlash is.

75

General Mach Discussion / Loosing steps or backlash

« on: September 20, 2010, 11:03:41 AM »

I have a series I ridgid ram that appears to either be loosing steps or has excessive backlash. I'm not too sure where to start. I am machining multiples of the same part, but the inconsistencies vary. One part will be off on the "top" of the part the other on the "bottom". I attached some pics to show the problem. It's hard to see, but in the first picture the bottom is smaller than the top and in the second the opposite, the top is smaller than the bottom.

Here's some further information. I removed the drive belt and installed a dial indicator on the y axis. I then moved the axis and compared the dial indicator reading to the DRO in Mach, typically I had about a .0003 - .0006 difference. But the difference didn't compound, meaning it didn't keep adding up, the axis was always within this difference. Of course I wasn't able to see what happens when the table moves a few inches. I am wondering now if maybe my motors are loosing steps?

76

General Mach Discussion / Re: External Button for Auto Tool Zero

« on: September 20, 2010, 11:00:33 AM »

Johnv, here are my files. I have to tell you that this worked great for awhile, then Mach would start to run the ATZ feature on it's own. I did have an issue with my computer and I have replaced it, but I haven't tried using this macro since then. Please let me know if you run into the same problem.

77

General Mach Discussion / Re: New problem with Mach

« on: September 14, 2010, 02:40:35 AM »

Also I am the only one who is here in the shop.

78

General Mach Discussion / Re: New problem with Mach

« on: September 14, 2010, 02:32:00 AM »

I don't use Homing and Limits. I checked it and nothing is active.

79

General Mach Discussion / Re: New problem with Mach

« on: September 13, 2010, 08:52:00 PM »

Hi Hood, sorry I guess I wasn't clear. Let's start over. The first hole is to be drilled at -1.7250, .5250 in Quadrant 2 (upper left), Mach drills it in Quadrant 3 at -1.7250, -.5250. I did go into my motor settings and change Y axis DIR to Active Low. Now everything is running properly, but why didn't this occur when I first set up Mach?

80

General Mach Discussion / New problem with Mach

« on: September 13, 2010, 05:22:59 PM »

I managed to cut a few parts correctly. I am starting a new run of parts that I haven't made before. I noticed that my x coordinates are flipped about the y axis. What I mean is I need the first hole at -1.7250,.5250. I need the second hole at 2.6393,-.6377. Mach will drill the first hole at the second holes location. I've checked my g code and it is correct. I didn't change anything in my settings between yesterday and today, but obviously something has happened. Any ideas??