[mike2768]

Hello everyone, I've been having trouble with my X2 that i converted. Here a little bit about my machine. I used cnc fusion kit #4 I believe for the hard ware part of it. For steppers and controller i bought a package from Keiling with 425oz steppers if i remember right.

The problem i'm having is right from the first pass it seems that it's not going back to where it started and ever pass there after it's going a little more. Please see picture i hope it shows what i'm talking about. What do you guys thing. Maybe spinning on the ball screw shaft. I ground a little flat spot on the shaft because it didnt have one, could it be the love joy connector because of the rubber flex section. I'm just about ready to pull my hair out. Any info would be great. Thanks.

Thanks again, Mike

[ironDigit]

from the info you're giving us, backlash or even just a part slipping from poor clamping.

check for backlash with a dialindicator and my guess is you'll find your lash much easier then just milling away and pulling your hairs out

more info and pics will result you in much more/better suggestions.

[escott76]

This sounds a lot more like a missing steps issue than anything mechanical. You can rule out some problems by taking the motors off, and moving the axis by hand, spinning the screw to check for binding on an axis.
Fixing missing steps can be a little more tricky. It can be motor tuning, computer issues, etc. A good first step is to try lowering acceleration and maximum velocity.
Again, more details on the system as a whole. What kind of computer, software, motor drivers, power supply, etc.

[mike2768]

Thank for te replys, Heres a link of what i got for a control box and driver. It is kit #5 from what i remember from this guy.
http://www.kelinginc.net/CNCNEMA23Package.html

As far as the PC goes i'm using a compac EVO penium 4 op system is windows XP. I hope this is what you where talking about.

Mike

[Waldermac]

Did you check that the screw on the right side of the x axis ballscrew is tight? Use threadlocker to secure it and make sure the ballscrew it tight against the bearings.
Check all gib screws and make sure they are tightened correctly as well.
Check connector set screws and make sure tight as well.
Then use dial indicator to set proper stepping in mach 3. Then do backlash setting in mach 3. Then test results with dial indicator again using MDI.
Where in Canada are you? I'm in Toronto.

I had to grind the underside of the x axis table to allow ballscrew coupler clearance, and reduce the size of the aluminum extension on the right side by .2 inches to allow enough of the ballscrew to insert into the helical coupler.

I also set the kernal speed to 45000Hz.

[rwestbr]

Quote
"As far as the PC goes i'm using a compac EVO penium 4 op system is windows XP. I hope this is what you where talking about.

Mike"

Is this a Laptop computer? Are you using Mach3 for the controll software?

Robert

[escott76]

Thank for te replys, Heres a link of what i got for a control box and driver. It is kit #5 from what i remember from this guy.
http://www.kelinginc.net/CNCNEMA23Package.html

As far as the PC goes i'm using a compac EVO penium 4 op system is windows XP. I hope this is what you where talking about.

Mike

Software, not operating system, although it's helpfull to know. A 24V power supply isn't going to be giving you a whole lot either.

[mike2768]

I am not running a laptop. I'm also using mach 3. Hey Waldermac I'm like 1 hour from you. I live just north of Newmarket in Sutton. This machine is starting to get to me

[escott76]

I am not running a laptop. I'm also using mach 3. Hey Waldermac I'm like 1 hour from you. I live just north of Newmarket in Sutton. This machine is starting to get to me

What are your motor tunings set at? Kernel speed? If you are trying to make the motors go faster, or accelerate at a higher rate than they can handle, they can lose steps, leading to problems like what you somewhat show in the pictures.
Although you certainly need to make sure that the mechanicals are working smoothly, problems like this can be a result of many causes. You need to systematically go through things, checking to make sure that they are operating properly. Software, drivers, power supply, and the software settings can all cause issues.
I know it all sounds like a lot, but take a deep breath and if you need to take a day off because it's frustrating, do it. Things that are worth doing can be hard, and when you fix it, you'll have new knowledge of how things work in greater detail.

[mike2768]

I just had a look at what controllor i got, heres the link. 3rd one down it has a 36v power supply not the 24 volt one.

http://www.kelinginc.net/ControlSystem.html

[Dougal]

What does the Mach3 drivertest say?
I had similar problems in tuning, it was due to pulse quality. Running the rightmark cpu utility to stop the xp idling the cpu down. That fixed it.

[mike2768]

What does the Mach3 drivertest say?
I had similar problems in tuning, it was due to pulse quality. Running the rightmark cpu utility to stop the xp idling the cpu down. That fixed it.

Thanks for your reply, Where would the drivertest be. As for what you said about running the rightmark what are you referring to.

Mike

[Dougal]

Thanks for your reply, Where would the drivertest be. As for what you said about running the rightmark what are you referring to.

Mike

Have a read through this thread here:
http://www.cnczone.com/forums/showthread.php?t=81045

The drivertest.exe is in the mach3 directory. It gives a graph of lag in pulse time. Mine was all over the place until I ran the rightmark cpu utility. Then it cleared right up and was only showing the occasional small glitch.

[mike2768]

Well a little update to my problem. I took all the motors off and check to make sure all the slids where slidding free. Well they are, so with the X axis off i was running the Y axis and the X axis at the same time just to see if i could see anything. I could see nothing but the axis where making a different sound from running one of them at a time. The sound was almost like there was some bynding (sorry for the spelling) and it was lossing a ton of steps, but the X table was not even installed. So i set everything back to the stock settings and it seams ok. I'm still wondering what the heck would make this happen. I cut the same plastic part as in my first post and it cut it well with no missed steps.

Mike

[Dougal]

Well a little update to my problem. I took all the motors off and check to make sure all the slids where slidding free. Well they are, so with the X axis off i was running the Y axis and the X axis at the same time just to see if i could see anything. I could see nothing but the axis where making a different sound from running one of them at a time. The sound was almost like there was some bynding (sorry for the spelling) and it was lossing a ton of steps, but the X table was not even installed. So i set everything back to the stock settings and it seams ok. I'm still wondering what the heck would make this happen. I cut the same plastic part as in my first post and it cut it well with no missed steps.

Mike

Here's another thread which was helpful in tracing my step problems.
http://www.cnczone.com/forums/showth...t=53254&page=2

[mike2768]

What are your motor tunings set at? Kernel speed? If you are trying to make the motors go faster, or accelerate at a higher rate than they can handle, they can lose steps, leading to problems like what you somewhat show in the pictures.
Although you certainly need to make sure that the mechanicals are working smoothly, problems like this can be a result of many causes. You need to systematically go through things, checking to make sure that they are operating properly. Software, drivers, power supply, and the software settings can all cause issues.
I know it all sounds like a lot, but take a deep breath and if you need to take a day off because it's frustrating, do it. Things that are worth doing can be hard, and when you fix it, you'll have new knowledge of how things work in greater detail.

My motors settings are Velocity 79.98 Acceleration 10 Kernal speed is 25000 Hz. When i"m cutting something i never go above 15 IPM.

[dang]

It looks to me as though you're experiencing a backlash problem. I have the same setup as you do.

Zero in your backlash by changing the settings in Mach3 and referring to a known home location on all three axes.

Some other mods that you may choose to undertake.
1- Replace the gib screws and adjustment nuts on the X & Y axes. I used stainless steel, hex head screws and store brand nuts. They look better and are easier to adjust, as well as being generally low maintenance. Form and function.

2- If you have a lathe, you can make a custom washer to eliminate some measure of backlash by providing a solid surface between any gap between the coupler at the end of the ball screw and the lock nuts. This way when the axis changes direction, the entire works moves as one piece with no way to slip. Without a lathe, you can stack hardware store washers.

Good luck.