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Offline c30232

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Re: Please Help!!
« Reply #10 on: August 11, 2014, 01:12:43 PM »
Gerry’s comments are sage; however, I encourage that you not toss in he towel just yet. 

When I shopped for a project specific router I looked at a machine that appeared to identical to the one you have.  That is, the same appearance, color, size, and configuration. It was used by the then owner to machine plastics.  The parts that I saw coming from the machine were just fine.

I did not buy the machine and a several months later I continued my search.  During the search I stumbled upon the same machine at its new owner’s shop and he too was machining plastic with excellent results.

Certainly the seller of the machine has a vested interest in not accepting fault on behalf of the machine.  But, the seller also has a vested interest in your machine performing as it was designed.

As I said before, just as Gerry noted, rigidity is key, but don’t get caught up in how much you can move a static machine by leaning on it.  And keep in mind that the part/material shown in your supplied photo can be machined with excellent results using fixtures and a handheld router.  Is your machine less than a fixture and handheld router?

I am very new to Mach but not to PC based controllers.  I am not yet persuaded that the computer is your issue, but I can positively tell you that a computer can make difference with other control software.   Although Mach seems to have addressed those issues, I would listen somewhat to your manufacturer’s rep.

I assume your machine has a centerline drive?  I have a small router that has a centerline drive.  When we set it up 15 years ago I believed that it would never work properly/accurately.  I set up the old dial indicators and leaned on the gantry.  Yep the old dials starter to spin.  Well, 15 years later the machine will hold about ½ thousandth.  The tool defection is greater than that.



Re: Please Help!!
« Reply #11 on: August 11, 2014, 01:25:48 PM »
That's the problem right now. I used to do all this same stuff by hand with jigs and got stellar results. Just takes to long and I can't keep up which is why I bought a machine. If it was an intermittent problem I can possibly understand the computer issue as far as an inconsistency in pulse. It appears that there is extreme vibration though. It seems to be in the machine though not the work piece. I have clamped screwed and glued pieces down and gotten the same results. I have tried different bits, spindle speeds, and feed rates with no change. The y axis isn't bad but the x is horrible which is why I am leaning toward machine. I would think if it was software or computer related it would be on all axis not just consistently on one of them. Rigidity is the only thing I can think of at this point.

Offline c30232

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Re: Please Help!!
« Reply #12 on: August 11, 2014, 01:50:15 PM »
Oh my!  I sent you an email, hopefully you can respond. 

Offline ger21

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Re: Please Help!!
« Reply #13 on: August 11, 2014, 02:39:54 PM »
If you just jog the X axis back and forth, without cutting are you getting the extreme vibration? If so, then you need to get rid of that. It sounds like a mechanical issue, perhaps due to rack and pinion alignment.

Yes, while rigidity is very important, it's also possible to get good results with poor rigidity.

On my wood machine, with skate bearings, I can push and pull the spindle about 1/8" of an inch, and yet I can get much better cuts than you are getting.

I seriously doubt that it's a software issue, but anythings possible. For it to be software, you'd see really horrendous movement, very rough and jerky.

Also, go back and try my suggestions earlier, about climb cutting, and making a finishing pass.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Please Help!!
« Reply #14 on: August 11, 2014, 02:56:57 PM »
As I keep bracing it is improving. Before jogging around was creating a very loud vibration and just turning on the spindle would cause everything to vibrate. Now I can barely hear it jogging around or the spindle running. Even at 24k rpm its extremely quiet. Hopefully eliminating this vibration will have a positive effect on the cutting as well

Offline c30232

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Re: Please Help!!
« Reply #15 on: August 11, 2014, 03:26:06 PM »
What type of router motor does your machine have?  You say that the "vibration" starts when the router spindle is turned on????.  If yes, then you have a balance issue.  Tightening or bracing everything does not solve the problem, it only makes it less noticeable.

 
Re: Please Help!!
« Reply #16 on: August 11, 2014, 03:31:01 PM »
Some water cooled 3 HP china motor. I don"t think it's the motor. I have done fine line engraving that has come out perfect. I would think it wouldn't if there was an issue with a balance issue in the motor. I only have a problem when the machine is under a load from actually cutting material which keeps taking me back to a flex issue in the structure

Offline c30232

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Re: Please Help!!
« Reply #17 on: August 11, 2014, 04:14:46 PM »
I am surprised that a decent part can't be produced following Gerry's advice.  I have a similar spindle and it performs as well as our high buck spindles.  But keep in mind that engraving does not product the same spindle load.  If by chance you have a bad spindle the heavier load my induce the vibration.

As I noted earlier, we use a strobe to troubleshoot chatter issues.  It really removes much of the speculation 90% of the time.

Did you visit a happy owner nearby before you selected your machine?  Perhaps they would run a part for you to compare. Or did you get a demo from the seller?    

Offline RICH

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Re: Please Help!!
« Reply #18 on: August 11, 2014, 09:18:25 PM »
1. With the spindle / router not running, when you jog, do you get vibration? One axis at a time for now!
    if yes,
1A. Is the vibration constant when jogging, ie; jog the full travel length, and when jogging does it change when at say the start, 1/4 of travel,1/2 of travel?
2A. Do the same as in 1A, but at three rates of velocity, say low, medium, high , and max velocity. Is the vibration constant or changing?

Reply the best you can to the above,

BTW, Can you post a pic of the machine since the Industrial CNC Site didn't show one.

RICH