Problem- My brand new K2 machine is real noisy...

[Robot Dude]

Ok I purchased this unit from K2.



o KG-2525-G
o 305 oz.in. servos
o 3 axis Gecko controller
o THK Rails and screws
o Colombo 3hp 18k rpm spindle with Delta drive
o Mach 3
o .750" t-slots table

$11,638.99

I have powered it up and jogged it around. It has a horrible growling sound when moved. The Y axis (bottom) is the worst. But both X and Y are very noisy. Also the PID isn't right because both the X and Y axis make a constant wining sound. Again the Y axis is the worst.

I have contacted them and apparently it's my responsibility to verify that this isn't effecting the accuracy. They are telling me a small percentage of the machines have this problem, if it is a problem...

I'm not new to CNC, but it's been a long time. My first machine was really quiet and smooth moving. It was called the CNC Crafter when they were in business.

Am I expecting too much?

Does the hunting sound from the servos indicate a problem?

I also have a bunch of Mach3 questions, but will start a thread in a more appropriate place for that. Looking for feedback good or bad.

[JoeyInCali]

Wow!
That's a major spindle.

[TOTALLYRC]

Originally Posted by Robot Dude Ok I purchased this unit from K2. o KG-2525-G o 305 oz.in. servos o 3 axis Gecko controller o THK Rails and screws o Colombo 3hp 18k rpm spindle with Delta drive o Mach 3 o .750" t-slots table $11,638.99 I have powered it up and jogged it around. It has a horrible growling sound when moved. The Y axis (bottom) is the worst. But both X and Y are very noisy. Also the PID isn't right because both the X and Y axis make a constant wining sound. Again the Y axis is the worst. I have contacted them and apparently it's my responsibility to verify that this isn't effecting the accuracy. They are telling me a small percentage of the machines have this problem, if it is a problem... I'm not new to CNC, but it's been a long time. My first machine was really quiet and smooth moving. It was called the CNC Crafter when they were in business. Am I expecting too much? Does the hunting sound from the servos indicate a problem? I also have a bunch of Mach3 questions, but will start a thread in a more appropriate place for that. Looking for feedback good or bad.

If the servo motors are using G320 servo drives they just might need to be tuned.

http://www.geckodrive.com/upload/G320-REV-7-Manual.pdf


Under the tuning section they explain gain and dampening and noises and such.

I would unbolt one motor unless this voids the warrenty and then run it bolted to something so it can't move and fall on the floor. I would see how it sounds then. This way you can isolate the motor and drive from the rest of the machine.
For $11K plus, I would expect a better explanation other than some units have this "problem"???

Originally Posted by JoeyInCali Wow! That's a major spindle.

I agree, I need 2 or 3 for myself, I guess I had better get going on making money.

[Robot Dude]

It's difficult to know if there is a problem from a description, so here is a video of it in action. I will also post another illustrating the whining noise the motors are making at rest.

http://www.youtube.com/watch?v=K8sCPihgVjc

http://www.youtube.com/watch?v=K8sCPihgVjc

Let me know... Thanks

[TOTALLYRC]

I will say the cause of that noise is beyond me.

I will also say if I had just spent $11k and the machine made that kind of noise, I would be calling them every day.

My home made router with steppers and mismatched parts is quieter than that.

I did notice that it is noiser when moving both the x and y together.

Mike

[Robot Dude]

Here are two videos, just for the audio, of what the motors are doing with the machine at rest. The first is cycling, but the second is a constant buzzing. It just depends on where the motor is stopped.

http://www.youtube.com/watch?v=viBJ7vVgcLo

http://www.youtube.com/watch?v=viBJ7vVgcLo

http://www.youtube.com/watch?v=yHY7c2Wq9DE

http://www.youtube.com/watch?v=yHY7c2Wq9DE

[TOTALLYRC]

Bottom of page three in the owners manual from my earlier post, there is a section called gain and dampening. It sounds like in the second video that you are getting what is called dithering. The encoder is bouncing between encoder counts rather enthusiastically. The first video may be the same thing but at a slower speed.

I am still not sure what is causing the noise in the videos of the machine moving.
A call or email to Gecko directly may be in order.

[WayneHill]

The second video sounds like the axis is dithering between encoder positions.

Could there be any alignment problems that happened during shipping?

[Robot Dude]

Originally Posted by TOTALLYRC Bottom of page three in the owners manual from my earlier post, there is a section called gain and dampening. It sounds like in the second video that you are getting what is called dithering. The encoder is bouncing between encoder counts rather enthusiastically. The first video may be the same thing but at a slower speed. I am still not sure what is causing the noise in the videos of the machine moving. A call or email to Gecko directly may be in order.

I'm reluctant to do the sort of alignment described in the manual because I'm not comfortable taking stuff apart. That's why I opted for the complete package and not a DIY kit.

[Robot Dude]

Originally Posted by WayneHill The second video sounds like the axis is dithering between encoder positions. Could there be any alignment problems that happened during shipping?

There were no obvious signs of damage to the shipping crate.

[reithguitars]

Hi Robot Dude,

I own 3 K2 machines with a similar setup. A few ideas you may consider.

A) Check the alignment of the belts. On one of my machines, the Y axis belt was rubbing.

B) Check the alignment of the Y axis. It is possible during shipment, the nut mount or the rear motor assembly mount may have moved. I think K2 has a document on the process of getting your ballscrew assembly in alignment.

C) One thing to keep in mind, the K2 machines use roller bearings at the end mounts of the ballscrews, which are much more nosier than a thrust bearing would be. It is hard to tell from your video if the noise I am hearing is being amplified from your table. My table is a 4" square open frame steel table. It appears your table is made from wood and would act like an acoustic guitar sound box - making the noise louder than it really is.

D) I would also check as previous mentioned the setup with the gecko drivers. If your servos are stuttering, you will need to tweak them.

--

Best regards,

- Todd Reith

Todd M. Reith - todd@customluthier.com
Custom Luthier - Blueprint for Success!
P.O. Box 1306, Kennett Square, PA 19348 USA
www.customluthier.com - www.reithguitars.com
T: 610.925.2613 F: 610.514.3737

MySpace URL: http://www.myspace.com/customluthier

[Robot Dude]

Originally Posted by reithguitars Hi Robot Dude, I own 3 K2 machines with a similar setup. A few ideas you may consider. A) Check the alignment of the belts. On one of my machines, the Y axis belt was rubbing.

Interesting, so's this one. The two pulleys aren't even close to aligned.

Originally Posted by reithguitars B) Check the alignment of the Y axis. It is possible during shipment, the nut mount or the rear motor assembly mount may have moved. I think K2 has a document on the process of getting your ballscrew assembly in alignment.

I will have to look for it. They never mentioned it in my communications with them.

Originally Posted by reithguitars C) One thing to keep in mind, the K2 machines use roller bearings at the end mounts of the ballscrews, which are much more nosier than a thrust bearing would be. It is hard to tell from your video if the noise I am hearing is being amplified from your table. My table is a 4" square open frame steel table. It appears your table is made from wood and would act like an acoustic guitar sound box - making the noise louder than it really is. D) I would also check as previous mentioned the setup with the gecko drivers. If your servos are stuttering, you will need to tweak them.

Well the instructions tell you the motor has to be removed from the machine as part of the tuning. That's more than I'm comfortable with.

Originally Posted by reithguitars -- Best regards, - Todd Reith Todd M. Reith - todd@customluthier.com Custom Luthier - Blueprint for Success! P.O. Box 1306, Kennett Square, PA 19348 USA www.customluthier.com - www.reithguitars.com T: 610.925.2613 F: 610.514.3737 MySpace URL: http://www.myspace.com/customluthier

Hey nice websites! I like those mini guitars you make! 8)