I have recently started to build a cnc using a Gerber system 48 frame. This frame was from ebay and has got its own quirks and has been bastardized from a previous owner. I have bought stepper motors and abreakout board from ebay specifics below. I have the stepper motors on and have setup a box under one side of the cnc machine where everything runs back to.
I have very little knowledge and have followed youtube videos thus far but I am at a point where I look to wisdom of the forum to hopefully guide me. I have mach 3 installed and the majority of my ports setup.I have no limit switches setup as I have run into some dreadful screeching noises when testing the roadrunner code. Im uncertain to what is making the noises I believe it might be a combination of the gears/cogs on the frameand the need of fine tuning the step motor settings. But when I use the jog button testing the axis the sound of stalling and screeching isnít as loud or not present at all.
I have recorded a video of the running of the roadrunner program and just using the jog button. With hope that the faults and fixes needed are easily deciphered by all of your experience and knowledge. Anymore information needed im ready to reply.
Details of purchases
Wantai Nema34 Stepper Motor 3Axis 1600oz-in Dual Shaft&Driver 7.8A
5 Axis CNC Breakout Board Adapter for Stepper Motor Driver Mach3+USB Cable TE240
Thankyou for all your help in advance.
Links to video and photos.
Most of your trouble is coming from the poor mechanical setup of the machine. The Motor for instance on the Gantry being fastend with just 2 bolts and washers will have massive affect on how they work. The poor fastening means Resonance will cripple them and cause issues just like what you are having.
The fact you have Cheap Analog drives means they won't be able to deal with the Resonance so you get these kinds of issues. You'll often hear this called Mid band resonance but cheaper drives can suffer badly at lower speeds.
Funnly enough I just had machine which was using Cheap analog drives and it was giving issues similair but not any where near as bad, mostly because the motors where fastend correctly and much better made machine. But still the same horrible noises and resonance affecting motors while cutting. To the untrained ear you'd swear it was a mechanical issue. When infact it was Resonance affecting the drives which couldn't deal with it and cancle it out.
Just changing the Drives for Digital drives cured the problem and doubled the speed. It was night and day which was instantly noticable by audible change from the motors. Difference is comparable to 6 cyclinder engine running on only 2 cyl.!!
In your case I suggest you make a much better job of the mechanical setup and then play with Micro stepping to move the resonance to differant range.
With a little playing about you may hit a frequency the drives will work in.
I also Notice the High steps Per setting so I'm presuming you are using Imperial Units not Metric.? . . . If not then your probably completely setup wrong.
Hi Jazz thanks for the fast reply. I will be definitely taking your advice. The screenshots are settings the machine were videoed at.
What is the difference in sound between running the roadrunner and jog button noise? Does the job button move with different settings?
Thanks again for the speed and advice of your reply I'm all ears.
The stepper motors are set inside the cabinet
Z axis 3.5a, 10000
Y axis 3.5a, 3200
X axis 3.5a, 3200
Last edited by toby; 21-01-2016 at 11:17 PM.
Ok well first I need to know if Mach3 is set to Metric or imperial Units.?
Also you have the Micro stepping set way too high. Turn all down to 1600 for starters.
Do you know how far one revolution of the Motor moves each Axis.? I will need to know this to help setup the Steps Per setting correctly.
The difference between Jogging and running road runner code is the motor is running at higher RPM where Mid band resonance isn't an issue.
Last edited by JAZZCNC; 21-01-2016 at 11:33 PM.
The mach3 is set to metric. I don't know the revolutions and unfortunately I've got commitments till monday. So I won't get back to the machine til next week. I really appreciate the help, once I work out the revolutions I will get back to you.
Hope you have a good weekend.
Here's what to do.!
First Jog each axis into clear space with room to move.
Set the drives micro steps to 1600. Then in Motor tuning set the Steps per number to 60, this is just tempory and I'm guessing the pitch will be 10mm. Set velocity and Accel to 1000 & 300. In motor tuning Remember to Click on each Axis to change then save after making changes.
Then check to see if machine moves ok. If stalls then lower velocity.
Now goto Settings Tab and just above Reset you'll see button called "Set steps per unit" . click on it and select the axis you want to set first. Enter a movement amount, make it small at first say 10mm. Then before pushing Enter mark the axis so can measure how far it moves.
When you push enter it will and box will appeat asking how far it moved. Enter distance it traveled and it will work out the steps per setting for you and enter it into Motor tuning.
Do this for each axis but remember the Z axis will need Negative number to move down.
This will get you very close to correct and machine should move ok now. Now repeat but measure over a longer distance and try to measure accurate possible.
Now your set to tune the velocity and acceleration to higher numbers but don't go to high else you'll get stalling motors.
Also other reason why you struggled with Road runner was because the G-code is set for Inches not metric so the moves are tiny and because your machine is so badly setup it was double edge sword.
Jazz you deliver. Looking forward to get through this weekend and back to the machine on Monday now. Will report back with updates next week.
I've had a hectic few months with work but I've finally got a break in my schedule to dedicate the next 2 weeks to getting this machine up and running. I managed to take out the previous configuration of the x axis stepper motor and now instead of the the x axis stepper motor being on top of the gantry its fixed securely inside now with the full four bolts. On doing so I noticed one of the cogs had damaged teeth and had to get a new one made.
Last night I had a couple hours free so I thought foolishly that I could get the VFD setup with mach 3 in this time. Anyway I followed the manual here http://www.omc-stepperonline.com/dow...ers_Manual.pdf but I wasnt entirely sure with the setup coming out of the VFD ASKPOWER A131 as all I could find were these instructions http://www.instructables.com/id/6-Ax...reak/?ALLSTEPS
The spindles runs from the panel fine. All and any help is appreciated thank you in advance
Last edited by toby; 02-04-2016 at 08:37 PM.
Ok this is easy to make happen but will require you changing some parameters in the VFD so you'll need the manual.
If you can find the VFD manual I can describe how to do it. What you want to know is the Parmeter number for External frequency control for the Speed control. Also parameter for ON/OFF so can set to External control.
On the Huanyang VFD's which this looks like but Isn't then it's parameter 01 & 02
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