Topics

1

General Mach Discussion / Problems setting up lathe.

« on: September 18, 2022, 01:20:59 PM »

Hi out there. I am having some odd problems trying to set up my cnc lathe. Having worked out the steps per revolution for the motors I went about trying to set up the lathe like this. My original steps came out at 1000. After setting the motor speed etc, I entered the following command. G0 Z+30. The lathe moved 35mm. So I reduced the steps to 850. Again entered G0 Z+30. The machine moved 20mm. I then entered G0 Z-30 and the machine moved 60mm. Ok something wrong. There is no play on the machine, so it’s not that. I am using a cheap eBay breakout board. The z axis is a closed loop stepper driver and motor. The power supply for the stepper driver states 48v, I am running on 24v which is the minimum, would this course the problem. The other stepper motor is open loop. A few times trying to set the lathe up, I have had no movement from the closed loop motor until I turn all the power off and start again. Any help would be great. Thanks

2

General Mach Discussion / Lathe calibration problems

« on: August 21, 2022, 12:04:44 PM »

Hi. After help from a member of this forum I was able to get the number of steps correct to calibrate the axis. However I have hit a second problem. If I enter let’s say x-40 in the g-code box. The motor turns but very very slowly. No matter how I set it in motor tuning it just moves slowly. If I jog the axis it moves at speed. I just don’t know what’s going on. How can I tune the motor if means nothing in the program. What am I doing wrong. Thanks.

3

General Mach Discussion / Cnc lathe calibration.

« on: August 20, 2022, 10:08:47 AM »

Ok, I have been fooling around most of the day with this. If I try to calibrate the stepper motors using the milling program. I get very high speeds which change each time I turn on mach3. If I switch from the milling side to turn, then the motors go on a dead slow. The information from one side of the program is not transferred to the other, which is a bit silly.  So can anyone help. I have tried to follow the manual, but the last instruction on the calculation is just nonsense. So here is the information I have. My leadscrew is 18 TPI . The motor encoder is set to 4000 steps per revolution. The motor is set to 200 turns per revolution. The motor is connected to a pulley with 19teeth, this connects to the leadscrew pulley with 22 teeth.  Can someone please help me out here. Why can,t calibration of a lathe be simple like the milling machine.

4

General Mach Discussion / Calibration of a lathe

« on: August 20, 2022, 06:35:26 AM »

Hi, can anyone please help. I am trying to calibrate my cnc lathe and hitting a few problems. If I try to set the axis using the milling software I get some very odd settings like the motor is in overdrive. If I try to set the calibration in the turn program by inputting a distance to move and checking, the motor moves like a snell. Can anyone please let me know what is the best way. Has mach4 a better turning set up, or is it just has bad. Thanks

5

General Mach Discussion / Help needed.

« on: October 15, 2021, 08:31:04 AM »

Yesterday my router started to move in just one direction. I tried to reverse in Mach3, but know joy. I reset the motor to active low and the motor turned ok in both directions. Today however it again will only move in one direction. I tried to reverse in Mach3, no joy. Reset to active high, no joy, reset to active low and still no joy. If trying an air cut path for a square. The machine just makes a path like it’s cutting the top of a castle wall. Anyone have any ideas. Thanks.

6

General Mach Discussion / Unable to reverse direction of motor

« on: October 12, 2021, 10:41:26 AM »

Hi, for some reason I am unable to reverse the direction of the motors on all axis. I go to homing page on Mach3, click the green tick to Red Cross press enter. And the motor just travels in the same direction. So at the moment the x+ and x- are around the wrong way, and it’s the same on the y axis. Any idea what is going wrong. Thanks,

7

General Mach Discussion / Running two machines from one pc

« on: September 20, 2021, 11:40:55 AM »

Hi, I wish to run a milling machine and a router from one pc and using only one smooth stepper. The motor tuning is different for each machine, so my question is. 1. If I have the milling machine set up in Mach3, under mill. Would it be possible to download a second copy of Mach3 on the same pc, run the same plug in and then set up the router. Thanks,

8

General Mach Discussion / Running three cnc machines from one pc.

« on: September 12, 2021, 09:38:04 AM »

Hi, most of you know that the most expensive thing apart from the machine is the stepper motor drives, power units, Bob etc. I have three cnc machines. A milling machine, a router and a lathe. I would like to run the all from the same Bob etc. Should say I don’t wish to run them at the same time. To keep things easy, is it possible to run more then one copy of Mach3 on a single pc. I can then just plug in the motor signal cables into the correct machine and run it. Anyone out there no the answer. Thanks.

9

General Mach Discussion / Hi, circles to big

« on: February 18, 2019, 01:56:39 PM »

Hi, I wish to cut a job which as 22mm circles, but for some reason Mach 3 is cutting them a lot larger. The g code comes from vcarve pro. I have tried the following.
1. Edit the g code by adding on G91.1 command after G90 on the line. Result same large circles.
2. Still with G91.1 changed the ij from absolilute to incelmental. Result mach3 would not run g code at all.
3. Removed G91.1 from line, but ij the same. Result large circles.

I then tried using some g code for circles using fusion 360. Circles correct size.

I wish to use vcarve but what do I need to do to get the circles the correct size.