Topics

1

Show"N"Tell ( Your Machines) / Can anyone identify this machine?

« on: October 09, 2021, 07:32:15 PM »

I bought this CNC router from a man named Kwong Kim. He had owned it several years, and did not recall who he bought it from. Only that they had said they used it, for machining aluminum. It is a very well made machine, with steel (supported) rails, with 1.594" dia ball bearings riding against them on 2 sides. The X and Y drives are gear rack and pinions, driven by toothed belts with toothed pulleys. The belts are in good shape, but I would like to know the specifics, for the day when they are no longer in good shape. I have searched all over the machine, and not found any sort of labels, or identifying marks from the manufacturer.
  It is driven by Mach3 (the computer was included in the purchase, with Mach3 already installed). The frame is all aluminum, and features a satin finish, so I am not sure if it is T6061 or 2024, or What? If this was a home-built machine, my hat is off, to the person who designed, and built this machine. Most of the frame components are aluminum I beam-like. I say "Like", because instead of a traditional T at the top, and bottom of the I beam, they sort of taper out from a center thickness of about 0.25" to the T thickness of 0.695" The T slot table seems to be extruded aluminum, which accommodates 1/4" T bolt hold-down clamps from Rockler. Does anyone recognize this machine? Sound off! Thanks! -Michael

2

General Mach Discussion / Help in diagnosing tool path problems created in LazyCAM

« on: September 01, 2019, 12:55:10 AM »

I designed and built a 4 axis router table. (Basically a mill table, with 4th axis functioning as a lathe). I purchased the Mach3 software with LazyCAM Pro, and have been running the machine since 2008 with few problems. However, lately I have been experiencing things that I cannot seem to pin down. About my machine:
48vdc Keling Technologies power supply to a Gecko G540 driver. All motors are NEMA 34 steppers wired in Bipolar Parallel configuration. I use CorelDRAW to create most basic tool path artwork, and export the files from Corel DRAW as Hewlett Packard Graphics Language *.plt files. These files are then imported into LazyCAM, and edited for tool path creation. Most files of this type are used to engrave wood carvings that I do (using MeshCAM Art software). However, something is causing the X axis to "Drift" during the engraving process. I have tried cancelling all G41 or G42 moves (so that the tool path follows at center line with No cutter diameter compensation), yet the problem persists. The artwork is a simple arrangement of lines and arcs which form the letters in the word "Lieutenant". The letters are arranged in an arc, and engrave with absolute precision and repeatability with the exception of the letters T and E near the center of the arc. The vertical lines of those two letters seem to "step over" approximately 0.050" with each pass of the cutting tool.  Obsessed, with finding the cause, I filled in the damaged areas surrounding those two letters with wood putty. Then re-homed the machine, and tried it again. The cutter followed the existing cut lines with absolute precision. And repeated the "step over" on the vertical lines of the T and E AGAIN! I have checked the G code, line by line, and there does not appear to be any variation at all in the starting and ending coordinates of each of those vertical lines. The G91.1 code is inserted by LazyCAM due to the single arc that appears in the letter U. The only other G codes that appear in the file are G0 and G1. So, I am baffled. I can upload the gcode file so others may inspect it for themselves. The specific size of the area to be engraved measures 7.5" wide x 10.75" tall. The zero coordinates are at center (X3.75 Y5.355) the cutting depth starts at Z-.4200" and cuts to a depth of Z-.452" The tool I am using, is a 1/8" diameter engraving cutter which features a very sharp V cut which measures about 0.02" wide at the tip, and flares out to about 0.025" at the top. (Relative to the depth of cut). It would be great, if someone else could do a test cut of this file, and report whether or not the letters engrave correctly. The attached Lieutenant.tap file is the one I am referencing here. Any advice, or suggestions as to the possible cause is greatly appreciated!

3

G-Code, CAD, and CAM discussions / Home command

« on: August 13, 2019, 09:18:38 PM »

I am experiencing problems with my machine. It seems that the X axis is losing steps (or some other problem). What happens, is that the X axis will get progressively off in the + direction during the carving process. I am not very fluent with G code, but was wondering if it would be possible to enter a Macro command within the G code, which would re-home the machine between each pass, then continue where it left off at. If so, what is the correct G code, or macro I would need to enter? What I am referring to, in particular, is to invoke the same macro command that is built in to the 2010 Screen set. Please HELP!

4

LazyCam (Beta) / Slot cutting

« on: December 24, 2018, 01:23:05 AM »

Does anyone know if there is an easier way to use LazyCAM to generate a toolpath with the following:
1 Constant Z height setting of ZERO
2 Rapid moves back to X0, then Y0 after each pass
WITHOUT the need to manually code it!!

What I did, was import a *.plt file which contained vertical lines (of the desired cut length) which measure 1.75", and are spaced 0.003" apart
The tool I am using, is a carbide slot cutter which measures 1.75" diameter, with 1/16" wide cutting teeth.
The theory was, that LazyCAM would generate a toolpath which would equate to the normal "Depth per pass" along the X axis, instead of the Z. The Rapid Height, Starting Depth, and Cutting Depth are all set to ZERO to prevent ANY Z movement during cutting. One must pay attention during cutting, and FeedHold the machine, then jog to at least X-1.0" before hitting the STOP button, (as this causes the Z axis to raise completely, resulting in a broken cutter, if it is still positioned within the current slot being cut!).

The G code generated by LazyCAM had to be modified, in order to force the machine to return to X0, then Y0 before each "Step Over" of the X axis of 0.003"
by entering G0 X0.0000
G0 Y0.0000 in front of each pass (for example G1 X0.0000 Y0.0000, G1 X0.0030 Y1.7500)
What I was hoping for, was to pass each pass starting at Y0 and cutting to Y1.75, "Stepping Over" to X0.0030 and repeating. THEN rapid back to X0 first, then Y0, And stepping over to the next cut (x0.0060) at the current feed rate (of 6 IPM), and continuing in this manner. I was able to achieve this, but it was after a couple of HOURS of hand-coding. I really feel that LazyCAM is capable of doing such a toolpath, But I am just not familiar with it enough to know what settings/ options need to be changed in order to achieve this. Can anyone steer me on this?
THANKS in advance, and Merry Christmas!
-Mike

5

General Mach Discussion / Laser limit switch

« on: December 09, 2018, 12:01:44 AM »

Does anyone know of a supplier of limit switches, which utilize a laser (or other light source) and a photo cell to sense when the machine has reached it's limit of travel? I currently use mechanical limit switches, which are not very precise (when homing the Z axis, in particular). And I just thought that light/photo cell system would probably be much more consistent. Thanks in advance, for any help you can offer!

6

General Mach Discussion / What would be the best sensor method to detect spindle speed?

« on: March 03, 2017, 02:28:19 AM »

Is there a way, to wire a speed sensor (light source, and photo-cell perhaps), and set up Mach3 to trigger an error (And thereby STOP program execution at the current line number)? The reason I ask, is because motor brushes wear out! And when they wear down enough, they no longer contact the armature, so the router motor stops running. Invariably resulting in a broken bit, as Mach3 continues to run (unaware that the router motor has actually stopped!). Has anyone else done this? What sort of circuit, and speed sensor device could be used for this purpose?
Thanks, in advance for any help!
-Michael

7

G-Code, CAD, and CAM discussions / WHAT has changed in Mach 3?

« on: January 14, 2017, 10:05:31 AM »

I have been using Mach 3 since 2008, when I built my first CNC router table. The software that I use to create tool paths include MeshCAM Art, Corel Draw, and LazyCAM Pro. I have not learned much, in terms of memorizing the various G code command set. So, I am unsure how to address a problem that has recently come up. In the past, any time I was running Mach 3 driving the machine (with either a *.NC or *.tap file loaded into Mach 3), and needed to pause program execution, I simply pressed the space bar. Which paused the machine. If I needed to make changes to things like cutting depth, etc. I would then click on the Rewind button, and click on the Router button, (to turn OFF the router). Then I would go into LazyCAM to make the needed changes. (in the case of *.tap files). However, when I attempt to do this now, I receive the following message "Unable to reverse execution, No jogging available". Any attempts at entering manual commands have no effect. Except to hit the Escape Key on the keyboard, which stops everything. Clicking the Reset button in Mach 3, runs the initialization script with the default settings that Mach 3 came with. (It loads, and executes a series of G codes which set up various things such as Metric or Inch measurement preferences, etc.) My question is this: Is there a setting in Mach 3, which prevents Rewinding a G code file during it's execution? Or perhaps a G code command, which does this? SOMETHING HAS CHANGED, and I need help understanding WHAT!
Any help with this problem will be greatly appreciated!
Thanks! -Michael

8

G-Code, CAD, and CAM discussions / Parabolic Dish

« on: January 09, 2017, 06:42:22 PM »

This is for the more advanced g-code wizards: Can anyone post an example g-code program to cut a parabolic dish?
I am not (yet) familiar enough with the g code command set to accomplish this. Even just a small, six inch diameter program would be helpful in learning the math involved. I know that it is possible to cut a ramp. Having tried this last night:
M3
Z0
X14 Z-.25 F6
M5
results in a groove which tapers from the stock's surface, to a depth of 1/4" across a span of 14 inches at a feed rate of 6 inches per minute.
What I am looking for, is similar g code for cutting a circular pocket. With a starting depth of 0, a center depth of .5 inches, and a finishing depth of 0 (at the opposite side of the circle). I.E. a DISH! How would one express this, in g code? I know that the machine is capable, I just ain't smart enough to communicate to it the steps such a cut involves!
HELP!
Thanks in advance -Michael

9

Show"N"Tell ( Your Machines) / Vise for wood carving

« on: May 14, 2014, 01:24:08 AM »

I just thought I would sound off, on what I have been working on for the past week.
I use my home built CNC Router table mostly for doing wood carvings. I work with recycled tractor-trailer flooring. Most of the time, the finished carvings are slightly thicker (or thinner, depending on the point of view) on one end (or the other). And depending on the piece carved, may actually be purposely carved thicker on one side or the other. I like to "Sign" each piece carved, with a special engraving on the backside of each piece. The inconsistent thicknesses of the carvings makes this task nearly impossible. Or at least, a very large pain in the neck- using shims, etc. in an effort to "level" the back side of the carved pieces.
     So, as they say: "necessity is the mother of invention" I designed, (and have now built) a vise, which will accommodate pieces up to 24 inches wide (in the Y direction) and 48 inches long (in the X direction). This vise can be tilted in the Y direction, as well as the X direction. And the adjustment mechanism is a single knob for each axis of movement, which is locked with a thumb screw. This provides very precise control in "leveling" the piece in relation to the router bit. And it is accomplished tool-free. (No wrenches are involved in making these adjustments, just loosen the thumb screw, and turn the knob for each axis, then relock the thumbscrew).
      After completion (and the first trial run to test this device), it occurred to me, that a similar design could be utlized in the actual table surface mounting. Of course, it would involve the use of much heavier-duty materials than those I used in constructing this prototype. But I think that this design could be the answer to the constant problem folks experience with home made CNC mills of the task of leveling the table. I have never seen a device which does what this thing does, and just thought that I would talk about it here, and perhaps on the Zone, to see if there is any interest. Ya'll let me know your thoughts.

10

General Mach Discussion / Refresh my Memory (or LACK of it!)

« on: February 11, 2014, 12:23:18 PM »

Last night I experienced a problem with my machine, which I have been unable to determine for certain whether or not it is a mechanical problem, or electrical.
I started a MeshCAM carving, which completed the roughing cut without problems. I changed the tool to the finishing cutter, and continued with the finishing cut.
That is when the problems began. For some reason, the X axis started either losing steps, or failed to move as far as it was commanded to. This resulted in the piece being ruined. I stopped the machine, and returned all axis to zero to verify that it was correct. Sure enough, it was off by about 0.170" on the x axis. I re-homed the machine, returned all axis to zero (and it was then in the correct position).
I then entered the correct line number (following the tool change to the finishing cutter) and selected Run From Here, to continue the finishing cut. I could hear the X axis motor make unusual sounds occassionally during it's movement. As I observed the movement, the x axis seemed to be losing steps progressively, with each pass. It is important to note, that this machine has been in operation for a few years now, doing similar cuts without any problems.
Anyway, my point here, is to request someone to "Jog my Memory" on which utility it is in the Mach3 folder to test the pulse rate of the computer. As I simply cannot recall what the program's name is called. My problem may simply be that the threads of the lead screw nut have become so worn, that an excessive amount of backlash has now been introduced. However, the strange sounds coming from the x axis motor occassionally, is what makes me suspect that it may be a pulse problem. I just wanted to run that program, and watch it to see if there are any sudden changes which may be the actual problem. (And don't remember it's name)