Messages

81

Show"N"Tell ( Your Machines) / Re: Home built CNC Router.

« on: October 30, 2012, 08:43:26 PM »

Have constructed custom design CNC router using Baltic burch 3/4 plywood with aluminum and hardened steel rails.

Trying to run Mach3 and am having difficulty in getting the motors to run.  Can anyone let me know of a person or company in the Central Texas area that is using Mach3 in their shop that I could contact and get some one on one info on set up and runining programs?

Have tried to  load some photos of CNC router machine but can not get them into this message.... Sorry.

Best regards,
Marc

Don't know of a Texas user, but there if you are running Mach3, there is much you can learn by simply watching the support videos. And if you can provide some of the specific info about your machine - the electronics used, stepper motors, etc. it will provide a starting point where others can chime in to help you get things set up and running.

82

Show"N"Tell ( Your Machines) / Re: Adding a 4th axis to my mill

« on: March 20, 2012, 09:56:49 AM »

I don't have any photos to post of it, but I added a 4th axis to my machine about a year ago. Basically, I just constructed an upside down U shape out of 2" aluminum blocks, and mounted the headstock shaft to the assembly using 2 pillow block bearing assemblies. (With eccentric collars on each). For the shaft itself, I used 2" diameter stock, and turned the ends down on my lathe to fit inside the eccentric collars of the pillow bearings. This created a shoulder on the shaft, which the collars seat against.

 Once I mounted everything up, I used a dial indicator the set the shaft to absolute center- then locked the set screws on the eccentric collars of each bearing. A tooth belt and gear assembly was used for installing the stepper motor to drive the headstock. I threaded a round-head bolt into the side of the shaft (between the two pillow blocks) which strikes against a microswitch to index the A axis to zero.

I used a similar construction in building the tailstock assembly. Both the headstock and tailstock assemblies are cradled between two pieces of angle steel. The headstock is of course bolted to these angles, while the tailstock slides along the length of the angles. The tailstock assembly itself is free to slide along the angle rails, and is adjusted by use of a lead screw threaded into the tailstock mounting blocks. The opposite end of the lead screw is inserted thru a second aluminum block upright which also slide along these rails. Two bolts pass through the aluminum block upright, (at the knob end) and thread into a piece of 1/4" flat stock suspended below the horizontal planes of the angle rails, which acts as a clamp mechanism to secure the position of tailstock.

This allows for easy (rapid) adjustments of the tailstock position from the top side of the machine. The lead screw has about 14" of travel, so plenty of adjustment capability. However, adjusting the position by turning the lead screw knob is a slow process. This was the reason I added the 1/4" threaded flat stock to clamp the assembly to the rails. For rapid adjustments, I simply loosen the two locking bolts, and slide the entire tailstock assembly to the desired position. Re-lock the two bolts, and then turn the lead screw knob to load the tailstock against the work piece.

The rails were added alongside the table, for the 4th axis assembly. Which allows use of the machine in 3 axis mode. I later added an adjustable limit switch (the positive Y axis limit) to allow for rapid setup for 4th axis use. I simply change the Homing from Negative, to Postive for the Y axis when preparing Mach3 for 4th axis work. This took some trial and error the set the Y axis positive limit switch in the correct position, so that the router's center is moved to top dead center of the 4th axis during Homing. Because of the distance Mach3 backs off the switch, once contact is made during Homing.

This assembly being a direct-drive system requires a LOT of torque! I originally had a 900 oz in stepper, which just wasn't up to the task. So I upgraded to a 1200 oz in stepper to drive the 4th axis -which worked.

After adding the 4th axis, and experimenting with it a few times, it has largely remained unused since. I do not have an encoder setup, but rely on the limit switch for indexing to zero on the A axis. Which of course, is not reliable enough for cutting gears, and such. But does function for doing things like small columns such as chair legs, etc. up to 30" long and 8" diameter. I use CNC Wrapper to create the 4th axis tool paths.

83

Show"N"Tell ( What you have made with your CNC machine.) / Re: Harley Davidson w/ Eagle Logo Wood Carving.

« on: March 20, 2012, 08:47:54 AM »

Here's the photo.

84

Show"N"Tell ( What you have made with your CNC machine.) / Re: Harley Davidson w/ Eagle Logo Wood Carving.

« on: March 20, 2012, 08:46:31 AM »

Mike,
(FROM another Mike) I too use MeshCAM Art. To critique your work (although VERY Nice!) I have learned that Pine is pretty much a waste of time, and material. It just doesn't hold up for much carving details without chipping, splitting, cracking, or breaking off. Oak is a much better material to work with. And regarding speed- even though a machine may be capable of faster speeds, this does not necessarily improve things.

But can instead, make it even worse -even if cutting Oak. The reason is, the cutter needs TIME to do it's thing. Sure, you can speed things up to 60 IPM feed rates, with a router running at 27,000 RPM, but it will result in the cutter just Knocking the wood instead of actually cutting it. (Think hitting it with a 27,000 RPM hammer!). I usually do my roughing cuts at about 40 IPM, with a 1/4" straight flute bit. And the finishing cuts at about 22 IPM, with a 1/8" single flute round tip bit. And for really fine details, a 1/16" carbide tile cutter bit.


Patience is the key to getting good results with MC Art. Most of my carvings average about 5 hours total cut time, depending on size, depth of cut, complexity of the shapes edited, etc. I have just finished the tool path for a carving which measures X=21 Y=10 Z=-.75 and the estimated cutting time for that piece is over 12 hours! Have a look at the Marine Corps logo for an example of my work (approximately 9x10).

85

Feature Requests / Re: Probing Surface to adjust Depth of Carvings on Non-Planar Surface??

« on: March 01, 2012, 10:48:39 AM »

Engraving is a true test of machine accuracy, repeatability, table flatness, etc. And even wood which has been planed flat directly on the machine can sometimes present problems when doing an engraving. (Because it IS, after all- WOOD!). Changes in wood grain density, knots, and direction changes of the grain around knots, etc. can create apparent cutting depth variations in an engraving. Particularly very delicate text engravings, with very fine lines, and small characters. What I have learned to do, through trial and error (a LOT of the error part!) is to start with a cutting depth which is VERY SHALLOW -maybe 0.003" deep. Engrave the first pass, and inspect the result. If not deep enough, I usually load the file into LazyCAM, and set the cutting depth a little deeper (maybe 0.002" at a time), and repost to Mach, and run a second pass. Inspect the results again, and repeat as needed. The wood grain density problems I mentioned above, can sometimes be overcome by using a little trick I have learned: with the file loaded into LazyCAM, select all characters EXCEPT the one (or more) character(s) that appear not to have engraved deep enough into the wood (due to a denser area of the wood grain) and DELETE them! Repost the file to Mach3, and run the program again. If they still don't appear cut deeply enough to match the other characters, you can always go back into LazyCAM and set the cutting depth a little deeper, and repeat until you achieve the best results. Using a V bit for engravings, to create a BOLD font, just select the desired characters to be cut as BOLD, and set the cutting depth a little deeper for these. You are still using the same font, but the results in the engraving make the characters appear as a BOLD font. Yeah, I know. It's a PITA process. But necessary sometimes to overcome the MANY variables which working with wood presents in order to achieve a quality engraving. It is a bit of an Art form, and learning to control the machine to become your "Artist's Brush" does invlove some rather tedious WORK! Starting with the "Fonts" I use, which are actually hand-drawn groups of lines, circles, and arcs which mimic actual fonts for the best engraving results. Hope this helps!

86

Feature Requests / DRO Box which displays Tool Change Line Numbers

« on: March 01, 2012, 10:17:50 AM »

This has been suggested before elsewhere in the forums. However, it would be really nice to have this feature as a part of the Main Program Screen in Mach3.
Additonally, perhaps a "Count down to Tool Change" Timer box.

87

Show"N"Tell ( What you have made with your CNC machine.) / Re: Hot Foiling/Embossing blocks

« on: January 13, 2012, 01:57:54 PM »

So, it looks like a combination moving gantry AND moving table. If so, what is the advantage of this setup? (And what axis is assigned to each- Gantry, and Table)?

88

Show"N"Tell ( What you have made with your CNC machine.) / Re: Hot Foiling/Embossing blocks

« on: January 13, 2012, 03:51:33 AM »

So what software do you use for artwork creation?

89

Show"N"Tell ( What you have made with your CNC machine.) / Re: Impact Engraving.

« on: January 05, 2012, 12:26:54 PM »

Cool stuff Tweakie!

90

Show"N"Tell ( What you have made with your CNC machine.) / Re: Custom Wood Carvings

« on: January 02, 2012, 11:37:46 AM »

.
Looks very nice, especially the Palmers one, a nice colour on the wood.

Brian

Believe it or not, the Huckabees one actually looks very similar to the Palmers one. The woodgrain of Oak, after finishing with polyurethane, is an almost infinite light-catcher. It depends on the lighting, and the viewing angle. These photos were actually taken by two different cameras by the recipients of these plaques, and posted on facebook at my request (since I forgot to get a photo record of these carvings before shipping). Both of these pieces were carved from the same piece of wood.