Messages

41

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

« on: May 14, 2014, 05:15:39 PM »

Sounds really good - any chance of some pictures ?

Tweakie.

Sorry, my camera batteries are dead! I am currently working on an improvement of the vise jaw.
As is true with almost any vise, as it closes onto the work piece it tends to want to tilt the surface of the jaw away from the work piece.
This causes the work piece to "ride up" the surface of the jaw, sometimes to the point of actually squirting it out!
So, again necessity rules. Ball bearing rail guides which ride along the back side of the jaw, loaded against the top surface of the rails will (hopefully) prevent the jaw from tilting away from the work piece. I tried designing a mount for ball bearing guides which would ride along the bottom surface of the rails, (positioned inside of the jaw's inner surface) but there just isn't enough clearance between the bottom surface of the guide rails, and the top surface of the vise lead screw to accommodate. At least not without doing a complete re-design and rebuild of the vise assembly. Which may actually be in the future, as I feel confident that positioning of the bearings in front of the inner surface of the jaw would be a much sturdier orientation in terms of preserving the perpendicularity of the jaw. Ultimately, the use of BOTH would be even stronger.
The vise jaw in this case, is threaded for the lead screw. The lead screw is mounted with thrust bearings at each end of the rail assembly.
Unlike a normal direct-screw driven jaw, with a thrust bearing mounted on the jaw of the vise at the screw end.  The reason for this design, was to eliminate a 24" long lead screw from sticking out. Which is what would be the case in a normal direct-screw driven vise.
I have never seen a device offered anywhere, which does all that this thing can do. I just wanted to post, and see what interest it invoked. As I am seriously considering perhaps a patent on the design. And start making a few of these things to sell. What sort of price do ya'll think something like this would be worth?

42

Show"N"Tell ( What you have made with your CNC machine.) / Re: Small project not going well

« on: May 14, 2014, 01:45:12 AM »

What I was going to clean up with the dermal was little areas in between the letters that the 1/16" bit could not fit into. Is there another way to clean out these areas with the code?

I work with MeshCAM Art, for my 3D stuff. It does a great job, since it creates a tool path for the roughing cut, as well as the finishing cut. (I usually use a 1/4" bit for the rough, and a 1/8" bit for the finishing cut). You can actually "LIE" to MeshCAM about the diameter of a tool (I tell it the .125" bit is a 0.94" bit). This forces the software to create a more detailed tool path for the finishing cut. However, since most of what I carve is recycled tractor-trailer flooring, (Oak) it still sometimes requires some touch-up work by hand using a Dremel tool. As for areas that are too small for the tooling to reach into, this is best handled at the artwork design phase. Simply space the letters further apart, to accommodate the tool diameter. I use Corel Draw in designing my artwork. And what I typically do, is to draw a circle .125" diameter, and drag it around the drawing using it as a "measuring device" to check the spacing of my artwork. If it won't fit between letters in the design phase, then the bit won't fit between them when you are carving. I have found it to be a great time-saver, for checking the artwork prior to tool path creation.

43

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.

44

Show"N"Tell ( What you have made with your CNC machine.) / Re: Small project not going well

« on: May 06, 2014, 09:19:22 PM »

I tried the Corian with some new bits I got. It works great, cuts like I imagine Ivory would. Letters look great and the little weeds in between the letters are pretty tough to get out, I'll have to get the Dremal out and finish the clean up.

I see that I am not alone, in using a Dremel for the detail work!
How much did the Corian set you back? (and what size pieces for the price?)

45

Show"N"Tell ( What you have made with your CNC machine.) / Re: Small project not going well

« on: April 24, 2014, 12:21:00 AM »

I'm working on some small patterns and having a lot of trouble with the wood chipping out. My spindle is running at 30,000 rpm and I'm using new carbide bits. I've tried some MDF, Basswood, and something else I think was elm, it was terrible. Any suggestions? I'm using F-Engrave and the letters are very small. I guess I need a Laser.
What kind of wood carves best? Should I coat it with some kind of sealer?
This is like a coaster, about 4" diameter.
A couple of points here, Oak or similar hard woods make the best engraving materials. Also, even though you may have high speed on the spindle RPM, if you are also attempting a high-speed feed rate, it will yield poor results. The tool needs time to do it's thing (and eat away the material to be removed) if you are trying to drive it at a high feed rate, then the "Contact Time" of the cutter to the material is reduced, and can be part of the problem.
So, try: 1-hard wood material 2-slower feed rate and see if it yields an improvement.

46

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

« on: February 22, 2014, 01:11:46 AM »

  Is this correct? You said " I re-homed the machine, returned all axis to zero (and it was then in the correct position). How could you tell the machine was in the correct position after rehoming and returning all axis to 0?
-I have adopted the practice of drilling an index hole through the stock at the X0Y0 position, and the X Limit Y0 position to allow for flipping the stock over, for machining the backside in perfect alignment with the front side. What I meant by "returning all axis to zero" was just that: after rehoming the machine, I simply entered X0 Y0 in the MDI screen, then jogged the Z down into my index hole. Perfect alignment!

  How has this machine been maintained? Might be a good time for cleaning, inspection and adjustment.
-The suggestion for inspection was good advice, as I discovered a shattered bearing on my Y axis. After a quick disassembly, and replacement bearing all is good!
Thanks!

47

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

« on: February 22, 2014, 12:59:44 AM »

Thanks, Rich-
I found the problem- it was a software problem. I had installed MeshCAM version 4 on my shop computer, however when it prompted for the registration code (I didn't have it with me, at the time) a message popped up that I was using an un-registered copy (which defaults to only creating toolpaths for the included sample files). However, I went ahead and used it with my own file. It seemed to work just fine, all the way up to the tool change for the finishing cut. Perhaps Robert wrote the program to discourage unregistered users, since the rough cut worked great. (I don't know for sure, if it was intentional, but if so -Absolute Genius strategy to safeguard against software piracy). It was only on the finishing cut that things went awry.
I un-installed version 4, found my registration code, and re-installed it. No further problems.

48

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)

49

Show"N"Tell ( Your Machines) / Re: Plastic Injection Molding

« on: January 28, 2014, 09:46:26 AM »

I will try and take some photos later. It will require some disassembly, in order to get the mold into a position suitable for taking a photo. I was so obsessed, with alignment of the two halves, that I designed them to be mounted on rails. Unfortunately, this design prevents a "quick removal" of the mold from the machine. As for the milk jugs, I will have to wait until amassing a few of those, before I will have enough volume to work with.

50

Show"N"Tell ( Your Machines) / Re: Plastic Injection Molding

« on: January 28, 2014, 08:45:59 AM »

Oh, I forgot to mention the problem I was having with the cheap chinese ebay purchase for the heat controller. I finally figured out, that it needed an external DC power supply (which I happened to have a 24VDC unit in my shop- left over after upgrading my CNC Router table from 24VDC to a 48VDC unit). I THINK that the heat controller unit is supposed to be supplying it's own DC power, but simply isn't. However, it's internal relay does function to control the series circuit of an external DC power supply. (For controlling the external relay for switching the cartridges heaters on and off). Anyway, the system does function to maintain the temperature automatically to whatever level one chooses to set the target temperature at. It has an upper limit of 400 degrees C. This made things a little less frustrating, without the need to manually flip the switch ON to the heaters every time the output light of the heat controller came on. (And OFF every time it turned off).