Messages

81

Video P*r*o*b*i*n*g / Re: Video Edge Finder

« on: July 28, 2012, 01:20:19 PM »

A

Don’t know If anyone is interested. This is the result using a 208c cmos cam and a usb easy cap. pic is a 0.004 feeler gage.

Actually that is a very useful photo.  It might also be a good suggestion for how to use a video edge finder for greater precision.  Use a known thickness gage like that to get the scale of the projected line before proceeding.  This way you know the tolerance you are setting for your camera to your part.  Obviously the part edge and the gage edge would need to be close to the same height from the table. 

82

General Mach Discussion / Backlash compensation

« on: July 28, 2012, 01:15:31 PM »

Over time I have noticed if I leave the Taig fairly sloppy it tends to stay close to the same amount of sloppy for much longer than if I adjust and tighten it up to reduce mechanical backlash.  One of Hoss's videos inspired me to try leaving it that way and instead using backlash compensation.  At his settings the machine would lose position and walk across the face of the work piece fairly quickly.   I used very conservative settings compared to what He had used and it seemed to work ok.  I cut a 1" register pocket with a .250" end mill and I was modestly satisfied with the results.  It was within .003" total tolerance of round.  Then I tried to cut some parts.  With a 1/4" ball end mill the 3D pocket I was cutting seemed to rough out very nicely, but when I tried to do a "finish" pass with tighter resolution and percentage of step over it seemed to drift a little on each pass.  No machine settings where changed between passes. 

I was cutting in constant velocity mode, but with a very small rounding number. 

83

SmoothStepper USB / Re: How It Works ???

« on: February 23, 2012, 10:43:29 PM »

The next major revision of Mach (V4) will have the graphics processing done in a separate thread so the main body of Mach will not get bogged down.

  Is this planned any time soon? 

84

SmoothStepper USB / How It Works ???

« on: January 31, 2012, 08:59:34 PM »

Ok...  I have heard that the Smooth Stepper takes a lot of load off the CPU. How exactly does it do that?

How does it deal with the typical erratic on demand not hardware driven behavior of a USB port?  Does it actually buffer instructions internally? 

Would using a Smooth Stepper allow for use of the tool path screen with larger files?  If so, how much larger? 


I already own one I am laying out on a mill, and these questions keep me up late at night. 

85

Newfangled Solutions Mach3 Wizards / Re: Threading Multiple Start

« on: December 16, 2011, 06:42:54 PM »

http://youtu.be/BMoKvHjf32g

86

Newfangled Solutions Mach3 Wizards / Re: Threading Multiple Start

« on: December 10, 2011, 10:55:52 AM »

I'll shoot a video when I cut it and if it works I'll post it. 

87

Newfangled Solutions Mach3 Wizards / Re: Threading Multiple Start

« on: December 10, 2011, 10:54:43 AM »

What obvious fubar am I am missing?

I am thinking that the gotcha will be timing even if you rotated the part 180 degrees.
I will admit that i never did any thread milling.

Actually cut and paste the helix and rotate it 180 degrees in CAM.  Rotate the primitive, not the part. 

Using exact stop milling of course. 

I did just now think of one problem with my helix approach.  I have to join a line to the bottom (and probably the top) so that the cutter is not engaged with the part when it tries to retract if it starts at the top, or gouges its way down if it starts at the bottom. 

You calculate the thread height for 1/2 rev then add that to the starting point. Have done it several times for large threads. It will put the second start 180 deg out from the first.

Justa thought, (;-)TP

Makes sense. 

88

Newfangled Solutions Mach3 Wizards / Re: Threading Multiple Start

« on: December 09, 2011, 08:30:12 PM »

Not really appropriate now since this is an NFS forum, but I think I found a solution using ViaCad 2d/3d and Cambam.

Ok, how is this.  In this case it seems simple because the larger threaded hole happens to be at the origin of the machine. 

I have ViaCad 2d/3d which has a helix tool.  I make a helix of the correct pitch, and the diameter of (Major diameter - cutter diameter) and then do an engrave MOP at a depth of .000001".  I can copy and rotate the helix 180 degrees and then duplicate the mop using the second rotated primitive. 

Seems relatively straight forward.  What obvious fubar am I am missing?

If the hole were at a different location I should be able to do the work at the origin for the simplicty of the rotation, and then move it to where ever my hole is. 

89

Newfangled Solutions Mach3 Wizards / Re: Threading Multiple Start

« on: December 09, 2011, 08:05:46 PM »

I don't think doing this on my lathe is really an option.  I don't think I have gears that fast, and even if I did this is an irregular shaped part and I need to thread through.

I can do one thread easy enough on the mill using the mill threading Wizard in NFS Wizards.  I just need to figure out how to rotate it 180 degrees for the second thread.  I actually need to check the geometry of that wizard, because some of the results don't look right. 

90

Newfangled Solutions Mach3 Wizards / Re: Threading Multiple Start

« on: December 09, 2011, 06:14:33 PM »

This a a thread milling operation.  Nopt a lathe operation.  Spinning this part on my lathe even if possible would probably be dangerous.  I am threading a 3.5" minor diameter hole to 3.7" major thread diameter.  Its a loose fit application.  I suppose I could do it all after the part is completely finished at the sacrifice of my thread placement, and just over cut them slightly.