Messages

646

CamBam help (General usage) / Re: Stencil Cutting Profile with Swivel Drag Knife Question

« on: September 09, 2010, 23:33:09 pm »

It appears either the Engraving or Profile MOP work equally well for stencil cutting.  I found that by just defining the tool diameter to very, very small (.0005")  it works okay.

647

Members Projects / DIY Stencil Cutting Drag Knife Solution - Update 4!

« on: September 06, 2010, 21:07:05 pm »

Here is a link to a site where someone has already solved the problems involved with taking a stock vinyl drag knife and mounting into swivel bearings and holder. His trial and error process is well documented which brought him to his final solution.

http://www.cuttingedgecnc.com/vinyl.htm

My solution is a variation that adds a compression spring.

To make your own DIY Swivel Drag Knife Cutter all you need are:
  1.  one .25" x .125" rare earth magnet from Amazon.com
  2.  one 5mm OD, 2mm ID bearing from http://www.bocabearings.com
  3.  one 4mm OD, 1.5mm ID bearing from http://www.bocabearings.com
  4.  one 3/8" x 12" brass tube from Hobby Town USA or your local hobby store
  5.  three Carl Goldberg 3/16" wheel collars from Hobby Town USA or local hobby store
  6.  one spring that slides easily down the 3/8" brass tube, has an ID > .25" and a compression force of 80-150 grams when compressed 3/16"
  7.  Roland replacement blades 45 or 60 degree from Ebay.com
  8.  A copper pipe cutter such as a Rigid Model 104.
  9.  A tiny amount of thin CA (Cyanoacrolate also known as Super Glue)
 10.  A tiny amount of Loctite 609
 11.  Digital calipers (very helpful)

To see more of this article go to http://www.buildyourtools.com/forums/index.php?f=8&t=944&rb_v=viewtopic

Hope it inspires you.

648

Members Machines / Re: Home made 3-axis CNC machine

« on: September 06, 2010, 20:58:49 pm »

Hey Bob,

Like Woodworkerb, I use my Model 395 Dremel on my CNC as well as a PC Model 892.  This model Dremel does turn close to 30K rpm. 

At first I found the Dremel's lower bearing had a lot of run-out, but upon opening the case I found the moldings in the case halves which capture this bearing deformed over time allowing the bearing to wobble inside the case.  The bearing was fine, it just wasn't captured tightly.  The upper bearing didn't have this problem.  I've had this Dremel for over 10 years and only had about 5-10 hrs of run time on it.

To solve this issue I wrapped the lower bearing's outer race with a couple of tight turns of aluminum duct tape until it pressed firmly into the motor halves.  This eliminated any run-out and now works great.

Cheers,

649

CamBam help (General usage) / Re: Stencil Cutting Profile with Swivel Drag Knife Question

« on: August 30, 2010, 04:08:16 am »

Thanks Scott and Ralf.  I appreciate your input.

Scott, I will give the Tangent Leadout a whirl and see how it goes.

Ralf, I had no problem understanding your explanation.  Your drawing was helpful as well.

650

CamBam help (General usage) / Stencil Cutting Profile with Swivel Drag Knife Question

« on: August 28, 2010, 03:46:12 am »

I just made my DIY swivel drag knife for cutting adhesive and non-adhesive vinyl/Mylar stencils.  The swivel blade is a Roland 60 degree blade angle with a tip offset of .25mm.  You can see images here:
http://www.buildyourtools.com/phpBB3/viewtopic.php?f=8&t=944&sid=1baefa911e8fb2b53f9131382d71b83c

FYI: The knife tool shaft is 2mm where it rotates in the bearing.  My table XY resolution is better than .00075" and Z is better than .00025".

My first trial stencil cuts were very good using the latest Mach3.  I cut out the letters "CNC" in Times New Roman with the actual font height about 1.5".  I used a profile MOP: tool diameter .001" and later .0005". Both worked, however, when inspecting the cuts I noticed the start and end of the tool path on each letter did not close exactly, I'm mean just a sliver off.  This is most noticeable when trying to lift the letters from the backing.  There is a tiniest undefined "holding tab" which usually breaks but sometimes will cause a tear in the vinyl.

Is there a way to define the knife point offset in the profile MOP or anywhere?  I'm not sure I understand about the Tool Offset parameter.  I currently don't use tool tables.

Any help appreciated.

Thanks

airnocker
Everything depends on everything else

651

CamBam plus feedback / Re: CamBam plus 0.9.8 minor bugs

« on: August 21, 2010, 21:24:31 pm »

Hi,

Just started playing around with 0.9.8.  I like it and the improvements you have made.

I found two minor bugs.

The html Help file incorrectly points to where the Sample files are.  It currently points to here:
file:///C:/Program%20Files/CamBam%20plus%200.9.8/help/samples/heart-shaped-box.cb but "/help" should be omitted from the path.

When setting the Text font size, anything smaller that "1" generates an error shown in the attached jpg file.

airnocker

652

CamBam help (General usage) / Re: How do I radius the corners on a Polyline?

« on: August 21, 2010, 20:35:05 pm »

Very clever George.  I like your method.

airnocker

653

CamBam help (General usage) / Re: How do I radius the corners on a Polyline?

« on: August 19, 2010, 22:35:36 pm »

I ran into an identical scenario today with an "L" shaped object that I need to radius some inside corners , some outside but not all corners.

The Edit > Offset trick works great but it does all outside or all inside corners.

The method I used takes a bit longer but allows one corner at a time to be radius'd either inside or outside corners. 

Start by drawing a circle with the radius you want for corner rounding and position the circle into the corner so that the circle is tangent to two adjacent sides.  I then selected both the circle and the "L" shaped polygon and did "Edit > Break at Intersections" and used .001" as the intersection tolerance.  (I had to zoom way in to be sure the circle was just intersecting the polygon.) 

Then remove the bits that aren't part of the rounded corner which should be a small right angle corner of the polygon and a 270 deg. arc.  Select the polygon and the remaining 90 deg. arc and do "Edit > Join".

Where there is a will there is a way.

 

654

CamBam help (General usage) / Re: Spiral Drilling Large Holes ?

« on: August 19, 2010, 00:32:06 am »

As you noticed, the ratio of the CutFeedRate to the PlungeFeedRate determines how many spirals per Target Depth.  If you want really smooth walls keep the ratio high.  I haven't encountered any "crash" issues and have used anywhere between 3:1 and 10:1 ratios with excellent results on wood.

airnocker

655

CamBam help (General usage) / Re: Drill MOP G-Code Problem

« on: June 23, 2010, 21:14:50 pm »

I get it now, duh!  So you have to have the target object selected when choosing the MOP that will act on the object.  I ran my 2nd .nc file in Mach3 and it worked perfectly.

Thanks Martin

656

CamBam help (General usage) / Re: Drill MOP G-Code Problem

« on: June 23, 2010, 20:49:53 pm »

Thanks, but that wasn't it.  I had selected the points to begin with prior to generating tool paths.

657

CamBam help (General usage) / Re: Drill MOP G-Code Problem

« on: June 23, 2010, 20:48:32 pm »

Not intuitive but I think I figured it out.  I would like to know if this is the normal process, however.

Here is what I did:
1. In the Drill MOP > General > PrimitivesID was the number "5"
2. I clicked in the "5" field and clicked on the "..." selection button on the right
3. A prompt appeared stating " Select objects, (use ctrl+click to deselect), then press enter or esc"
4. I clicked on one of the points and they all became highlighted with green circles around each
5. I pressed enter to complete the action
6. The Primitivesid incremented to "6"
7.  re-did  generate tool paths and produce G-Code
8.  Now the G-Code looks like the attached file

but why is the tool change still there?? since it starts with Tool 0 anyway?

658

CamBam help (General usage) / Re: Command explanations

« on: June 23, 2010, 20:29:08 pm »

Clicking CamBam's Help > Contents should open the local html file at file:
///C:/Program Files/CamBam plus 0.9.7/help/Contents.htm

Maybe you should check where your CamBam install directory is or re-install on the laptop.

Cheers

659

CamBam help (General usage) / Drill MOP G-Code Problem

« on: June 23, 2010, 20:10:38 pm »

Newbie here, trying to do a test drill MOP.  I have a really simple 9 point rectangular point list I want to drill down to -0.050" with a .1" dia. bit, but the G-Code has a tool change code I didn't ask for and there are no G1 position or Z plunge change codes.  The point list was created by right clicking the inner rectangle then selecting Draw > Points > Fill Geometry.  I then added the Drill MOP.

Why is this not working?  See attached files.

Many Thanks

660

CamBam help (General usage) / Re: Translation Matrix needs some explanation

« on: June 15, 2010, 01:16:52 am »

Awesome.

Don't apologize for a long response as I prefer the thoroughness and detail of your explanations, and the valuable insights to object moves.

(bow, bow) all hail, Andy rules.