Messages

11

General Mach Discussion / Re: Digitizing

« on: June 08, 2007, 03:58:18 AM »

I'm thinking the price will be $150. I am doing extensive testing for the past couple of days and I am still not satisfied with the assembly enough to sell it. Have to work out some details. I am attaching the point cloud file for FDR's ear on the front of the dime. That is the one that I posted an image of earlier in this thread -- there is a giant pimple on FDR's ear lobe where an error occurred (a false surface detection). The area of this scan is (if I remember right) 0.12" by 0.12" and I had to scale it all up in order to work with it. I don't know if it will work with whatever you try to do with it.

12

General Mach Discussion / Re: Digitizing

« on: June 06, 2007, 09:43:14 PM »

I will definitely check that out, Gerry. Thanks! I found a point cloud macro for ACAD online somewhere, but they wanted money for their version that wasn't crippled. I have MeshCAM so I can try out your method.

WYO_123, are you getting this?

Today I am testing repeatability of my digitizing probe design down to resolutions in the 1 hundred-thousandths range (0.00001") and getting some interesting and amazing results. I am scanning an area of the table of my Taig mill as a test surface. When I get it all sorted out and interpretted correctly I will post the results on http://tetralite.com/probe

Update: I have posted some test results on that page. The probe seems to have measurement repeatability better than 0.0002" and actually somewhere around 0.0001". I also discovered the the table of my mill slopes down from front to back at the rate of roughly 0.0001" per inch (a real rough estimate).

Probes will be available for sale soon at www.tetralite.com/probe.

13

General Mach Discussion / Re: Digitizing

« on: June 05, 2007, 06:57:27 PM »

Bertho,

With my latest plan, it will be just as easy to make the probe accept 5mm styli as 4mm ones -- just a matter of hole and tap size on the threaded coupler. I will make that an option.

14

General Mach Discussion / Re: Digitizing

« on: June 05, 2007, 06:51:46 PM »

WYO_123,
Mach3 stores the output of a digitizing file in ASCII text format. Each line of text represents a sample point. Here is an example of a tiny part of a file from a scan using the digitizing wizard that is clumped in with the other wizards:

0.00000,0.00000,-0.01859
0.00100,0.00000,-0.01859
0.00200,0.00000,-0.01844
0.00300,0.00000,-0.01847
0.00400,0.00000,-0.01844

These five lines define five points with x, y and z values delimited with commas, so the first line says x=0, y=0 and z=-0.01859.

As the program samples points, it increments the x location by the x step value you specified, taking a z sample every step, until it reaches the maximum x dimension that you specify in the set up. Then it increments y by one step unit and then, starting at the maximum value of x, it decrements the x value back down to x=0 taking a z sample at every step. Then it increments y and so on.

You need to turn this "point cloud" output into G-code and I haven't even tried yet and I don't know what program would be the best for doing that. If you have a program that accepts comma delimited x,y,z point cloud files and can convert them to dxf files, I think that might be a good way to go. I'm sure there are people on this forum that have some experience with turning point clouds into G-code. I haven't got that far yet myself. I do know that the Global Mapper program will accept point cloud files and turn them into dxf or JPEG image files and these can be converted to G-code with the right program, perhaps even with LCAM.

This is new territory for me also! Sorry I don't know more about it.

15

General Mach Discussion / Re: Digitizing

« on: June 05, 2007, 10:01:00 AM »

Is that how they attach those balls commercially?

Waitg a sec... what am I thinking!... I can just use a female threaded coupler in place of the nut that holds the screw in the hub. Then a 4mm stylus can just mount directly. (I could save a part if the hub didn't have to be an insulator.)

16

General Mach Discussion / Re: Digitizing

« on: June 05, 2007, 09:56:17 AM »

That sounds like a good idea. I am taking a look at itpstyli.com. The first thing I notice is their styli have male threads. One of the things that makes my assembly economical is having male threads on the shaft coming out of the bottom of my probe. It is actually a 4mm x 0.7mm cap screw that runs through the hub (the part that holds the contacting pins). I am making the hub out of Delrin now (HDPE is just too gooshy) and it is easiest to make if I only have to drill out the center to fit the screw rather than tapping it. Then a nut is put on the end to hold the screw in the hub. If I tapped it, then I wouldn't have the cap head of the screw to hold the main spring from moving lateraly and I don't want to rely on tapped plastic because it is too easy to wreck the threads and they loosen faster with use. So I don't want to make the hub with female threads. So all I have to do is supply a threaded female coupler that will thread onto my probe's male thread and accept a 4mm male threaded stylus, which can be found at itpstyli.com.

Jeff Birt, thanks for your input. I have decided to include the threaded female coupler so people can buy a standard stylus. Also, if they wanted to use a stylus with a different size thread, they can make an adapter that has 4mm threads on one end (to fit the probe) and whatever size thread on the other end for their stylus. Or they can still just make their own stylus with femaile threads.

I still want to know how they attach ruby balls to styli -- can't find that yet!

17

LazyCam (Beta) / Re: OK, I give up! How do I get ACAD dxf files to open in LCAM 2.02?

« on: June 05, 2007, 09:06:10 AM »

Exactly!

18

General Mach Discussion / Re: Digitizing

« on: June 05, 2007, 04:07:43 AM »

I have begun assembly of several probes and when I have a few built I will begin offering them for sale on a web page at http://tetralite.com/probe. I have completed the time study and I have decided the price will be $150 plus a flat rate for shipping anywhere in the US plus a PayPal fee (orders will be only through PayPal). I will not be selling to foreign countries. I just don't want the extra hassle of filling out customs forms and calculating the shipping charges. I have enough of that to do with my other product (TetraMouse).

During this short initial run I will be refining my tooling (jigs and etc.). I am considering offering the probe without a stylus, which would mean it would be a do-it-yourself stylus situation. On the other hand, if I come up with a simple all-metal one piece stylus I will offer that. The problem is I can find no info regarding how to attach ruby balls to a stylus for the tip. Anybody know about that?

As soon as I have probes for sale I will put a PayPal link on the above mentioned web page. If I get more requests for probes I will begin another run right away. Lead times will be short -- a couple or three days probably. I will try to keep an up to date total of probes on hand on the web page. If I have to put orders on hold and anyone doesn't want to wait, I will refund their PayPal payment at their request immediately.

The first run is 5 units and two of them are already spoken for. I expect to put them up for sale within two days (June 7th probably -- maybe tomorrow the 6th).

19

LazyCam (Beta) / Re: OK, I give up! How do I get ACAD dxf files to open in LCAM 2.02?

« on: June 02, 2007, 05:32:43 PM »

When ACAD is installed in Windows, by default, it sets Notepad as it's text editor, so ACAD and Notepad do not conflict. When I can't open a file in LCAM that is currently open in ACAD, and then, when I close that file in ACAD it will open in LCAM, that can mean only one thing as far as I can tell. ACAD has a hold on that file while it is open in ACAD. There are security settings in ACAD that allow or disallow users concurrent access to files, however I haven't seen any user settings in ACAD for allowing or disallowing concurrent access by other programs. Many programs won't allow changes to files that are currently open. This protects the file from being altered by two people at the same time and changes by one user may not be seen by the other (the file would have to be reloaded to see the changes) -- could be a real mess! However, ACAD will allow it (from another ACAD user) if it is set up that way.

All I know for sure is that I can open a file in LCAM if the same file is not currently open in ACAD, and I can't open the file if it is currently open in ACAD.

20

General Mach Discussion / Re: Digitizing

« on: June 01, 2007, 07:06:28 PM »

If that is true that would mean that the probe plugin is generating errors in the output file that would amount to elevations being reported at the wrong (shifted by 1 x step) x,y point. Is that what you are saying?