Hello Guest it is August 18, 2019, 07:55:27 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - freshwatermodels

Pages: 1 2 3 4 5 6 »
1
Rich,

I'm aware of "David" which is very limited and has been around for a while.    Dentists use a scanner but they don't have much size capability. I use a dental lab to do my 3D printing and probably ask about their scanning capability.   I have farmed out scanning, both laser and white light, and they are very expensive but in the case of the laser very accurate.     The big problem was converting the resultant stl file to a nurbs model.   I spent many hours one one of the projects.    What I did was to do a numbrer of mesh splits and develop cross sections from the edges where the mesh was split.   

I may well just use the router to manually take off point coordinates from the parts.   Not fun but gets the job done.

I have found Mach3 very useful but my main issue with it is that information on the various wizards is sketchy at best and wading through many forums and yet many more posts seems quite cumbersome and in many cases hasn't answered my question as is the case in this thread.   If only there was a reasonable way to sort out the facts and organize them in an easy to access manner.

Jack

2
I assumed laser scanning was way too complicated and expensive?   Am I missing something?   About the only thing I have considered is shooting a laser at the object and taking pictures at 45deg angle and using them as bit map backgrounds to trace contours.   I have seen this done at a museum using fancy software.    I wouldn't have a clue where to find a suitable laser that I could afford.

Jack

3
TP,

Thanks, I think I understand the wiring.    I'll have to look at Mach3 as installed in my router computer and take another look at the Gecko.

I'm a model maker and a lot of the design work I do is reverse engineering and doing it so a model can be built.   Most of what I design is pretty simple but some stuff like model outboard motor cowls and lower units are tough to design from scratch.

Most of what I design is intended to be cast in Britannia metal or resin though I do machine some wood/plastic/metal parts.    Once I have the design done I send it out as an stl file for 3D printing which is what those blue parts are.   The printed parts are used as patterns to make either a low temperature vulcanized silicone rubber mold or an RTV silicone rubber mold.  Once in a while I machine brass patterns.    Once the mold is made the parts are cast using a spincasting machine.

In the past we have spent as much as $2000 in scanning and my time to develop a shape in Rhino and it was a tough slog convertng the mesh to a nurbs model.   Rhino doesn't do well in editing meshes even with the wiz bang gaming computer I now use.    I need to work out a way to get reasonable price reverse engineering and I think the easiest way is to use the router to determine points that I can work from.

Regards,

jack

4
TP,

OK, now we're on the same page!  Thanks!     I were to machine the part I would start with a model in Rhino and then run it through Rhinocam to post the G code to run in Mach3.

OK, now, where shold I start to learn about how to use the wizard and wire a probe to the Gecko?    Is there anything like Art's wonderful Mach3 set-up tutorial?

Jack

5
HIYA Jack, Yes I understand what you are trying to do. The point I was making is that point probing in MACH can be a very tidious process and very time consuming to gather very detail shapes (high resolution).

You would probably have to set up a 4th axis to auto rotate the parts to gather ALL the data at one setting. That would make the final points file all relative to the base coords and it stay very accurate. OR you could do separate scans and then merge them into points file.

The point I was making with the nurbs is you will need to make sure that the final output does not contain NURBS shapes as MACH3 cannot process a nurb in the Gcode side it only understands lines and arcs in Gcode.

Other controllers can deal with nurbs directly in Gcode but not Mach3.

Please keep us up to date on your project, (;-)TP




TP

I am very confused.   Will Mach3 probing wizard output a point(s) or a point cloud that I can load into Rhino.?   I don't want G code since there is no machining involved.   Just need to get points off a part.  Once I have points in Rhino, I can go from there easily.    I am also considering manually using the router with a simple probe to obtain point coordinates but dread the task.   I don't need high accuracy,  if I am with in .015" I'm good, the parts I am designing are often off more than that!

Jack


6
I hope you have a LOT of Time on your hands as Point probing in Mach3 is a painfully slow process (;-) And looking at your SAMPLE product it is not going to work well WITHOUT a LOT of work.

Also further refinement is needed as MACH3 can not understand NURBS it only works in SIMPLE lines and arcs.

Just a thought, (;-) TP

TP,

My understanding is that Rhino is a nurbs based software. Maybe I am wrong? The rendering above is from Flamingo, a Rhino plug in renderer.

If I can get some cross sections I can loft them in Rhino.   Ideally I can probe to Z coordinate along an X or y axis and end up with points.  The points are connected to form a cross section.  That is what I am after.   I can then add some of the small details like the screw heads manually in Rhino.   Mostly I need to get the complex shape into a form that I can edit.    

I am trying to get away from laser or white light scans which are to expensive for what I am trying to do.   Having the router, I am hoping to use it to take shapes off parts to be modeled.

Jack


7
Rich,

I do a lot of tracing over pictures and drawings in Rhino using jpegs as bitmap backgrounds.

The rub comes when trying to model organic shapes like the following that was done from an expensive laser scan:



The result was used to have printed patterns made for rubber mold casting:



Sadly this project didn't work out well and wasted a lot of time converting a mesh to a nurbs model.

Jack

8
Sorry about this and off subject.
Is the blue circular item on top of the tan cabinet a Powerstat / variac and being used as the power supply for your controller by any chance?
If it is, discontinue using it since the ac primary is probably not isolated from the secondary and there is potential for a shock hazard.
Again sorry but just had to comment on what i think i am seeing.

RICH
 

Rich,

I am using it to control the speed of the router.    I have a standard power supply for the Gecko drives.

Jack
Quote
Occassionally I need to reverse engineer an existing part
Other than digitizing the part you could also use CopyCat using a cheap web cam ( you will get gcode ) or can take a picture of the part and trace over it in Cadd for
2d outlines. Just something to consider.

RICH


9
General Mach Discussion / Mach3 digitizing wizard instructions and set up
« on: December 03, 2011, 10:13:39 PM »
I am interested in making a probe and using the Mach3 digitizing wizard.    I have a 3 axis cnc router I am running on Mach3 with a Gecko 540 controlling it.   I design in Rhino/Rhinocam.   

Occassionally I need to reverse engineer an existing part.   Usually it is a fairly complex organic shape that isn't easy to model in Rhino.    I'd like to build or buy a probing head which doesn't look too difficult.   

The question is where can I find some step by step information on how to wire the probe to the Gecko and where can I find step by step how to set-up and run the digitizing wizard?

I found Mach3 tough to set up but finally got it up and running with the Gecko.    I just don't know where to begin to set up a probe or the digitizing wizard.

Any assistance in helping me find the information I need would be appreciated.

Jack


10
General Mach Discussion / Re: HELP! SLOW JOG SPEED PROBLEM
« on: February 20, 2010, 03:26:44 PM »
Thanks,    that was very helpful!!!     Problem solved!    Interesting that the gecko didn't show a fault light.   Now I know where to look if the problem occurs again.  An afternoon lost BUT something learned.

Regards,

jack

Pages: 1 2 3 4 5 6 »