Can anyone help

?

I have been using MattVS's Roland cutter .. it's a 650 .. very very good !

He was under the impression that STLs were the right way to get data in from CU. However, Modela .. which is a delightfully simple toolpath software .. takes literally hours and hours to generate decent toolpaths from STL data. Anyone know why that may be ? What is it about STL files that choke up the process of (presumable) projecting ines onto faces ?

(RolandNZ have been unforthcoming with his questions and their forum is poor)

Iges data is accepted too .. but the surfaces seem to blow out here and there .. making for example .. a slice through an object I'm trying to cut - thicker than it really is. However, it's quick to process. Presumably the faceting happens at the Modela end .. whereas with STL it happens at the CU end where you can control the amount of facets etc

So neither STL nor IGS work well at all

In looking through the manual, I see it takes DXF12 files. I've tested running toolpaths under various conditions .. and it seems much more reliable and fast. I remember a conversation about a 5 axis router - and that took dxf12 as it's standard format

What format do other people use for CAM .. is dxf12 the way to go .. and is there any way I can UP the number of facets in a CU dxf export ? One for Tim perhaps ?

Another thing .. STL outputs in ASCII or Binary. From what I can see .. ASCII is the default. Yet ASCII is the older format (text file readable) and makes file sizes 4 times bigger than Binary. Is there A.) a case here for making Binary the default option ? or perhaps B.) doing away with the ASCII method altogether ?

Comments here would be much appreciated !! Waiting 4 hours for a bunch of splines to generate totally cooks my sprout !

In trying to mill from Concepts STL data

I find that for given object A

- tool path generation from CU STL data takes 6 hours
- tool path generation from SW STL data takes 12 mins

The two STL files were generated from these in the respective apps

Note: 'Binary' option was used .. ASCII option is not advantageous as far as I can see (and should be demoted from our default)

Also Note: CU & SW were set to their default STL outputs .. ie : The apps were allowed to choose the number of facets

CU chose to make 3576 'facets'
SW chose to make 6432 'triangles'

CU file size 3.3Mb
SW file size 315Kb

If I try to print a txt file of each stl .. SW proposes 118 pages and CU gives me 1020 !!! 10 times bigger !!!

So .. 4 questions:

1.) Why are the file sizes so very different ?

2.) Why does it take 6 hours to make my toolpaths from CU .. and from SolidWorks .. 12 Mins ?

3.) IGES also has problems in the toolpath software .. failed surface trimming .. hence can't build object .. yet if I send an iges of the same thing from SolidWorks .. it works just fine. Incidentally, Solidworks choked on CU's Iges file .. so it is obviously munted

4.) So .. DXF12 being my only option left - produces very big facets .. How can I change the resolution of the dxf12 file so that I can show somewhat smoother facets ?

JL

As Colombo would say on his way out

.. " .. one more thing"

The STL facets checkbox is stuck ON according to Tim. This results in 10x as many facets as requested

He plans to fix in the next service pack

This can't come soon enough in my opinion

PS Don't use ASCII .. Binary should be our default .. files are then apparently 20% of the size

I'm assuming that your CAM software won't take ACIS files. If it did, that would be your best solution.

It might be as well be your surface tolerance settings, or your surface complexity, but, either way, facets are probably the least desireable method of exporting a surface to a CAM system, and probably the least accurate.

Good CAM surfacers also support rest machining/reroughing, which evaluates material left (the "rest") from larger cutters so that the follow up smaller cutter doesn't cut a lot of "air". Most good systems also create arcs in lieu of straight line segments which are a bit more efficient.

Without seeing your file, I'm only guessing, of course, but 4 to 6 hours seems excessive.

For the record, I use GibbsCAM 2006, and it is scheduled to get rest and high-speed machining in the 2008 version this fall, plus improved step-over for faster, smoother surfaces. It outputs G code.

tom

Brilliant Tom .. thanks !

Some questions:

- What sort of price are we looking at for GibbsCAM ?
- Is it nice / straight forward to use ?
- Presumably you've compared with other solutions .. are there other names worthy of some research?
- Ideally, there'd be a Mac solution .. if you've heard of one, please share !

As I said, Modela is lovely and simple .. but does appear to have limitations

(By the way, the slowness turned out to be a CU faceting issue)

I have done a lot of CNC machining. I use CU for part design. I use Delcam (Artcam),and Mastercam for Toolpaths. I have experimented with all of the export file formats, and without a doubt DXF R2004 works the best. It maintains all the surfaces, vectors, colours, and layers perfectly. I struggled with ACIS, IGES, and other DXF, DWG versions. Nothing maintains the file as well as DXF R2004.... I have never used GIBBSCAM.

Mayka, MC & Gibbs all look interesting to me .. no response from them yet tho'

Looking through their sites .. all I read is "blah blah" .. so I'm really looking for help in cutting (smoothly) to the chase

I'm interested in profile cutting and 3D cutting in 3 axis .. possibly on 1300 x 1300 x 150 router

Still looking for some rough prices for entry into this market .. any thoughts would be much appreciated

I was in the same boat as you a few years back. I was able to design parts in CU, and give my files to CNC shops.

I was then able to start using a friends CNC machining center, and CNC Router. I used Artcam at first for the CNC router, and Mastercam for the Machining Center. Artcam was very easy to learn, just to get the basics of CNC. I started using Mastercam to CNC 3D parts on the Machining center. Mastercam has a little steeper learning curve, but is alot more powerfull, and easier to use one you learn understand how the CNC will cut (speed and feed, finishing etc.).

Mastercam and Artcam are in the $10,000 (CDN)+ range. I think the best "bang for buck" CAM program is Visual Mill. I used an online demo, and it imported IGES files fine surfaces and vectors... I don't know if the layers were maintained. It seemed to have most toolpath options you would need. I also used the OneCNC demo, I was not impressed. I found it had fewer features, and toolpaths than Visual Mill. OneCNC is for someone who has no CAM software and needs to design parts, and generate G-code from one package.

The only problem with all CAM software is it is only available for Windows.

Eek ! Gibbscam 3D is 15k US here in NZ

Might buy me some chisels

Visual Mill 1K US for the 'basic' setup (4K for a non-partial 3D version) .. will try to find a demo

Take a look at meshcam $150.00
I've heard many good things about it.
http://www.grzsoftware.com/
hope this helps some
Victor