AutoCad

[bleeth]

The long process of picking and choosing a cad program has come to an end for me and I am now the owner of Autocad 2006. Naturally, the last time I did anything at all with Autocad I think it was release 8 and to say I don't even remember much of that is to be mild.
So the request is, for you out there knowledgeable in learning Autocad; Advise on clearest how to books, discs, on-line tutorial spots, etc. would be most welcome.

Dave

[scott_smith]

The book “Mastering AutoCAD” by Sybex is great. But the V13 is 1200 pages. Not exactly a quick read. I didn’t use it starting out but it was helpful when I plunged into the 3D end of the program. It’s Ok you don’t remember much of V8. I started using AutoCAD at V3.?? And I’m now using V14. At V11 they went to Windows and the whole interface changed. Fell free to e-mail me with questions when you run into a snag and I’ll watch this forum also if you want to give everyone a chance to answer.

Scott

[mikejohn]

Dave
I followed a similar startegy to Scot.
The difficult question is, "what can AutoCad do?'
The simple question is "What is the fastest way to accurately repeat a drawing 50 times to allow 5 rows of 10 pieces?" (or a thousand similar questions.)
"How do I........?" questions, post them here, and we'll try to answer.
I have found over the years that computer manuals are written on special paper with special ink. When you read them after first buying the software they make no sense at all. After using the software for some time, a lot of the words have changed around and moved about, and now everything becomes very clear

.............Mike

[joe]

Dave,

What are you planning on doing with this program.

I've looked at these architectural programs but couldn't figure out I could make any money with my router using them.

Joe
www.normansignco.com (http://www.normansignco.com)

[mikejohn]

Nothing like this then Joe?

4189
Only spent 10 minutes on it, so its nothing special.
Not a lot of time because its party day here in England to celebrate the freeing of the colonialists (or some of them)

[joe]

Nice drawing John.

Now where do you go from this illustration? Can you convert this over to a DXF, and start routing?

Also, does the latest CAD programs use a continuious line to make the image, or is it still lots of small segmented lines, with a node at the end of each.

Joe
www.normansignco.com (http://www.normansignco.com)

[bleeth]

Joe: For me I will be using it primarily for furniture and casework. I think that toolpathing is still best done by putting it through Part Wizard, but we should have others chiming in that have more experience. AutoCad is actually used for far more than Architectural. It applies to all aspects of mechanical drafting. A guy just posted a couple of autocad sketches on Artcam and one was of a raised letter tire and hubcap and the other for a ray gun looking water pistol.

Dave

[joe]

Dave,

Thank you for assisting me.

I have Artcam Insignia, and Parts Wizard, but don't understand how a conversion from CAD is done. I'd love to hear from someone who has found an easy conversion process.

We design in Flexisign Pro, which is a vector program and do our color work in Photoshop. I'm allways open to the latest process and look forward to finding the cleanest way to get to the finished product.

Joe
www.normansignco.com (http://www.normansignco.com)

[bleeth]

Joe: In PW (and I assume Insignia) and Artcam Pro you can import from a variety of files including dxf and dwg, which are typical cad files. In PW you create a new model the size you want and then go to the Import command under the file drop down menu. I understand that with all the different types of dxf out there if you are using Autocad you want to save your autocad files as no newer than release 12. The same is true in Pro. Dave Buchsbaum in Atlanta uses DesignCad for all his furniture and imports it easily through PW also. If you go straight to the file convertor in SB3 then the order of parts cutting is usually a problem. Once in PW or higher you can then start combining, joining, and grouping vectors if necessary to effect clean toolpathing.

Happy 4th to all and pray for peace.


Dave

[mikejohn]

Joe
I was quickly trying to illustrate that CAD programs are flexible.
I do not advocate the use of any one program against another. I have stated on more than one occasion that the software that works for you is the right software for you.
The small picture I drew is already .dxf, but you would use a much simpler method to draw it for making tool paths.
AutoCad is a vector program that produces straight lines,and arcs (circles are special arcs). There are no other types of lines.
So AutoCad has a start point(in x,y,z), and end point(in x,y,z), and in the case of arcs it has in addition the necessary factor that gives you the curve of the arc. By joining all these together you can arrive at a 3D model of the space shuttle.
For CAD conversion I'll let Gerald answer. He teaches me


...........Mike

[gerald_d]

...and there Mike drops me right into it. I use a "conversion" program that most ShopBotters hate, the name is Vector. I only recommend it to folk who are really proficient in a CAD program and who have a good grasp of what Mike said above: "AutoCad is a vector program that produces straight lines,and arcs (circles are special arcs). There are no other types of lines.
So AutoCad has a start point(in x,y,z), and end point(in x,y,z), and in the case of arcs it has in addition the necessary factor that gives you the curve of the arc. "

If you already have your head around lines (straight or arc'ed) in 3D space, it is easy to think of tool movements in 3D space. Now you only want a "conversion" to write the machine code - but you want the "CAM" program also to be clever enough to control important things such as:
- starting point of job
- direction of cut
- sequence of parts

ShopBot was supplying Vector before PW, but it was a bear to learn if you tried to design in it. It was touted as a CAD plus CAM program, but most of us here who like it, only use Vector's CAM side.

[mikejohn]

I can draw an arc going from x,y,z to x1,y1,z1. Can the ShopBot cut this arc? Replacing the straight lines in this (http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=29&post=25646#POST25646) thread.
..............Mike

[gerald_d]

The last time I looked, the ShopBot controlling software only did arcs in the flat x,y plane. ie. z = constant. It couldn't do arcs in any of the other planes either. (It doesn't do "helical interpolation" either - what fancy CNC's use for cutting threads, etc.).

[mikejohn]

So when we are V-carving, its actually a series of short straight lines?
............Mike

[gerald_d]

Yup. Look at the .sbp file and you will see all M3 commands (straight line interpolation).

[srwtlc]

Mike,

You can take that arc that you just made in AutoCad into Vector (or you can make or modify a flat one in Vector) and break interpolate it into segments of a desired size , generate code and Shopbot will cut that. I make ramped leads this way often. Look here (http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=29&post=13495#POST13495) also.

[bill.young]

Mike,

Remember it ALL boils down to small straight lines at the lowest level...stepper motor steps in X,Y, and Z

Bill

[jeff_maitre]

Hi all,
new to form but have been a shopbot owner for 5 years. I'm a long time user of Autocad versions 12 and up and i still learn something new as years pass. It's very complex software. users have recently asked how to convert your .dxf files and control your tool path's in the order you want them to,for all acad versions. When you save as .dxf the dialogue box has a optoins button sellect it next box select .dxf options tab then check select items,this put's you back in your drawing to sellect the order you wish this will allow you to keep the tool order in Shopbot or part wizard. Good luck for acad seekers.

Jeff

[gerald_d]

Jeff, that's very interesting. My AutoCad LT2000 does not have this "Options" dialogue box when I save as DXF. Maybe because mine is an LT version?

[mikejohn]

Gerald
When you save as .dfx go to the tools menu,then options,then select .dfx and then check the select items box
.........Mike

[gerald_d]

Found it! Okay, that's fine for selecting order, now how do we find direction?

[mikejohn]

Gerald, typing "Finding Direction in Your Life" in Google returns over 16 million 'hits'.
Or did I misunderstand you?

..........Mike

[mikejohn]

Gerald
A line always seems to go from the first point to the last point as drawn.
Circles go anti-clockwise, even after mirroring and 'flipping' (rotate 180 around the diameter, not the centre!)
...............Mike

[gerald_d]

I realise that lines go from first to last drawn points, but the SB converter also reads that as the cutting direction. There must be a method inside AutoCad to change the drawn direction so that we end up with the desired cutting direction.

There is a guy over on another Forum (http://www.cnczone.com/forums/showthread.php?t=8226&page=1&pp=10) who has cracked this issue inside AutoCad, and he will give you a free macro to generate G-Code directly out of AutoCad.

[hespj]

Swapping ends.

Anybody want to try this:

SWAPLINE.LSP - Swaps the endpoints of a line. Helpful for direction control, especially with text linetypes for which direction the text reads.

http://www.dotsoft.com/freestuff.htm

[gerald_d]

Hi John, that's an interesting list of macros. One snag for us though, AutoCad LT does not execute macros.

Anyway, sequence (order) and direction inside of AutoCad is only academic to us because our .sbp converter (Vector) sorts them out with one click. I was only pursuing the discussion because of the guys who want to use CAD together with the SB file converter (dxf to sbp).

[jeff_maitre]

Mike,
Autocad by default is set to counter clockwise can be changed to clockwize. This can be done by sellecting format then units there would be your angle and clockwise settings. Gerald, macros is what drives all cad programs and can be loaded to edit in note pad including LT. If you are good with acad comands and how they work the sky has no limits.

[mikejohn]

Gerald
Save the .lsp file into a folder, type APPLOAD on the command line select the .lsp file
Now its loaded you call it by the filename.
It should work, but I haven't got LT.
..............Mike

[gerald_d]

APPLOAD is an "unknown command" in LT.

[hespj]

Jeff, that doesn't seem to be the case for me. A circle drawn with "Units" set in either direction produces a counter clockwise toolpath when I convert it and simulate in SB control software. Loading into Partwizard produces clockwise circles.

[mikejohn]

John
This is also my experience. I know with any of the 'C' commands you can chose either clockwise or anti-clockwise, but when converting it always seems to go anti-clock.
...........Mike

[jeff_maitre]

JOHN,
MIKE, I THOUGHT YOU WAS ASKING HOW TO CHANGE DIRECTION FOR CIRCLES IN ACAD ITSELF
4190

I'VE TRYED MYSELF SB CONTROL SOFTWARE CUTS COUNTER CLOCKWISE BUT PARTWIZARD WORKS BOTH DIRECTIONS.

[Brady Watson]

John & group,
When you toolpath a profile in PW2, always choose Conventional cut strategy...inside profiles will go CW and outside profiles will go CCW. This is a little different than the way PW1 handles it.

-Brady

[wayne_walker]

I'm very new to AutoCAD and have been trying to figure out how to get a smooth arc.

When I convert a dfx to sbp file it will create the arc in flat sections. It appears to be OK in preview but when I cut, it has the flat sections on all arcs. I looked thru all the settings and could not see anything I thought would solve the problem. But since I'm not sure what I'm looking for it is to figure out thru the terms.

I'm using AutoCAD 2002. Any help is appreciated!!

Thanks

Wayne

[gerald_d]

Wayne, you must realise that a ShopBot can only cut straight lines or circular arcs. Therefore, if you draw an ellipse or spline in AutoCad, the ShopBot at best can only make a compromise.

So, find ways in AutoCad to restrict yourself to straight lines and arcs. One way is to draw curves that consist only of many tiny straight lines......

If you are converting your .dxf arcs to .sbp with PartsWizard, then there is sometimes another problem. I don't use PW so I can't explain that, but there is a setting that must be made.

[richards]

Wayne,

In PartWizard, you can select different output file formats. Just before you save a file, you'll see the prompt: Machine output file is formatted for:

You would normally select either Shopbot(arcs)(inch)(*.sbp)", if you're using inches as your measurement system, or "Shopbot(mm)(arcs)(*.sbp)", if you're using metric.

[wayne_walker]

Gerald,

Thanks for the input.

I don't think I explained my problem very well. I am drawing in arc's and circles. When I am done drawing and zoom-in it is shown as segmented lines. A 1/4" hole broken into 8 segments. I used a 1/4" bit so it does not show up there. On a 1/2" radiused corner, it is broken down into 3 segments and it cuts that way.

I'm pathing in PW2 and looked it over but could not see where I could make any changes for differant file to be imported.

Thanks,

Wayne

[wayne_walker]

Mike,

I just checked the file and it was saved as a Shopbot (inch)(*.sbp)" file type.

So... for all files that have an arc, you have to save it as a arc file? I thought I had cut files before just using the inch setting but I have put the v16 update since then. Is there a problem leaving it set for arc for everything. Why the differance between drill and arc when you save?? Any idea?

I will save the file as a arc file and see what that does in the morning and let you know the result. I headed for bed.

Thank for the help.

Wayne

[gerald_d]

"When I am done drawing and zoom-in it is shown as segmented lines." If you see this on the AutoCad screen, then it is fairly normal. Go to View ----> Regen to show it as a proper arc again. AutoCad sometimes speeds up its screen display by showing arcs that way - you can change the setting for "Arcs and circle smoothness" under Tools ---> Options ----> Display. (in my version of AutoCad). The output file will however contain a true arc irrespective of this setting.

But I think that you were seeing it in PartsWizard. Snag is, this is the AutoCad thread and you only mentioned AutoCad in your post, so I have to cover that aspect first.

[joe]

Wayne,

I know exactly what your talking about with AutoCad programs. When Drawing a circle, for example, it builds the image with dozens of small segments with a node at each end. What a mess. That's the way cadcam works.

A better drawing option, for router heads, are programs which make a circle with as little as two or four more nodes. There are lots of sophisticated drawing softwares. Perhaps you should give Corel Draw a go. It costs about $500. for the full version.

You can even get a Wacom table which will allow you to freehand draw right on the screen. For most of us sign folks Cadcam programs aren't very effecient. We kringe when a new client suggest they will send us a Cadcam file.

We use Flexi and Illustrator, combined with Photoshop.

Joe
www.normansignco.com (http://www.normansignco.com)

[mikejohn]

Autocad draws perfect circles Arcs and eliptical Arcs.
When you view circles, arcs and elipses in AutoCad, if you haven't got the correct viewing setting, the curves appear to be little lines. (See Geralds post above).
All AutoCad curved lines are, in fact, smooth, including curves changing in x,y and z.
No matter how you draw your arcs,in any program, if the arcs are not parts of a perfect circle, ShopBot interprets them as a series of straight lines, even with arc,mms or arc inches set. Shopbot does not interpret arcs of a circle with changes in the z direction. This need to be created with a series of straight lines. I use a technique in Autocad of creating these type of arcs using straight lines quite simply, if anyone is interested

...........Mike

[richards]

Wayne,
I have PartWizard set to Shopbot(arcs)(inch)(*.sbp) for all of my work.

[wayne_walker]

Mike R.,

I removed all of the tool paths and re-did them. I appeared to have fixed some of them but not all. I took another dfx file and tool pathed it and it looks real good. (saved in arcs) I have not tried to cut it yet so I will see what happens then.

Gerald,

Thanks, I have change my view setting as you discribed. I posted under AutoCAD thinking that is the problem.

Mike J.,

I would like to hear your technique on making arcs with straight lines.

Thanks, all of you for your input.

Wayne

[les_linton]

Hi all. Been off the forum for a while, but I had this problem cutting some trim for an eyebrow window where it cut the arc in straight line segments. I simply adjusted the tolerance setting when creating the cut file to a smaller number and it took care of the problem. Worth a shot. I use AutoCad 2006 save in dxf format and import into partwizard.

Les

[wayne_walker]

Les,

I went in and changed the tolerance as you indicated and that solved the problem, in the preview at least. I will cut some parts in the next day or so and see what happens.

Do you know if there is a way to set the higher tolerance as a default, so it does not have to be set every time?

Thanks,

Wayne

[mikejohn]

Wayne,
Notice Les says "I simply adjusted the tolerance setting when creating the cut file to a smaller number".
Irregardless of the AutoCad settings, the ShopBot will still cut straight lines.
I will post my method of creating vertical arcs with short lines in AutoCad very shortly.
.............Mike

[gerald_d]

Mike, the basic issue is PW taking a circular arc from a dxf and then converting that to either a single C- command or multiple M- commands in the cut file. PW can be set to do either method. If the multiple M- commands method is chosen, then apparently a tolerance is required. So, your statement "Irregardless of the AutoCad settings, the ShopBot will still cut straight lines." is a bit confusing. We already know that Wayne's issue has nothing to do with AutoCad and everything to do with PartsWizard settings - but he should be able to get C- commands and then the bot will not cut straight lines (unless you are referring to the stepper increments).

(Vertical arcs with short lines? Vector -> Change -> Break -> Interpolate)

[mikejohn]

OK
Looking back I see that he is talking about circles, and arcs that are parts of a circle (which I did mention in my post earlier).
I also see that, with a 'wrong' setting, even circles may be cut as straight line segments.
(I recognise your Vector method, but this was an AutoCad thread
)
..............Mike

[gerald_d]

Arcs with short lines in AutoCad must be easiest with a polar array - no?


4191

[mikejohn]

Precisely the way to do it.
Draw your arc.Measure the angle the the arc subtends from the centre. divide that angle by the number of line segment you want.Draw a line from the centre to arc end
Draw a second line from the centre at the angle calculated.
Trim the long side of the arc.
Polar array number of items
...........Mike

[gerald_d]

Mike, you don't even have to measure or calculate much - you can click on the "cursor" icons and just point out the "Angle to fill" and "Angle between items". But Vector is soooo much easier - it interpolates arcs, ellipses, splines in any plane into straight segments with defineable tolerances. I sometimes get lazy to explode polylines and fit arcs to splines, etc, then I just blast the whole darn thing into tiny straight lines - fortunately my computer can handle long files! Vector packs a very powerful fragmentation grenade.

[rhfurniture]

If you like I will send you a lsp that takes any line, arc, spline ellipse (anything that can be "divide"ed etc), and draws a 3dpoly to your chosen segment length with proof and change option in about 3 cliks. Needs acad full though.

R

[gerald_d]

Ralph, I would like to try that lsp on my turbo-charged (http://www.caddigest.com/subjects/AutoCAD/select/102203_grabowski_ltextender.htm) AutoCad LT2000.

[mikejohn]

rh
I would also like that .lsp if possible.

Gerald
You need something of the right segment size and the correct start angle, and a centre point to make a succesful polar array.

However, as you point out, there are easier ways.

Anyone want a 3Dspiral .lsp?

...............Mike