AutoScaled Projects - choosing cutters, mat. thickness, etc.
 

I would like to make some projects that I can build full scale and at scaled down sizes, that I don't need to re-draw, by running the same g-code file. Things like chairs for adults and kids, benches, etc.

I have seen it done but normally folks go in and re-adjust slots, etc to make sure things fit.

Does anyone have some guidelines, like start with 'reducible sizes'. Design for 3/4" plywood with 1/2" dia router bit, and you can reduce size in half by curring 3/8" with 1/4" bit. ( am not sure that would work, since plywood is not really 3/4" and 3/8" thick, they are a bit less than that ).

Suggestions?

Try to convert to pdf then using the scale function make changes, export file. Import to your cnc program and convert to gcode. Its quick and easy. If you don't have adobe, use open office.org it has a pdf converter for free.

Good luck,
Tim

Normally I would suggest to use a design package that can handle that parametrically like Pro Engineer.

I don't think there is a good short cut for scaling unless you are not worried about technical design constrains and if the project can still be build and used.

To answer your question, I do think it's technically possible to scale g_code I don't know a tool that can really do that .

Ries

Jack, we do the scaling in AutoCad. In fact, we do nearly everything in AutoCad. And then we have an unpopular converter (Vector) that converts the AutoCad stuff to G-Code in a minute.

The point that I am trying to get to is that the G-Code file is never opened by hand to edit it for scaling. Our way of working is not the norm. Most others would use a better CAM program to select tools and speeds and then "post-process" to spit out G-Code for the cutting machine. The norm is also that most people do not touch the G-code file after it has been generated by their CAD/CAM programs.

An approach that helps for scaling artistic/décor/toy type pieces, where fits are not critical, is to use a cutter diameter that is slightly more than the material thickness. Slots are then programmed to cut down their centerlines.

I don't know offhand if Mach can apply a global scale factor like we could in ShopBot . . .

Gerald,

Would you share what converter program you are using to convert AutoCAD to GCode? Thanks

see bold text

It is called Vector. . . . . which seems too simple a name in this context. Last updated more than 5 years ago. My son has the licenced copy, so I don't know the version number. It used to be the free CAD/CAM handed out with ShopBots until end-2000 but it got a bad reception from the users. Written in millimeters in Holland originally (badly translated docs & help screens), but that suited us fine :)

Edit: Alan, we overlapped!

Ok, I looked at it now cost $1295.00 with a list price of $1995.00. I will look around a little more but at that price I won't be buying but it is good to know it exist.

My short experience has been that most of my time is spent in Rhino (CAD). I even set my layers to correspond to my tool paths (cut files). To generate G-code, I've been using (and happy with) Vectric's VCarve Pro and Cut3D.

My latest project was to create a 3D model in Rhino. Rhino has a cool feature ("heightfield from image") for making textures from images. Anyways, all scaling was done in Rhino, imported into Cut3D to generate the G-Code.

Mach can apply scaling to a g-code file by inserting a G51 command into the file.

(Looks like EMC2 does not do scaling.)

Greg J

It appears that you have decided not to use Rhino CAM but VCarve Pro and 3D Cut. Why did you decided to go that way?

Nils,

I bought the Vectric products first. My AutoCAD 2000 was not functioning properly under Microsoft's Vista so I "upgraded" to Rhino.

After using VCarve Pro and Cut3D, for 7 months now, I still enjoy them.

Greg,
Maybe you could upgrade to Win XP while you are at it. ;)

Heath,

You have to be careful about using XP on a Vista computer. If the computer was designed to be used with Vista, there is a chance that you can not go back. You can still buy some machine from Dell that are new and capable of using XP and Vista. I personally do not want to move to Vista if I can help it. I am looking to buy a new computer and I want my next computer to have dual or quad processors or I will wait for the new Intel i7 processor.

Greg J,

Thanks. I also have AutoCAD 2000 and don't want to lose it. I am considering to purchase Rhino but after I give Aspire some time. I am still waiting on the DVD so I can go through the tutorials.

Nils,
I have built many computers from the componet level up and have not found any reason why a computer would not load XP. Usually I can have XP/Vista and linux all on the same hardware with multiboot. I think you are refering to the packaged systems and they tell you that because they dont want to support XP as well as Vista in there troubleshooting dept. It will run on the hardware though. :) (You can also run XP on Intel based Mac computers too.)