OK... it's not rocket science here, but if you get even the tiniest of thrills watching computer-controlled power tools, then you may be interested in this. :icon_scra
This is a video I made of me using a ShopBot CNC router on particleboard:
http://www.youtube.com/watch?v=qti1xM3Jv6k
This is the final product:
Here's a basic explanation of how I got there:
I am reconstructing the molds I use to build the drums I make (celtic drum known as a bodhran...see my gallery).
My original mold is identical, but made from MDF. I used a homemade circle-cutting router jig and a table saw (ShopSmith). It works ok, but gets a bit beat up after each use. In particular, the MDF splits occasionally after all the clamping and epoxying. I decided to redo the mold out of particleboard. By using the ShopBot, I'm also able to make precision inserts for smaller diameter drums.
The first step is drawing the parts. This is a 2D project (only worried about cutting through the wood, rather than dimensionally carving the wood), so a standard vector drawing program works fine. I use Microsoft Visio for most of my woodworking projects. This is an example of one of a drawing used for one of the parts in the video:
Then I export as a .dxf file and import that into the ShopBot PartWorks software (rebranded software from Vectric). In PartWorks you have to define all the 3D aspects of the work, such as the thickness of the wood and the maximum depth of each cut (from which it then automatically calculates how many passes through the material will be needed). Here's an example of a rendered drawing it makes, so you can check it before milling:
By FAR the trickiest part is assigning the speed of the spindle and feed rate. These are based on the type of material and the number of flutes on the mill (bit) you use. Info is available on the web, and there are several ways to adjust through trial-and-error... watching and listening to it as it cuts. Technically, you are attempting to optimize for the correct "chip load". In practice, you are basically trying to make sure the tool gives off tiny chips rather than dust. In my video, I used 12,000 RPM, 4 in/sec feed rate, and a standard 1/4" 2-flute carbide router bit with .26" max pass depth.
This is a video I made of me using a ShopBot CNC router on particleboard:
http://www.youtube.com/watch?v=qti1xM3Jv6k
This is the final product:
Here's a basic explanation of how I got there:
I am reconstructing the molds I use to build the drums I make (celtic drum known as a bodhran...see my gallery).
My original mold is identical, but made from MDF. I used a homemade circle-cutting router jig and a table saw (ShopSmith). It works ok, but gets a bit beat up after each use. In particular, the MDF splits occasionally after all the clamping and epoxying. I decided to redo the mold out of particleboard. By using the ShopBot, I'm also able to make precision inserts for smaller diameter drums.
The first step is drawing the parts. This is a 2D project (only worried about cutting through the wood, rather than dimensionally carving the wood), so a standard vector drawing program works fine. I use Microsoft Visio for most of my woodworking projects. This is an example of one of a drawing used for one of the parts in the video:
Then I export as a .dxf file and import that into the ShopBot PartWorks software (rebranded software from Vectric). In PartWorks you have to define all the 3D aspects of the work, such as the thickness of the wood and the maximum depth of each cut (from which it then automatically calculates how many passes through the material will be needed). Here's an example of a rendered drawing it makes, so you can check it before milling:
By FAR the trickiest part is assigning the speed of the spindle and feed rate. These are based on the type of material and the number of flutes on the mill (bit) you use. Info is available on the web, and there are several ways to adjust through trial-and-error... watching and listening to it as it cuts. Technically, you are attempting to optimize for the correct "chip load". In practice, you are basically trying to make sure the tool gives off tiny chips rather than dust. In my video, I used 12,000 RPM, 4 in/sec feed rate, and a standard 1/4" 2-flute carbide router bit with .26" max pass depth.
and robotics I can't think of a more fun project, though lately woodworking has been monopolizing all my time.
