[Winterdragon]

Hi All,

I am in need of some expertise here.

I have a piece of wood. 2" wide x 6" long and 3/4" thick. I want to carve a 1" wide cove 3/8" deep and 5" long in said piece of wood.

Attachment 207350

For those who are much more experienced than I, this is probably very simple.

If you could provide details/steps on how to accomplish this, I would greatly appreciate it.

Winterdragon

[keebler303]

Most likely this would be done on a router table or a shaper. You can buy the correct shape of router bit and then setup a fence, similar to a table saw, to run the work over the bit.

[Winterdragon]

Yes. I have the 1/2 Router Bit and router table. However I am looking at how to do this using the CNC Router.

[Dylwad]

For that, I would draw a single line 4" long in cad, use cam to toolpath it to cut on the center of the line, plunging 3/8" deep.

Could write the code long hand too, but cam is faster.

What cad/cam and router do you have?

Or are you saying you want to make the 1" wide cove with a 1/2" round bit?

[Winterdragon]

I have a Chinese model 3040 CNC. It uses 1/8 Shank Bits. For this example I will plan on using a 1.5MM End Mill. I have a piece of wood 2" wide, 6" long, and 3/4" Thick. My "cove" needs to be 1" wide , 5" long and 3/8" deep. Thus leaving 1/2" border around the cutout on each side.

I have done the above using a full size router and router table using the 1/2" shank 1" cove bit with fence and such. This setup cuts the cut through the entire 6" piece and I have to add end caps to close the openings.

What my goal is to be able to CNC this cove cutout and leave the borders around the edges so I do not have to add end caps.

[mmoe]

I have a Chinese model 3040 CNC. It uses 1/8 Shank Bits. For this example I will plan on using a 1.5MM End Mill. I have a piece of wood 2" wide, 6" long, and 3/4" Thick. My "cove" needs to be 1" wide , 5" long and 3/8" deep. Thus leaving 1/2" border around the cutout on each side.

I have done the above using a full size router and router table using the 1/2" shank 1" cove bit with fence and such. This setup cuts the cut through the entire 6" piece and I have to add end caps to close the openings.

What my goal is to be able to CNC this cove cutout and leave the borders around the edges so I do not have to add end caps.

First, you'll need to be able to model the part in 3d, so software with this capability is going to be necessary. You'll then also need CAM software that is capable of 3d toolpaths. In some cases, such as Bobcad/cam, you can do both in the same software, while in other cases you will need two separate software products. You haven't really said what you have for software, so I'll just give a quick demonstration using Viacad and Bobcad to produce the part. Keep in mind that there are really many ways to do the same thing, so this is just one possible scenario. Also, I did not do a roughing pass to save time in the video, but you would probably want to use a roughing pass first, then the Planar Slice toolpath as I've shown. I would not recommend using a 1.5mm bit. It would be better if you used a 1/8" ball end bit. Ball end bits are always cutting a surface tangent to the finished face, so you don't have nearly as much to sand out later. Also, the larger the ball end bit, the smoother the surface will come out (even though that seems counter intuitive). For example, since the ball end bit is engaging the surface at a tangent, if you were cutting a 45 degree face with a smaller bit, it will produce a noticeable scallop, while a larger bit will produce significantly less scallop. The only downside to a larger bit is that it can't get into the corners as well, which is why a 1/8" ball end bit is probably a good compromise.

I show the toolpath running the length of the part, which would probably be with the grain, but you'd get a better finish running it across the part if grain isn't an issue. The reason would be that it's easier for the bit to enter going across this geometry due to the shallow drop at the edges vs. the very deep drop and the ends of the cove running long ways. I think that running the tool 90 degrees from the way I've shown would give a better finish at the ends of the cove, but if it's against the grain you might also get a bit of fuzzy finish. Again, there are many ways to do these things, so you'll have to determine what is best for your own situation which may require some experimentation since you are new to it.


Making a Coved Block with CNC Router - YouTube

[Winterdragon]

My apologies. I am using an older version of ArtCam I think its version 9 and Mach3 for controlling the CNC.

[Winterdragon]

MMOE,

Just watched your video. That is Exactly what I am trying to accomplish.

[mmoe]

Mach 3 is really not a factor. The code that Artcam outputs should be adjusted by the software to match what Mach 3 needs via the post processor. The code I showed at the end of the video was for a Mach 3 driven machine as well.

I can't really find any info on Artcam version 9, so it's hard to give you a specific method. If it's like the basic current Artcam, I'm not sure you'll be able to model this in Artcam. They don't really address what the CAD features of Artcam are on their website, but they do suggest that it can import various formats from other software, which makes me believe that it may not have much modeling capabilities at the basic package. It should be able to generate a toolpath that will work off of a model, but it may need the model to already exist (if that makes sense). If you can see what kind of files your version can open, I can post the 3d model of the part for you and you'll be able to bring that into Artcam to generate the toolpath. Here's a link to the model in IGES format, which is usually a pretty generic format that many products can open (I included both inches and metric):

https://files.secureserver.net/0seFaSwx5DkZNJ

[Winterdragon]

mmoe,

I got the files and had to find an app that would open the .igs files so I got Bobcam-cad. Now that I have the file opened, How do I generate the toolpath for Mach3? I know this probably a newbie question and by all rights I am one.

Winterdragon

[mmoe]

I'll try and put together a quick video later tonight. Which version of Bobcad do you have installed (I'm familiar with most of them and can tailor it to your specific version)?

[ger21]

I have a piece of wood. 2" wide x 6" long and 3/4" thick. I want to carve a 1" wide cove 3/8" deep and 5" long in said piece of wood.

For those who are much more experienced than I, this is probably very simple.

If you could provide details/steps on how to accomplish this, I would greatly appreciate it.

First, you need to learn how to use a CAD or 3D modeling program to create a 3D model of your part.
Then, you need to load the model into a CAM program to create the toolpaths and g-code.

If you have no 3D CAD experience at all, be prepared for a possibly very steep learning curve.

Also, I think that you'd find a CAM program like Meshcam to be much easier to use than BobCAD. But it won't load the file that was posted here.

Here's a quick sample.

[mmoe]

As Gerry suggests, Meshcam is an easier piece of software to use initially. It is pretty much a 3d software though, so if you do a lot of 2d profile cutting as well, it might be less limiting to use Bobcad. Or you could use a couple different pieces of software like Meshcam and EstlCAM to cover both 2d and 3d work. If you don't mind spending the time to learn it, Bobcad does offer a bit more on the whole as there are many more toolpath strategies available, built in CAD (though I'm not a fan and use other products to model/draw with), and the ability to work of of true solids rather than mesh files. You can get great results either way, but it will take some learning no matter which way you go.

For CAD, I think ViaCAD and Bonzai 3d are my two preferences right now. ViaCAD is cheaper than Bonzai and a bit easier to learn (there are great tutorials built into the program). If you are willing to spend some great effort learning to save money, Creo Elements Design Express is a very powerful (and free) 3d modeling software that will output STL files, which is what Meshcam works from. It is less intuitive, but probably as capable as any 3d modeling program out there. I think you could learn to model in Bobcad just as easily as Creo, so if you went with a product like Meshcam, you might use Creo, but if you went with Bobcad, you could just learn the CAD side of Bobcad. If you're not already proficient in other CAD systems, Bobcad is probably not any harder to learn and there is probably more forum support for it than any other CAM software here on CNCZone.

The previous video I did shows Bobcad V24 pretty well, though if you had specific questions I could answer them since it was more of a quick workflow video. V25 is a bit different and I haven't covered that, so you'll need to let me know if that's what you're using. If you were a regular user, you'd find them all pretty familiar and easy to learn when things are updated from version to version, but since you're new to the whole product then it will be important that I give you specifics to the version you start with.

Here's a quick video of using Bobcad V26 to produce the toolpath. Some of the things not entirely obvious just from watching is that you hold the shift key down while you click on a line of a closed set of curves or lines, such as when I select the boundary. You can also select each line individually, but it's just faster to hold shift down and select the entire chain at once. Also, anytime you select something and want to accept it, such as when you select the solid model to create toolpaths or when I chose the boundary, you then right click on the screen and click on OK in the drop down menu to continue. It becomes a habit rather quickly and I do like that part of the workflow since it allows you to continue with selections until you are completely finished. When you want a menu in the CAM tree (the frame of the window to the left of the screen), you right click on that part of the tree to get the options for that component. Otherwise, it should be pretty easy to follow along. I work in metric most of the time, so you'll have to adjust your numbers for imperial if that's what you use. I also selected some arbitrary tools. You could use the same tool for both the roughing and finish passes if you like.

Bobcad V26 - Basic Toolpath - YouTube

[Winterdragon]

i Have BobCad24. Ive noticed that I do not have some of the options that you show in the video.

Winterdragon

[mmoe]

Go back to the first video I posted and it shows V24 starting at around the 2:45 mark. The main difference is setting up the material stock and where to right-click on the cam tree to start a feature/strategy. At the end, you would click on "CAM Part" in the tree to expand that section, then right-click on "Milling Tool" and select "Post" to generate the G-code file. Then just right click on the G-code in the lower window and save it as a file. Try going through it and let me know if you have any questions.

[louieatienza]

I have a Chinese model 3040 CNC. It uses 1/8 Shank Bits. For this example I will plan on using a 1.5MM End Mill. I have a piece of wood 2" wide, 6" long, and 3/4" Thick. My "cove" needs to be 1" wide , 5" long and 3/8" deep. Thus leaving 1/2" border around the cutout on each side.

I have done the above using a full size router and router table using the 1/2" shank 1" cove bit with fence and such. This setup cuts the cut through the entire 6" piece and I have to add end caps to close the openings.

What my goal is to be able to CNC this cove cutout and leave the borders around the edges so I do not have to add end caps.

Set your router table as you normally do. Make a mark 4-1/2" from the edge of your 1" cove bit on both sides, and clamp stops to the fence. Then you just hold the piece against the first stop, drop down to the bit, push until you hit the second stop, and lift up. Pretty basic router table stuff. I could do 100 of then before you cut 5 with an 1/8" bit. The other easy way would be with a plunge router and guide collet. Just make a jig using the CNC so the guide collet fits tightly, place the wood underneath and clamp, plunge and go.