I am attempting to create a jig that would allow me to easily position the top and bottom of a box for a 2 sided carving. My intention was to cut out the box parts and also create a corresponding negative cut out in the jig that would allow me securely position the pieces with a consistent reference point.
My issue is that the shaded areas on the jig and the part don’t match. I’m assuming that this is because the jig was cut from the inside out and the part was cut from the outside in.
My question for everyone is if there is an approach to this that is possible or am I just going about things all wrong? The only other idea I had was to try an set it up like an inlay, but I’ve never done that before so I thought I’d ask before attempting and being wrong anyways.
I believe you’re on the right track, and it seems like you’re dealing with a situation where you’re cutting on the outside of the vector for the workpiece while cutting on the inside for the jig. It’s important to consider the size of the bit you’re using, similar to accounting for the kerf of a blade in a power tool.
I’m not sure which software you’re using, but in the case of Vectric VCarve, there are a couple of ways to address this issue. If it’s a pocket operation, you can utilize the “Pocket Allowance” feature, which enables you to extend or retract the bit beyond the actual vector path. For Vectric, setting a negative value for the Pocket Allowance will move the bit outward, while using a positive value for the offset will move it inward on a “Profile” toolpath.
Sometimes, when I want sharp 90-degree inside corners, I prefer to use a VCarve toolpath with a V-Bit. In such cases, I simply duplicate the border vector(s) and use the “Offset” drawing tool to slightly increase their size.
I recommend conducting a test on scrap material to determine the exact amount of offset required. For example, in one of my previous projects, I added a 0.03" increase in size to the pocket toolpath to ensure the main part fits inside without excessive force.
It is difficult to understand from the picture how your piece fits in the holder.
I would also keep in mind that you do not need the full thickness of the material to keep your piece in place, a few mm in height might be just enough. This will prevent your workpiece from getting stuck in the holder as well.
Aside from that you will only need a few spots that your piece can be pushed against.
You could just cut that pencil marked area off.
Another trick would be to cut the outside profile with a say 1mm tapered flat end mill bit while telling your CAM software that you are using an endmill. That way your toolholder will have slanted sides and the piece you are milling will be tight only when it reache the bottom of the holder.
Thank you both for the replies. I am using Carbide Create and given that it’s not as capable (I don’t think) as Vectric I went with the simple solution of trimming off the areas that were preventing the piece from sitting in the jig.
Trimming it in a few places worked great and the cutout is way too deep and the pieces get stuck lol.
Next step will be a shallower cutout and then onto carving.
You could use indexing pins (dowels) in the waste area of your model. There are plenty Youtube videos. Here’s a link from Carbide Create and below that, Mark Lindsay describes it perfectly in his video.
