I’ve got a large carving I’d like to do. My idea due to the size and complexity would be to carve it out of the “pink foam” that gets used sometimes on large complex cuts and then cast it accordingly. Given the softness of the material I’d presume it’s easy to up the speed of the cutting?
to clarify, this thing would be, like, 4 feet wide
also! when people in the past have suggested pink foam. I assume they’re just talking about the large sheets of pink foam that can be bought at lowe’s etc?
Look into procuring your own endmill(s) that are optimized for cutting foam.
thank you for sharing. would the multi cam be able to cut that level of detail that I’m showing in the image? I’m hearing mixed answers.
I’ve never personally done it. How much detail you’ll get is largely going to be up to using endmills that are suitable for your material.
I’m not sure of VCarve’s abilities here either. This might be better done with Aspire but we don’t have a license for that.
Yes, training is required but if you can’t get that (currently, previously trained members are being accommodated as quickly as possible) then a number of us are happy to help you.
@bertberaht for your opinion on software capabilities…
Detail: First, you have to be sure all the elements are vertically accessible. The bit can only work in a 90 degree orientation … no undercutting. I don’t see that in the image, so I suspect you are good on that front. As for capability, the MultiCam is able to get that level of detail. (It’s not actually that detailed when you blow it up to 4 feet in width.) The key on detail is your patience and expected viewing distance. Go to a museum and look at an old masters painting … from a proper viewing distance it is magnificent, but get too close and it is cracked paint. To avoid the equivalent of “cracked paint”, you must use smaller ball nose bits and the carving time goes way up. Typically one would carve with a moderate level of detail for speed and come back with a smaller bit in selected areas where absolutely necessary to sharpen details. I have done this using bits less than 1mm, but only for very small sections … making 10-20% stepovers with a 1mm bit makes watching paint dry seem fast.
Software: It’s been a very long minute since I used VCarve, but I don’t think it handles modification of 3D models. I “think” it will import an STL or similar 3D model and CAM it to create the toolpath, but I am not clear on where the limitations might be.
3D Model: One way or another, you need to get a 3D model and create the gcode with software that can allow selecting smaller sections to fine tune details where necessary. Aspire allows that, but there are options.
Carving speed: Yes, you can carve foam faster than harder materials, especially if the bits are small. That said, just about every CNC has some practical speed limits where the machine mechanics cause accuracy to suffer. And most CNCs will go fast enough to break tiny bits even in soft material. It’s a balancing act.
Fun project if patience is abundant!
Thanks for the input, @bertberaht. I didn’t think about the time this will take. That could easily be a 20 hour job and the machine must be attended the entire time.
Thanks for the feedback! I’ve taken the class before at DMS but never did the final test clearance (it was juuuust before the Plague).
A lot of the limitations you mentioned bert make sense and some of them are things I’ve considered. I’ve actually compressed the Z axis in this to greatly reduce cutting time, it was originally three times as deep in details. A lot of the planning to reduce workload I’ve done is seperating and isolating Z peaks so they dont end up being dragged out across the entire piece I was planning on taking some of the edge details off (ie faces etc) and doing them as separate cuts since those are the prominent Z points.
I might have to recruit someone for a small portion of it so I can nap or whatever.
and yes I do have the 3d model. been using Blender and i can store it as a handful of major file formats for Gcode conversion.
thanks guys! Maybe I will get this done before the end of the year after all.
Vertical moves are a time killer on a CNC. Most of the time the Z speed movement is set at ~1/2 the horizontal speed. That is probably unnecessary in foam as long as you have a Z speed the ball screw can support. Many (most?) machines have faster mechanical capability in the horizontal direction than in the vertical. I’d suggest finding out the recommended top vertical working speed on the Multicam and using that for Z. Then test to see what horizontal speed is obtainable with quality cuts. All that plus coffee!
Might also be worth cutting the project into chunks and cleaning up the seams in post-process if you don’t want to babysit it for 20 hours
