I’m wondering if the Carvey would be capable, and practical, to do these portraits at a high detail with a good surface finish. I’ve had these CNC’d before and the results were great, so I’m hoping that the Carvey will be able to provide similar results. I realize the Carvey’s not out yet but I figure if it’d work on the X-Carve it should work on the Carvey. I’ve taken a look at the Nomad 833, which has very similar specs to the Carvey, and it’s done a great job with things like this so I’m optimistic. I’ve contacted customer support about this as well but I’d like advice from the community. I’m looking to mill these out of wax, HDU foam, and renshape.
My main concerns are getting appropriate detail/surface finish and the milling time needed to get to that quality. I’m also interested in necessary bits needed for this type of job given the materials I’m using.(I’m new to CNC)
Here’s a link to an .STL of one of my portraits as well as some pictures and a link to my (WIP) site. The model is both front and back (needs to be hollow) so I’d need to use something like the pin method for milling both sides. The back side would just need to be roughed in.
I am seeing a lot of under cuts in both the examples you have here and the examples I see on the link to your site.
The X-Carve will not deal with under cuts. In the specs for the X-Carve the accuracy is listed as being .075mm = .0029" to .13mm = .005" for a stock machine. This would make it hard to get the finish you may be looking for.
Carvey has accuracy specs of .001" to .003" so you could possibly get the finish you are looking for. Again the under cuts would be a problem. Z height is 2.75" so using a 4th axis would be a problem.
Do you know what kind of CNC machine these were done on in the past. If it was a 4 or 5 axis CNC machining center that can hold .0005" or better and they were generating there Gcode with a high dollar CAM program that will handle 4 or 5 axis machining then you will never get the results that you got from the shop doing the work for you.
Hope this helps.
1000X18000 running Mach3
Tormach 770 CNC mill running Path Pilot
Thanks for the reply. As far as I know, when I design these, there are no undercuts on either respective side (front and back). If there are they should be so small to the point of being a non-factor. The file I attached was an old, cancelled order so the finalization on it might not be perfect. The end models I send to my clients are undercut-free on either side due to their bronze sand casting process.
Yeah the Carvey is what I’m mainly looking at. It has good specs for what I need as far as I can tell and it being fully enclosed and ready-to-go is a huge selling point for me.
The HDU foam model pictured in my post was milled on a 3-axis CNC machine and milled on both sides (back first, then front) with a rough-in and finishing pass using pins and flipping. I don’t know about the specifics of the machine though.
The limiting number for the Carvey is the Z height at 2.75" so a bust can not be more than that from the tip of the nose to the back of the head. If you are doing a split pattern that goes on a match board then you have twice that distance so 2.75 from tip of nose to parting line and 2.75 from parting line to the back of the head. Developing that parting line will be fun though.
What kind of sizes are you looking at nose to back of head, shoulder to shoulder, and table to top of head.
Yeah I’m aware of the depth limitations, which aren’t a problem at all. I might have forgotten to mention that these are bas relief portraits (oops), so the most depth they have is a little over an inch and they’re flat and hollow on the back. I’m including some more pictures to show different angles to give a better idea.
(units in inches)
I’m aware that this piece in particular is a bit too wide for the Carvey but in those cases I can separate the model at natural seams, like where the right/left part of his suit begins at the shoulder.
Very interesting. It looks like Carvey will work for what you want to do. Now you just have to hope they can get you one before Xmas.
Alright, great, that’s good to hear. Thanks Dave. I’ll see if I can get more specifics from customer support.
Hi Angus, they’re hollow to ensure even cooling during the bronze casting process. Anything that’s cast bronze and not particularly small is going to be hollow. If bronze is cast too thick, the cast piece will cool unevenly resulting in things like warping and a variety of other problematic issues, all of which would ruin the cast piece. Optimal thickness is 1/8"-1/4".
All casting suffer from uneven shrinkage if the foundry does not take into account the differences in casting thickness. If you have a large thickness next to a thin thickness then the thicker will pull metal from the thinner as it cools. You have two ways to go make all thicknesses as close to the same as possible or add risers that will feed the thicker areas as the casting cools.
All the pattern I have made had risers and gates to allow for shrinkage.
So from what I understand I’ll just need MeshCam and then UGS to generate and drive the tool path from my models, correct? It’s unfortunate that Easle is solely limited to 2.5d.