I’m interested in getting a cnc cut done (Already took the class, pending the in person test / clearance)
I’m curious about the level of detail possible on any of the cnc machines (including the new larger shapeoko coming up)
I’m hoping to cut something resembling the image below as a bed headboard. My plan is to cut it out of pink foam, and then do a cast. I was going to remove the large top and bottom straight sections as they add too much depth. Basically only the angels and flames would be still in.
I have lots of blender experience so I’ve already done a mock up of this model that is significantly less deep to reduce the level of Z travels.
Is this feasabile? how long would a cut like this take (in pink foam, or in other materials) am i in over my head? tell me stories!
Kee Fedak probably did the most detailed work on the multicam that has been done at DMS, so searching the forum for his work might be helpful…
Here’s one example…
The MultiCam was made to cut stuff like this. The more important the detail, the smaller the step over needs to be. Pack a lunch. Maybe dinner and breakfast too. My 3x3" stamps can take as long as 6 hours due to a 4% stepover and a 1/16" ballnose. So extrapolate from there. And the detail is great when the endmill fits. Being larger you can probably go with a bigger endmill. My speeds for woods is usually between 100-150 IPM with no roughing due to the shallow depth. With foam you can probably do a roughing at 200 IPM or more before dropping speed and endmill. If you do it in Fusion do a rest machining process so that it doesn’t try to redo what it has already roughed out.
Cheers!
Thank you guys for the tips and feedback! I was already planning on just camping out but i might try to work out with another acquaintance that’s also multi cam cleared to cut in shifts.
Check out this incredible 3D carved piece that Brian @tapper made:
It should give you some idea of what’s possible. If you search through the Woodshop posts for things he has posted (mostly around late 2016 and early 2017) he also has a lot of technical advice.
Just the insert? Or figures on the corners too? How committed are you to having it be stainable wood?
It’s possible but would take an insane amount of time. I’d honestly toy with wood filament or even a 3D printed mold unless the finish requires actual wooden panels.
Just offering a bit of a different perspective on the tooling. It is common to think that you must use tiny bits and small stepovers to get good detail. The real answer in my opinion is " it depends". The big question is how close will the typical viewer be to the final product? Think about a great masters oil painting at the museum … get too close and you start to see cracked paint and surface defects. Stand back a bit, and it looks wonderful.
You need small bits to get into tiny crevices that are must have elements, however, small bits force you to run small stepovers to avoid scalloping. Larger ballnose bits can actually produce a smoother finish under a surprising number of situations. The best article I have seen on this is here: How To Choose a Stepover for 3D Profiling - CNCCookbook: Be A Better CNC'er
If you use a product like VCarve for the toolpaths, you can run roughing passes to hog out the bulk of the carving and then do finish paths for the detail. However you do it, preview various tooling strategies and check the time estimate associated with each. In all likelihood you will find a sweet spot where time required and detail quality offer a good compromise.
But whatever conditions are finally chosen, that image will be a long cut.
PS: Just to be complete, you can define the image by zones and use different bits & strategies in each zone for one more idea that can save time.
Ain’t that the truth!
I cut a wood mockup of the chase for the small printing press to a tight tolerance. I let it sit for two days and it swelled about 20 thousandth’s - enough that it wouldn’t go into the press. Same file was used on an aluminum one and it slid right in.
I always say that measure twice cut once really doesn’t mean anything when it comes to wood. Measure a thousand times and it will have moved the second you cut it. Hence the invention of sandpaper. cheers!
i appreciate all the feedback. I have NO intention of doing a wood cut of it that was something i just threw out and your feedback was what i was expecting. My plan was to cut it as a foam item. and then do a slip cast. Possibly aircrete with lightweight fillers.
the intention is to do a bed headboard / above bed style. however, if the final cast comes off as too heavy i will find better places for it. The original scan of it is from a table / desk /altar at a eastern european orthodox church. and it sits on the front.
i’m not sure if an additive 3d print would work. maybe if it was a few inches and i did a resin print. but if it’s going to be a few feet or so i ~believe that subtractive is the most time effective method?
Also I really appreciate all the feedback I’m getting. You guys ROCK!
also as an added clue the ORIGINAL model I was working with was actually a lower resolution lower detail version of this same historical furniture piece. The person went on a second trip to the church and did a MUCH HIGHER resolution scan and reasonably started charging $20 for the 3d asset.
I just took a second look and realized its a higher res version of the one I was chopping up in blender
