[mmoe]

Hey BurrMan,
Don't know if you downloaded the full res file before it disappeared from the link, but I can barely get the model to load in V25 or V26. I think my video card has been giving me some trouble ever since updating the NVIDIA drivers in September but it's not enough of a difference that I think it would be the difference between success or failure. While I've invested in Bobcad and probably will continue to do so for a full featured CAM system, in this case I think Meshcam is just the right tool for the job and will pay for itself quickly in time saved. In side by side comparisons where I can get Bobcad to work with these large STLs, Meshcam simply wipes the floor with Bobcad (usually about 6 times faster with comparable tolerance settings and step overs). More often than not, Bobcad crashes before generating code and you start over. I haven't had a crash with Meshcam on these files yet and it's really, really cool to see 8 cores humming along at 100% for 4 hours straight. I can't think of a single piece of software out there that is that well optimized for multicore hyperthreading. In talking to the developer in the Meshcam forum, he said that it was a point of emphasis when he wrote the software. There are some periods where it only uses about 25% of the system (particularly at the start of a Planar Slice calc), but then it kicks into high gear for the bulk of the calcs.

[Bob La Londe]

Cambam is a good piece of software and I don't want to give the impression that I think poorly of it, but you are underestimating the difficulty of handling the files we're talking about. CamBam will work with STLs, but the problem with STLs is that they do get very large when you're dealing with surface scans. If you're the typical home machinist, you'll be dealing with STLs that were modeled from software that are perhaps betwen 2 and 30mb. A big one might get to 100mb, and that would be a very fine mesh as well (most people don't even know how to tighten up the mesh, so they never get very large). For that, CamBam is a well featured program that works with those files for a good price. CamBam, from my experimentation, does not have the horsepower to open a 300mb STL mesh. I can provide you with a topographical mesh of that size if you want to try it, but what you'll get is "Cambam is thinking" followed by a memory error.

Bobcad V24 can barely open STLs in the 300mb range, but even then it's a bit hit or miss which is why I cropped it down to a much smaller portion of the mesh. For a 100-500mb STL, Bobcad tends to crash opening it about half the time (V25 will do better due to 64 bit memory access). Even if you manage to get it open in Bobcad, don't even think about rotating it or applying a transformation. It will crash again about 50% of the time. Basically, you have to get them mesh properly oriented before you bring it into Bobcad so that you can skip right to toolpaths, which will then take up to 20 hours to calculate a Planar Slice.

The OP's sample was 328mb, which is really a very modest file size for a scan. I generated a high resolution STL of the island of Oahu based on USGS DEMs which is closer to 4gb in Binary format (ASCII would be larger still, possibly 24gb or so). A thinned version, where 1/4 of the data is dropped, is still around 1gb. Meshcam is the only CAM software I've been able to open a file like that with (at least for under $5000), and the main reason for this is that it was designed to use multicore, hyperthreading and 64bit technology from the ground up, along with the fact that I've got a pretty above average computer. It will run with 100% of 8 cores while using 99% of the available 16gb of RAM to generate toolpaths. It still takes about 4 to 6 hours for one toolpath with tolerances set to very moderate levels.

I do some pseudo organic 3D modeling, and I do run into memory errors with CB frm time to time so I can understand. I run CamBam on XP 32 so memory is always an issue for me with heavy processing. I always wondered how it would do on a 64 bit OS with access to more memory.

[ger21]

If CamBam is ony 32bit, it can't access any more memory in a 64bit OS. Unless there's a native 64bit version of CamBam.

[BurrMan]

Hey mmoe,
Dont get me wrong about the other softwares. CamBam and MeshCam are very cool programs and also very good at work with stls.

I understand what you see with the BobCad and large stl's that you refer to with regard to loading them, viewport manipulation, and toolpathing.

But just wanted to point out that you can make some settings when you need to work with these, that will change that behaviour. It would be a combo of your "viewport mesh angle" to allow the large stl to "rotate/move fast",
and also for the toolpath calc, the machine tolerance dropped. With BobCad, you can get that "4 hour toolpath" in the minutes and seconds too, but there will be some point, where the calc gets long. The computer will then determine the success of that.

Getting CamBam and MeshCam as an added tool for you, would be cool. Like you said, they can eat the STL cuts for snack. I just didnt want you left with "My other one CANT".....

[BurrMan]

BTW: I didnt get to the download of the file you are working with. Didnt realize it was gone. I was going to download it and see if I could produce the difference that I am describing.

[headscraper]

From my experience both surfaces and solids are far better than mesh models to work with. Apart from the angular rough shapes you get with meshes CAM systems generally have functionality that is geared to dealing with surfaces and solids.

[Bob La Londe]

Heck Windows 32 bit can't access anymore memory. LOL.

[BurrMan]

Hey mmoe,
Just downloaded the model your speaking of. It IS a very dense mesh and even the display settings change I was speaking of doesnt give usable performance.

However, to use large datasets like this, I would use BobArt and it's emboss from component command. If you have BobArt, this will give you the same thing you get from CamBam and the others.

If you have BobArt and want to see this, I can make you a video with that model.

Anyway, I dont want to turn this into a "my software thing". We can move it to the appropriate forum if you want to explore it a little....

Burr

[jininjin]

Hey thanks again. So with this mesh would you have any issues to CNC? I am not looking to do this at the moment but I definitely will be in the future. I recently 3D printed the whole model. It Looks great.

I'm curious if this file originated from a point cloud? If so, what is your preferred software for meshing the point cloud?

Yes this was from a point cloud that was laser scanned. I received the point cloud then proceeded to mesh it. I used a combination of software to get the mesh where it is now. I had the best results with Geomagic but of course its a bit ridiculous in pricing. You can use Meshlab, I think Visual SFM can do it, Polyworks, 3D Reshaper etc.. Check out my reddit forum 3D scan talk might give more insight to potential software.

[BurrMan]

So with this mesh would you have any issues to CNC?

Not sure who you are asking.

I could toolpath that pretty quick, but the result will depend on what you're after.... Using a solid like that, would be a straight 3d toolpath and would be a long program to get any of the detail out of it. The other part to address would be areas like the heads of the little figures, look to be free floating? Those would'nt get any "undercutting" on a simple 3d planar toolpath. It would be more like a Bas-Relief in those areas. If you needed more fancy stuff there, it would take alot more effort. I may even suggest to start moving into 2d and v-carving.....as opposed to making 3d solids from point clouds.

[mmoe]

From what I saw of the initial model, I'd say that part would be difficult to cut, but not really something that can't be done. I'm guessing that the scale would be too large for 3d printing? If not, 3d printing is probably the best method for that part as you've already been doing it. If it need to be larger, then some other factors come into play. As I said earlier in the thread, one of the main obstacles is simply the cost of doing a part like that when you hire someone to do it. I would guess that the low end of the scale for rates is going to be around $60/hour, with many at closer to $100/hr. If the part is larger, but you want good detail, you're probably looking at somewhere around 10-20 hours of cutting. That's not really even considering the programming end, which probably would be an hour or two to get all the setups tooled up, since there are many faces to the part and you probably can't just set it on the table and hit start. I would not be surprised to be charging well over $2000 to cut a part like that out and depending on what the scale is, it could be quite a lot more. That's not even getting into the specifics of how you'd produce the side and top portions from a technical standpoint.

This is why most people doing carving type projects seem to very quickly discover that it's much more economical to just buy a machine to do the job. If you take light passes, or if the material is soft (such as foam), you can probably get a machine that is more than capable enough for around $10k, so it doesn't take very many projects to pay for itself. You have to be the self motivated type for learning new things as you'll need to figure out the programming and also the mechanical aspects of the machine. In that price range, it will likely be a machine that requires some frequent maintenance or repairs here or there, but many are doing this and getting by without a whole lot of trouble.

[jininjin]

Yes, it seems most 3D printers have an upper limit for size and the price increases exponentially with scale. The pic below is 6" tall which is around $300 to $1500 depending on the printer. I am basically experimenting right now with no real purpose yet. I do want to eventually try 1:1 on a small piece foam via CNC.
Thanks you have helped let me know it's possible and I will look into purchasing a machine when I am that point.

[BurrMan]

The pic below is 6" tall which is around $300 to $1500 depending on the printer.

Although to toolpath that detail at 6 inches will have alot of the detail "missed" by even a 1/16th ball mill. You have to consider how the tooling will fit also.

If you were routing it at 9 feet, then the detail is there.....

[jininjin]

Thanks Burrman. I would be toolpathing at a larger scale than what I 3D Printed.