Can a Shopbot produce this level of detail?

[luger]

Hello everyone,

I'm a photographer planning to produce low relief photographs. I have found a program, VS3D, that produces excellent 3D reliefs from grayscale images very easily and is apparently compatible with Shopbot, exporting shopbot files.

My question is, can the shopbot machine reproduce the level of detail you can see in the attached images?

The numbered scale along the sides of the images is in inches, giving you an idea of the size. The relief height is 1/8th of an inch (or around 3mm) and the final dimensions of the piece would be appox 16 inches x 24 inches (these images are cropped into the original image quite a lot).

I am concerned that I might be left with machine lines or grooves in the surface, or maybe the machine simply can't reproduce this level of resolution? I don't want to finish the final piece by hand with sandpaper or anything that will remove the fine detail in the relief, so it must come off the shopbot in finished condition I guess. I am hoping an extremely small bit size will achieve the perfect quality, maching time is not an issue but quality of finish most definitely is!

I am planning to purchase a machine, but only if I know it can perform this job. I have seen less detailed reliefs produced on the website with impressive quality, so I am hoping I will be in luck! Once I have made the relief I will create a mold from it to cast the final peices in various materials. I would be extremely gratefull for any advice, help or ideas!

Ben


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[bleeth]

Ben: The level of detail is definitely related to the size of the bit and the percentage of stepover. A relief of this size with "no" sanding would require going to a very small bit (1/16" MAX)and a stepover as small as .025. This would be a long cutting file but would likely get you where you want to go. You also need to select the right material and feed speed and rpm and by the time you got the results you wanted you would probably end up rastering the file in both x and y direction. If I were you I would look for someone who does a lot of 3-d in your area and go visit them and pay for their time for some experimentation to verify the results. You need someone who keeps their machine well tuned and I also suggest a spindle and high quality tooling (Onsrud or better) for minimum runout.

[luger]

Thanks for your advice Dave, great to know it could possibly work!

I have managed to see a shopbot in action already since Shopbot put me in touch with an owner not too far from me, they kindly spared a good few hours of their time to tell me all they know and show me the beast in action. The only problem was that they were producing custom kitchen work tops, nowhere near the complexity or 3D detail I'm looking for so they were unable to help me in regard to that. I was still blown away by the machine though!

A big complication is that I am based in London UK, as yet I have not found anyone here producing this kind of work on a shopbot (anyone out there in the UK?). I will put a message on the shopboters wanted forum soon though. I am able to come to the states to visit Shopbot (which I'd definitely do if am to buy one for training etc), but I do not want to make the trip only to find it will never achieve what I want!
I will keep searching for a UK shopbotter who can run tests for me, it seems few people use the machine for this kind of work though?

Many thanks for your advice again, Ben.

[fleinbach]

Ben,

Have you seen the Coin sample on the VS3D website here http://www.designscomputed.com/vs3d/examples/md.html
I cut this sample 3 years ago at the request of Daniel Carr the developer of the software to demonstrate how well it would work with the shopbot. I was relatively new with the shop at that time, and I had an older PRT machine. I do remember running the file twice. Once in the X direction, and then again, in the Y direction. Since this was just a test to show how well the software worked I use a piece of scrap low-grade MDF. Not the best material for very fine detail.

In that picture on his website you can not see the finest detail. It is masked by the roughness of the MDF. I am sure that if I cut it out of a denser material you would see detail as fine as you are trying to create above.

[luger]

Ahhh! That's the example that first got me thinking of using a shopbot for my work! So thanks for putting it on the web... It seems I'll be able to produce what I require then, as true to the original image as possible. I just want to get one made now in the UK so I can hold it in my hands and scrutinise it!

Many thanks for your advice.

[bearcat]

Ben,

The machining will leave trails in the flatter areas. Since you are casting, maybe you could use the Shopbot to cut the negative, which would leave the flatter areas high, making it easy to sand the marks out without removing deeper, finer detail.

With cutting a negative, you might also try a smaller ball mill (1/16" - 1/32") or engraver cutter for the detail areas.

Ed

[lex]

Flames????? With color that would be a fantastic piece

[fleinbach]

I neglected to mention I did apsoplutly no sanding whatsoever. The only thing I did was spray it with a can of gold paint I had on the shelf.