Cutting clipart

[twhaley]

yes i was wandering if anyone could help me. i have started cutting clipart on my shopbot.i have a buddy. older one. the thing is im using a 1/8 inch bit ,when i go to cut the clipart it takes me like over an hour to clear the area out. i tell it to use like 75 percent of the bit thinking it would cut down on the time. but when it is cutting it is only using a little bit of the bit.like maybe 29 percent if that . could anyone help me.

[jsfrost]

Travis,

There are many ways to cut clip art, each giving different effects It can be done by cutting along vectors, by V carving, or by clearing areas, perhaps with beveled sides. If, as it sounds, you are doing area clears and your toolpath software and available bits allow, clear the large areas with a bigger bit and use the 1/8 to finish the finer detail.

What software are you using, and what are your goals? How big is your project?

It sounds like your stepover settings may be be incorrect. Stepover is effectivly the amount of overlap between passes. A 1/8 bit has .125 diameter, and .034 stepover setting would result in about .097 (3/4 of the bit) stock removal in each pass.

Speed settings will also effect cut time. What XY speed are you using?

How deep are you cutting? With the small 1/8 bit you can't cut too deep in a single pass without risking bit breakage.

Re-reading your post, maybe you are cutting 3D clipard with a 1/8 ball? If so, for a modest size project the times are about right. With 3D, a small stepover is needed for good detail and minimum end of project sanding. Tell us more about your project, and you will get better answers.

[twhaley]

ok im an airbrush artist trying to add wood signs to my customers. i would say for the most part the biggest sign i will cut will be 24longx12tallx1/4thick. i usually add names and then a design. im using some clipart that a friend gave me. ok first off i have my stepover set to like what i belive to be 50% of the bit and im cutting at 2 inches per second for the x and y and im cutting about an eighth inch deep. when i send the clipart art to part wizard 3.0. i know an old version but the shopbot was given to me by my father inlaw for free wow right. well any way i got it with no books and he didnt really know much about it cause right after he bought it he got a laser engraver. i said that to say upfront plese forgive me for any stupidity lol. ok lets say i send a horse over just a simple shillouet about 4 or so inches wide and maybe ten inches tall. it takes like 2 hours just to cut the horse then with a vbit it takes another hour or so to do the lettering. thats a long time for a 40 dollar sign. hey jim thanks so much for the help im truly lost . ive got 3d images pretty much figured out thanks to vector art3d. i would just really like to cut the time down on these simple signs. oh and im not sure how to do the big bit little bit thing. cause when i do an area clearance on the clipart i the bits gos from one spot to the other how do you seperate where the big bit will go and then the lil bit . thanks again for the info . your really helping out a dumb ol country boy .

[harryball]

wow you're opening a whole keg of worms :-)

Search the forums on cutting 3D and learn all you can. It's an art and I think all of us start with visions of cutting 3D in 10 minutes, go into shock when it takes 2 hours and then learn how to adjust the ramping and keep tuning to get that down to 30 minutes to an hour.

I'm not an expert on 3D so I'm sure some others with more experience can chime in, but here's what I learned...

Keep your step over passes between 8% to 12%. It takes longer up front but saves later when sanding and cleaning up the work.

Run your X, Y and Z at 3 ips and tune your ramps etc... Set the 3D threshold to 150. You can tune ramps (Brady has a very good tutorial on that available) and pick up speed. You want to get as fast as possible without the machine slamming around... it's an art.

For the 1/8" ballnose tapered bit that comes with the starter bit set (or if you buy one) you can make your 3D cut at full depth cut in a single pass so long as you keep your step over low. You do have to start in slow though. For a dished image do a 45 degree raster, you cut in slowly gaining depth in a full depth. You may also have to create a beginning tool path for this approach for non-dished carving. You want to avoid making a full depth cut while taking on the entire material.

All that said... go get some 1" blue foam from one of the big box stores, the stuff you put on the outside of houses, and carve on that. Much safer when you make a mistake, can't break the bit as easy.

Hope that helps, ask questions, that's how you learn.

/RB

[twhaley]

well i know pretty much about the 3d cutting i just use vector art and the 3d machinist program. my probablem is simple clipart. i cut out a silouete of a man and women fading into a heart. it was 6 inches tall and about 5 inches wide and 1/8 inch deep i cut it with an 1/8 inch end mill. its only using a very very small amount of the bit to cut. it took almost two hours just to cut the clipart.

[twhaley]

oh and my cut speed was 2 inches per second

[jsfrost]

Are you trying to do the clipart as an island that stands proud of the base material, by clearing an area around the vector outline? Or?

Unlike some other software, Part Wizard will not directly do an area clear with multiple bit sizes. If the level of detail you need requires a 1/8 bit clearing a large area will take some time. With some effort you can get around this. Using the the offset vector, create a vector offset out toward the area to be cleared with a larger bit diameter (say a 1/2 bit, use 1/4 (.250.)), and then offset the resulting vector inward by the same amount. Delete the outermost vector just created. Next create a toolpath using a 1/2 bit and the original vector and a second toolpath clearing the area betwqeen the original vector and the new vector using your 1/8 bit.

Play a bit, there are may ways to skin a cat. If your budget allows consider upgrading software to Vcarve Pro, which will do all this for you and much more.

A very simple line art strategy that may work is to toolpath as a trace along vector at a fixed depth using a V bit. With a 90 degree V the line width will be twice the cut depth.

If you feel the need to talk, give me a call in the evening except Tuesdays (after 5 central). Email me at the address in my profile, and I will respond with my phone number.