hi i have a next door nabour who has access to a cnc machine at his workplace and i was tryign to explain this stuff to him and hes not sure if the files used in pepakura will work on it does anyone have any 3d files that is compatible with a cnc machine and any other info for me that i should know im planning on making m armor and using cnc for weapon props and possible some of the more complicated helmets ? hope this makes sence sorry if it dont
Cnc Machine
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gbaromman said:
Not sure what type of files a CNC machine needs but if you need 3D files you can export OBJ files (universal 3D files)from Pepakura. Just pop open the file that you want, go to file then export, then export OBJ and your set. You now have that pep in a 3d form that can be opened and edited in most 3D software programs.
Hope that helps and good luck.
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gbaromman said:ok thanks for the info ill convert a few files to cnc and see what he can do once he understands what i want done helps to know someone who makes submerines
as I remember if you model it in a regular 3d program,.. you'll need to edit it in a CAD/CAM program,.. then from there convert into G-code or whatever specific method the particular CNC machine uses
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Depending on how many axes the CNC machine has, and it's range of motion, you won't simply be able to just mill them out and put them on. The reason is that most machines are only 3-axis, meaning they can move forward/back, left/right, and up/down. They can not move in the 4th and 5th axes, which are TILTING the cutter forward/back and left/right. 3-axis machines only see things from the "top down". Only the most sophisticated and expensive machines operate in 5 axes, and they are typically not found in shops. An issue that you may run into is the cost of materials, because large 3D parts like armor are going to require large blocks of material, most of which will just end up being milled away.
Think of like a camera. If you take a picture of the front of a helmet, for example, the cutting bit can only access the things visible in the picture. It can not cut back around the back of the helmet, or inside it, or under the visor, etc.
To get around this, you're going to have to do a lot of work to break apart the 3D models into pieces that can actually be machined. For instance, you might break a helmet into the top of the head, the left side, the right side, the back, and the mouth guard/face mask. You could machine the outside of each of these pieces, then assemble them, then make a mold, then roto-cast in the mold. You could also use the pieces as forms for vacu-forming.
Alternatively, since the thickness of pieces doesn't need to be incredibly accurate, you could try to machine the insides of the pieces too. (you could probably be off by 0.1", which is a HUGE amount in machinist-land, and it wouldn't affect you wearing it any). After breaking the pieces apart, you could add "tabs" to them, to let them remain attached to the waste material of the original block. You should be able to flip them over and accurately zero to the block, in order to machine out the other side.
Here is a 2D part with tabs attached. See how the tabs keep the part attached to the waste material? This would allow you to flip it over, and work on the backside. This would work in 3D too.
As Amancue posted above, going from a 3D model to the cut part is a 3 step process. You first design (or in your case aquire and edit) the part in 3D modeling or CAD software. Second, you take the 3D part file and load it into CAM software, which determines the toolpaths. Toolpaths are the complete set of instructions on all the movements the machine must perform to cut the part, and are written in an instruction language called "gcode". The third step is for the CNC controller software to read the gcode toolpath instructions, and transmit signals to the CNC machine to cause it to perform the dictated movements. If this is a little confusing, imagine that you want to go to the store. You have the address of the store, which defines exactly where it is, this is like the 3D model since it is the destination or the final desired result. You then use Google Maps to get directions for all the streets you need to take, and turns you need to make, in order to get there, which is like the CAM software generating the toolpaths. Then you get in your car and drive there, where you act like the CNC controller by actually making the car perform the movements dictated in the directions, in order to get to the result.
I currently have a small CNC machine, and I'm working on a new, larger one, that I hope to have done next month. I plan on testing out machining some parts in these ways, and I'll post a tutorial once I've figured things out well.
Think of like a camera. If you take a picture of the front of a helmet, for example, the cutting bit can only access the things visible in the picture. It can not cut back around the back of the helmet, or inside it, or under the visor, etc.
To get around this, you're going to have to do a lot of work to break apart the 3D models into pieces that can actually be machined. For instance, you might break a helmet into the top of the head, the left side, the right side, the back, and the mouth guard/face mask. You could machine the outside of each of these pieces, then assemble them, then make a mold, then roto-cast in the mold. You could also use the pieces as forms for vacu-forming.
Alternatively, since the thickness of pieces doesn't need to be incredibly accurate, you could try to machine the insides of the pieces too. (you could probably be off by 0.1", which is a HUGE amount in machinist-land, and it wouldn't affect you wearing it any). After breaking the pieces apart, you could add "tabs" to them, to let them remain attached to the waste material of the original block. You should be able to flip them over and accurately zero to the block, in order to machine out the other side.
Here is a 2D part with tabs attached. See how the tabs keep the part attached to the waste material? This would allow you to flip it over, and work on the backside. This would work in 3D too.
As Amancue posted above, going from a 3D model to the cut part is a 3 step process. You first design (or in your case aquire and edit) the part in 3D modeling or CAD software. Second, you take the 3D part file and load it into CAM software, which determines the toolpaths. Toolpaths are the complete set of instructions on all the movements the machine must perform to cut the part, and are written in an instruction language called "gcode". The third step is for the CNC controller software to read the gcode toolpath instructions, and transmit signals to the CNC machine to cause it to perform the dictated movements. If this is a little confusing, imagine that you want to go to the store. You have the address of the store, which defines exactly where it is, this is like the 3D model since it is the destination or the final desired result. You then use Google Maps to get directions for all the streets you need to take, and turns you need to make, in order to get there, which is like the CAM software generating the toolpaths. Then you get in your car and drive there, where you act like the CNC controller by actually making the car perform the movements dictated in the directions, in order to get to the result.
I currently have a small CNC machine, and I'm working on a new, larger one, that I hope to have done next month. I plan on testing out machining some parts in these ways, and I'll post a tutorial once I've figured things out well.
Sniperbaas
Well-Known Member
From what I've seen, cnc machines aren't really effective for the reasons that Awesomeness said; however, I've seen several handplates that were made from in a cnc machine (they had to be cut out of the finished piece. (I'll find the links if you want)) I also saw a battle rifle that a guy made in a CNC machine. He cut the rifle in half (the model of it) then used a cnc machine to mill each half, cut the pieces out, attached them, and viola! easy made assault rifle. To get a pepakura into a cad program you need to export it from pepakura to .obj (requires a full version), convert it in meshlab (free program) to a .stl, and open it in a cad/cam program. That should do it!
Cheers!
Cheers!
Belakor
Well-Known Member
Since it's been brought up I just wanted to add re. exporting from Pepakura. If you're going to do that make sure you contact the original modeler of the pep file before you do anything with it, they might not like the idea of you yanking their file for other purposes... and you never know, they may be able to provide the original file or something better.
Honestly though I think you'd be wasting your time and money just machining pep files, sure some are pretty detailed but I think you'd be much better off getting someone to model some purpose built models specifically for CNC'ing (or doing them yourself if you've got the skills/tools)
Honestly though I think you'd be wasting your time and money just machining pep files, sure some are pretty detailed but I think you'd be much better off getting someone to model some purpose built models specifically for CNC'ing (or doing them yourself if you've got the skills/tools)
Belakor said:
Belakor is right, and I didn't really think of that. The Pepakura models have intentionally had their resolution decreased, to create lots of flat faces that will fold nicely from paper. The CNC machine will cut exactly that, a solid item with lots of flat faces. Yet the machine is fully capable of cutting all the smooth curves correctly, so you should definately find original (smooth) 3D models and work from those.
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Yodajammies
Well-Known Member
If you want phenomenally high res models of the Mk VI suit, talk to Nugget. I'm sure he'd let them go for a fair price. He did the models for my suit that I CNCed (mostly).
Milling armor is not something to take up lightly. You'll go through several blocks of material and several days of tweaking before really getting the hang of things.
Milling armor is not something to take up lightly. You'll go through several blocks of material and several days of tweaking before really getting the hang of things.
LastSpartan
Sr Member
Yodajammies said:
And alot of money. Paying for the model is one thing. Paying the machinist + materials for it is another.
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One thing I wanted to mention was 3d Printing. And its hobby level project form of Fab@Home. These can achieve hollow helmets and phenomenal detail as they print the model in slices.
This process including the construction of your own fab machine might be cheaper than the material cost alone of cnc milling. You will still need to convert the original model to cad files. But the fab@home project open source controllers can print directly from autocad. I am currently researching large construction arrays of about a meter cubed or something that could handle a chest piece.
Finally, pay attention to your model details you will be surprised how much the game 'cheats' by using decals
This process including the construction of your own fab machine might be cheaper than the material cost alone of cnc milling. You will still need to convert the original model to cad files. But the fab@home project open source controllers can print directly from autocad. I am currently researching large construction arrays of about a meter cubed or something that could handle a chest piece.
Finally, pay attention to your model details you will be surprised how much the game 'cheats' by using decals
GremlinLord
Member
Ok, I've been around this block once, or twice.... or three times... damn I lost count. At first I was thinking cnc routers are freaking expensive (they are) and you really need to know what your doing (again true) so I counted them out completely. I took a look at Fab@home and RepRap. Both seemed good but the build area is very small for anything on our scale. Then I bumped into this blog Home made 3dp. It looked good. Fast high quality parts using cheap discarded printers. Sure the build area is smallish but I could just split a model in 4 pieces and do them one at a time. So getting in the yahoo group that is mentioned in the blog I found that everything isn't so peachy. First off you need to get a easily trick-able printer. Next is low friction linear rails($$$) or powerful steppers and again tricking the computer. Finally is the actual powder/ink mix. To boot you need to worry about environmental conditions and cure times and hardening the part afterwords... the list goes on.
So I finally came back to the cnc realm and found two rather cheap options. First is a completely do it yourself machine (except for the electronics) http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/. This boast a extremely cheap construction but I wouldn't use it for anything more than foam/mdf(maybe). Next is this http://www.probotix.com/FireBall_v90_cnc_router_kit/. This is only the frame, no steppers and other electronics. But the machine will do aluminum if you do very shallow path depths.
If you see a problem with both machines you get a cookie... ... ... OK the problem is the z-axis, it is only 3" good luck fitting a part under that. But wait there's more. http://www.vectric.com/WebSite/Vectric/cut3d/c3d_index.htm This software lets you do a whole bunch of cool things to a model like 4 sided milling for small parts and slicing up models to print them on thinner materials. The down side is the price but the software lets you do some things that are hard to do on a 3-axis machine and a 4-axis cnc or a 5-axis cnc(drool) cost a wee bit much. The last bit of course is the actual CNC software. For the DIY/Hobby cnc owner and many professionals it comes down to Mach3 and EMC2. EMC2 is free Mach3 is not. If I was just making a machine for this hobby I would probably make the machine on the diy machine on instructables website and make all my parts out of the pink foam.... Then again "pink foam" is really extruded polystyrene so you will need to use epoxy to seal it. The blue foam could be polystyrene or extruded polyurethane but I can't say for sure.
Now that you have that part done you need to worry about endmills/routerbits and parallel port latency since not all computers are equal. O'yeah don't forget about power supply and noise as a simple helmet I sliced up to see the estimated time took around 4 hours per slice the helmet is 7 slices >_< and routers are really, really loud. Don't forget about garage space ether. Your not gona run this thing inside your house or out on the front/back lawn.
My advice to anyone who wants a cnc/3d printer is to really think about what you want. I personally like the CNC side better since you can mount a 3d printer extruder to the cnc and get the best of both. For those who are serious try this first http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ for the cnc. You can scale it up to about twice the size before it gets inaccurate. Since stepper controllers and drivers are expensive you can drive it with this http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/. Just check the specs on the driver before you go buying steppers. Last resource is the CNCZone I wish I knew 1% of what those people know.
Best case scenario $500 for a diy cnc for foam not including software and endmills. It ain't cheap but I tend to go towards the higher end around $1300 (frame + motor + software + old Pentium 3 "liberated from the e-waste pile"). Take my advice with a grain of salt because the cnc I'm looking at isn't just for this hobby.
Last thing most cnc jobs at our scale will take hours if not days so it will be hard to get a cnc machine at a work place to get a job in. Most of the time those things will run all day every day for work related projects. Try downloading the trial software and figure out how long it will take to mill a model you will be shocked I guarantee it (there is a reason milling cost so much, it ain't the materials).
Wow, I wrote a novel... in a forum post (>_<)
/end rant.
So I finally came back to the cnc realm and found two rather cheap options. First is a completely do it yourself machine (except for the electronics) http://www.instructables.com/id/How-to-Make-a-Three-Axis-CNC-Machine-Cheaply-and-/. This boast a extremely cheap construction but I wouldn't use it for anything more than foam/mdf(maybe). Next is this http://www.probotix.com/FireBall_v90_cnc_router_kit/. This is only the frame, no steppers and other electronics. But the machine will do aluminum if you do very shallow path depths.
If you see a problem with both machines you get a cookie... ... ... OK the problem is the z-axis, it is only 3" good luck fitting a part under that. But wait there's more. http://www.vectric.com/WebSite/Vectric/cut3d/c3d_index.htm This software lets you do a whole bunch of cool things to a model like 4 sided milling for small parts and slicing up models to print them on thinner materials. The down side is the price but the software lets you do some things that are hard to do on a 3-axis machine and a 4-axis cnc or a 5-axis cnc(drool) cost a wee bit much. The last bit of course is the actual CNC software. For the DIY/Hobby cnc owner and many professionals it comes down to Mach3 and EMC2. EMC2 is free Mach3 is not. If I was just making a machine for this hobby I would probably make the machine on the diy machine on instructables website and make all my parts out of the pink foam.... Then again "pink foam" is really extruded polystyrene so you will need to use epoxy to seal it. The blue foam could be polystyrene or extruded polyurethane but I can't say for sure.
Now that you have that part done you need to worry about endmills/routerbits and parallel port latency since not all computers are equal. O'yeah don't forget about power supply and noise as a simple helmet I sliced up to see the estimated time took around 4 hours per slice the helmet is 7 slices >_< and routers are really, really loud. Don't forget about garage space ether. Your not gona run this thing inside your house or out on the front/back lawn.
My advice to anyone who wants a cnc/3d printer is to really think about what you want. I personally like the CNC side better since you can mount a 3d printer extruder to the cnc and get the best of both. For those who are serious try this first http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ for the cnc. You can scale it up to about twice the size before it gets inaccurate. Since stepper controllers and drivers are expensive you can drive it with this http://www.instructables.com/id/Easy-to-build-CNC-Mill-Stepper-Motor-and-Driver-ci/. Just check the specs on the driver before you go buying steppers. Last resource is the CNCZone I wish I knew 1% of what those people know.
Best case scenario $500 for a diy cnc for foam not including software and endmills. It ain't cheap but I tend to go towards the higher end around $1300 (frame + motor + software + old Pentium 3 "liberated from the e-waste pile"). Take my advice with a grain of salt because the cnc I'm looking at isn't just for this hobby.
Last thing most cnc jobs at our scale will take hours if not days so it will be hard to get a cnc machine at a work place to get a job in. Most of the time those things will run all day every day for work related projects. Try downloading the trial software and figure out how long it will take to mill a model you will be shocked I guarantee it (there is a reason milling cost so much, it ain't the materials).
Wow, I wrote a novel... in a forum post (>_<)
/end rant.
GremlinLord
Member
ennder said:
G code is the actual code that drives the machine/controller it is an industry standard for 3d and 2d. .stl .dxf and the others are file formats for a 3d object. They need to be processed by a CAM software to calculate tool paths and turning it in code your cnc/printer can understand (most likely g-code or some proprietary code).
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GremlinLord
Member
The build on instructables was a $600 build I though. I would also choose your threaded rod more carefully than the builder on the site as his machine maxes out at 60ipm. You will burn wear out bits unless your router head goes really slow due to low chipload. 100ipm is real nice. Also he payed way to much for 127 oz steppers + controller. Better price atm http://www.probotix.com/index.php?view=product&path=22&product_id=88 Those motors max at 24v so don't get the psu upgrade, unless you want a smoke machine... a "magic" smoke machine.
Gremlin117 said:
First things first, he said he has a neighbor that works on a CNC machine. I assume that means he won't be building/owning one, and in fact he may never even see the machine himself if his buddy does all the work. But since we've started talking about DIY machines, I'll elaborate...
Gremlin, you've definitely done your homework, and hopefully you'll get yours [built] soon. You'll love it, and it's not nearly as bad as you fear. These MDF-structure CNC routers are great, and pretty easy to build. I really recommend that you check out http://www.buildyourcnc.com because the routers there are, in my opinion, better than any other similar machines around, including the Fireball V90. The BuildYourCNC ones also use a real wood router, not a Dremel, so they are far more powerful and can even cut aluminum.
You're absolutely correct that $1000-$1500 is a more appropriate figure for the bottom line. The price that the Instructibles article claims is the product of "creative accounting"; it leaves out the hidden costs of a lot of things (tax, tools, shipping, bits/accessories), goes to some ridiculous lengths to save money, uses only free/trial software (that you will probably want to replace with $200-700 worth of commercial stuff), and still comes out to over $550 without counting the $100 Dremel/router or computer. A lot of the people that build these things are tinkerers by nature, like myself, and have lots of these "extras" around the house already, so they forget to include them in their appraisals.
Depending what material you are cutting, even these DIY CNC routers can be very fast. In foam, mine (built from http://www.buildyourcnc.com) can cut at maximum speed because the foam will never bog down the bit. You can adjust the speed faster by reducing the resolution of the stepper motors. Before you panic, this resolution reduction is in "machinishland", so it only actually amounts to a reduction of a couple thousandths of an inch of accuracy, which is perfectly acceptable for carving costume pieces. Nobody is going to notice that the notch in your chestplate is 0.005" off center.
You can sand the foam smooth quickly to finish it.You are absolutely correct that the router is loud. They also produce a lot of dust. You'll only want it in your garage, realistically. The ones that use a Dremel are probably considerably quieter, and you might be able to get away with running in your basement, in some kind of construction "tent" to contain the dust.
The 3" z-axis isn't a problem, especially if you're building it yourself. You just build it taller! (Granted, that takes some re-engineering.) Most of them are only a couple inches high because most of the people are using them in 2D to cut out flat parts from board/MDF. The machines are capable of supporting larger z-axis travel, software-wise/etc. The biggest concern is that if you give it too much travel, you run the risk of the bit trying to cut a deep enough point that the collet/tool runs into the material. This is a problem with full-size commercial CNC as well.
ennder said:
No, G-code is just a tool movement language. You can actually open it and read it with Notepad. It just tells the machine what to do, like driving directions,... "Go to position 0,0,0. Set movement speed to 2 in/sec. Move to position 0,1,0. Plunge the bit down 1" by moving to position 0,1,-1." Even 2D mahines are really 3D machines, so you're probably really talking about 3-axis vs. 5-axis machines, both of which still use g-code.
It doesn't matter what format your original file is in (all the ones you mentioned are viable), it will have to be converted into g-code instructions (or some other proprietary language) to tell the machine the movements needed to actually cut out the part. The machine has no idea what it's making, only the movements it's supposed to follow, the same way that I can give you directions to somewhere and you don't know where you're going. This g-code is pretty industry-standard, and you can load it into almost any CNC controller.
The CNC controller is a device/software that talks 2 languages: g-code and the digital language of the actual machine. It takes the g-code instructions, converts them to digital pulses, and sends them to the machine's motors.
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