Hello Everyone I am a High School AP Physics Teacher and Robotics Team Head Coach in Dallas, TX. Next year I am offering two classes of a new course "Engineering Design & Problem Solving" offered to juniors and seniors. There will be introductory units on CAD, basic programming (Java, G code, etc), electronics, and feed-back control systems. Our goal is we want our kids both in this class and robotics to learn how to design simple parts in CAD and make them using CNC machines. We have education licenses for AutoDesk and Sketchup. I am hoping to get a grant for a 3D printer (they're all the rage now in education) and I'm planning on buying for myself a Grizzly G0704 and eventually CNC it following Daniel Kemp's (aka Hoss) excellent guidance on g0704.com. My questions to this community... 1. After my students have gone through the introductory units, I want my students to learn something about system integration. To that end, I think the Routy would be a great first project for our classes. This coming year I would have each class build a basic Routy as a class project. Each following year, I would have a class create and build improvements to the prior year's machines. Thoughts? Assuming we go with the Routy... http://www.openbuilds.com/builds/routy-cnc-router-v-slot-belt-pinion.101/ 2. Here in the US, its most convenient for me to get MDF and plastics precut to 24" X 24" (610mm X 620 mm) blanks. It would great if we could expand the Routy's working area to easily clamp parts of that dimension. Would a 700x700 working area be of sufficient size? Sounds like to do that, we may have to stiffen the gantry? With this in mind, would that be a follow-on project or would a different initial OpenBuild project be better? 3 For the mechanical portion + motors (no cutter, tooling, electronics, computer or software) what would be a good "not-to-exceed" budget amount for one Routy? Any economic benefit to purchasing the kit for two at once? 5. What would you recommend as an out-of-the-box cutter? Bear in mind kids (and me! LOL) are using this thing and I'll need something cheap and easily replaceable. It would be great if we could also cut 2 mm aluminum sheet with that tool using conservative feed rates. (I will eventually have the mill/drill to work thicker aluminum plate.) Perhaps the Dewalt DNP611? http://www.amazon.com/DEWALT-DNP611...54LXWKA/ref=cm_sw_em_r_dpcod_VSzFvb0ZD67D9_tt 6. And yes, I see a full-blown OX (perhaps with ballscrews?) in my future! Any thoughts and suggestions would be most appreciated!
Start with the Ox, All NEMA23, GT3 (GT2 3mm), plates from Chris on eBay, go for the extra height plates, thus 4 wheels at the Z axis, 16 wheels on the X axis. Dual Acme block as well for the Z axis. I'll PM you about some projects I'm working on but still have to publish . -Ronald
Thank you Ronald! I've been ill the past week and I'm only now getting back up to speed. I think an OX as you outlined will be my first "personal" project. Then I'll have another look at deciding what a good project would be for my students, in part based on that experience. It will also give me a machine I can use to fabricate some of the parts needed for my G0704 Mill/Drill CNC conversion.
I've been building different Routy models and I can say that when you build a machine that has a cutting area of 611*611 mm you are better of with the Ox. You need to make indeed the X-axis sturdier, plus the 3mm sideplates are just a bit too weak for a 1hp router, well, that is when you want to use the power of it. Using a 14t pulley with the NEMA17 motor is recommended but you need the holding-torque of a NEMA23 motor at least. This is why going for an Ox is your best pick and it's not that much more expensive. -Ronald
Hello Jestah, The double nut block might be outdated as the new Anti-Backlash Nut Block for 8mm Metric Acme Lead Screw is now in store. But, you might use one anti backlash with a normal nut block when you use a long Acme screw: Place the blocks as far apart to reduce vibration and resonance. Just place them with a distance of multiples of 2mm from each other (8mm/4). I would just keep them multiples of 8mm as it would take one turn of the screw to advance 8mm (just for my feeling, no other reason really). If you buy plates it's easy to add the 2 extra holes. -Ronald
So, having Sketchup you can add the SketchUcam plugin and go direct from Sketchup to Gcode (-: Get it here (free and open source) http://www.phlatforum.com/xenforo/threads/sketchucam-download.3128/ Do watch the howto videos, makes it a lot easier to get started (-: This is, I believe, the simplest way to learn to draw and generate Gcode. I have watched a lot of videos on various CAM solutions and they are all a LOT more complicated, except maybe Vcarve Pro that appears to be mostly automated, ie the kids will not learn a lot. So far I have not needed any other Gcode generator when using my friends RJ1325 (we do cut faster than that! I generally run a 2 flute 6mm bit at 2000mm/min in plywood, 4 to 6mm deep per pass)
Hello David, Mark warned me about you! Do you have anything on paper (printable PDF or so) that can be used to translate or given to the people so they can start to use the plugin without using a device that has to be connected to the internet? I'm working on Spanish/English PDF manuals that can be printed. These manual explain how to build machines and the kits sold on OB. They will also include the adjustment of the wheels, acme, belts and some basic wiring with an Arduino. Would be great if there would be some "get started with CAM" included in every manual if it's a complete CNC build. I would also include some calibration and test information if possible. Spreek je later, -Ronald
oh good, then I don't need to explain myself (-: No, no such paper instruction on getting started. There is the help for SketchUcam in the form of HTML that is installed when you install SketchUcam, but few people read it so I started making videos (-: You should read through the help and see if it gives you what you need before doing any extra work. As for not being connected, you can download the videos from Youtube (I use a Firefox plugin) and put them on the school computers for local access. you could even translate what I say to Spanish and then redo the voiceover, I use the free Movie Maker from Microsoft. you are welcome to convert the videos to printed materials for your students.
Did you look at using a simulator, like OpenSCAM, so the kids don't have to use an actual machine to 'test' out their work. It's also a good idea to get them used to simulating before cutting, even air. A step I initially skipped in my initiation to DIY CNC world (doh). SketchUp Make (free), SketchUcam (free), a few plug-ins/extensions to help with SketchUp (free) and OpenScam (free) would allow students to CAD, CAM and (virtually) CNC ... all they need is a computer to run it all on, either PC or Mac will do with these software These computers don't need to be recent or high end, especially if the user is more patient, nor connected to the Internet or network, sneaker network is fine to exchange files, if need be. You could start on the cheap and grow into the actual CNC machines ($) and other software ($) OpenBuild and the community here certainly makes it easier on all levels ...
