Hi, and thanks in advance for your help and opinions. This site and the open source stuff is great. I would of liked to of found out about it years ago. I have almost no hands on cnc experience. I have been in construction ( carpentry / contracting ) & boat repair and customization for more than a few years. More times than I can count I thought how fun and usefull a cnc setup would be. Untill now it always seemed a too expensive idea. Not now, so the idea - plan is a usable size for my ideas learning project build. I know I need much more hands on time before I could build a good long term fit. Here is the hope - wish list. To start I have ideas then involve router / plastic - light aluminum milling, plotter pen and drag knife use. A 3'x4' work area could handle all the ideas that come to mind, 3'x3' 90%. I don't know at what dimension things need to be upgraded to the next level of strength and more expensive componants. I can make due with a smaller working area but the 1000 x 750 seems to small. What advise can you give me? Best regards, Rod
Hi Rodm Welcome to the Forum. I think just about everybody wants to build a large CNC at the outset. After all, it makes sense, why build a small one when you can build a larger one for just a little extra. However, as you have realised, larger can incur flexing and twist, which in turn will affect the finished product. Generally, the larger it gets the more strength and rigidity is required, which means beefing it up more and more, and of course, it gets more and more expensive when following this path. But, the main area to consider is the X Axis, the gantry across the machine. This is where you will need to pay attention and consider the weaknesses it can bring into the concept. As far as the Y Axis is concerned, as long as it is firmly well built and is without any twist within itself, then the world is your oyster so to speak. However, the larger you get, the more you need to consider the type of drive you will use. Screws are great for small to medium sized CNCs. Then for larger beds you will need to think of using possibly belts, or even Rack and Pinion. They will all work, but cost is going to be a consideration always. Your 3' x 4' CNC is definitely going to fall in the Belt or R & P bracket. The same for your 3' x 3'. The 1000 x 750 would be good with screws. Anyhow, you've come to the right place to start your CNC habit, and I'm sure others will chip in with good advice and help. Keep reading and watch as many videos as you can. Gray
I built a larger CNC (850mm X by 1500mm Y) and used acme 1/2 inch 5 start lead screws (Y axis) and 3/8 inch 4 start (x axis) I ordered from McMaster Carr which came in 6 foot lengths. This did complicate things a bit because metric components are cheaper and easier to come by, but I came up with some money (but definitely not time) saving workarounds. Those workarounds were only possible because I had a friend with a metal lathe. I also made my own anti-backlash nuts, however these are available from Dumpster CNC. I actually found these screws to be cheaper than a double belted system of this length. The funny thing is, I can easily cut 2' x 4' pieces on it and yet I most often use the 1' x 1' corner at the X0, Y0 point. The reason I went bigger was so I could cut out longer parts for boats and kayaks using pin hole registration, and for cabinets. Here is a link to the build if you are interested. Lead Screw Driven Ox Derivative (850x1500)
Gary UK and Giarc, Thanks for the quick response. Giarc, great build post. It helped me understand a lot of things I have been thinking about. Your 100% right and I will be adding craft beer to my parts list. Portland - Oregon is a great area. My sister was in Portland and now Newport. My next visit might be a one way trip. Two questions Bed support, I noticed in several of the ox builds the bed seemed to only be supported by the front - rear brackets and a single center support? Even with a small bed size it didn't seem right. How much support do you think the bed should have? Screw vrs belt. GaryUK you feel larger platforms are beter off belt or r&p driven. Giarc you chose a screw drive. Could you guys tell me a bit more about your opinions? Regards, Rod
I just updated my sketchup file which shows how my bed is supported in more detail. I did a grid which was attached to a very heavy torsion box table top. The bed is supported all around the perimeter, the center, and then additional supported roughly every 350 mm. I didn't want it sagging . I recently have put it on its final frame work (https://www.amazon.com/Hopkins-9016...rd_wg=s18sF&psc=1&refRID=J1Q1Q8NZX2GDBZK6218Z) which will be an enclosed cabinet with electronics stored below. I went with screws because I wanted the precision, I didn't want to deal with potential belt stretch, and I figured they would be better for cutting aluminum. The downside: I am not sure they will be fast enough for a laser add-on.
Two huge lessons i have learned along the way i wish i had known at the start... well three really: First is that its not economical to start small and simple and upgrade a machine as you grow as a cnc'er. It is good as a learning process but later you will realize that upgrades and new machines have cost way more than the sweet setup you ultimately really want would have. I started with a shapeoko 2, then upgraded it, then built a beastly OX machine, and am now considering upgrading again and wish i had started with a cncrouterparts machine from the beginning, would have been cheaper. Now to be fair experience is how you learn what you want and need but the moral of the story is build more machine than you think you will need and know you will still outgrow it in no time! Second is that even knowing this you will still want to do upgrades and rebuilds later. Cnc building is a bug! With this in mind make upgrades easy by starting with really solid, industrial electronics from the outset. Any machine can be run by the same drivers and such if they are good enough so if you have to cut costs dont cut them with electronics. Upgrading to a new machine is a lot easier and cheaper when all the motors and stuff get reused. I would start with a gecko g540 or similar and have steppers in the 300 oz/inch range or more. You may never need to upgrade, but if you do its a lifesaver and besides, nobodys cnc ever died from having too much engine under the hood. Third is that the rigidity (or lack thereof) of the z axis and spindle mount will account for easily half of your headaches... build these parts like a tank!!! I would really recommend going on ebay and getting a z axis assembly rather than using openbuilds parts also i would get a router mount from cncrouterparts. Com. These cost a bit more up front but again they will make a tremendous difference in the output of your machine and the quality of your experience using it. Save yourself the headaches... file these parts away with the electronics and motors... buy them right and buy them once!!! Happy building!!!
Thanks, The cncrouter.com stuff looks great but a bit to pricy for my first machine. I checked out eBay for the z axis but I don't know enough to know what is a quality unit or good choice for my use. The thickest material I could see using now would be 3.5". How do you figure the hight dimension needed? I'm thinking 3' x 4' and have a decent idea for table - stand. I'm going to try the openbuilds part calculator to start a build kit. Has anyone used it? Opinions? I'm trying to decide on a router vrs spindle and still working - looking for control / electronics box ideas. Regards Rod
Yeah it is a bit steep up front but absolutely awesome. The dust shoe they sell from kentcnc is just unbelievable and worth every dime! For the z axis i found one that had 5" of travel i believe and just went for it. There should be a link on my build page to the seller i used... real good parts. ultimately the tool is only moving 4 inches max so 5-6 inches of z travel give or take and you should be good with some elbow room to spare for experimentation on setup. Spindles are way nicer overall but pricey compared to routers. Also for a router you could get a superPID controller and have closed loop control of your rpm's for a decent price. This requires modding the router though which is permanent. An option would be to use a trim router like the dewalt 611 just as it is w/no mods. Get some experience on this and if later you spring for the spindle, you still have a great compact router to add to the toolbox.
I highly suggest you design your CNC with Sketchup or some other CAD software. Then, you can measure everything and determine if it is what you want and can cut the size of material you need. I had never used CAD software before I stumbled across this site. It was well worth the effort, because you are going to need to know how to use it to make, and cut, things later. I know I am able to cut 26" by 50" inch material on mine because I drew it in Sketchup and can measure the dimensions in the drawing. The clearance between the spoilboard and the lowest part attached to the x axis is 94.7 mm or 3.72 inches. 3.5" was a requirement for me in case I want to carve on 4x4s. On top of the two layers of MDF I can add other pieces of MDF that was scrap from other projects. These are what I use as my primary spoil boards. This way way I can just toss out a board when it has fulfilled its usefulness. It also decreases the amount my end mill has to drop below the X axis, which increases the rigidity. I have another confession. I found this site in January of 2015. I started reading everything on this site about GRBL, drivers, and all other things CNC. I read though almost every build and the discussions regarding the builds. Of course, there were a lot fewer then. I read a lot of the resources posted in the "resources" section. Then, I stole a bunch of ideas from a lot of smart folks here, incorporated some of my own, and made a couple dozen changes before finalizing the Sketchup design. Some changes were incorporated in real life then later added to the Sketchup drawing. It was a lot of fun and I learned a ton. I assembled everything carefully, wired everything up properly, read the Github info on GRBL to set up the arduino board and to understand what the various settings meant, turned it on and I was off and running. I have had absolutely no issues other than a minor GRBL setting to keep my Z from dropping when not moving. Started building it in March of 2016 and I was producing useful things by August. It is now January 2017, two years from when I got serious about it and I am finally wrapping up the minor details like limit switches, proper grounding, and the cabinet it sits on. My point is, if you are not 100% sure of what you want, don't rush yourself or you may be disappointed. If you want to get into it fast, I would buy a kit or use one of the designs on here where people have written a manual on how to build it. I never used the parts calculator, because that would have required me to place every screw and nut into the CAD drawing. That was where I was lazy. I just counted them manually by looking at the drawing, then added a few of each for spares.
Thanks Craig, that was interesting reading. What you said there was really just a common sense path, which a lot of us probably followed, with a few variations. I think sometimes people do rush into this CNC world, and do come a cropper. We should have a "Words of Wisdom" page, and your post above should be at the top. It was hard for me, at that time, to read through all the Postings, but a natural thirst for information in this CNC world just kept me going. I must admit I did have my Favorites to follow, who seemed to talk an awful lot of common sense. There was Tweakie, RobertHummel, short stories by Serge and some guy called Mark. However, now, I hate to think how long it would take to plough through all the available pages. Especially that Ox Posting!!! Perhaps it still happens the same way, people get to know who they like to read and follow them. Anyway, well done for that great post. Gray
LOL!, Good stuff Gairc. I'll confess a few things too. I was so ready to rush right in. After I decided do a diy cnc, I was reading (still am) everything I have time for. Have felt a need to limit myself to builds similar to what I'm thinking about. So much great info and ideas to check out. I was ready to order an OX 750 x 1000 and figure the rest out later. In my mind I could see the wood and aluminium chips flying and all sorts of cool stuff stacking up around me. Luckily the other voice in my head said " hey dumbass, the machine is only as good as the programer and think about what you want to do once you now how to do things before spending a chunk of change. My plan now is very similar to yours. Learn - hands on with some of the programs I'll be using to start, incorporate some of the great ideas to be found here with some of my own and design a good machine for what I think I'll be doing. I'm sure the OX kit would have been a great way to learn but I would of been looking to upsize right away. I see myself planing for at least a few more weeks before starting to source - order things. Regards, Rod
Thanks Gray and good choice Rod. I wish I would have kept better track of the build threads which delved into a specific topic in detail. There are so many great builds here and I have read most of them, but luckily I got in on the learnin' early on. It would be tough to read through them all now. Currently, I read almost all of the new CNC Mills/Routers posts by people because that is what most interests me. When first researching builds, I found that one of the best build threads is The Frog thread The Frog CNC Router. This is particularly true if you are building a larger CNC machine. Unfortunately, some of the photos are now gone. The reason why I feel this is a good read, both the build and the discussion tabs, is because it touched on a lot of sub- topics in detail which was understandable by a noob like me at the time. He kept people from thread-jacking (even though there was an interesting discussion on anodizing) so it is all done in a 10 paged "focused" thread. It is like a CliffsNotes version of CNC with a lot of knowledgeable people chiming in and helping out. The build and discussion go into detail how he made the decision to modify from belts to screws, how to make a vacuum table from scratch, why he chose a router over a spindle, a lot of trouble shooting, a dash of Mach3 & Artcam, plus lots of well explained "lessons learned." I would encourage new folks to read through it, particularly the lessons learned.
Getting started! I'm making a few choices for componants and have downloaded sketchup - cam and fusion 360 to experiment with. I made a bit of am impulse buy the Anet a8 3d printer kit. It seemed like a fun way to learn a few lessons. There are so many decisions to make for a good build and trying to balance performance and budget is causing a few headaches. You can only plan for so long so my next decision will be an order date for parts. It reminds me a bit like buying my first car. You decide to do it - need to for work ect...... the I want side of the brain is thinking Cadillac style or muscle car performance (yes I'm north of 50). So the day comes to put your $ on the table and the tricked out Mustang you wanted is more like a Pinto . Financialy I have more flexibility now and want a bit of frosting on the cake but a Cadillac budget is not something I want to do. So I think this build will be called "The Pinto +". More questions coming soon. Thanks!
the fun is in the build. OK thats less than expected. How do you add pictures to a post? I created an album.
Hi, Interesting development - option. I was discussing - drinking or drinking - discussing my cnc project with a friend. He was pretty entertained and interested by the idea and my tale of trying to learn and design a build. His laughter almost brought a tear to his eye after I mentioned every Internet - info search seemed to result in a idea - find that added more ? and $ to the idea. So just before I had to much of his joy and right before it was my turn to buy a round he admitted owning a cnc was something he had also thought about and something like the 750 x 1000 ox is more than enough machine for his ideas. So the conversation ended with this idea. I would get an ox kit, we would build - learn on that. Use it and what was learned to design - build the bigger machine I would like. At that point he would buy the smaller machine from me. Even if he decided he didn't want it I imagine it would sell easily. It's hard to make decisions on what to do or not on a build with so little experience. So an option that gains me that, a helping set of hands and doesn't have a big price tag is tempting.
Next step, One corner of the basement is starting to look like a workshop but not contest worthy yet. The DIY anet a8 3d printer kit I ordered to help me build some building and computer skills showed up this morning. After some "what if" talk with my cnc interested friend I've committed to go ahead with a 750 x 1000 OX style pre "Pinto +" build. I'm looking at it like a scaled-down test dummy prototype. I started putting my plan together and hope to start ordering stuff by next weekend. I wanted a build name in line with my "Pinto +" first ride theme and have decided to call this one "The Stingray" (schwin bike inspired). I'll post up my draft plan for comment and suggestions soon, maybe later tonight.
