Is this the correct dimensions for the wheels on a OX build? These dimensions are displayed on a seller's web site and if they are correct I will be buying a batch of these.
Hello Dean, Please have a look at the dimensions listed in the OpenBuilds Part Library Resources There is a folder in there called PDF drawings Beware of knock offs as we receive complaints about these bad wheels and we do not support them. Even if the dimensions show correct (most of the time the pictures are just taken from OpenBuilds sites, like the one above). Moreover you will want to support the OpenBuilds mission so they can keep bringing cutting edge open source hardware to the community! Thank you
I just bought non-OB solid V wheels from an eBay seller. I did feel bad whilst doing it though, haha. But the theme of my current project is prioritizing "price" and "quality" and letting the "speed" corner of the triangle do what it will. I was also aware that there was a non-zero chance that I was going to have to spend much more than 85c worth of time per wheel to fix them in order to be usable. If I didn't have machining capability, it'd almost certainly be worth the extra five bucks or whatever to have the peace of mind that comes with ordering direct from the OBPS. Plus, supporting FairShare! The next project, I hope and believe will be a mainly-OBPS-project, which will be super nice (way less time second-guessing yourself on eBay search results and raging at aliexpress minimum order requirements).
Oh I certainly understand,... but when you buy 70+ wheels at once it hits the wallet and then I get hit by the wife. A fixed income sometimes doesn't allow for the $5 peace of mind spend. LOL
70?! That's a huge machine! I certainly hope the ones you end up going with are good, 'cause that's a lot of money even with knockoff parts...
Oops,... almost 50 wheels I guess it is... I added an extra set of wheels in there, plus I was guessing off of the cuff. I am figuring double rails on the X with a Y-plate, a double rail on the Y and then whatever Z is and if I can bolster that any I will.
Are you sure it wouldn't be cheaper/better to use linear rail? It's designed for the kind of loading you appear to be going for. Aluminum extrusion isn't really for building serious monster rigs with... It sounds like you're building a linear bearing and ballscrews kinda deal?
Uh.... yeah... whatever that is... LOL I am really new to this so I am not being sarcastic, seriously. I just don't know what you mean by name. If I saw it I would probably recognize it. I am building a Blue Ox Tall version. Joe has seen me describe it as "beefy" in another thread. The beefy part is because I want to make sure that I take any deflection out of it due to it's size, 1m x 1m or maybe just under that 3ft x 3ft.
Linear rail is this stuff: 20mm 42.5'' Rail Guideway System Square Slide Unit Linear Motion See the 17.75kN dynamic loading? That means if your spindle hits your material with enough force to make a pallet of concrete jump, that bearing block won't care. That's 20mm rail, it also comes in smaller sizes. WAY more force than v-wheels could ever take. That's something you're gonna have to consider, because your spindle is going to be applying huge leverage against the outer rails. Imagine trying to use a router on the end of a two-foot stick to drill holes. There's also fully-supported linear rod: 12mm 60'' Rail Guideway System Linear Motion A little cheaper, still pretty strong though, and comes in much more variety. 5, 8, 10, 12mm tend to be for smaller machines, then 16, 20, 25mm are for big machines. Unless you have a relatively tiny spindle (say 300W/Dremel-class) in the middle of the monster, you're gonna have a hard time taking deflection out of it. If you're planning on hanging, like, a 3kW (*cough*BS*cough*) router off the top, things will get interesting. Aluminum is good at being rigid for its weight. That's about it. Its "absolute rigidity" isn't off the charts, and it's horrible at damping vibrations (an accuracy killer). If you're looking at a 900mm machine with huge dynamic loading and leverages, you probably need to start looking more into reinforced-concrete-filled steel structures, maybe with some aluminum parts to assist with rigidity whilst not adding too much weight. I don't know the exact nature of the machine you're planning on doing, I haven't seen any precision requirements or intended work materials (just cutting acrylic, or are you attempting steel bar?), but "tall" is altogether likely to mean "rethink your plans". Alu extrusion is excellent for relatively small-scale 3D printing, laser/plasma, cutting MDF... That kind of thing. Remember, commercial CNC mills weigh about 20 tons and operate on parts typically around 8" cubed.
3Kw are heavy sobs. The rail you mention also goes by the name profile rail and square rail. I'm using vxb #2 dual V and I'm very satisfied with the quality and price. Eccentrics were a pain to get though.
Cool. Yeah, that profile's what I'll be using when I can eventually afford to spring for the holy grail: 5 axis, epoxy granite/polymer concrete, 2.2kW VFD'd water-cooled spindle, ballscrew and chain drives, the works. For the time being, I'm gonna settle for a lower power V-Slot version that can still work wood, foam and plastics.
I am building an Ox and I am using this Charging Ox as an example to go by. Right now I am planning on using a Dewalt DW660 (5amps) for my routing tool which weighs 3.2lbs. But down the road I want to upgrade to a larger 5.6 lb. router the Dewalt DW611. Yes I am familiar with both of those rails and have considered them. The price has kept me from doing anything other than "considering" them. LOL As far as stiffness, I could always bolt a 1/4" thick 80x1000 plate of aluminum on all of the 20x80 V-Slot Linear Rail. Then open up the holes on the gantry to accept a larger diameter bolt, then run the bearing directly on the plate? LOL
If it's any help, the motor part of the DW611 is only 3.4 lb., considerably less than the shipping weight that is given on Amazon. And honestly, I wouldn't waste the money on the DW660. (I'm not saying it itself is a waste of money just that if you intend to replace it in the near future there's no reason the spend the money on it. Go where you're going first time around.)
