Open Rail, Or, Why Didn’t We Think Of This?

Hackaday readers familiar with the with the CNC and automated machinery scene will be familiar with MakerSlide, the open-source linear bearing system. This linear movement system composed of special aluminum extrusions and mounting plates riding on v-wheels has been used in a lot of awesome builds including the Quantum ORD Bot 3D printer and the Shapeoko CNC router. If there’s one downside to the MakerSlide, it’s the hard-to-source aluminum extrusion with the requisite v-wheel guides. [Mark] and [Trish] of Phlatboyz have an ingenious solution to this problem: just have bolt-on v-wheel guides. It’s an idea so simple we’re kicking ourselves for not thinking of it first.

Open Rail is completely compatible with the MakerSlide linear bearing system. Instead of requiring a special aluminum extrusion, the Open rail system uses regular, plain-jane aluminum extrusions available at any reputable hardware store. Just pop a few t-nut into the Open Rail and attach it to your extrusion. Couldn’t be easier.

Considering how easy it is to find surplus aluminum extrusion, we’ll expect a few gigantic MakerSlide and Open Rail derived CNC projects in the very near future.

54 thoughts on “Open Rail, Or, Why Didn’t We Think Of This?

  1. How is this any different? It’s just replacing one specialized extrusion with a different specialized extrusion. It’s not any better, just a different approach.

      1. It’s not specialized – it’s VERY common aluminum extrusion. The makerslide is specialized – only one very small quantity manufacturer makes it has it made for them.

      2. I’m not arguing the fact that the 80/20 extrusion part is common but that the _rail_ itself is still a specialized extruded part. Either way you are still relying on one source for that specialized part.

        1. Apparently you don’t understand that complexity of the extrusion has a HUGE bearing on who has the capability of making it, and cost, etc, etc. If you only have to make a single extrusion, and can then use it with the COUNTLESS other framing extrusions that are already available, it’s a definite win.

          It has its own set of downsides, but availability/manufacturability isn’t among them.

  2. It’s been around forever already in hardened steel. You can buy a foot of it at McMaster Carr for under $10. Search them for the string “v rail” and this should come up:

    It’s a good idea, but it’s already been thought of and sold for a long time now. It’s even the same lipped contour, so I’m guessing that they probably saw it somewhere and thought they invented it. It wouldn’t be the first time. I’ve re-invented the wheel a few times in my life too.

      1. You people with your aluminum. There is a good reason for using steel: rigidity. You might not need it, but s.o. out there will want to use machines for steel aswell, not only for softer metals which really restrict you to low torque and low force applications (or you go super-big).

    1. This is true, the whole reason Bart came up with makerslide was to simplify the process and to try to make it cheaper. The idea of bolting v-rail to extrusion is the old standard, not new.

  3. Why is this a kickstarter project?

    The parts are available at any hardware store. Also anyone capable of working with this Open Rail is capable of building this open rail.

    This gives me a great idea for a kickstarter project of my own. I’ll call it Apple for the world. I’ll make some crappy video and then say anyone who pledges $15 will get sent an Apple ex shipping of course. I will naturally work with suppliers to get the cheapest possible Apple and then go take the profits and buy some chocolate.

    Still more useful than this kickstarter project.

  4. True this has been around for awhile. That’s why there are off the self components such as this page from McMaster-Carr

    This has the rollers and the rail on the same page. Don’t know if the rail has holes already in it but that can be addressed.
    I have some maker rail, I may use the steel rails on the gantry since I am concerned about the stress on an aluminum v-groove.

    1. Ouch. I should have looked closer the rail is not bad at McMaster but the rollers. Those seem expensive. Any suggestions on a cheaper v-groove roller.

      What they are doing is another option for people who access to surplus or scrap extrusion.

    2. Thanks for the link. This looks useful but the lack of pre-drilled holes could be a problem. One can’t hope to use a drill press and get the kind of accuracy you’d want for such a critical component of a CNC setup.

      – Robot

      1. I realize I’m a little behind the curve here but if you’re using the bolt holes for reference you’re doing it wrong. The V-rail has a precision lip on the backside that references the part and the bolts simply secure it. Like a wheel on a modern car. The concentric ring does the locating and the bolts simply keep the wheel from falling off.

  5. Bishop Wisecarver

    The stuff isn’t crazy cheap, but it’s durable, will run under the nastiest conditions, and it’s really easy to design around. I’ve been using this stuff on industrial systems for years now.

    They sell everything from basic components all the way up to fully assembled tracks.

  6. Hey guys, Mark and Trish here from the Open Rail project. We would like to clear up a few things and hopefully answer some of the questions you have.

    As it has been pointed out, bolt on v groove rails are nothing new to the cnc world and most of us are familiar with them. . Intergrated v rails like the MakerSlide system have been around and available as well. But both Open Rail and Makeslide have put their own spin on proven designs.

    A few key features that make the OpenRail attractive to the Maker in us all, is the ability to span the t-slot with pre-drilled holes and use t-nuts for easy mounting to t-slot extrusion.

    Open Rail will be hard coat anodized (harder than tool steel)

    The Open Rail system is versatile in that it has the ability to overlap and create a single double v rail extrusion system as well as fit onto other extrusion configurations.

    But most of all, what we feel is the most important and exciting aspect of the Open Rail system is the ability to bring this to the open source world so that others can build from it. Our intention is to share this idea completely with everyone who wants to create with it. When the drawings are final they will be open to anyone who wants to create the Open Rail. There are no commercial limitations so small maker businesses are free to sell these extrusions to help further seed this system to others. We are working to have dies made overseas so that the guys over there will not have to pay large shipping to have an inexpensive and customizable linear rail system for making their next cool projects.

    So, yes, the Open Rail is not an earth shattering new discovery. Its built up on from others ideas, like most ideas and creations are, but we feel its a step in the right direction to making what was once out of our reach, possible.

    Hope this helps in seeing what our intentions are for sharing the Open Rail idea with the community. We think it’s awesome and we have so many plans to build and share machines using it. Our Kickstarter project is fully funded and we are moving forward with it. We couldn’t be happier as we believe Open Rail will help many people, like ourselves, complete their projects and achieve their goals.

    Mark and Trish

    1. You should read that a little better. The rockwell C is the same as a hardened tool steel which reaches well above 65-70C before it is tempered. The other thing you fail to mention…its only going to be ~.005 thick. Tool steel is 65-70C through the whole part(depending on cross section) but it is still holding more than the anodizing.

  7. Except you can’t actually buy any Makerslide, at least not in a timely fashion.

    I check into it from time to time when it’s mentioned here. It’s always been out of stock. Best I can tell, it’s still operating on a batch pre-order system, with six week lead time.

    Which is exactly the situation I thought collecting an initial round of funds on Kickstarter was supposed to solve. From their website:

    “The goal is to have material, wheels and carriages in stock so builders can quickly get it cut to length and ready to install.”

    They greatly exceeded their Kickstarter goal, raising $26,268 instead of the required $5,900. Yet still haven’t fulfilled the stated goal, a year later. Fail.

  8. I’ve been on he buildlog forum since the 1.0 build (and did my own 1.0) and you have completely missed the point.

    We were all doing this before makerslide. Bolting v rails is fairly time consumimng, less accurate and far more expensive than buying a length of makerslide.

    The makerslide profile was based on attaching v-rail to 40-20 and is identical to this “homemade” makerslide.

  9. Is there any compelling reason why this rail system can’t be two plates suitably profiled to accept the V bearings bolted to a piece of wood? Laminated oak or maple is dimensionally stable, can be machined as straight or straighter than some random extrusion from the surplus pile, and its -cheap-.

  10. I’m happy to see more people pushing for open source frame and carriage hardware plans since the motor control seems so well fleshed out.
    However I do wish people would invest as much in their Kickstarter presentation as they have in the details of the project they are attempting to present. Open Rail will do well because so many people are hungry for better framing hardware for their CNC project, but the video for Open Rail has no introduction, no explanation, admittedly no script. Please, people– write AT LEAST an outline! Get to the point! Do multiple takes!

  11. I deal with machinery all day long and still don’t “get” the benefits. I wish the project all the best and hope they have fun and make profit. But if it were me, I’d still prefer to just buy the hardened steel ones for less money over aluminum ones. I’ve drilled the hardened steel ones and they are still plenty machinable. Just have to spin the drill bit slower than for mild steel.

    Hard anodizing only goes so deep (not very) so when it wears under that layer you’re into raw aluminum. Wear may not happen very fast thus not a big deal depending on the machine.

    As for pre-drilled holes, it is an inherent thing with thru holes for screws/bolts that there is clearance. Also, screws/bolts are slightly undersize when properly made, so add it up and there is plenty of clearance for things to move around slightly. The point is pre-drilled holes aren’t going to help you align anything perfectly. The alignment is made by butting the step up against the corner of the block you’re bolting it to – simple. If you want to double-check you can do that with a cheap $15 caliper and adjust a bit if necessary – also simple.

    Anyways, good luck to these folks. Aluminum rails like this don’t exist (for sale) so maybe there’s a niche for them.

    1. The whole concept of having an “open source” linear rail is cool and all, but completely impractical.

      There are plenty of linear systems out there as previously stated. What isn’t really stated is the tolerances. the tolerance stackup of these rails is going to be enormous and you’ll have spent comparable money to get much worse repeatability. Bearing and guide companies like RollOn, Winkel, PBC, an Thomas have had many years to get their costs down and keep their tolerances low.

      For an individual or a few individuals trying to get the same quality and precision of any bearing is ludicrous. Bearing manufactures consistently manufacture bearings with tolerances in the realm of 0.2-5 MICRONS. Your anodizing alone will blow any tolerance you might have wanted. And then when you bolt it to an aluminum extrusion, say goodbye to repeatability.

      I appreciate the effort, however, this is an exercise in futility.

  12. Greetings Hack A Day readers,
    First things first. I’m an engineer at Bishop-Wisecarver. This discussion caught my attention and I wanted to respond to this concept.
    A big thankx to driedsponge for the BWC link, to Tony for the recommendation to buy from BWC, and to Vinito64 and Wm-Atl for the McMaster Carr link.
    Bishop-Wisecarver invented the 90-degree vee groove linear guide wheel and track combination which is sold under the Dual-Vee product line. The linear guide track products are available in 1045 carbon steel and 420 stainless steel in the soft condition as well as in the hardened condition. Dual-Vee track can be supplied with or without holes and in custom length configurations in quick lead-times. We stock standard catalog products for immediate shipment and can make-to-order custom tracks which ship within a few days from our factory in California. The hardened steel tracks are extremely durable and will last for many years in light-duty applications. Dual-Vee is the best solution for industrial grade machinery applications.
    Please keep your eyes on us over the next few months. We recently launched a new 90-degree guide wheel under our MadeWell product line which is much more affordable and intended for light duty applications. We call this new product the MadeWell Radial Wheel as it is a simplified design of a single row deep groove ball bearing design intended for primarily radial loading application. Call us to get a price quote on these. You will be surprised.
    May all of your designs and builds be successful!
    Engineer @ Bishop-Wisecarver

  13. Hey guys,

    After doing some searching for different extrusion profiles, we found that by adding an oblong hole pattern to the OpenRail we were able to make the OpenRail compatible with a lot more extrusion profiles out there from many different companies. We only did a few as an example but we are sure there are more. It looks like all the 20mm and now 25 mm profiles will work! So this is really exciting news for us all. This allows you to use extrusion local to your country as well as give us all a much larger selection of many unique profiles available from lots of different companies out there.
    We are still in the process of finalizing the design but this is a great leap in the right direction!

    You can check out some of the pics here:

    We have also added a new updated file to the Thingiverse page as well.

    Here are a few of the extrusion profile companies that we have tried to use the Open Rail system with so far:
    MK –

    Bosch –

    8020 –

    Misumi –

    OpenBeam –

    MakerBeam –

    Thank you
    Mark and Trish

  14. Aluminum v groove rail has been on the market for two years. sells hard coat anodizes track but its not some goofy kickstarter project so you dont knoe about it, just a biz that sells rail for two bucks a foot.

    1. I agree – these baby rails are useful only for very small machines. One option might be to use a Series 20 rail in a 4040 or 4080 configuration. It is a 40mmx40mm/80mm extrusion with spacing compatible with these v-rails. I may try this as the cost is very reasonable.

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