by Barton Dring
is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License
Based on a work at www.makerslide.com
The biggest design, cost and fabrication hurdles in a new CNC design are the linear bearings. There are a lot of commercial and DIY solutions out there, but none support an easy, low cost and rapid fabrication philosphy. I want to create a solution to this. The idea is to use a method that seamlessly integrates into standard alumunum extrusion systems.
The basic bearing concept is not new. I have used it for years in my own designs and many high end commercial systems use it. It is the V wheel running on V rail. The problem with the commercial systems is that they are expensive, require a lot of accurate fabrication to integrate and don't seamlessly integrate into standard extrusion systems.
MakerSlide is a V rail integrated into a standard extrusion profile. Since it is based on a standard profile from several sources.
Go to the Kickstarter page and donate!
The goal is to have material, wheels and carriages in stock so builders can quickly get it cut to length and ready to install. The target cost for the extrusion is a penny a millimeter or about $3.00/ft. The wheels will be in the $2-$3 range.
Where the money go.
- Extrusion Tool. - The extrusion tool and expenses related to selecting the suppier.
- Initial Buy - The minumum buy for most extruders is about 1,000 lbs of material .
- Carriages. - Several types of univeral carrige parts will be procured.
- Wheels - At least two types of wheel designs will be procured.
- Cutting Tools - Tools for accurately and cleanly cutting the the raw material into precise lengths will be procured. This will most likely be an industrial chop/cold saw or horizontal band saw.
- MakerShip Program. - Give back to the the open source communitee. (see next paragraph)
This is available to any level supporter. Submit a new, innovative or interesting open source design or basic idea that uses the material and I will supply enough to build a prototype. You pay for shipping only. All you need to do is submit something visually presentable, via sketch, rendering, etc. The purpose is to generate a little excitement and some good ideas. All worthy ideas will be posted. A building sized XY plotter might be a great idea, but prototyping it a smaller scale would be a better idea :-) I will be the sole final judge of winners and there is no preset maximum or minimum number of winners. This assumes the project gets fully funded of course.
Depending on the success of the project, this may continue after the initial program completes. I already help sponsor some innovative projects on buildlog.net with materials and fabrication and would like to continue that.
The MakerSlide idea has been kicked around the buildlog.net web site for nearly half a year now and has gone through several minor changes. I'll describe how we arrived at the final configuration.
- Basic Profile - The idea was to make the profile directly compatible with existing extrusions. This allows us to tap into thousands of readily available accessories like brackets, hinges and t-nuts. These extrusuions are avialble from multiple vendors world wide.
- V Location - The center of the V was centered on the edge of the extrusion. This moves it away from the t slot enough that you can place a mounting bracket on that surface. The location also makes alignment and design easy because it is an easy plane to reference.
- Open Side - The side with the v grooves was left flat without any radius to the V. This allows a plain 20x40 extrusion to butt into the MakerSlide extrusion. That is a design feature that I found found essencial in many design ideas.
- One V Face Groove - The face with the V on it went through several iterations. For ultimate strength in compression, you would want it flat, without any slots, but the slots are very handy for mounting items in designs. I decided to leave one slot. The MakerSlide design is based on the fact that one side of the carriage has fixed wheels. This is the reference side. The other side wheels move in to tension the system. You want the fixed wheel side taking the greatest load where it was not symetrical. There are drill guides along the flat faces, but the whole concept of MakerSlide is rapid design with minimal drilling and tapping. In reality, even the slotted side is quite strong anyway.
- Wheel Spacing - The height of the V was chosen to make it compatible with the existing, separate rail and extrusion system that many people use including the 2.x laser.
- Derail Notch - Machine or sand a notch into one v rail. This allows you to derail a carriage and remove/replace it. A laser cutter could become a plotter or 3D printer.
- Drive Methods
- Belt Drive -
- Rack and pinion.
- Lead Screw
- Traction Wheel
- Open Ended Belt -
- Stationary Wheels - The carriage does not need to be the moving item, the Makerslide could be the moving item. A deep plunging Z axis might use this method.
- Telescoping - Stack MakerSlide, carraige, MakerSlide and you can telescope.
- Join Rails- MakerSlide extrusions could be placed end to end for a really long slide.
- What is the spacing between the wheels? - 64.4mm
- How much adjustment is in the eccentric spacers? - About 1.5mm maximum
- What is the maximum length of the extrusion available? - That is to be determined. It is more of a logistical issue than production issue. The extruder will do 6 meters or longer, but transportation and storage issues will probably limit it to 3-5 meters.
- What suppliers have compatible extrusions? - Here is a list of a few with 20mm based systems.
Mechanical Properties (calculated)
Send comments, suggestions, corrections to firstname.lastname@example.org