Cyberwizzards Alternative X-end
by Cyberwizzard, published
In an attempt to upgrade my Mendel to a MendelMax alike X axis (where the X belt is 90 degrees rotated like the Pruse belt path) I redesigned the X-ends to hold a 22mm trapezoid or ACME nut.
Aditionally, I added a tensioner system in order to be able to modify belt tension on the X axis without abusing the carriage attachment for that.
The goal is to use the original Mendel length of smooth rod. As such the block is a fair bit longer than some of the MendelMax designs I have seen; this allows the tensioner system to be placed on it as well.
- Modelled in SolidWorks 2012
- Uses 2 LM8UU bearings
- Bearings are clamped down with 2x 3mm screws
- Rods are clamped down with 2x 4mm screws
- Uses 4x 608 bearings for the belt path
Why not in OpenSCAD? Because prototyping and fitting things together is a breeze in SW - as soon as I work out the issues with this design I will put up a link to the design with an OpenSCAD version as well.
There are 2 versions of this design, one with nice curves and one with a square base block. The rounded version turned out to be impossible to print in one piece using ABS; splitting it into two halves did not help much.
The normal version is using a square base and has much material removed in an attempt to reduce warping and decrease print times.
Both designs most likely require a heated chamber and/or the use of PLA to print properly; as I only have ABS at the moment and only a heated bed I can not get this to print straight.
Words of Wisdom
I have posted this for inspiration and as a base for another iteration of this design. It should fit a Mendel (standard rod length) and MendelMax (assuming your rods are long enough).
The distance between the centers of the smooth rod and trapezoid spindle is 29mm, NOT 30mm like on the... errr... prusa?
- Use a heated chamber with ABS or PLA if you have non-warping plastic.
- Print the rounded version without support
- Print the normal version with support as the clamping section is sticking out in thin air
- Print a tensioner bracket and push block
- Put a 40mm bolt through the tensioner block from the back, through the tensioner, add the push block, a washer and a nut
- Optionally: use a longer bolt, add a spring to generate an even tension (use a strong spring or you will induce back-lash!)
- Optionally: print a second tensioner bracket and insert it into the second holder on the other side of the body. Use a longer 8mm bolt or threaded rod to extend from the primary tensioner to the secondary tensioner. This should allow for more force on the tensioner before it breaks.