Experimenting with Mendel Z-axis capacity

I've been staring at my RepRapPro Mendel Legacy printer lately contemplating modifications that might increase the usable Z-axis range. Several thoughts that have come to mind, which I'm considering:

* Upgrade to new X-axis design which is narrower and moves the (now MXL) belt to inside the carriage. I've printed the parts and have all the miscellaneous parts to complete the upgrade.

* Relocate the extruder assemblies to move the stepper motor bodies up and outside of the main frame of the printer to increase usable space. Contemplating rotating them 45-90 degrees forward and modifying the mounting clips to raise them and hold them in place above the frame.

* Modify the y-axis belt fastening clamp pieces to reduce their height and add usable clearance between the frog and bed (slightly lower the bed height above frog.) This seems to have already been implemented with a slight redesign on the current Mendel Mono/Tri. Can the belt be clamped on the under side of the frog instead of the top to maximize clearance?

* Modify the printed U clips that hold the Y-axis smooth rods (redesign them so they hang the Y smooth rods lower from the threaded rod as low as clearance will allow.) There's a fair bit of unused space under there that might be useful (poss. down to the middle cross threaded rod, which could be lowered, but would necessitate extending the Z smooth rods.) This would probably necessitate changing the belt bearings arrangement and/or the routing to some degree. May also shorten Y-axis travel range as frog/bed approach interfering with the horizontal threaded rods front and rear. Though looking at it, you might get the bed to run under the top front threaded rod with no issue. There seems to be plenty of unused z-axis threaded rod travel to allow this. Maybe design a part that extends between the front horizontal threaded rods that holds the Y-axis smooth rod in place.

* Flip the printed bearing holders upside down and swap sides (modify part so that nut trap is on opposite face), mount the frog slung underneath the Y-axis smooth rods, then mount the bed as usual. Probably would want to move the motor/bearing/belt assembly over to the right side of the printer as well.

I've seen an extensive redesign of the top of the frame to extend the Z-axis travel, I'll save that approach for later.
[www.thingiverse.com]

Has anyone contemplated or executed any of these changes? Thoughts? Other ideas?

For all the new printed parts and time invested in reassembling the printer, I think you'd get a lot more for your effort by converting to a Prusa i3.

Just trying to push the print envelope of this printer a bit. $600-$1200 plus shipping for a Prusa i3 DIY kit would cover a whole lot of printing and tweaking time, blood, sweat, and tears.

* Relocate the extruder assemblies to move the stepper motor bodies up and outside of the main frame of the printer to increase usable space. Contemplating rotating them 45-90 degrees forward and modifying the mounting clips to raise them and hold them in place above the frame

Yup that's a simple fix lots of people have done with a few bracket designs to help with this on thingiverse incuding my own

[www.thingiverse.com]

Ben

I have just increased my Mendel Z height by 40% with virtually no re-engineering :-)

Check my recently poseted Thingiverse for details.

[www.thingiverse.com]

BR,
Steve

I have documented different extruder positions (new style extruders) and updating the Legacy Mendel with the new axis here:
[reprappro.com]

For the Y axis, you can lower the bed a bit by removing the belt adjuster, and using clamps similart to the Tricolour. You may need an 'inline' belt adjuster, like [www.thingiverse.com]

Ian
RepRapPro tech support