Light-weight Extruder & Printable X carriage Released

[crispyfry]

http://www.thingiverse.com/thing:27234

CAD View

Main advantage over the wades style is the mass is much less, and kept much closer to the wheels. This drastically reduces oscillations in the print head. The reduced mass should enable higher travel speeds.

I haven't been able to test it much because I cooked my X axis stepper driver.

As it says in the instructions, the x carriage NEEDS to be PLA. ABS is simply not stiff enough to maintain the dimensional precision required.

A word of caution about the motor: it runs hot, and requires a 40mm cooling fan. The motor can be found here: http://store.trinitylabs.com/trinitylab ... d-options/

[Enraged]

looks good. I'd print one if I wasn't getting the Kickstarter ones. I like how you integrated all the Makerslide mounts and the belt mount.

[dzach]

Main advantage over the wades style is the mass is much less, and kept much closer to the wheels. This drastically reduces oscillations in the print head. The reduced mass should enable higher travel speeds.

What a brilliant idea!
Replaceable X carriages for different print/mill/plotter/anything heads. One only needs spare V wheels and eccentric spacers and a printable X carriage.
So simple and so elegant, thank you crispyfry !

Now, where can one buy these spare parts? Inventables charge $73.06 for a set of 5 V-wheel kits + shipping to Europe.
This sounds like the best way to kill makerslide once and for all, and all possible new and innovative uses of an ORDbot with it
Except if there is another source for these spare parts that I don't know yet.

EDIT:

FreeCAD cannot load the STL files, but can open the STEP file, so I got the parts from there.

[dzach]

Here is a picture of the concept "printable X carriage plate" that crispyfry created for the ORDbot PG35L Extruder & X Carriage

and something like this could be used to mount a spindle or a pen:

[crispyfry]

Glad you guys like it.

I updated the instructions with some more details on how it goes together, and 2 pictures of the prototype I printed. Please let me know if you have questions on assembly, so I know what is unclear.

Please remember that this is untested hardware - I have not had the opportunity to print with this extruder or carriage yet.

[dzach]

I don't know if the ORDbot assembly STL file I got from the wiki is up to date but it shows a mismatch with the carriage plate openings for the belt:

It would be nice to be able to change the carriage quickly by just unscrewing the one screw holding the idler wheel bracket. That would be possible if the belt wasn't necessary to pass though the carriage openings, but the openings are obviously there to make the plate stronger.

[crispyfry]

...shows a mismatch with the carriage plate openings for the belt:

First, in the picture you've got the plate on upside down - the single wheel should be on the bottom (yes, in the CAD my coordinate system is upside down). Second, I'm using slightly larger pulleys than the standard ORDbot kit and these slots were spaced accordingly. If you're using T2.5 belts I don't think the teeth will catch on the edges of the opening much. T5 or similar belts may have issues.

You could try moving the features in the solidworks model, I'm not sure how badly this will break things. Making the belt pass-throughs required several steps so it may be a pain to adjust their spacing.

It would be nice to be able to change the carriage quickly by just unscrewing the one screw holding the idler wheel bracket.

It took me a minute to figure out what you meant. I don't anticipate removing the carriage that often, so this wasn't a concern during the design.
EDIT: It's easier to remove the idler plate and just slide the carriage off the end of the axis. This way you don't have to re-adjust the eccentric spacer every time as well.

[dzach]

The upside down plate is just one 'variation on a theme' based on your carriage plate idea. It doesn't matter which way is up for the distance between the openings, they are wider than the STP file in the wiki. My Hadron belts and pulleys are the standard MXL ones.

In any case, when I print the plate I'll probably use FreeCAD and copy your details which look quite functional.

EDIT: It's easier to remove the idler plate and just slide the carriage off the end of the axis. This way you don't have to re-adjust the eccentric spacer every time as well.

Why would one have to adjust the eccentric spacer? Each carriage plate would have its own set of V wheels and eccentric spacer and would carry them with it when removed. The next time the same carriage will need to be mounted it will just slide in the extrusion without a change.

EDIT:

I think I forgot that the belt is screwed on the plate, in which case the gaps don't matter at all if the belt itself has to be screwed/unscrewed on the belt clamp.

[crispyfry]

Based on the behavior during calibration I anticipate one major redesign to better cope with the bending moments the v-wheels exert on the wheel plate. May have time to get to it this weekend...

[gazorp]

This project is really awesome!

Cant wait to try the final version!