Sunday, April 19, 2009


Give me a wedgy

Hey all,

After placing my order for a Cupcake I have had a burst of design enthusiasm. I thought I'd have a crack at a the 'Wedge' design.

So after a whole Sunday and lots off caffeine here are the results.

The source blend file is here.

Still needs some work as there are some issues with the design.

1. The supports for the X axis do not have enough clearance from the frame.
2. No primary carriage ( need to investigate tool changer)
3. Not sure to use pully/belt drives or running threads.

I have tried to keep the number of unique parts to a minimum, however there are still some systems that need to be added.

Anyway I need some sleep , If this post is incoherent ramblings please feel safe to ignore it.

Phew , what a day. I hope some other reprappers get some inspiration from this design.

This comment has been removed by the author.
I'd like to see the drive system for both horizontal axes be based on a threaded rod, as a new builder, to alleviate the need for a belt tensioner.

I understand that this would require the creation of brand new brackets, and, as I am just now beginning work with Blender (why is it so hard??), I don't know how much more work that is.

Also, what with the inherent pull of the plastic on the top of the machine(if it's housed below), do we really need a NEMA17 mounted at the top of the printer? I wouldn't mind having the base be a bit thicker in the z dimension, so that the motor could be housed at the base. In addition, if the printing plate was made with a peg-and-hole fitting to the y axis chassis, we could remove the printing plate and gain access to an electronics level, room for which is made possible by giving space to the z-axis motor.

What I'm envisioning is a z axis motor just off the midline of the printer plate (the threaded rod driving it should be at the middle, with smooth rods on either side), with it's belt attached to two threaded rods running vertically.

Furthermore, would it be overkill to add a smooth rod adjacent to the z-threaded rod, maybe spaced 2-3 inches away from the drive rod, or 5-8 centimeters if you live in a smarter land. This would allow us to push the edges of machine out in the direction that the plate moves. The top bracket would be widened so that the diagonal supports wouldn't interfere with the additional guide bar.

I'm just starting out with this project and am going to be building the Wedge design in my dorm when I get to college, but I'm always happy to help out with ideas and a set of eyes new to the world of RepRap.
Two things:

First, that is going to need some cross-bracing for the Z axis supports.

Second, See if you can figure out how to do it using readily available angle instead of the polished round rod - as an option if you wish.

Vik :v)
I like your ideas there Vik, especially the angle iron. The wooden wedge looked fantastic with it.

What with the angles and all, I think he's using the same rods for the angles as he is for the cross supports, so it's not like we'll be cutting inch-long sections willie nillie during construction.

Looking closely now, I do worry about the rigidity of the supporting brackets. I know this is a roughed out idea (I do like how this model features at the least a car on the x-axis gantry), but maybe whilst constructing the brackets to mount the supports to, we could insert a nut into an inner cavity so that we can add a tightening screw to clamp down on the smooth bars around the structure.
Hi there. I think Vik is right, this design lacks of proper x-wise support for the top axis and it may lead to undesirable vibrations.

A cross brace is the cheapest way of fixing it but it may interfere with the movement of the piece being extruded. Another possibility would be to add two bars to drag the top from both sides of the machine but I'm unable to find a good way of doing this without having to modify the basement :-S

Good luck
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