Tuesday, June 26, 2012

Simpleton Dimensions

Okay, first data points on the Simpleton design:

200mm x 200mm x 200mm working volume, give or take.
400mm x 400mm desk footprint, but does want to drop over the edge a bit.

Tests with an electric drill, while frankly terrifying, confirmed that things will rotate in a stable manner at speed. I'm only expecting to see 20mm/s out of this, which is nigh on 1,000RPM for the M8 shaft, though only about 300RPM for the actual stepper motor. For comparison, a Mendel X axis is typically doing about 100RPM.

This all dictates that I'm going to need an Arduino Mega to flip the steps fast enough, and that  I'll not be doing much in the way of micro-stepping. This is cool: It raises the possibility of cheap and simple stepper motor drivers for those building "in the wild."

No pictures today as the thing is in bits: I'm replacing the Z motor corner. The only screws involved are the ones that screw in to the Z motor itself. The rest is done by mallet. Hammerrrrrrr!

Sunday, June 10, 2012

"Patches" is born

So the Simpleton design is progressing. Suz named it "Patches" after the wide variety of colours that seem to have become integrated with it.

In short, it's all coming together. The lower bearings for the Z drive screws are out of position by 10mm and the platform still raises and lowers smoothly, which bodes well for when I get it right.

The bearing brackets on the transverse drive shaft are  a bit flimsy, the wall that the Z motor is mounted on has an unwanted beam in it, and the motor that slides the deposition bed back and forth is about 20mm too low. A few more parts can be integrated and fasteners removed when I get the positioning finalised. No show stoppers though.

In about a month there should be some design files worth sharing with the world.

Tuesday, June 5, 2012

Back to R&D, phew!

Finally got to spend some more time working on my new RepRap design, so I guess I owe people a picture. We've been busy reorganising our business, looking for new premises, increasing our production volumes of PLA at Diamond Age Solutions and developing new stock. Anyhow, thanks to Her Majesty giving me an extra day off, The Simpleton design is now back on track.

As you can see, I'm opting for bevel gears to drive a cantilevered Z axis that in turn supports a cantilevered Y bed. The smooth tubing is all extruded aluminium, and both Z and Y axes have 608 bearings. Nothing is yet in its final place, and I still haven't designed the actual Y bed, but this baby is going to turn heads when she's done.

Yes I am using rather a lot of threaded rod still - it's the material for the job and because of the cantilevering I actually want a bit of weight in places. But there are a lot of places where the lighter aluminium tube can be used, and a few where it can be replaced with lengths of bamboo or whatever you have handy!