Sunday, August 11, 2013

Spell Bounded

Earlier Reprap are Cartesian machine consisting of linear motion in X, Y & Z axis.
Plain vanilla in my eye...

Then the delta robot 3D printer shown up. Its love on 1st sight

Rostock by Johann in 2012 is earliest delta robot variant.. With many varients sprung off since its creation since. Namely Kossel, Delta-pi, Cerberus and others

BUT the 3DR by Richard Horne A.K.A Richrap is mesmerizing...
 I can see more reprap of delta format sprouting in a hurry.

Saturday, August 3, 2013

Reprap Rekindle

When I first discovered Reprap in 2005, I was a complete idiot in all thing electronics, microprocessors & even power electronics. Everything Reprap is like Holy, inevitably I idolize everything Reprap to the extend of superstitious...
Reprap Morgan, a parallel SCARA arm implemetation. Mesmerizing....
After a few year away from it, Looking at Reprap today, I see things very differently....

FDM (fused deposition modeling) is still the de-facto 3D printing form for the masses, mainly for its cost effective filament material & low tech nature, in layman terms its basically squeezing hot glue with your hot glue gun at places where you desire with great precision.

Reprap is no doubt a fantastic first step towards many better things to come.

Unfortunately there are many short coming due to many factors, you can say its the infancy period, you can say its cost related or even lack of it...

Mechanical Department
1) Structural Rigidity of almost all the Reprap pedigree fall short of my expectations. Maybe builders got too tired after they tried to figure out all the moving parts....
2) Most of the Linear motion schemes are either primitive or overly optimistic. There are plenty alternative to running plastic bush on rods...
3) Dynamic kinetics is far from from ideal
4) parts tolerance are overly compromised. screws studs aren't anywhere near precision engineering... not even near "proper" engineering... Reduce Vitamin count for the sake of reducing is irrational.
5) Hot end material & heating solution needs more finesse. I reckon J-head is right about there. 
6) Resolution can be tighter with rational implementation of speed reduction belt drive.
7) Can't say much about the assortment of extruders, can only comment after I played with them.

Electronics Department
1) Arduino computing speed is too modest by to day's standard.

Power Electronics Department
1) stepper motor are not optimized for it best performance or even not bothered with from what I observed. 
2) 1/2 step micro stepping IMHO produce jerky motion, better than full step, but still very jirky. 1/8 to 1/10 micro-steps should be ideal, unfortunately this is too much processing power for the Arduino to handle.
3) Regulated power supply isn't suitable for induction machine, including stepper motors.

Software Department
I'm still an idiot coder.... hence not qualified to comment...

Will I wet my head & plunge into another RepRap?
Let me do more reading & I'll have an answer.... some time....

3D Printer Rekindle

Reprap Project caught immediately the moment I laid my eye on it since end 2005. Believing it is the biggest thing since PC. But live intervene & I stopped looking at it since 2009.

Lately, the 3D printer movement has gain momentum & broke to the surface. Everywhere you look, you will find report of this wonderful thing.

OhmEye's video is a great introduction & orientation to 3D Printing