Saturday, May 31, 2008


Writing and reading on the 24FC1025 EEPROM

Writing to and reading from the 24FC1025 EEPROM proves trivial... read more

Sunday, May 25, 2008


Building and running the T2 x-axis

After getting the y-axis running, building and testing the x-axis was almost a snap... read more

Friday, May 23, 2008


Running the Tommelise 2.0 y-axis

It appears that the Haydon 26000 series linear stepper is more than adequate to run the y-axis... read more

Thursday, May 22, 2008


Building the y-axis table for T2

Stealing ideas from the McWire CNC makes the work go quickly... read more


Tuesday, May 20, 2008


T2 takes shape

Work begins on Tommelise 2.0's y-axis... read more


Partial replication. First functional parts printed!

"If I can build a RepRap Darwin, I can build almost any machine."

-- Me

Because of the experience I got from it, and because of the fabrication possibilities it creates. This was one reason for me to start this project. There are many more, but I wish to share results, not philosophy (at least not now). Ten days ago I had completed the build of the machine (with many time lapses of builds of sub-assemblies). Yesterday I printed a pretty decent mini-mug. This was proof-of-concept 'working', but the prints were of mediocre quality (nothing was configured or calibrated yet). Now I'm able to print functional parts for more machines! (And I even had other things to do!)

First functional printed part!
Printed the optoswitch bracket as end-stop for the Z-axis.

My first functional print (see pic on the right) may also offer an inspirational way to make the undocumented Z-EndStop (the Z-origin is documented)

The part required some cutting and a drill to make the holes (for the screw) that should have been there. Right now, where my RepRap attempts to print a hole (nothing should be there) it prints more than anywhere else: a complete fill with plastic. This is because the outline is really thick and because of the curvature takes longer to process than a straight line. I thought that AngleSpeedFactor might need to be lower, but this didn't change it much (yet).

I'm printing in HDPE, and through the time lapses I make you can clearly see the material shrink causing the warping. If this happens a lot, the object will detach, even with my sandpaper-hairspray combination to adjust the stickiness. Also in this video, you'll see that the X opto flag is perhaps too thin to print? It doesn't attempt to print a layer that is too thin? Any ideas? The part was not designed to be printed on its side, which it could be (as a work-around).

If you like, take a look at the RepRap section of my Blog.

Labels: , , ,

Monday, May 19, 2008


Tuning the voltage on the Haydon Series 26000 linear stepper

Results from running the Haydon series 26000 linear stepper at its design voltage... read more


Testing the Haydon 26000 series linear stepper motor

The performance of the used 26000 series linear stepper motors proves much better than expected... read more

Friday, May 16, 2008


Cheap capa in the USA

I'm having problems getting the right tools to make the parts I need, so I'll show you guys my progress later.
In the mean time I found a cheaper place than what's listed on the reprap Polymorph page.
The stuff from The Compleat Sculptor (28oz) was the lowest price, but must have changed prices since the reprap page was made, because now it's $41.99 for 28oz. I found a place that sells it cheaper than the other 2 places listed for the US also.

The nightmare factory, a costume and halloween store have a 28oz jar for $30.
I'm sure I'm not the only one that wants cheap material, so I thought I'd give everyone the link.

Happy reprapping.



Showing our Darwin Repstrap in Providence RI DC401

my son and I presented our RepStrap at the May DC401 meeting to a good sized group.


Wiring up the 24FC1025 EEPROM

Integrating the 24FC1025 EEPROM on an existing board proves much easier than expected... read more

Sunday, May 11, 2008


Breaking the PC/Microcontroller comms bottleneck

I2C EEPROMS offer the possibility of cheap, huge byte buckets to even out comms flows from the PC to Tommelise 2.0 (T2)... read more

Tuesday, May 06, 2008


Good to go

My hand full of used 26000 series linear actuators arrived yesterday. While they had no lead screws, I was able to wire one up and assure myself that one, at least, wasn't broken.

Here is a look at the 26000's alongside of the 36000 that I already own.

Being native bipolar rather than unipolar as my 36000 series unit is the 26000's are near as powerful as it is. Having the 26000's in-hand I was able to verify that they require a 0.002"/step lead screw rather than the 0.004"/step lead screw that the 36000 does.

This morning I called in an order for six feet uncut of each of the two types of lead screw. When it arrives I should be able to build Tommelise 2 quite quickly.

(No additional content at

Sunday, May 04, 2008


Nophead spots a major boo boo...

I began with a kidney stone on Thursday morning and have been on pain meds the whole weekend. The smooth muscle pain meds make me feel like my head is in a sack of unwashed wool.

Chris (nophead) noticed that although I was trying to measure the HDPE/aluminum friction coefficient, I'd neglected to take the HDPE cutting board out of the polythene bag it was in. He said...

I read somewhere that the coefficient for friction for HDPE is not far behind PTFE but it looks like your chopping board was still in its bag when you did the first test. Mind you I just got a new chopping board which is black like yours and it is labeled PE LLD which I assume is LLDPE.

After a few moments of disbelief that I could have done something so stupid I finally accepted that he was right and redid the experiment.

(Read the whole story)

Saturday, May 03, 2008


Figuring required thrusts for linear actuators

Linear actuators typically provide thrust charts taking a form not unlike this.

The different traces on the chart indicate the amount of thrust vs step rate that you can expect for a particular amount of linear travel/step.

(Read the whole story)

This page is powered by Blogger. Isn't yours?

Subscribe to
Posts [Atom]