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.
http://www.nightmarefactory.com/cgi-bin/shopper?sku=IA83&search=action
I'm sure I'm not the only one that wants cheap material, so I thought I'd give everyone the link.
Happy reprapping.
~Dylan
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.
http://www.nightmarefactory.com/cgi-bin/shopper?sku=IA83&search=action
I'm sure I'm not the only one that wants cheap material, so I thought I'd give everyone the link.
Happy reprapping.
~Dylan
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
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 http://3DReplicators.com)
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 http://3DReplicators.com)
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)
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)
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)
Monday, April 28, 2008
First tests of the Haydon linear actuator stepper motor
The linear actuator stepper motor that I acquired arrived today. I slapped it on to the Tommelise 2 Big Board and it ran immediately without complaint.
What you see here is the board cycling it backwards and forwards for 240 steps with a 7 msec interval. It transitions at a rate of roughly 14.5 mm/sec at that setting.
In that it is like the other tin can steppers I've been working with. It can be made to run as fast as 17 mm/sec, but not reliably. A 7 msec interval is the fastest setting that it can operate at and deliver substantial force with no skipping.
The really amazing thing about this tin can stepper, however, is that it is dead silent. As you can recall from other videoclips I've posted the microphone on my camera is incredibly sensitive and made previous steppers and gearmotors I've taped sound very loud. This one you simply don't hear at all.
Mind, that is double what Darwin is currently achieving and means that it can print a maximum of roughly 0.8 kg of plastic in 24 hours.
(No additional content at 3DReplicators.com)
What you see here is the board cycling it backwards and forwards for 240 steps with a 7 msec interval. It transitions at a rate of roughly 14.5 mm/sec at that setting.
In that it is like the other tin can steppers I've been working with. It can be made to run as fast as 17 mm/sec, but not reliably. A 7 msec interval is the fastest setting that it can operate at and deliver substantial force with no skipping.
The really amazing thing about this tin can stepper, however, is that it is dead silent. As you can recall from other videoclips I've posted the microphone on my camera is incredibly sensitive and made previous steppers and gearmotors I've taped sound very loud. This one you simply don't hear at all.
Mind, that is double what Darwin is currently achieving and means that it can print a maximum of roughly 0.8 kg of plastic in 24 hours.
(No additional content at 3DReplicators.com)
Sunday, April 27, 2008
More PCB Plotting
I've done a bit more work on my Gerber (PCB) plotter. It now has a GUI! The script will show all the lines to be plotted, then colour them black in real-time as they are plotted.
I've also finally made myself a Y axis so I can now lift the pen.
The resolution on my repstrap is a little limited so i'm having to use quite large tracks and pads.
More photos on flickr
I've also finally made myself a Y axis so I can now lift the pen.
The resolution on my repstrap is a little limited so i'm having to use quite large tracks and pads.
More photos on flickr
