ProfileMaker thoughts…

Looking at Dave’s Profileinator seems really well suited to a stepper extruder.  However, he also suggests adding a “Flow Fudge Factor.”  I just use this set to 1.0, so I’m not sure if I’m using it correctly.

Flow Fudge Factor: I have to enter 1.0 into the flow rate to get 2.0 RPMs on the extruder.. I got tired of doing this math so I added flow fudge factor and set it to 0.5. This doesn’t change the volume calculations – it just modifies the flow rate on the table. If you have a MK4/MK5 extruder with a DC motor, start this at 127.5 to get the PWM value to use

In any case, it looks like by multiplying it by 127.5 you can get the required flowrate for a DC motor.  In printing with a DC motor, I never wanted to drop the speed below 255, because the DC motor had such a small range of speeds.  I could print between about 230 – 255.  Given this, I can understand why so many others, probably using a DC motor, would rather pick their flowrate as 255 and then determine the proper feedrates.

ReplicatorG v0023 error

“This should never happen, deltaX in addValueSegmentToPixelTable in euclidean is 0.”

And, really, this is just one of MANY such errors.

Also, Marty was kind enough to slice it up in Zaggo’s Pleasant 3D software.  He took a look at the OpenSCAD code and didn’t see anything nasty in there.

I dunno.  Do you?

Argh.

I spent WAY too long this morning working on a post here…  got ready to hit print…  and was told by WordPress the post no longer existed.  Even better?  Every post and page on the entire site was gone.  Even better?  MySQL said the posts table had crashed.

I use a plugin that backs up this website regularly, so it wouldn’t have been tragic – just painful.  However the post I spent the morning working on was totally gone.  I was able to repair the posts table using the MySQL repair function, but that post was GONE.

That sucks.

November 18, 2010 | Comments Closed

Chess set: 1/4 complete

I’ve been working on printing a chess set today.

Yesterday I was troubleshooting my automated build platform.  I could use it reasonably well as a heated build platform, but the automated part was not working so well.  The main issues I was having were the thermistor only registered 255, the automated build platform only ran backwards1 , and the extrusion would not stick to the conveyor belt.

Believe me, some of these issues were incredibly dumb.  No worries, I’ll fill you in on the extent of my ignorance soon enough.  It’s not like I’ve got a finite supply, right?

I took out the automated build platform conveyor belt – and lost one of the little plastic bushings in the process.  I’m pretty sure I can rig a serviceable facsimile, but my printer has been down so much lately that I just want to actually PRINT things.  I’ll work on fixing up the automated build platform and troubleshooting it later.

So far I have, in black ABS, 8x pawns, 2x knights, 2x rooks, and am in the process of printing a bishop right now.  (I know that’s more than 1/4 of the way done – but I was 1/4 of the way when I started this post).

  1. WTF? []

Working on my automated build platform

I had some technical trouble with my automated build platform today.  (Yesterday?  Last night?  It all blurs.  :) )

I’ve fixed some problems and found others.

Right now I think there may be a slight kink in my filament spindle box.  The extruder motor kept running but no plastic came out in one build job.  I can successfully print using the ABP as a heated build platform – but it is only really successful with single print tasks.  More than that and it screws up the raft.

I’m tempted to lightly sand the automated build platform belt to see if that helps.  If not, a friend suggested using blue painter’s tape on the platform.  I’ll try the tape first tomorrow.

October 16, 2010 | Comments Closed

MakerBlock apologies

I’m not ignoring you, I swear.  I totally misconfigured my “Contact” page e-mail form plugin.

That’s not the worst part – I contributed a big chunk of the code to that plugin and really should have known better.

So, if you’ve tried to send me an e-mail, please try again.  :)

MakerBot Calibration

After my design-print failure I thought it was about time I recalibrated my ‘bot:

  1. Starting from scratch, I’m using the 0.5mm test pieces from Spacexula’s calibration set.  Before starting I set Skeinforge->Carve->Layer Thickness (mm) to 0.4.  Thus, I came to test piece 815.1.  The piece came out well, but I noticed that where the Z axis raises there is some slight blobbing and just before the blobbing, some sparse areas I can see through.  Otherwise, great interlayer adhesion.  The height of the piece is 10.25, 10.31, 10.30, 10.55.  Throwing out the high and low, there’s an average of 10.305mm.  It is 22.29mm x 22.29mm.
  2. Skeinforge->Carve->Layer Thickness (mm) to 0.38.  Test piece 815.2.  Again, slight blobbing, very small sparse areas and great interlayer adhesion.  Piece height is 10.39, 10.40, 10.18, 10.19, we’ll call this 10.29mm.  It is 22.41mm x 22.13mm.
  3. Skeinforge->Carve->Layer Thickness (mm) to 0.36.  Test piece 815.3.  Slight blobbing, very small sparse areas and great interlayer adhesion.  Piece height is 10.25, 10.31, 10.14, 10.30, we’ll call this 10.275mm.  This one was 22.33mm x 22.29mm.
August 15, 2010 | Comments Closed

Design-print fail

I’ve been slowly working on the design of a printable (and fully MakerBottable) sonic screwdriver.  This model of the sonic screwdriver is built up of a number of concentric cylinders, has several significant overhangs well in excess of 45 degrees, and is larger than the MakerBot’s built capacity.  In order to deal with these design problems, I modeled it in sections.

In order to make the overall result something I could just pop/snap/slide together I designed it making some sections which were split vertically and other sections which slide around those sections to keep them together.  In order to make the parts quickly printable I designed all the parts at around 0.5mm thickness.

About 40% of the way through the print one of the vertical sections wasn’t coming out properly – probably because it was too thin.  The parts were too thin and flexible and ended up tearing between layers and just being too flimsy.

I also noticed something odd – the extrusion was too thin on that side of the model.   I can’t be sure why this is happening – but I suspect it’s due to the extruder not getting a good enough grip.  Perhaps I need to floss the extruder pulley or install a new extruder idler wheel.  However, it doesn’t explain why the extrusion was too thin on just that one side and no other spots.

Suggestions?

How do upgrade your extruder firmware

Just as an FYI for anyone who’s having trouble upgrading your MakerBot Cupcake CNC plastruder firmware, the instructions built into ReplicatorG don’t tell you to unplug the TTL cable from the motherboard and plug it into the extruder board.

So, save yourself 5 minutes of frustration and googling for the answer…  and just plug the TTL cable into the extruder board.  :)

April 25, 2010 | Comments Closed