20100716

http://lcamtuf.coredump.cx/guerrilla_cnc1.shtml

... I should build a mill, instead of 3D printer... sounds like they are strictly superior ?

20100715

I'm really, really tired of Ubuntu automatic updates breaking my NVIDIA drivers. This happens every time there is a major update. For a while it was ok, because the hacks to correct it were constant. Now they've changed something else and the usual config tweaks don't work.


ok, I get it

-- there are no default NVIDIA drivers for ubuntu
-- drivers are kernel modules and need to become part of a kernel
-- every time ubuntu updates to a new kernel, it doesn't have the NVIDA module built for it yet
-- so, every time ubuntu updates its kernel you will have to rebuild your driver modules

and, these sites explain where to put the new config tweaks [1,2,3]

20100712

MakerBot Note :

even with a properly working extruder, I sometimes strip filament, usually either extruding too cold or crashing the nozzle into the stage.

for a while, I was taking out the motor to clean it, which took.. a very long time.

I just realized that an unfolded paperclip will do the job without disassembling anything. just back out the filament, then keep the motor turning and pick around with the paperclip. It seems fairly easy to dislodge the plastic from the teeth and push it down into the barrel. This has already saved me a lot of time.

or.. did everyone else know this and I just missed the note ?

20100708

MakerBot Note :

MakerBot is printing again, but I'm not going to rescind my posts of frustration just yet.

It turns out the problem was that my threaded Z rods were really bent. Most MakerBot rods apparently are. This was causing a wobble, which was causing a variance in the tension of my Z belt.

Solution : rotate each Z rod such that its wobble is in phase with the other. Then, when they wobble about, they will all move in the same direction at the same time. This causes less variance in the tension on the Z belt, so you can actually adjust it to turn reliably.

MakerBot Note :

day 13, still having problems with Z stage slipping

MakerBot Note :

I'm searching for a way to decrease the infill density without affecting feed rate or perimeters. I'm told that slowing down the filament flow is not an option since PWM will reduce the torque available to the motor.

Infill width over thickness : affects perimeter as well as infill. good job ... naming that one.
Feed rate : can't turn that up, makes curves render poorly
Flow rate : can't turn that down, motor wont have enough torque

but, there is a
Perimeter Feed rate over Operating Feed rate
Perimeter Flow rate over Operating Flow rate

so.. if I want to change just the infill feed rate, I can speed up the global feed rate then apply a correction here ? Lets try it.

20100706

MakerBot Note :

Recently my heated build platform stopped reading a sane temperature and was reporting a constant temperature of 255 Celsius. The problem was the thermistor was shorting where it was attached to the board. I think they could probably re-do the HBP board design with the thermistor mount contacts larger and rotated 90 degrees to reduce the chances of this happening. I re-did the joint and put down lots of kapton tape for insulation. Everything seems fine now.

update : temperature reading is more noisy and spiky than it was before. I'm not sure whats up, but at least its working.

debug process looked something like this :
- disassembled, all connections are visibly intact
- signal cable is intact
poking around with multimeter ( power, signal cable disconnected )
- "sig" line appears to be contiguous with ground
- gnd, 5V intact
- [sig.gnd] to 5V : 4.6 Kohm resistance
with signal cable connected
- gnd,5V do in fact have 5V between them
- signal line is resting at gnd
assumption is that the signal line should probably not be shorted to ground like this

MakerBot Note :

It sounds like the Z rods that MakerBot ships with are inferior and possibly should be replaced to get a fully functioning makerbot. On my kit, version 11, I have rebuilt the Z stage assembly several times and keep it excessively well oiled to prevent slipping. Essentially, the problem is that the rods are slightly bent and also corrode which adds friction. Replacing them with stainless steel equivalents seems to solve these problems. For now I am running a software patch that slows down the Z axis to reduce the odds of lost steps during a build.

http://groups.google.com/group/makerbot/browse_thread/thread/dd42b58921ff32a7

20100703

Remeber this link


Proles/Makers (Sterling/Doctorow)

Open source fabrication :
means of creation, not means of production
but for small scale thats all you need
it also facilitates boot-strapping, where people have resources but lack investors.

I hope this works.

MakerBot Note :

Day 10 of makerbot assembly attempt.

morale is low

alternating between cursing my own failures, cursing the makerbot makers, and just plain cursing.

I have determined that the gcode from whatever old version of skeinforge I downloaded does still build.

The present skeinforge does not produce successful builds.

Z stage slipping is still a major problem, may have been exacerbated by trying to install the Z stage wobble arresters.

must... keep... trying...

MakerBot Note :

The extruder is jamming again. Backed out filament looks like this. I wonder what is wrong ?

MakerBot Note :

My Z stage was slipping, so I tried printing the springy parts of the Z axis wobble arrestor ( from thingiverse ). I can print things as long as I monitor them and correct the Z stage when it slips. Attaching these guys didn't seem to make a difference though. Adjusting the bearings might have helped a little, before I cranked the Z stage into the bolts at the top and cracked it. I think the only thing thats worked reliably for me so far is lots of oil and slowing down the travel feed rate ( which I think is whats used to calculate the Z state movement rate during builds ).

Update : these do nothing to help with the slipping. If anything they make it worse. They may help remove some of the wobble, but they also seem to increase the resistance to moving the Z stage. I found that using the latest version of skeinforge lets me slow down the Z stage movement, which seems to correct the problem.

20100702

MakerBot Note :

Spend a good hour leveling your build platform with masking tape or painter's tape. I am putting the tape on the Y stage platform.

Move the stage using the control panel from corner to corner until all corners are the same distance from the nozzle.

MakerBot Note :

The heated build platform kit as it ships is incomplete. The way they suggest hooking it up to the extruder board will not work. To complete the kit, you either need to procure a heat-sink setup for the power mosfets on the extruder board, or a relay to take the load off the extruder mosfet. I used a relay.

They recommend insulating a part of the wire with heat shrink tubing, but I didn't see any heat shrink tubing in my kit. I could just have missed it though.. unclear.

Other surprises may include : you need to do some surface mount soldering. The instructions recommend solder paste, but it is possible to do this with a normal soldering iron if you are careful.