The main cartisian robot almost put together
picture from above
The Y axis stepper motor
The x axis motor and carrige
The z axis stepper
This is the thing that holds the extruder or will do when I've built it
a reel of plastic (black HDPE what chopping boards are made of) ... sat on a crisp packet for aesthetic reasons. This stuff turned out to be a pain in the backside later as it clogged the extruder and led to me breaking it.
The machine fully assembled
Powered up ready for action
Main body of the extruder head with some mystery filament loaded. The screw tread in the middle of the picture drives the filament forward into the heater element so it melts.
Some of the mystery filament extruding
A better look at the heater part of the extruder the orange tape is Kapton tape which is high temperature sticky tape.
A better look at the nozzle extruding the mystery filament now that I've secured the silicon insulation out of the way. Under the silicon is a metal barrel and secured to that by the Kapton tape is a coil of Nichrome wire which gets hot when you run a current through it. It's used in all sorts hair dryers and toasters. There is also a thermistor which allows the device to regulate the temperature of the extruder usually 230 deg c ish depending on the polymer.
A shot of the controller board, pic based with an SD card that contains the code and a little OLED screen for info, usb for firmware upgrades. It's running a test raft program you can see the temperaturen and various speed settings as well as the file name and line of gcode it's on.
The test raft printing (a basic test file for calibration purposes) here the polymer flow doesn't look very even need to adjust the tension springs
Some initial test rafts not very good
Another test still patchy the polymer isn't flowing evenly
This is quite some time later, i ran out of mystery polymer and switched to the black HDPE which promptly clogged the head and in the process of unclogging it I broke the thermistor. So this is after I bought replacement parts and a reel of white ABS which is a easier to use plastic than HDPE it's what lego is made of.
I fitted some terminal blocks so I could more easilly disasemble the extruder if I need to declog it again.
The new reel of ABS
Looking pretty good even lines the back right looks a touch wiggly which may mean the extruder is too far from the base.
the test rafts after I've broken them off the base with a knife the one on the right was a little low and got mangled.
first attempt at a proper object the minimug promising but went a bit wrong on one of the lower layers
you can see it's just all gone horribly wrong inside.
Some more tweaking and adjustment later
second time round looks a lot better
Side view still on its raft, the raft allows better addession to the base plate makes larger objects deform less.
fairly round some splurge on the inside where it's pulled away
minimug with raft removed and tidied up
Not quite water tight
The base has some tiny holes where it's not quite covered
Time lapse of toy car being built
a far more complex object a small car with captive wheels i got off thingiverse and parsed in Skeinforge to get gcode for the machine to print. This print had a couple of problems you can see it warped a bit this is due to the polymer shrinking sligthly as it cools. There are a few ways round this you can heat the build area with a heated bed or some such or structure the model with removable pads that prevent it warping. Warping also varies depending on the polymer used
you can see the warping here how it bends upwards there was also a failure in the y axis where the drive rod came off for some reason hence then notch just down from the top
looks pretty good some of the setting in the slice tool Skeinforge probably need tweaking but not bad for a first go
Second go at it this time the y axis stayed together the drive rod in the background was the culprit that shaft connector on the left came undone and it's some weird no metric hex key to tighten it.#
Still some warping but otherwise came out pretty well
warping always worst at the corners
The captive wheels do rotate and on some surfaces it will roll a little
The first go is on the right as you can see the second attempt came out much straighter
A dodecahedron I printed
I replaced a damaged corner block and some of the diagonal tie grips with new printed parts.
one of the corner blocks I printed the holes and such needed a quick going over with a suitably sized drill bit but for the most part they are pretty good right off the bat.
And off we go again with yet more recalibration
3/4 corners replaced with printed parts and quite a few of the cross brace grips
Printing a dodecahedron just to check print quality
Here you can see one of the replacement corners and cross braces.
Unfortunately still having issues with Y axis slippage, there are a lot of connectors on that axis making it problematic
Up close you can see the effects of the y axis slipping on this set of mendel parts
After some tightening and fiddling this is what it should have looked like
Some parts for reprap v2 mendel
A gear I printed for a work collegue, I supect it is just bellow the possible resolution of the printer but even so it might do the job with some filing
Ran out of ABS plastic and the PLA I ordered hasn't shown up yet so had another go with HDPE. This stuff warps like nobodies business and it won't stick to anything. This part should be a simple square but you can see it has warped all over the shop.
I tried printing the dodecahedron in this stuff and all I got was a melted mess the walls would deform while it was printing. Here you can see the side of the shape and how it has bent in. I suspect without a heated bed this stuff is unusable for anything.
An attempt at using aprons to reduce the warping not that successful
You can see it's pulled the tape off the base with quite a lot of force
Nozzel become a little encased due to polymer leaking due to a deformed PEEK insulator. Not sure how it got deformed.
And to balance the white abs this side is encased in black HDPE
here you can see how severe the warping is on HDPE
Notice the through holes are teardrop shaped, this is deliberate round holes would probably violate the overhang limitations so making them teardrop shaped works around that without the need for support.
The encased nozzle. Because of all the plastic stuck to it the thing took ages to heat up so I bought a new nozzle kit to replace it
The new and improved nozzle ready for action. The beige gunge is fire cement it keeps the thermistor and nichrome all contained and safe while withstanding the heat.
A new reel of PLA polymer I order with the new nozzle. This stuff is quite nice lower temp but biofegradable made from corn starch in its natural state it's clear. It also doesn't warp much.
First successful print in PLA. Had one go haywire before this due to an axis slip. This is also using the Netfabb basic engine for rapman software I just got which is a lot easier than Skeinforge but comercial. It also doesn't have the anti ooze command yet that is why there is a lot of strings all over these two parts.
I printed this without a raft as you don't really need one for PLA just make the first layer a bit slower. You can see there is only a little warping on the right. The vaguely crystal look of the parts is quite fun. PLA seems fairly sturdy quite stiff less give in it than other polymers.
It really could use the anti ooze command
