The good thing about a RepRap is, that you can print many upgrades for it yourself.
But not everything works with PLA. Some parts just need to be metal. And some should be clear and the easiest way to build them is sheet material. The hood is an example for that.
Because the heated bed did not reach 100 °C (although I already stuffed cork below it – pictures here) and the parts were warping away I tought this would be a good idea. Not a proper heated build chamber, but good enough.
With the cabinet closed 100°C are exceeded (after a few hours of printing even 110°C are reached at the middle of the underside of the bed, where the sensor is).
When printing in PLA you can save a print by gluing the warping edges to your (glass) build plate with hot-melt. This does not work with ABS on hot Kapton however.
Instead I used the “hot knive” of my gas solder iron (depicted above).
The Sunglasses Holder – expandable and modular by Tony_D was the test object for a long print (although I used 0.25mm layers) starting from a large surface. The brim was still necessary however.
Over time I got extrusion problems.
Apart from the ABS filament itself not being that good…
…the feeder mechanism was not deburred properly.
The shavings went through the bowden tube into the hot end and caused blocks there.
The pneumatic connector also had some sharp edges, which had to be sunk. I punched the motor shaft to prevent the drive gear from spinning (screwlock is a bad idea, beaucse the hexagon socket is so small).
A short piece of tube now guides the filament to the drive gear. But the clamping mechanism wears out, when you adjust it.
Despite all those problems I managed to get two good prints of Corellian Engineering Corporation YT-2000 light freighter “Otana”. I was aked to print http://community.fantasyflightgames.com/index.php?/topic/92450-yt-2000-otana/ on the FFF-machine and although this definitely is Resin Printer (Stereolithography) stuff, I gave it a try.
And I am quite impressed with the result. It does not get any better than this with this kind of “electronically controlled hot glue gun”.
One of the two Otanas was later painted by the guy who asked – and put into the gallery of his own site: http://www.swordandpaintbrush.de/p/galerie.html
So much for the cold end – now the hot one:
The Sumpod Hot End is similar to the E3D All Metal HotEnd. The latter worked fine in my RoStrap, so I switched to this one. To no avail. There were still some random jams, which could often be overpowered by hand – and then again not at all.
Cold pulling (http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#underextrusion) did not bring particles to light. Instead using Teflon oil (Interflon Fin Lube TF) to grease the bore in the heat break stopped the jams.
Here is the Hot End in Simple universal E3d double fan cooler. The Nozzle Fan is smaller, so I scaled down this part.
I continued to use PLA in the E3D.
A general design flaw is the current distribution on the RAMPS-PCB. The Sanguinololu documentation does mention that this PCB may need reinforcement, but I used the RAMPS-Board right out of the box. And the two 12V connections are completley seperated.
Then came the high current consumption of the heated bed and after a few ten hours of printing the connector was done.
I connected the two 12V-rails to distribute the current more easily.
The 5V-Regulator also failed. Another thing the Sanguinololu-page forestalled. So I disconnected it via the polyfuse.
I did not escape the problems with the X-Driver. The axis stuttered, obviously something regarding the “enable”-pin.
Changing the jumpers was one approach, but in the end I had to re-define the pins of this driver and use the slot of Extruder 2 instead.
The Heatbed was finally put onto some springs, when I changed to the E3Dv5. And I improved thermal insulation.
Now I use a carbon fiber plate on top. You need to set 75°C to get 65°C on it and to degrease this plate before every print, but as a result I can now print gears without “elefant foot”, so they mesh fine without carving every single tooth.
On the other hand: C_D’s Dual Drive Bowden Extruder by C_D contains gears designed to be printed (with chamfers). 😉
On the other hand: it greatly helps not only to set print speed to 50% for the first layer und temperature to 210°C instead of 190°C later, but also to reduce flow rate under these conditions to 80%
The “Tweak at Z” plugin for Cura is extremely helpful for this.
The hot melt here was a precautionary measure, because I coudn’t watch the print all the time.
Test for bed levelling and removal of the object: