Morgan 2

Morgan 2 is slowly coming along (nothing has happened over the last week), the frame is assembled.  I forgot to fit the linear bearings on the smooth rods, however, so I will have to disassemble slightly to rectify that.

I am still battling to print the large parts, which is the arms, drive wheels, and bed frame.  The replacement J-head is not performing as well as the first one.

The first one I broke by accidentally heating it up too far (I still don't know how I did that), and the PEEK body cracked where the nozzle/body screws in.  This causes molten plastic to leak out, resulting in under-extrusion through the nozzle, and me having to wipe off dripping plastic every 15 minutes. 

The attempts at fixing were less than successful - I tried PTFE tape and a hose clamp to tighten the crack, I tried two brands of exhaust-fixing putty, but still it leaks.

I replaced the J-head with another off e-bay, but this one is not working as well.  This one is for both 3mm and 1.75mm filament (the previous one only for 1.75), so the lock nut at the back has a 3mm hole, the PTFE lining is made up of two sleeves one inside the other (take out the inner one to go 3mm), and most importantly, the heating body/nozzle is 3mm ID.

This seems to cause problems after cooling down - it does not print well the second time.  It seems clogged.

At the moment the hot-end is disassembled for cleaning, this weekend I intend printing some parts.

Manual bed levelling

At this point in time, to preserve my sanity, I have decided to call it quits with automatic bed levelling.  It simply does not work for me.  I can SEE the Morgan dropping the bed at certain points (X, Y points) in the print, completely stuffing up the first (and to a lesser extent subsequent) layers.  Only some spots in the print, and repeatably.

I have converted Morgan 1 to have four spring-loaded screws on the four corners of the heated bed, simplifying manual levelling.  Previously it was supported on three screws, but manual levelling becomes much more difficult this way.

Manually levelling the bed is a bit of a mission, but the prints look so much better.

Previously I calibrated 3 X and 3 Y points for auto bed levelling.

Hats off to the postal service

Just as I was resigning myself to a long wait for the replacement J-head for the Morgan, the postal service (from Hong Kong to Witbank) amazes me!  I ordered two J-heads on eBay on the 20th of March and they were in my post box today.

Eleven days might not, in itself, be that short, but I also ordered 5 RAMPS 1.4 boards on 9 March, which I'm still waiting for.  That was mainly what set my expectation.

Now I can try and finish up the urgent parts for the new build (and a Minnie Mouse cookie cutter I promised to a family member).

Noteworthy things #5

This particular thing is not that applicable to the Morgan design, but handy in other RepRap printers.  It is a 3D printed implementation of the flexible pipes often found on lathes (to transport the cutting fluid to the tool/workpiece).

Ideal for printers with extruders mounted directly on the head.  Adding a small bit more weight and you can have optimum cooling of the extruded filament without compromising the hot-end.

See the Flex Pipe Nozzle Cooler on Thingiverse.

Morgan 2

Most of my Morgans time since receiving PLA filament has been spent printing Morgan parts.  And calibration parts....

The first printer was assembled in a week flat.  The platform is of chipboard, and a few parts broke during assembly (documented earlier). 

I have now embarked on the second Morgan build,with the intention of building one "the right way", having learnt a few lessons along the way.  This one will have a platform of 12mm plywood, I intend for it to have an LCD display (from the parts bin) and possibly an SD card reader if I can source one.

Building the frame, the problem areas were the captive nuts in the pipe end caps coming loose, and me forgetting the wire through the ported caps.  This will be fixed by glueing the nuts in place this time (and remembering the wire...).

Unfortunately, the top and bottom smooth rod brackets still need to be printed, so final assembly cannot yet take place, and I also still need the drive wheels (so I cannot complete the drive shaft).  As soon as the new J-head is here, though.

I started cutting the PVC pipe, but a cutting error (skew, not measurement error) left me with no option but to shorten the entire printer height by 18mm.  The parts to be shortened will be the PVC pipes, smooth rods, copper pipes and lead screw.  There is enough height on the design that I will not be compromising build height.

I will post photos of the (bright yellow) Morgan build as I go along.

Waiting for new J-head

The fix to the J-head (using exhaust putty to patch a cracked PEEK body) is not a success.  It still leaks molten plastic, resulting in me having to "wipe its nose" every few minutes, and also messes up the extrusion calculation (sometimes too little material comes out the nozzle).

I have ordered replacement J-heads (two, since I am also building a second, better Morgan), but that will only be here in a week or two.

In the mean time I have "fixed" the hot-end three or four times, using the abovementioned putty (alone and in combination with PTFE plumbers tape), and the most recent "fix" seems to have blocked the nozzle itself.  No material extruding.

I will try to fix the nozzle by purchasing a very thin PCB drill (0.4mm), but that is not available here so it will only happen when I visit Jhb/Pretoria again.

Getting old

I have decided, I must be getting old.  A grumpy old man, to be precise.

I used to be a HUGE Linux fan (when I left formal employment in 2001 and started freelancing I converted lock, stock and barrel).  Initially I ran SuSE (started with version 9) and later switched to Ubuntu.

I am considering building a second Morgan, and have allocated the wife's old HP laptop to control the printers.  I have re-formatted, making the laptop a dual-boot machine (XP and Ubuntu 10.04).  Unfortunately, the HP does NOT have wi-fi connection, and all internet in our house is wireless.

E-bay will sell me the wi-fi module for ZAR1000 (I don't want it THAT badly), so I spent some time setting up a LAN to the other laptop and sharing that one's internet connection, in order to install all the software I need.

Starting with Pronterface, for I first need to control the printer.  I can slice and visualize and design on the other PC, but Pronterface needs to run on the HP.  So I embark on the journey...  Going directly to the kliment Printrun github page, I start following the instructions (by the way, MacOS and Windows has single, precompiled packages that you download and run).

First hiccup:  pycairo will not set up via pip (according to instructions).  So I read up how to install, and attempt it, leading to the second hiccup:  pycairo requires Python 3, and Ubuntu 10.04 came with Python 2.

Upgrade python (374 MB later) I have the LATEST VERSION OF Python 2.  So now learn how to install Python 3.  Another few hundred MB later...  I also installed Python 3 alongside Python 2, but pycairo doesn't like that.  I changed the first line of the waf script to reflect Python 3.2, but when I configure the build it still complains about python being the wrong version.

Currently I am replacing 2 with 3, but I cannot see this ending well...