Monday, February 17, 2014

Frustration

Another weekend passed  and I've spent it being frustrated.
at first I've tried fixing the Z axis and adding smooth rods instead of the previous piece of wood.
and then passed to motor calibration.

for some reason I've noticed that when the motors move to one direction they move faster that the other way around.
Google searching the issue suggested that that may occur because the endstops were not installed.
I've tried connecting one endstop and checked it is working by clicking the mechanical switch - and then the Arduino restarted -weird.
I've checked and found out I've switched pins in the endstop connection and switch them back.
But then it occurred to me that the LCD was in full brightness so I couldn't see if it is running or not, and the repetier software couldn't find the arduino through USB.

when removing the Ramps 12V input I've noticed that the LCD was back to normal and I could control the UI, and whe I've reconnected the 12V and the brightness was full again I could notice you can barely see the UI still operating.

I've decided to disconnect the Arduino Mega 2560 R3 board and fix it first - and made a total mess.
I've managed to get the board unrecognized when connected to the PC USB, probably by deleting the bootloader somehow.

I've found a similar case online here.

for now I think the Arduino board gone bad for one of the two reasons: 
1.software corrupted.
2. burned chip on the board.

I've ordered a new USBASP in order to maybe fixing the board bootloader and 16u2 USB serial connection chip firmware.
also bought a new Arduino Mega 2560 R3 in case that will fail. I will be able to sell it if I'll fail to fix.

This will delay the build for a while...

When I've decided to build the printer alone and with no kit I knew that it will be harder and have setbacks like this, but when it really happens it is still very frustrating.

now all I can do is wait for a while...

Sunday, February 9, 2014

The Building continues

Last weekend gave me the opportunity to continue a bit working on the Repstrap.
I have no definite design decisions because I know I'll have to improvise on the fly.

my main materials are wood and tie-raps. 

Y-carriage and Heatbed



The Y axis carriage was almost finished but needed modifications - the carriage needed to be raised a bit in order for the carriage full motion.
to do so I've super-glued 3  wooden supporter for the linear bearing.

The  heatbed needed wiring of the electrical input and attaching the 100K thermistor.
I'm using the 12V option on the MK2B heatbed and wiring is pretty straightforward.

The thermistor, although quite easy to assemble, needs the right materials, since it should withstand the heat.
when I've bought the heat shrink tubings I've asked for high temperature resistant tubes. hopefully I got the right kind - these should shrink but not burn or crumble when exposed  to high temperature over time.

It is also critical not to use soldering wire, because it might melt. 
the wire and the thermistor were clamped together and covered with the heat shrink.
all this assembly was glued to the heatbed bottom using Kapton tape.
an explanation of this can be found in here.

Z Axis

both Z axis lead screw M5 threaded rods were cut to size using Dremel multi tool( I dont have an original Dremel).
when connected to the stepper motors using coupling, I've discovered my first big mistake- the coupling are from M5 to M8 and needs to be M5 in both ends.
I've adjusted this using a tube to envelope to rod.

wood with 8mm holes drilled in them were used in order to hold the M8 smooth rods.

the Z carriage was made from another wooden stick with attached linear bearings, M5  lead screw nuts.


 on the Z carriage I've mounted the X motor using plywood and idler with spring I've scrapped from a printer.
the result is a little bit messy, but hopefully it will work

Power Supply Unit

As part of the effort to cut the price, I've tried to convert a PC ATX PSU to use on the reprap.
some guides can be found here and here.

unfortunately the first a attempt failed and the PSU was bricked, I actually didn't check it before  starting the work, so there is no way to tell if it was bricked when I've harvested it.

the second unit I got seems like a low end PSU, it works for now, but I'll try to find an alternative as soon as possible.

Arduino Mega 2560 R3 + Ramps 1.4 + Reprap Discount Full graphics LCD Marlin Firmware installation.

Installing the firmware on the electronics was one of the issues that worried me beforehand.
since I chose the electronics myself I knew that if something went wrong - if one of the parts wouldn't work it will be hard to pinpoint the problem.

luckily ,although not completely smooth, after few attempts I manged to upload the regular firmware.
I've used the Arduino 1.0.5, downloaded the Sanguino files and u8glib library.

but with this the LCD didn't work.

then I've tried downloading an updated firmware from both reprapdiscount site and Makersfarm site.
in these sites you can find an updated Marlin software that includes both the required libraries in the "Arduino addons" folders and the updated Marlin files.

learning what needs to be changed in the configuration.h and pins.h files required a few tries, but learning to work with the firmware is the beginning of learning how to operate the printer.


Next steps: building the Extruder and checking everything moves.

Wednesday, February 5, 2014

The Repstrap Alternative -challange accepted!

Decision making time

After failing to get only the printed parts, I've tried alternative sources such as asking the local Facebook reprap  group and asking a friend of a brother of a friend with no avail.

I've almost gave up and decided to find another eBay seller, when suddenly realized there is a much more interesting alternative: building a Repstrap!

Repstrap is a 3D printer built from a makeshift parts, usually used to print proper parts for a more stable Reprap.
This is exactly what I need if I choose not to wait, and actually it sounds like way more fun.
anyway I think that rebuilding and improving the printer is what most makers like to do....

so I took all the parts I have and started to build:



Meet the parts

















Building the Y Axis

Using some wooden parts and the 8mm smooth rods I've tried to create a Y axis and cradle,
unfortunately it is too low and the cradle cannot move all the way. 
I will try rebuilding it tomorrow with the rods on the top.








Sunday, February 2, 2014

Printed Parts Delivery case closed on eBay update

Hi all,
after ordering the parts things seemed to go so well - most of the parts ordered from aliexpress and Dealextreme arrived surprisingly quickly.
Unfortunately what kept me from really starting was the lack of the printed parts.
I've ordered from this seller the parts for 40$ + 22$ delivery in the 27th of last December, on the same date I've ordered most of the parts.
he contacted me and asked to postpone the delivery to the 2nd of January this because of the holidays and I've accepted.
in the 2nd I've received a message that the parts were sent but got no tracking number or any proof that the parts were really on the way.
I've tried contacting the seller on the 20th, when it was already the last package which failed to arrive but heard nothing back.
at last at the 27th I was able to open a case and ask for my money back.
last Friday, after the still didn't answer my claims eBay refunded me .(paid using Paypal) 

Luckily I can probably get the parts from a local Reprap owner and maybe even save the delivery rate.

in the meantime I've managed to cannibalize some parts from scanners and glasses I've found and got from friends.



Cutting the glass proved to be harder than I thought.
I bought a simple glass cutter on an office supply store at about 5$ and always managed to break or chip the glasses on the first tries.

my lesson learned from this experience is after you making the initial cut, try avoiding pressure on the glass.
use boiled water or a lighter in order to create a thermal shock that eventually will break the glass without using force.

tutorials on glass are plentiful on the web, here you can find one for dummies.
of course you can go to a hardware store and buy it hassle free, but what's the fun in that?

So hopefully I'll get the printed parts soon and will be able to have a more meaningful updates soon...