Opto's, F*%king opto's

hey all
having a bit of a frustratig time here. dont know whats going on.
i had opto's from techzone(guys have been real helpfull)
they stopped working randomly 1 after the other(still get saw by axis as clear no matter what)
techzone sent me new(differnet ones with no led)
they sent a bunch more.
i have opened them all,out of them 3 appeard to work at first now they too have quit.
this is all in the time its taking to mount flags.
they cant be just disposable surley??
is there ANY way i can run without opto's for a while?
never even ran the printer(all else would apear to be ready and working)
been at this for months now
anyone able to shed a little light before mendel becomes a doorstop?
t'anks

brian

was gonna start another topic but figured i shouldnt be greedy. has anyone run into this problem(just discovered after reversing all my axis to go back down)
my z axis seems to be getting tighter and tighter on the screws before it eventually cant be moved.
any idea's?
thanks again
brian

As you spin the Z axis, watch the top of the lead screws to see if they wobble. A minor wobble should not hurt much, but if the top is off center by maybe more than an 1/8 inch (guessing here) then this is probably too much slop. If you see that, then your lead screws might be bent. The easiest way to check that is to roll the screw on a surface that you know is flat. If you see light between the surface and the screw it is bent. Since that requires dismantling the machine, you might try some other things first though.

If the guide rods and lead screws are not parallel, they will cause the axis to bind. The lead screws are free to move a little bit at the top, so they are not as critical. The guide rods however are not able to move. It is very important to have these parallel. I used a miniature level while adjusting mine.

If the pulleys are out of round, they might compound the effect of bent rods. Try loosening the belt just a hair. Giving it some slack will help the machine self adjust a bit. If it is too lose, then the belt will start slipping on the pulleys so don't adjust it too far.

If you are not using set screws with your motor pulleys, I suggest popping off the pulleys and putting a couple of drops of super glue on em. Be careful not to let the glue drip down the shaft into the motor. If you only use a couple of drops, it should keep the pulley from slipping on the shaft, but you should still be able to pop it off with a flat head screw driver.

As for the end stops, I'm going to assume you are running the standard firmware. It does have an option to disable the endstops, but you will have to download and edit the firmware to make the change. Too bad reprap doesn't have this in the host software like makerbot does.

Download this, extract it wherever you want to "install" your mendel software, then install the arduino IDE. Going back to the reprap download, find "configuration.h.dist" and rename it to "configuration.h". In the same location, you should see "FiveD_GCode_Interpreter.pde". Open it with the arduino IDE. Find the tab for "configuation.h" and look for two lines like this:

#define ENDSTOPS_MIN_ENABLED 1 //1 is on (default),  0 is off -you need to change it to 0
#define ENDSTOPS_MAX_ENABLED 0 //1 is on,  0 is off (default)

Assuming none of the other settings need changed from the defaults, you should be able to upload the changes. You will probably have to configure the steps per mm later though.

As for why they don't work, if techzone is still using the stubborn connectors that I got with my kit, maybe you have a bad connection. Ditch the little push-in wire type connector and try to find some 0.1" female header connectors - like what you see on 12v fans or hobby servos. Alternatively, you could solder the wire to the pin, but be careful not to make a solder bridge. Also, carefully read the schematics and look at all the photos to be sure you have correctly assembled the cables and have them plugged in the right way. I burnt my first one up because I plugged it in backwards. The square pin is not "pin1" on the boards I got. I wired it like any normal hard drive or similar connector, meaning I assumed that the same wire should connect to the square peg at both ends. This was not true for the boards I got.

Hi Brian

I do think it is worth making separate threads for different problems.

Anyway, regarding the opto-switches. When I was testing I bridged 2 wires. Signal and the other - cannot remember if it is the GND or 5v wire. A little research will clarify. This allowed me to run the motors without the switches.

Cheers

Quote
Opto's, F*%king opto's

I have 1 left working out of a dozen. The rest I've replaced with 50 cent micro switches. They work great.

... when opto's worked first and randomly shut down, then either the emitting diode is killed by overheating (resistor not big enough or voltage to high), or the optical path is blocked by something

Can you give some specs of your optos?

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Re: Z binding

Sounds like the Z smooth rod is either not far enough apart or too far apart at the bottom.

Also make sure that your X axis carriage is level with respect to the base. I used a level to get mine very close to perfect well before I got to levelling it against the bed. Without it, it would appear to work fine (due to sideways give in the threaded rod) but bind as you got lower.

hey all.
thnx to everyone for the help(specially Cefiar and dazed.dnc you guys fixed both my problems exactly)
z axis goes up and down all the way
flags not needed using repsnapper(side note. this has some options im not familiar with. anyone here with a techzone nozzle know the size?)
just had a failed print(tryed to print directly onto aluminium bed and i dont know which happened first either it came unstuck and stopped extruding or it stopped extruding and pulled itself off.)
failed but yay. mendel is no longer an ornamnet(though its now still only a moving display till i sort out the extruder)
now my extruder is jammed
will have a tinker and see if i can do it myself without another post lol
thanks alot guys.
not the first time the forum saved my ass either my problem or reading other peoples problems only to run into them myself.
brian

Far as I know, you can't print straight onto the aluminum. You need to coat it with tape. Some people use blue painters tape, but I have much better luck with Kapton on my heated build plate. Maybe the painters tape works better for unheated beds?

If you don't run it as a heated bed, you could even remove the aluminum and replace it with an acrylic sheet from home depot or a hobby store. Your parts would probably stick better, but you would loose the ability to repair pits and scratches in your build plate. With tape you can just peel of the bad section and replace it. PLA reportedly works well enough without a heated bed, but if you want to run ABS you should really hook up another heater for it.

Once you fix your build plate, You might try slowing down your feed and flow rate. Once you find a feed and flow rate that produces a solid but not overfilled part, adjust both so that you maintain the same ratio as you try to find a speed that eliminates the jamming. Then you can start toying with some of the other settings to get your extrusion paths to connect into solid edges with no air gaps. At least, this is how I tuned my makerbot. The reprap has certainly been more fickle. I haven't managed to print for more than 30 minutes without a jam. I'm currently looking into hardware changes aimed at fixing the problem.

Also, especially while laying down the first few layers, if you do not lift the tip far enough off the build plate it will act as a plug stuffed in the nozzle hole. Plastic can't leave the nozzle as fast as it is being pushed in and you will eventually force the filament to strip out even though your speeds are well adjusted.

You might want to do an open air extrusion to see what the max feedrate for your extruder is without adding the build height as a variable. Take that speed and de-rate it by 20 to 30% as a rough starting point for your actual printing speed.

Edited 1 time(s). Last edit at 11/28/2010 04:17PM by dazed.dnc.

Dazed.dnc is correct on beds. An unheated aluminium bed will suck all the heat out of the plastic as you print on it. Acrylic will not suck as much heat (requires more heat to raise it's temp.

I've made a removable Acrylic bed to sit on top of my Aluminium one, so I can print PLA initially. The end goal is to make an insulator bed to replace the aluminium as the base and then modify the aluminium bed in the same way as the acrylic bed I have and add heating.

Part of the reason of doing it this way is that I won't be modifying any existing parts till I have a replacement in case I stuff things up. Sitting around waiting for parts is one of the main things that has stopped me printing.