Show all posts by user
Page 1 of 2
Pages: 12
Results 1 — 30 of 32
Here's the relevant bit from my configuration.h file. I think I reduced max_feedrate, acceleration, retract_acceleration and max_xy_jerk (the latter for an unrelated problem).
//// MOVEMENT SETTINGS
const int NUM_AXIS = 4; // The axis order in all axis related arrays is X, Y, Z, E
float max_feedrate[] = {40000, 40000, 240, 500000}; // Reduced to limit X-offsets?
float homing_feedrate[] = {
by
BrazenArtifice
-
RAMPS Electronics
I have a MakerGear Prusa Mendel, and I had the same problem with Marlin. It drove me crazy till I worked out what was happening.
Try lowering your acceleration and max extrusion speeds dramatically from the Marlin defaults in the configuration file. Our Prusas are often geared very differently to what Marlin is set up for. I found the extruder stalling on retractions while printing but fine usin
by
BrazenArtifice
-
RAMPS Electronics
Replying to myself
Yes, just confirmed that changing my retract_acceleration from 7000 to 2000 in Marlin's configuration.h now lets me retract reliably 10 times faster than I used to be able to do. So Sublime was right that the problem was in Marlin's default retract acceleration being way too fast for my printer.
Thanks again, Sublime
Andrew
by
BrazenArtifice
-
Slic3r
Thanks for correcting my misunderstanding, Sublime, I'm always glad to learn something.
Checking my Marlin config file, my retract_acceleration is set to 7000 mm/s/s, compared to 2000 for normal acceleration. So you're probably right that I should reduce the retract accel and then increase the retract speed in Slic3r. I'm sure that'd improve my retraction results.
Wouldn't be the first time I'v
by
BrazenArtifice
-
Slic3r
I had the same symptoms on my MakerGear Mendel Prusa kit with the brut-head extruder. Retraction didn't work, but retraction compensation worked fine, and I couldn't turn it off. So I ended up with blobs at the start of every segment.
Eventually I wondered if retraction speed was the issue. Short answer - yes it was. The default retraction speed in my slicing software was too high for my printer
by
BrazenArtifice
-
Slic3r
Sorry, I misread your initial description of the problem - I did say I didn't understand it ...
My only other suggestion would be to try re-routing the fan connections as far from the heated bed as possible, in case its some sort of cross-talk problem.
by
BrazenArtifice
-
RAMPS Electronics
I don't understand your description of how you've hooked up the fan, but that's ok.
What I'd like to suggest is that you measure the voltage on your 12V lines both with and without the heated bed and nozzle heater running. I'm guessing that you'll find the voltage drops quite a lot when the bed turns on, due to the high current draw from the bed and the cheap and nasty voltage regulation in ATX
by
BrazenArtifice
-
RAMPS Electronics
Many years ago I bought a cheap Yum-Cha special (as they were known) PC in a tower case - I think it was a 486, which shows how long ago it was. I had constant 50 Hz hum problems from the audio. Eventually tracked it down to the power supply. Inside the shielded box with its "no user servicable parts" sticker, the power supply PCB was screwed to the metal case on standoffs. One of the standoffs h
by
BrazenArtifice
-
RAMPS Electronics
As far as I can tell, the RAMPS system is about as good/reliable as it gets for controlling Prusa repraps. Anything else will likely be more difficult. But as you've found, the connectors are a bit of a pain. And I'd be happier if the Pololu boards could source a bit more current before going into thermal shutdown.
That said, most of your problems are either going to be electrical connections,
by
BrazenArtifice
-
RAMPS Electronics
Different PLA extrudes best at different temperatures, due to both the composition of the plastic and the effects of the colourants. Sometimes even batch by batch from the same supplier.
You don't say what temperature those objects were printed at. 175 degrees is way too hot for the filament I use, on my MakerGear Prusa. I can extrude some PLA at 150 Celsius, though I get striations in the surfa
by
BrazenArtifice
-
RAMPS Electronics
Nice as it was of rhmorrison to give you a resistor color code chart, you will really need a multimeter to put your MakerGear Mendel together. You'll have to be able to measure voltages to be sure your power supply is working, and measure resistances to check that things (like your thermistors) are connected properly. So you can use your multimeter to work out what your resistance values are too.
by
BrazenArtifice
-
RAMPS Electronics
I wrote a blog post back in december with step-by-step instructions on how to automatically load your own slic3r profile on windows.
hope that helps,
by
BrazenArtifice
-
Slic3r
Great stuff. Thanks for taking the time to confirm the solution.
by
BrazenArtifice
-
RAMPS Electronics
If you get the same temp reading regardless of whether the thermistor is plugged in or not, then either
1: You've got the wrong motherboard type selected (must be 33 for RAMPS 1.4), which means the pin assignments are wrong. That'll mess up lots of other things too.
2. You've got the thermistor connected to the wrong pins on the RAMPS. Must be T0, not T1 or T2
3: your thermistor leads are not
by
BrazenArtifice
-
RAMPS Electronics
Do you mean 30 degrees for the nozzle and 70 degrees for the heated bed?
If you have the same type of thermistor installed for both the heated bed and the extruder nozzle, they should both return the same ambient temperature (plus or minus a degree or two) if you don't have the external power supply switched on.
Oh - have you hard-wired your heated bed directly to the 12V power supply? I hope
by
BrazenArtifice
-
RAMPS Electronics
Have you chosen the right electronics in your sprinter configuration.h file? For RAMPS 1.4 you need to say
#define MOTHERBOARD 33
That should get you some readings from your thermistor, when you click 'monitor printer' in pronterface. I always recommend not even applying power to the steppers and heaters until you've got meaningful temperature readings. It is quite possible to destroy your hot-e
by
BrazenArtifice
-
RAMPS Electronics
In Sprinter's configuration.h file, use
const bool DISABLE_Z = false;
by
BrazenArtifice
-
RAMPS Electronics
Hi Barry
Is the 'test code' an arduino sketch that just flashes the lights and moves the motors? If so, you have to re-flash the RAMPS board with a real firmware (Sprinter or Marlin, for example) before pronterface can talk to it properly.
I recommend starting with Sprinter, because I found the defaults for Marlin didn't work at all for my Prusa. Now that I've got the configuration sorted, Marl
by
BrazenArtifice
-
RAMPS Electronics
Arghh. Sorry. That was a fix for a completely different problem - blobbing at the start of lines. Oh well, maybe it'll help someone else.
by
BrazenArtifice
-
Slic3r
I had similar problems. Experimentation showed that my retraction speed was set too high.
Seems like I could extrude at the default speed, but not retract reliably. So when the g-code tried to hop from one object to another, it failed to retract, then moved, then squirted out a blob that would have exactly compensated for the retraction that didn't happen. I couldn't find an option for 'do not
by
BrazenArtifice
-
Slic3r
Yay for getting the motors and endstops going.
If there is too much friction in the x-carriage movement at any point in its travel, the x-motor will stall.
If you take the x-belt off, you should be able to move the x-carriage by hand fully from side to side without much variation in the force required. If not, you've got alignment issues with your parallel rods, and you should fix that before wo
by
BrazenArtifice
-
RAMPS Electronics
Most likely causes.
1. Voltage problems. Lots of people misunderstand the power connections. You don't connect 5V (the red wires on an ATX supply) to >anything<. The sockets marked 11A and 5A are both 12V, but at different currents. The 5A socket is where the heated nozzle and stepper motors get their power, the 11A socket is for the heated build platform.
2. Wiring sequence. Lots of peop
by
BrazenArtifice
-
RAMPS Electronics
COM3 implies you are using some variety of Windows, right?
How sure are you that your arduino is connected to COM3?
Mine ended up on COM4. I checked in the Device Manager, under Ports (COM & LPT).
Have you installed the device driver for your arduino? If not, you need to find the file "Arduino MEGA 2560.inf" on the arduino website and copy it into your arduino-0022/drivers folder. Right-cl
by
BrazenArtifice
-
RAMPS Electronics
The hint for me is that you say you don't know what RAMPS firmware you are using. Since you've proved that the motor is working, and your communication is working (or you wouldn't have been able to test the motor in another driver connection), I'm guessing that the settings in your firmware are wrong. The firmware is probably trying to make the extruder motor move much too fast.
You have to be a
by
BrazenArtifice
-
RAMPS Electronics
OK, I've just hooked up a 4R7 ohm 10 watt resistor to red/black on a spare molex connector. My 12v line has gone from 11.65V to 12.5V unloaded. I haven't tried it fully loaded yet (motors + hot end + heatbed), because I need to rewind a whole spool of filament first
The resistor gets very hot, as it warns in that useful link you gave. Maybe I'll put two 10 ohm resistors in parallel in place of
by
BrazenArtifice
-
RAMPS Electronics
I love my MakerGear Mendel Prusa. It's the ultimate toy factory. I haven't done much modelling yet because it's so much fun printing objects from Thingiverse designed by other people. I get to learn the limits of my printer by trying things I would have thought were impossible (like the OpenSCAD pirate ship, and Soppho's head). There are pictures of some of my printed objects on my blog, and on T
by
BrazenArtifice
-
General
5 Volts into 5 ohms draws 1 amp, right ? And dissipates 5 Watts ?
Since 5 ohms is not a standard resistance value, how about a 4R7 ohm 10 watt 5% wire wound resistor ($1.85 at Jaycar). That would give a current of between 1 and 1.12 amps, depending on the accuracy of the resistor, and power dissipation of between 5.0 and 6.3 watts.
Can I just connect this between a red and a black wire on one
by
BrazenArtifice
-
RAMPS Electronics
Yeah, I read that on the github site some time ago. V1 was my first attempt at getting Marlin running on my MakerGear Mendel Prusa. You can read the thread on the MakerGear Google group where I asked for help getting my thermistor temperature readings to work again after changing from Sprinter.
Long story short, V1 didn't read thermistors right on my RAMPS v1.4
The non-gen6 version I linked to d
by
BrazenArtifice
-
RAMPS Electronics
Anti-clockwise decreases current, clockwise increases current. Just like a car speedometer. Turn it up to 120mph and it'll catch fire. Well, maybe
by
BrazenArtifice
-
RAMPS Electronics
If your pots are set too high, your stepper drivers will overheat and give you the symptoms you have now.
If you have a pot set too low, the motor will skip steps (or just sit still and buzz faintly, in extreme cases).
If an X or Y motor skips steps, you see an offset in the position of the current layer of the print, relative to the levels below. It's pretty obvious - you'll recognize it whe
by
BrazenArtifice
-
RAMPS Electronics
Page 1 of 2
Pages: 12