Calibration & 1st prints

Hi All,

I have finally built my kit store reprap with much help from the wiki & here, but none from the illusive James... O the surprise.

My printer is spec'ed as follows
- Sanguinololu v1.3 board with the sprinter firmware (newest update from kliment 5 days ago)
- pronterface
- Slic3r 0.8.4

Following the (BuggerIT) calibration steps identified by MotoBarsteward I have tested & measured the X, Y & Z and they are all moving the correct distance when instructed to via PF. The bed and tip's temperature is also being monitored correctly via the sensors, so the PLA comes out at the right viscosity.

I am struggling with two aspects now,
1. If you look at the thin-walled box jpeg. The initial 5 or so layers are put down perfectly but once this stage is passed there is an increasing wobble in the deposited PLA. This suggests to me that the head is not moving fast enough or the PLA is being extruded too quickly. Whats the thoughts there?

2. Looking at the shot glass jpeg. The base layer is put down correctly but once the next layer, which is at 90 deg to the 1st layer. Is deposited its miss-aligning this layer by 1.5 cm down (-Y) & 1.5 cm's to the left (-X). This is a bit confusing as the thin walled box does get each subsequent layer down correctly. So I am not sure where the offset is coming from here.

Thanks ahead,

Bow

Glad to see you've started to get things up and running. A few things to look for.

1. You have calibrated your x,y & z movements but have you calibrated your extruder? There are several tutorials out there which cover this topic but essentially the idea is to mark a point on your filament, ask pronterface to manually extrude 30mm of filament, and then measure how much filament was ACTUALLY extruded. You can then calculate how much you need to change your ESTEPs for your extruder. Looking at your first image (thin walled box) it looks like you are extruding almost twice as much filament as you need to.

2. The offset printing is almost always due to missing steps while the bed and/or platform are trying to move. This can be a result of a couple of things. First, make sure that your print head and bed can move freely, if there is too much friction from the bearings/bushings the motors may not be able to cope and cause the print to shift as they miss steps. Second, make sure you have your trim pots on your stepper drivers adjusted correctly. Turn each trim pot counterclockwise until the stepper motors start missing steps then turn them clockwise a couple of degrees. If the trim pots are too low or too high your motors will either miss steps or overheat (or both). This doesn't have to be exact but you just want to make sure you run through this step.

Not sure why this is happening with the octagon and not the thin walled box. That one is a little bit of a mystery. The only thing I can come up with is that something is binding or your stepper drivers are overheating (trim pots too high) and causing the missed steps.

1. what speed u use ? It looks for me like bad calibrated extruder (too much material) + low speed, whatabout temperature on first layer and on 10th layer?

2. something prevemts moving your axis. Could be anything. My five isssues during first mendel were:
1. too low power into stepper motors (1/3-1/2 on trimmer)
2. something is blocking linear bearings (washer)
3. sliping wheel on motor
4. deformed or badly positioned linear rods.
5. marlin/sprinter firmware with too high accelerate speed during "zigzag" movement (try decrease 3000mm/s2 to 1000) and second parameter value (do not remember name) from 20mm/s to 10mm/s.

Hope it helps.

Looking at your first layer of your shot glass, I'd say either your extruder is extruding too much plastic (check the calibration of the extruder) or the head is too close for the first layer. If you have one or both problems you get the ridges that you see formed in your first layer. When the second layer is printed, the head hits these bobbles and ridges and stalls the steppers.

---

Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

Hi all,

Thanks for the tips & as you can see from the photo I have the extruder properly calibrated however I am still being driven up the wall by this weird off-set problem which you can see when I have tried to print the shot glass.

@ archistrong, I am running off a Sanguinolou 1.3a board so I dont believe I have any POT's to manually adjust. I have reduced the tension on the X & Y axises to counter for any possible restriction that could be causing but to no avail.

All of the drive cogs on the steppers are very tight so there is no slip coming from them but while repeating the shot glass print there is a 'clunk' just before the off-set..!? I'm in the process of re-building the Y axis at the moment to see if I have done any thing wrong which could be causing the clunk but any ideas are more than welcome..

Thanks again,

Bow

Further to the last comment I dont think the occasional 'clunk' is responsible as all is checked, aligned & calibrated. Possibly the 'clunk' is over active ears looking for any thing obvious to resolve.

In the attached picture shows what it appears to be happening:

- prints fine upto layer 1000
- Point 1, rather than finish the fill it banks off at 30 degs ish
- Point 2, Attempts to finish the fill in thin air at which point I stopped it shortly after.

I have just upgraded slic3r to 0.9.1 & have set the printing, filament and printer configs so I am confident that nozzle dia, filament dia, print area (180 * 180) & temperature are correct.

I am loading the STL in to Slic3r then letting it generate the G-code rather than letting PF do it its self (seems like it runs with defaults which really dont work). I then load the G-code which Slic3r into PF & away.

:/

Thanks,

Bow

The pots are on each of the 4 stepper driver boards that plug into the Sanguinololu. If you don't know where they are then most likely they have not been set correctly.

---

[www.hydraraptor.blogspot.com]

Hi Nophead,

Looks like I was over looking the trees due to the woods as the POTs are on the Sanguinolou board, they are just less obvious.

The attached picture indicates what I believe to be them.

..

Thanks,

Bow

Yes those are they. Try increasing X and Y a little. As you don't have heatsinks you probably can't set them much higher without overheating the driver.

---

[www.hydraraptor.blogspot.com]

Not having the best day so far.

Long story short, can any body reccomend a good place to get replacement Pololu/StepStick Stepper Motor Driver's?

Thanks,

Bow

If you are located anywhere in Australia, I would Recommend LittleBirdElectronics , I ordered my replacement ones from them and they work great, they also sell a 5pack of mini heat sinks suitable for the stepper motor drivers for a couple of bucks.

Thanks Jaramaniac,

Unfortunately I am not based in OZ but I did find a cheap US seller on ebay. $10 a pop & those include heat sinks so I bought a few of them to cover then next hiccup.

B