Out of ideas / still learning

Hey
I have a Prusa Mendel, and have been doing ok, however i need to get into the fine details to get my prints perfect (especially for smaller items.

i have been playing around with different settings, fill patterns and densities etc but it seems that i cant get 2 parts to print the same.

My latest item i want to get ideal is a diff assembly for a RC car.

I have attached some pics of what crap has come out so far.

[docs.google.com]


What i have found is [richrap.blogspot.com.au] and im stuck on the firmware part, my extruder is way out, IE 30mm = 24 so i need to adjust this to start with.

I downloaded the arduino and can connect, however is there a way to download what is already on the machine? as it was setup when i got it.

and does anyone have any other tips i should be looking at?

i have tried masking tape and kapton, and my bed is 0.25 (-+0.3).

i have layer height of 0.25 and a 0.4 hotend with 3mm pla. i have tried prints from 180 up to 210.

Thanks in advance

Ok, im getting really close without calibration, however its still messy in 1 corner, it seems to just build up and ruin the print

(this is just a 4 edge square)

I have tried different retract settings and it seems to help a little with more retract, but not ideal.

is there a better way to get this?

I'm just at this stage myself. I have a reprap pro with recent firmware. I was reluctant to start dicking around with it, however, if you have recent Marlin firmware you can recalibrate without re-flashing the EPROM.

Put a mark on the filament, say 50mm from the place where the filament enters the extruder as described by Rich rap.
Command 'Extrude 30mm' Measure what you have left.

You can then send from the pronterface command line something like M92 E to increase or reduce the number of steps per mm. The default value is 980. I had to reduce mine to 970. Try a few more extrusions until you get it right.

This page, defines some extra commands that work on my control board.
M-codes etc

Here we find that M255 E is the same as M92 E but it is not lost every time you reset the machine IF you set the desired calibration value and follow it up with M500. M500 stores the value to EEPROM

So.
1) Try a few extrusions to determin how many steps per mm you need
2) send M255 E (new value)
3) send M500 to store these to EEPROM
4) you should see a message back saying firmware written or some such.

good luck
Terry Kidd

Edited 1 time(s). Last edit at 01/24/2013 07:48AM by TerryKidd.

Eeprom is not always enabled. If you download your own marlin firmware, you need to explicitly enable eeprom or the m500 command will be silently ignored and settings will not be saved.