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General Tuneup Questions

Posted by BrianRowes 
General Tuneup Questions
January 29, 2011 09:13AM
hey all
have been at it awhile now(just before xmas) and have a few problems i cant work out
i dont really know whats causing my problems.
my printer prints things in "generally" the right shape but nothing looks very good, gears have very fine teeth and a round buildup in the middle, surface details are VERY hit and miss(like dots on a die either being non existant or hard to see), and multi part beds are very stringy(will another stepper driver board instead of the built in extruder controller help this).
I can show a couple of pics if it helps but im assuming this is fairly normal(appart from how long ive been at this stage)
i have a techzone mendel with their gen 3 electronics(finally a full working set minus opto's)
im using PLA V2 from orbitech
here are my repsnapper settings(this generates my gcode as well as i have had NO success with steinforge(doesnt seem to move my Z axis enough))


let me know if any other information is needed
thanx
brian
Re: General Tuneup Questions
January 29, 2011 06:02PM
> my printer prints things in "generally" the right
> shape but nothing looks very good, gears have very
> fine teeth and a round buildup in the middle,
I'm not sure what you are describing. Sounds like maybe the infill isn't connected to the perimeter? Post a picture?

> surface details are VERY hit and miss(like dots on
> a die either being non existant or hard to see),
This could maybe be the result of extruding too much plastic, backlash (divots on the side probably won't be noticeable if there is backlash), or the effects described here.

> and multi part beds are very stringy
I have never seen a PLA print straight from the printer that didn't have at least a few thin hairs between towers. I get the impression that some strings are just a natural occurrence and the only way to completely get rid of them is to use a polymer valve. If there are lots of them or they are really thick, then you need to adjust your extruder reversal parameters to release the pressure before moving between towers/parts. I'm not familiar with how you do that in repsnapper, but in skeinforge you adjust the "dimension" tab.

> i have had NO success with
> steinforge(doesnt seem to move my Z axis enough))
Your layer thickness under the carve tab must not have been high enough. The "bottom" tab also has some settings that control the altitude at which the first layer is printed. Perhaps it was set to start printing too low? There are some "nozzle lift" settings in the "raft" tab that have similar effects and might lead you to think the Z axis wasn't moving enough if they were used/not adjusted.
Re: General Tuneup Questions
January 29, 2011 06:43PM
hey
thnx for the response, begining to think i owe you tech support dazed tongue sticking out smiley
right
1. will get pic up 2morrow as left cam at work(part of me phone) but i suppose what i mean is a gear for example would look more like a lumpy circle than a rounded gear.(doing a few at a time helps) but......
2. strings are very thick and are literally every layor or 2, cant see any repsnapper options for this
3. i set my layor thickness to the same as repsnapper(3.8), it would appear to be a speed or timing issue
i have adjusted Z speed in limit(i use 50mm/min on repsnapper but anything over 0.5mm/sec on steinforge just beeps at me. just now it seems to move the z belt a very tiny amount between layors, its like when i changed the limit the motor knows to go slower, but doesnt know it has to stay on longer.....

sorry its jsut bout bed time tonight, i'll clean this up/ make a new post in the morning.
cheers
brian
Re: General Tuneup Questions
January 30, 2011 04:26PM
BrianRowes Wrote:
-------------------------------------------------------
> hey
> thnx for the response, begining to think i owe you
> tech support dazed tongue sticking out smiley
> right
> 1. will get pic up 2morrow as left cam at
> work(part of me phone) but i suppose what i mean
> is a gear for example would look more like a lumpy
> circle than a rounded gear.(doing a few at a time
> helps) but......


> 2. strings are very thick and are literally every
> layor or 2, cant see any repsnapper options for
> this

Repsnapper has options to reverse the extruder to stop ooze. I couldn't get repsnapper to work right with this option turned on either. With skeinforge, I don't get strings between parts.

> 3. i set my layor thickness to the same as
> repsnapper(3.8), it would appear to be a speed or
> timing issue
> i have adjusted Z speed in limit(i use 50mm/min on
> repsnapper but anything over 0.5mm/sec on
> steinforge just beeps at me. just now it seems to
> move the z belt a very tiny amount between layors,
> its like when i changed the limit the motor knows
> to go slower, but doesnt know it has to stay on
> longer.....
>

Did you turn off acceleration in the firmware? I read on this forum that this needs to be off for Skeinforge to work right with the Mendel.

> sorry its jsut bout bed time tonight, i'll clean
> this up/ make a new post in the morning.
> cheers
> brian
Re: General Tuneup Questions
January 31, 2011 07:00AM
I'm using acceleration and skeinforge 39. Seems to be working ok for me. It doesn't seem to change speed a lot while printing, so maybe it isn't making enough of a difference to matter or maybe skeinforge doesn't produce Gcode in a way that acceleration actually gets used? The only time I notice acceleration is when it goes to home between layers, which is done by a few lines of hand written Gcode.

>i set my layor thickness to the same as repsnapper(3.8)
That must have been number of rotations or some sort of scale factor. In skeinforge, the layer thickness is set in millimeters, so if you did that it should have been going up by 3.8mm every layer - that is way too high unless you have a 4mm nozzle or something smiling smiley

My layer thickness is currently at 0.29mm with a 0.5mm nozzle.
Re: General Tuneup Questions
January 31, 2011 07:09AM
You have Repsnapper set to 0.38 mm which is a good value.
Have you set CARVE - LIMIT Z-axis maximum speed to 1.0?


Bob Morrison
W├Ârth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse
Re: General Tuneup Questions
January 31, 2011 02:12PM
hey all


brnrd Wrote:

> Did you turn off acceleration in the firmware? I
> read on this forum that this needs to be off for
> Skeinforge to work right with the Mendel.


thnx
this helped alot! still not getting good gears but steinforge worked and the quality difference is imediatly apparent. no more bumps and really nic finish on all side.
got my limit set to 0.8 just now and yeah your right im at 0.38 not 3.8 (height)
will adjust this when ive fixed up tight corners and know how steinforge works...

will read some more steinforge tuneup guides before i keep asking questions on making gears you prob heard a million times.
thank you everyone for all the help
think im at a quality level thats around normal now grinning smiley
time to find out how to make gears more defined and get their fill right.
from what ive saw common problems that i'll hopefully find answers to without having to start another "save me" thread

cheers everyone.... this is fast becomeing a "TECHZONE lasercut mendel, configured by COMMUNITY"
but with better spelling.....
cheers
brian
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