CTC Dual- great results after several essential Mods...

[Raymo]

Folks,
Thought I'd share my findings on the CTC Dual...

I finally have good consistant results from this puppy but I needed to make several essential modifications.

Essential mods/fixes
Glass Bed- use any hair spray for adhesion
Replace thermistor on heated bed- mine was ‘off’ by 30 degrees
Replace thermocouples on head- mine were ‘off’ by 40 degrees
Replaced filament extruder with adjustable tension, this ensures constant filament feed. Set correct tension when feeding at maximum (use feeder change function), too tight is just as bad so find the sweet spot.
Added front part cooler with 40mm x 20mm 24v fan, reduces droop and sag
Replace belt tensioners with non-spring type, reduces backlash
Add pillow block bearings to front and rear rods
Replace Z axis rod ends- make sure Z bed is not ‘rocking’ left and right
Check there is absolutely no play or slippage where belts connect to the carriages, add shims if necessary to get a tight grip on the GT2 belts.
Add Sailfish Firmware

Non essential mods
Replaced bearings with oil impregnated brass type- less noise
Replaced white drive cogs (X and Y) with aluminium type (with grub screw), reduces backlash
Added Bowden feeder- eliminates ‘pull’ on head
Added x axis cable holder, looks better!
Add internal LED light strips… easier to see prints in progress

Slicer settings: S3D or Slic3r (I have best results with S3D)
Print “Inside out” for best surface results
Measure extruded filament diameter and set in slicer
Use retraction: 1mm
Restart distance: -.1mm
Coast: 0.1mm
Print with skirt to clear feeder
Infill, 10% overlap
120% extra width
Print with lowest temp possible to achieve good bridging
Keep retractions to a minimum
Use aligned start points where possible
Allow reduced speed printing for small segments


Hope it works out for you all...

here is a short vid of my end results....
https://www.youtube.com/watch?v=k0Xa-TqmTNA

Ray

[noiseboy72]

Nice list!
I would add to essential mods moving the X-Axis wiring loom, as it is a major failure point on these machines. It bends over just a few inches and will fail after a few hundred hours. Let it hang down, or as you have done, put it in a cable guard flexing from the base of the machine.

I personally use Buildtak and find that all common filaments adhere well to it, including ABS, PLA, Ninja etc. I agree with replacing the heated bed thermister, but my extruder units were OK, being just a few degrees out at operating temps.

Pulling the belts too tight can add too much friction to the system and actually make things worse, as the motors take a moment to overcome the inertia and this causes accuracy issues. Nylon drive cogs and a reasonably tight set of belts is fine. Just make sure you get the tension on both Y Axis set ups the same. This is the main cause of problems, with one side moving slightly before the other.

I have also added LED lighting and a 2nd spool holder, along with lengths of tubing and positioners, a new mount for the top of the extruders to reduce cable stress and a sprung extruder setup for bother extruders. I found I did not require an adjustable system with any of the filaments tried so far.

Side and top covers will also help with temp consistency and help to prevent warping.