Two Extruders not Always Fun!

One of the nice features of the Wanhao Duplicator 4S is that it comes with two extruders.  I thought that this would be useful for a number of reasons such as being able to do two colors, do support structures in water soluble PVA, or using one side for ABS and the other for PLA. 

In reality I am finding my self just using the for having easy access to the two colors of ABS that I might have loaded.   Printing with both nozzles simultaneously is challenging!  Since this is the first post on the subject I will talk about some of the teething problems that I had and later about printing simultaneously.

Selecting the right base profile

 

I use Simplify3D and that caused me a couple of problems.  The first might be obvious but it was not to me.   There are four stock profiles available in Simplify3D for the Wanhao (single extruder, dual extruder left, dual extruder right, and dual extruder both).   The dual extruder left and dual extruder right only light up the left or right extruder while the dual one lets both be lit up.   At least I think this is what goes on behind the scenes.   I don't really understand the nuances of why there needs to be three profiles as temperature control for the extruders is granular.  But in any case, I use the profiles as they are named.

Adjustments to be able to use the left/secondary extruder

Simplify3D is a good piece of software.  It does a lot of things that the free alternatives don't do including more intelligent support structures, what I think is a faster print from the slicer, ability to print multiple profiles at the same time, and a good user interface to tweek a wide range of printer parameters.   It is, however, one of the BUGGIEST pieces of software that I use.  One of those bugs concerns how you need to configure to use the left nozzle assuming that you have selected the left profile as discussed above!

The problem is that anytime Simplify3D changes temperature on the secondary nozzle, or the build platform, the firmware needs to be reminded that we are using the secondary nozzle (assuming that is the case).  If you do not do this then you will be in for a surprise as the primary extruder will start clicking as it has not been heated up and the printer will be directing a cold nozzle at your print instead of a nice hot one with plastic coming out of it!

It is pretty easy to correct this problem.  Two changes are needed.  First under the "Tools" menu select "Firmware Configuration".  Get rid of the "T0" at the end of the "Set Bed Temperature" field.  This will keep things from going south if you adjust the Build Platform Temperature.  Second go to the "Scripts" tab of the active "Process".  Select the tab for "Tool Change G-Code" and enter the following code: "M135 T1".  This keeps the printer working on the secondary extruder.  

Note that the above steps are not needed if you are running under the dual extruder profile or with the primary/right extruder.

Adjusting the nozzles so they are level

Obviously the two nozzles need to be perfectly level in order to print in two materials.  

One way to make minor adjustments is to use a small piece of Klapton Tape as a shim.  Do this by taking the extruder assembly out of it's carriage.   The tape will go over the recess area where the bolt secures the extruder assembly to the carriage.   Tape on the side where you want to raise the nozzle!

The other way of adjustment is more likely to be needed if you have had the extruder assembly in bits and pieces for some reason.   In this case there are some printed things that can help:

http://www.thingiverse.com/thing:299331 (one example, there are more).

BTW, if you do have your extruder assembly in bits and pieces there are some good diagrams in this thread that show what is going on with the nozzles and heaters.

Keep the tips of the nozzles clean

 

If you switch back and forth between the two nozzles you need to remember to clean the nozzle that is not in use!   I find that there will often be a little pit of filament still attached to the nozzle that is not in use.   This little bit of filament will grab the stuff you are printing and make you want to kick the dog.   Clean the nozzle before use and the SPCA will not need to come for you.

OMG...another printer????

Have now got a major plastic factory going.  My wife is so very impressed that we have three 3D printers!

Not!

Hey, for most of my life I have had a boat sucking the boat units out of me (boat units being boater speak for the minimum increment of spend when talking about owning a boat...my last boat operated in boat units of $1K). So, with my health ruling out the boat what am I going to spend those boat units on? Technology stuff like 3D printers!

I was very impressed with the quality that I got when moving from my self built, plastic open platform, Prusa I3 to the closed box, steel frame, Wanhao Duplicator 4S.  I could immediately see the improvement in quality and speed.   With tuning it became more and more evident.  When I first got the Duplicator my plan was to sell the Prusa I3 on eBay.  After a while spent with having two printers I decided that I really liked having two printers!

There was a listing on eBay for a used Wanhao Duplicator 4S that caught my eye.   I like the printer.  I had mine pretty well tuned.  It would be efficient to not have to learn another printer.   It was only 400 quid.   Gee, some good reasons.  But I could not get the idea of going one more level up in the food chain out of my mind.   The Ultimaker 2 being that printer.  

There are few people in the world that are better than I am at rationalizing things.  So here was my thinking.  Due to the treatment I received earlier this year for my MS we had decided to cancel our big holiday this summer.  We had planned on a very nice cruise to Iceland and Norway.  Sara is still going to take a break...a high end spa retreat...but what about Will?  The answer is PRINTERS and the budget, compared to the cost of the cruise, could afford the discounted Ultimaker 2!!!

So one night, or morning, around 2AM I pulled the trigger and a couple days later I had another 3D printer!

Glass->FR-4->Klapton Tape->Glass

One of the challenges of 3D printing is model adherence to the build platform.   Searching for this topic will return many, many, many results.  Hours into a print and it pops off the platform can result in loud screams.

The only thing that I ever used with my Prusa I3 was glass.  This may or may not have been helped by the fact that I only ever printed with PLA.  In any case, it was glass with either ABS Goop or Hairspray to aid adhesion.

When I got my Duplicator 4S I started to play with ABS and ended up using FR-4 after finding reference to this stuff on the RepRap Forums.   I have written about FR-4 here as I really liked it at the time and for a while.  What I liked about it was how forgiving it was as a surface...you get good adhesion with a pretty wide range of platform leveling.   I also like the fact that as it cools prints just pop off.  What I decided that I did not like about it was that it was not a completely flat surface and that it seemed to be getting less flat with time!   I was using pretty thin FR-4, and there is thicker stock available, but still.

One of the print tasks that had me frustrated with FR-4 was a job that required a high degree of detail on the first layer (lettering done with 0.5mm strokes).  I found that I had difficulty getting this level of precision with the FR-4 so I got out the Klapton tape.  I have written disparagingly about Klapton tape but it wasn't too bad.   I have a roll the size of my platform and was able to get a new surface relatively easily.  Print adherence was great.  Here in lies the rub.   It was too great and Klapton tape is too fragile and putting on new tape is a pain.

So, it was back to glass.

Pretty Happy With Most Print Quality

I am not sure that I can get much better than this!   These were printed in ABS with a layer height of 0.1mm at 30mm/sec.

Still working on the issue with some angles but pretty happy with this kind of result.

BTW, those are 5mm cubes making up the stack on the left.  They are measuring in at 4.97mm x 5.02mm x 4.96mm.  I think that qualifies as reasonably good for dimensional accuracy as well.

Some more calibration objects, including my ongoing problems, are shown in the second image.  The surface finish test, left most is pretty good and the Marvin is great but for the ridge above his left eye.  The big problem are the edges of the pyramid.  I am assuming this is ooze but have not been able to get rid of it with the various ooze settings.

Finally, a couple more calibration objects.  Obviously the very extreme angle has an issue but I would never design an angle like that anyway.

Down to Brass Tacks...

...on getting the Duplicator 4S dialed in. This is pretty high level of detail work.  The layer height is 0.1mm and as you can see from the coin the objects are pretty small.  It is just certain angled shapes that seem to cause the printer some issues.  The columns are all nice as is the very base of the pyramid.   Even the loop at the top is good.  Just one corner of each of the columns going up at an angle has a rough edge!

On a larger (2x) version the effect is less but the back of the leg is much rougher than the front.