No updates

I need to apologize to all of you who have looked at my blog lately. With how busy summer is I just havent had time. Also being on a third floor apartment that has sun directly on it from morning to evening makes it really hot and the last thing i usually want to do is sit by a wicked hot printer. I have been printing things here and there, but just the garden supports as my plants are bigger and taller.

Farming meets Engineering

So I finally have a update! It involves my background in farming and my education in Engineering. I have been working hard at developing some much needed supports for our container garden. We live on the third floor of a building on top of a big hill, this means tons of wind. We wanted to grow some veggies this summer and the best option we had was some container gardening. The only problem, the wind out on the deck. I decided that I wanted to make some kind of support for the plants.

The second problem was, if I tied them directly to the pole it would limit the plants movement in the wind so much it could make it brittle (first zip tied plants directly to pole but eventually the plants broke). By allowing it a little freedom to move around they seem to be doing much better.


These little things are what I came up with.

These legs slide down onto a wooden rod stuck into the pots. They are fully configurable, 1 leg (not shown), 2 legs (not shown), 3 legs, 4 legs, 1 slot deep (not shown), 2 deep, and they all accept extension arms. There are holes that allow for zip ties to go through to attach the extensions, attach a clamp (shown above 4 arm) and to attack the plant in the large semi circles without crimping the stem of the plant.

This shows a 4 leg (development version not finals seen in previous) holding up the stems of some young cucumber plants. There is a small hole in the side of the part with a screw to tighten it against the pole at the height desired.

In this picture it shows 3 young tomato plant. You can also see an extension arm added to reach out to the one plant a little too far away. 

This picture is a little dark because I still have to keep this plant inside. These are some beans that grow very rapidly and damage easily in the high winds out on the deck. I have two of the 3 short legged arms and one normal 3 leg with extensions to spread the leaves out better for more sunlight in the window. 

Overall I couldn't be much happier with the way these turned out. Very easy to print parts, longest one taking 1 hour, and highly configurable. 

When printing I use a "Brim" to prevent the long skinny legs from curling up. The "Brim" technique takes the normal purge loops and puts them up tight to the part. This additional surface area helps the part stay stuck to the beg the entire print. 

Lions and Tigers and.... Whale Tails?

So the wife has been asking me to model the Whale Tails for a while since we always drive by them and they are visible from her office. After a lot of modeling and a few failed prints I finally got them to print well!

Now these are definitely very hairy when they print. That's because the printer prints the perimeter on the left one, the perimeter on the right, then back to the left for infill, then back to the right for infill, then back to the left for the next layer. In between each of the move stages a little bit of plastic oozes out of the nozzle and drags across the gap. 

I little post production cleaning and they are good to go! Also I printed some lion heads :) No real reason I guess, but why not?! PS maybe I lied a little... no tigers..

Calibrating again

So I decided recently that although I was happy with my prints, it was time to yet again try to improve them. I picked this object because I was previously having problems with overhangs, the nozzle being to hot, and extruding too much filament.

After printing a bunch of simple test perimeters (1 extrusion width cube walls 20 layers thick) at all different layer thicknesses, I decided to drop my layer height from .32mm to .28mm. I also adjusted my hot end temperature. I was running 250 degrees C but now lowered it to 220 degrees C. In slicing objects I set my retraction to .9mm. Finally, because of the lowered layer thickness there was just too much filament being extruded. I set the extrusion multiplier to .8 and now its just right. 

This is how a hollow cube printed with those settings. Wayyyy better than anything before with skinny features and bridging. With my previous settings the legs would have just melted and the print would have never completed. I used to have huge strings between features too. Now the strings are minimal and easy to clean up.  There are also no massive drag marks in the solid surface from the nozzle. 

Garden Spout

Printing a water spout to fit a 2 liter bottle for the wife and watering the garden 

Works like a charm! Threads on, a little loose but after taping the threads on the bottle its nice and snug

It was a pretty fast print since its mostly perimeters

Gen6 Board Enclosure

Ok so nothing really that new here for many RepRappers, but I made my own gen6 board enclosure. It was a really long print and took a lot of material (relatively to my other prints). I can now enclose my electronics to help protect them. A vent on top was placed for future hook up of a fan. 

In my older posts you will see that the board is mounted on the acrylic on the face of the machine. This limited my z-height to 43mm. I mounted the acrylic on top of the unit and spent hours rerunning the wires and getting them to look neat and out of the way. Now I have a max Z of 82mm (could go a little higher but being safe)

Soppha

Another complex print handled beautifully. Soppha's head is an excellently detailed miniature statue. when holding at a distance the print is truly beautiful. Unfortunately due to the position of my circuit board I am limited to 42mm of print height. I will soon be changing that! Then I can make her even bigger. 

My recommendation to fellow reprappers who try to print her this size, set the purge perimeter in slic3r to 5x around 3 layers thick 0mm from the part. It will make the base of the print for her a little bit bigger and easier to stick to the bed. The first print came off the bed when I got to her neck.

3d Knot!

So I decided with the new upgrade I should try something a little more complex. I downloaded the STL files for a knot. Which is one continuous loop printed on a little platform. The loop never touches it self and passes through the various openings. This is something that would be impossible to machine so it definitely shows the capabilities of 3d printing. 

Time lapse of print. 1400mm of filament, 70min 15sec of print time

Finished, looks a little hairy in some sections but it will clean up nice

Just another view before cleanup

Post cleanup Top

Post Cleanup Side

Software Upgrade

So I decided to make the firmware switch from Sprinter to Marlin. Wow what a difference! Before on sprinter my circles were out of round by 1.1mm and were very jittery. With Marlin my circles are out of round by .3mm and runs smooth as butter. It also runs so much quieter. 

This is a Wades Extrusion gear comparison. The one on the right was Sprinter, the one on the left Marlin. Although it may be hard to tell from the picture, the Marlin print is much more round. The rest of the print quality on this part had major improvements. 

Some thoughts on Marlin.... The change over was very difficult for me. It took a few nights and hours of programming to get it to work correctly. It definitely improved quite a lot but was very frustrating. The direction are very unclear at best, and because every printer runs differently it was hard to get it configured. 

I also decided to get Autodesk 123d this past weekend! Pretty cool, I like it better than sketchup but still nowhere near Solidworks (which I wish I had)

Tweaking

So I spent a long time playing with different temperatures and layer thicknesses. I also seemed to be having too much fill causing the nozzle to drag on solid filled areas. I adjusted the ratio of filament output.

All of my test pieces, was keeping prints small to not waste filament and just test with settings. My optimal settings were 240 Degrees C, .95% extrude ratio (extrudes .95% of calibrated rate), Layer thickness .32mm. Ambient room temp for all prints so far has been around 70-75 degrees F

These tests are using Pronterface (GUI), Sprinter (Firmware), Slic3r (Gcode generator) and Google Sketchup.

New Print Bed

So previously I had mentioned that I upgraded to printing on a piece of glass from the Home Depot. Well, that was working very well but I was still getting some warping issues and sometimes the glass wouldn't seem that hot. It was suggested to make ABS juice out of dissolved ABS scraps, but I didn't really want to store acetone in my apartment.

An opportunity arose to get a hold of a sheet of flat ceramic. This is a little bigger than the heat bed, but the corners are rounded enough to make it fit. It is flat and parallel within .0002" but failed due to a large chip on one of the edges. Instead of letting it get shattered in the dumpster I asked permission to test this $1095 plate as a print surface. 

The ceramic heats more evenly than the glass ever did, and I do not have insulation under the heatbed like many suggest. The ceramic holds the heat very constant. The ABS would not stick to the bare ceramic so I still needed to use Kapton Tape. I purchased a 1" wide roll from Amazon. So far I have had no warping and the adhesion has been awesome. Even on some bigger prints (no pictures of those)

Extrude Axis Cooling Upgrade

This is a sweet upgrade I did. Haven't tested the cooling capability, but it looks like it will work well

Here is a cooling kit that I purchased for just 9.99! 2 heat-sinks, thermal paste, double sided thermal tape, and a heat-sink with build in fan. It also has to quick attach pushpins.

I immediately whipped up a bracket to fit around the extrude motor and line up with the mounting holes. The holes needed slight reaming. The print as a hole looks beautiful and only required about 300mm of filament 

End view of fan heat-sink to see how bracket was fitted. Underneath the copper I put down a full layer of kapton tape, this was to protect the motor from the thermal paste but still provide good conductivity. It also works as a vibration shield. 

Here is a side view showing the quick push pin. Hopefully I will be doing some heat testing tomorrow!

The smaller additional heat-sink might be placed on the face thats showing in the picture if needed. If not both extras will be put to use on the other motors. 

Update! 4/23

The extrude motor was still getting fairly hot so I added the small heat sink to the side with some of the double sided tape. Major improvement.

Temporary Cooling

Some of my current temporary cooling for my stepper motors. On the two 30-40 minute prints I have done the Extrude Motor gets very hot. Not to mention the X and Y motors get pretty warm. I can only imagine what they would be like for a few hour print. 

A thin ceramic plate attached to the extrude motor with a cooling fan blowing down on it did the trick! Only limits me to a small print area for now (ok no big parts yet)

Haha the fan wiring I'm proud of. I used an old scavenged server power supply fan with a very high airflow rate. I ran the wire back to a nine volt battery that is taped in place to one of the Z axis motors. I also hooked up a scavenged 115/230V switch out of a power supply (works just like an on off switch if you know how they work). Some alligator clips, electrical tape, and a paperclip make it complete. Oh yeah and the zip ties holding the fan so it blows onto that ceramic plate

 

X axis cooling. Now I particularly like this one. The are three ceramic L shaped pieces with a hole in them. The fit pretty snug to the motor and were easily zip tied in place. Will do the same to the Y axis.

Ceramic is an excellent conductor of heat. These small amounts of ceramic are very efficient at pulling heat off the motors. These ceramic parts are scrap parts from my workplace and I do have permission to use them.