New Atari 8bit development pcb tool is available.
Some might find a use. Others may think it is useless. I’ll be adding additional development pcbs in the near future so stay tuned.
Post four in the continuing saga of the new 3d Printer. So far I’ve fixed a misaligned Y axis, discovered how to level the print bed, how to use the slicing software that came with the printer to get the gcode to the printer and printed a few objects of increasing complexity and print time to see how well the printer functions on long prints. I’ve noted a few strange noises that I am concerned about, but at this time do not seem to affect the print quality. With the last two prints I also began testing the detail capability of the printer.
So far I have been somewhat impressed with the printer. My previous printer, when it was working right, produced very good prints. This printer at about half the price is giving it a run for its money, and I’ve just been using the stock settings and filament. There are hints that using a more refined slicer program such as Simplyfy3D, playing with the layer height and/or changing the filament manufacturer could drastically improve the print quality even more. I intend to explore all three options in time. Durability of the printer is another concern, but can only be answered in time as I continue to print.
One of the first major problems any maker has when they first start out is getting the print to stick to the bed while printing and only come off when the printing is done. Sometimes it is not as easy as it seems. There are several reasons for print lifting.
1. Bed not level
Bed has to be level period.
2. Wrong bed temprature for the plastic used
ABS needs bed temperature of 90C at least
PLA needs no heated bed
Other plastics need somewhere inbetween
3. Mismatching the plastic adhesion to the bed material when hot/cold
ABS likes to stick to tape or glass, usually Kapton tape or borosilicate glass
ABS slurry or Scotch glue stick application gives extra adhesion
PLA can handle bare aluminum, but prefers blue painter’s tape
Polycarbonite needs heavy duty adhesion like BuildTak sheets
My first printer was notorious for psyching me out. Ten minutes into an hour long print, usually after I had convinced myself that I could pop out of the room to do a quick job somewhere else in the house, the print would lift from the print bed. It would then begin a tangled dance just above the print bed, growing with every extrusion of plastic. I’d come back in and discover a plastic art master piece that would win acceptance in the most famous art museum of the world if they had a category for it. I had a steadily growing pile of failed prints.
But I digress, so far once I had the bed leveled I haven’t had a failed print yet. Using Kapton tape and a light smear of Scotch glue stick. It’s so nice to finally have a printer that behaves itself. Or rather it hasn’t misbehaved yet. 🙂
The next major problem any maker has is the quality of print. Sometimes it’s a search that never ends. Just about the time you think you have the right formula dialed in, the slicer software upgrades and something minor in how it slices changes, now your prints are a mess again. Sometimes the filament manufacturer changes their formula and now you have to recalibrate your settings to get back the previous quality. Sometimes you never do and you have to start experimenting with other filament manufacturers product. Then you have the rest of the variables of temperature, different colors filament sensitivity, earthquake induced changes in bed leveling, (I’m serious….. Oklahoma is surpassing California in earthquake frequency) etc.
So this is where we are right now. Dialing in the right formula to produce the best quality print. When we last were here I had printed one half of the KM-20 cartridge shell with the stock settings and filament to see what quality came out. I was pleasently surprised. But of course it can be better. I tried mating the printed half shell with the injection molded copy. It wouldn’t. So I mused that maybe it would mate with another printed half shell. It still wouldn’t. So why?
There seems to be four most likely reasons.
First always is the model. If it ain’t there, your prints won’t be there. Could there be a problem in the model itself? Since I didn’t create the model, I don’t have source files just the end product of whatever cad program they used. I did load the .stl file into MeshLab and noticed no obvious problems. So for right now on this print I have to put this reason in the neutral catagory.
Second is the printer settings. Specifically the layer height. Currently I am using the default setting of .3. Going down to .2 would increase the accuracy of the print, but would increase the print time. It is a reasonable trade off for this type of print. So the next print session will be at .2
Third is the filament used. It’s amazing how much variety there is in a supposedly standard diameter of 1.75 amoung different filament manufactures. Currently I am using the filament that came with the printer from XYZprinting. I do have two rolls of Hatchbox, a black and a white. I also have a grey roll from Jet. I used Hatchbox with my other printer, but Jet is an unknown. Changing filament is a process that can take half an hour to do. It’s not just unload the old and load the new. There’s several additional software steps and info entry. And on this printer they did not supply a spool holder for 3rd party rolls. Besides in any testing you only want to change one thing at a time. So for now I will continue to use the supplied filament. This reason goes into the neutral category for now.
Four is the slicing software used. Currently I am using XYZPrinting Pro to slice and send the info to the printer. While recent software updates have addressed several critical voids, the software is still primitive compared to Cura, Slic3r or Simplyfy3D. My favorite is Simplyfy3D. I’ve owned it for a couple of years now and it is well maintained and very customizable. Granted it is not free, but you get what you pay for. Customizing support structures is one of the unique features I haven’t found in any other slicer program. Currently they do not officially support Da Vinci 1.0 Pro, but all the other XYZprinting models are, so it shouldn’t be very long before they do. In the meantime some enterprising souls on Thingaverse in the Da Vinci Printers group have been experimenting on their own with Simplyfy3D and have come up with some scripts that allow almost complete compatibility. The missing factor is direct transmission to the printer. Currently XYZprinting software is still needed to transmit the gcode to the printer. There’s no direct access to an SDcard, but there is a mod for that. 🙂
So for the next printing session I will print both halves in the same printing session, at .2 layer height 20 % infill using the same software, filament and model. Here goes……..
Okay printing session over. 3 hours and 50 minutes worth
First picture tells most of the story. Bringing the layer height down to .2 did make quite a bit of difference. You can see less defined printer layers at the .2 compared to the .3. The edges became more accurate. There is still the split in parts of the lip and grove and in the horizontal bar at the bottom of the half shell. Not much changed there, which leads me to believe that it is an error in the original .igs file or the conversion to .stl.
On the back of both half shells you can see the difference as well. In this case I think applying an acetone bath would smooth out most of the remaining printer layer striations. That would leave very smooth surfaces. To get a textured feel and look would require applying light grade of sand paper/rasp etc.
Still the halfs do not mate. Though it does look closer than before. It would seem that 3d printing at least with the printer I have does not have the same tolorances that an injection molded part would have. A redesign of the model allowing for thicker lip and groove measurements would be the next step.
Now I am feeling ten feet tall and bullet proof. The previous two real prints were tools that helped me make other things on my projects. On the smaller one the print time was only about 7 minutes. On the bigger clamp jig the time was around 40 minutes. Both came out as good as I was expecting.
Okay now it’s time to try some serious 3D printing. For my first serious print I want to see how well the stock ABS blue filament and stock settings on the printer handle finer details. I chose to try a print of the KM-20 cartridge shells made by Maszczyk. I dl the .igs file from their website, bring it into Solidworks and convert it to a .stl file. I then load that into the XYZPrinting Pro software for slicing and transmission to the printer. I chose to only do one half of the complete shell to keep the print time down. The estimated time is 1hr 30 minutes. It takes 1hr and 40 minutes.
The printer never balks. There’s a strange dragging sound sometimes when the extruder makes a long x axis run, but no obvious indication in the print that there is any resistance. I mark that down as something to investigate further.
So how does it do? Well see for yourself. I’ve put the printout in blue next to the original in black. Pretty good for stock settings. Not an exact copy, but I didn’t expect that.
The first thing I notice is that the original black half seems slightly smaller. ABS used in injection molding is notorious for shrinkage, 3D printing doesn’t seem as bad. I tried to mate the original with the 3D printed one and they do not fit together. Next I’ll try printing another half shell and see if it will fit the first one.
Then I notice the finish. The original has a nice textured feel and look on the back. The 3D printed one has the classic 3D printed look as each layer is built one upon another. I have some smoothing material that I will try and report on in a few days. I bought it a long time ago when I first got the FF Creator Pro, but never used it.
On the back of the original there is a round dimple that provides a very thin cover over the center screw hole from the back. The 3D printed version tries, but just can’t handle that dimple without support. The print was started with the back laying on the print bed. Truth be told I’m not sure how I could add support. It’s just so thin, maybe around .1 mm, definitely not more than .2 mm. The printer does handle the rounded top edge bottom very well. That’s called a slight overhang in 3d printer terms.
Now we turn the half shells over to compare the internal features. Again we see the classic telltale 3D printer finish in the center post and the inside sides of the half shell. This can be minimized by lowering the printer layer resolution, but it increases the print time significantly. I printed at the stock .3 mm layer resolution. The lip and groves seemed to print well, until you get towards the bottom of the half shell. Then we begin to see a strange split developing in an otherwise solid lip feature. We see the same issue in the horizontal bar running across at the bottom of the half shell. It’s pronounced enough that I can get my fingernail between the two halves. That I do not think is a printer issue. I believe that is a result of an error in converting from .igs to .stl in the 3D model.
Over all the print seems to turn out well. Definitely will need to fine tune the original .stl file to eliminate the splits in the lip and horizontal bar. The next thing would be to fine tune the layer height to improve the finish and accuracy of the print. Smoothing the print using acetone is also an option. The apparent size difference between the black original and the blue printed half shell is going to be harder to deal with. I think the filament used is a major factor there, with maybe a slight scaling down of the .stl file. But it’s a very slight scale amount.
More to come.
Over the next couple of days I begin dialing in the printer to a working state. First I have to learn how to level the bed, each printer is a little different. Then I experiment with various materials to find the right combination that will keep the print object stuck to the bed until the printing session ends and I want it to come loose. Kapton tape is a bitch to apply, but in my case seems to work better than the glass bed I tried. Add a little Scotch Glue stick application and it seems I’m ready.
I start my prints small. I have designed a couple of tools that I hope will help me put together my products for sale. First is a simple 1.5mm high 45mm long plastic piece that should help me crimp leads on the edge card connector for the SDX cartridge project. I adjust the height upwards and make several prints. The prints are coming out just fine.
I notice a ticking sound on the first layer or so and then it stops. Back to Google to see if anyone else is having the same sound. Yes, they are too. No immediate concern and no definite reason. A mystery still to be solved. I will track the discussion.
Then I try a bigger print. I am using a ribbon cable connector that can be soldered into a pcb on another project. But I am having problems getting the ribbon cable clamped into the harness without damaging the solder pins on the connector. So taking a page from the yellow plastic mold on my ribbon cable clamper, I design another mold to allow the pins to seat into a recessed rectangular hole while the body of the connector is held in the clamp and the ribbon cable is able to be firmly pressed against the forking pins. Anyway…. almost another flawless print. And it works.