Some Questions I have about 3D printing

Ttoch · August 10, 2014, 3:38am

I have visited this and a lot of other 3D printer sites a lot because I have been very interested in getting a 3D printer but I still have some questions that I am hoping some of the people on this forum can answer.

General printer questions

I am still trying to understand exactly what is the resolution of a 3D printer and how exactly resolution on a 3D printer works? I know the layer hight, but what about how thick the lines you are printing out are going to be?
Is the line thickness something that can be adjusted by changing the amount of plastic being pushed through?
And if you can change the line thickness does that also affect other properties like the strength of the layers bonding together or how smooth the finish is?

Also how smooth are the lines going to be, or how accurately can the print nozzle be positioned. If you print a line diagonally across the print surface or a circle and zoom in really close is it lots of small steps or is it one smooth movement?

Are there any videos online of a single printed line under a microscope or just magnified so I can get an idea of the line thickness compared to the layer height and accuracy of the printer nozzle?

I would also like to understand how good the printer is with stopping and starting and how stopping and starting affects the print quality? For example if I wanted to print a single dot of plastic is that possible or do I need to print a line that is at least a of a certain length so the plastic will stick to the surface being printed to more than it sticks to the printer nozzle?

If you could print a single dot then I would think you would be able to build up a picture by printing all the dots for one color and then changing colors and printing the next color.

Plastic Questions

Do you get any plastic when you get the printer?

The plastic is sold in Kilogram but I am interested in how that relates back to how much printing you could actually do. How long is 1Kg of plastic? How long would it take to a printer running none stop to print 1Kg of plastic? And will these answers change for different types of plastic/materials? For example will the same print in ABS take longer or use more plastic than it would if printer with PLA? Will properties like melting point change with different colors or with different batches of plastic?

Changing color or materials, do you need to clean the nozzle when changing from one color or material to another? Or can you change them quickly during a print?

Is cleaning the nozzle something easy to do or a big task? What do you have to do?

More printer hardware questions

I am also interested in seeing what else you could use the printer for.

So if I attach a pen (or paint brush) to the printer could I use it as a plotter and draw on paper? (has anyone done this already?)

Could you attach a small drill and turn it into a CNC machine?

I think it could be interesting to setup a chess board and have the printer move the pieces around, or make a different tool for it so it could be used as a pick and place machine. I think there are lots of other things the printer could do, (rake small desk zen garden, type on keyboard, play a piano, play guitar, draw, paint) but a lot would depend on how much force the printer can put out to be able to push on objects or to lift objects.

Software (Programming)

I am a software developer and I am interested in trying to write software to use the 3D printer as a plotter or for playing chess. So I would like to know how you can communicate with the printer from a computer to tell it to move. Is it just a usb to comm port and you can just send text strings, or is there a drive and an api used for communication with the 3D printer?

Where is a good place to get started with trying to program for the 3D printer?

Purchasing and postage

I live in Australia and would be really interested in hearing from anyone else in Australia that has brought a 3D printer and what your experience was like getting it through customs? And if you had to pay import tax on the printer?

I am also interested in finding out where the printer is shipped from because that also affects weather I would need to pay an import tax on the printer or not? (I am interested in the KITTAZ printer)

piercet · August 10, 2014, 8:19am

Ttoch:

I have visited this and a lot of other 3D printer sites a lot because I have been very interested in getting a 3D printer but I still have some questions that I am hoping some of the people on this forum can answer.

General printer questions

Ttoch:

I am still trying to understand exactly what is the resolution of a 3D printer and how exactly resolution on a 3D printer works? I know the layer hight, but what about how thick the lines you are printing out are going to be?
Is the line thickness something that can be adjusted by changing the amount of plastic being pushed through?
And if you can change the line thickness does that also affect other properties like the strength of the layers bonding together or how smooth the finish is?

On a filliament printer, resolution is determined by layer height, and the hole in the nozzle size. The smaller the hole in the nozzle, the finer detail possible, but also the longer it will take to print. A .5mm nozzle is the “large, fast” nozzle, the .35mm is the standard mid range compromise between speed and final quality. There are smaller ones, but they take literally forever to print with. Changing the amount of plastic being pushed through has some minor effect on the thickness, but usually that results in overextrusion and a blobby mess. The smoothness of the surface finish has very little to do with the nozzle size. a smaller layer height print done with a very small nozzle is capable of showing more fine detail, but even a .5mm nozzle can make a nice smooth surface on a well calibrated printer. Which one to choose really depends on what you will be printing the bulk of the time. a .35mm printer nozzle is a good place to start.

Ttoch:

Also how smooth are the lines going to be, or how accurately can the print nozzle be positioned. If you print a line diagonally across the print surface or a circle and zoom in really close is it lots of small steps or is it one smooth movement?

A lot of that depends on the mechanicals of the printer, how well it is dialed in and calibrated, quality of the filliament, starting layer height, bed calibration, and slicing method. A line or a circle outer perimeter will often be a single motion pass. A printer using high end NEMA servos would probably be smoother than the standard NEMA stepper motor, but there are many many other configuration and calibration tasks to look at before you even think of going that route. There is also a printer effect known as “Z-banding” that you will want to read up on, and ensure you get a printer that isn’t subject to it. THe Taz 4 is a good choice in that respect for what its worth.

Ttoch:

Are there any videos online of a single printed line under a microscope or just magnified so I can get an idea of the line thickness compared to the layer height and accuracy of the printer nozzle?

Probably, I don’t have them. It’s basically extruding frosting out of a cake decorating nozzle, but at a smaller scale. Humidity in the filliament and surrounding air can affect the output stream. It’s a round filliament output trying to build square layers too. Probably a square nozzle would be slightly more efficient, but drilling a square hole that small is not an easy task. and then you would have to worry about nozzle rotation alignment, etc.

Ttoch:

I would also like to understand how good the printer is with stopping and starting and how stopping and starting affects the print quality? For example if I wanted to print a single dot of plastic is that possible or do I need to print a line that is at least a of a certain length so the plastic will stick to the surface being printed to more than it sticks to the printer nozzle?

A very well calibrated printer can print a single dot of plastic. Prefferably a large one. But usually you want a bit of a run up to get the plastic flowing properly. It’s all fluid dynamics on a small scale. You can basically treat extruded plastic the same way you would molten lava. improper starting layer heights or uneven beds can cause pressure buildups that will equalize in later layers, etc. Surface adhesion is a completely different question entirely though. ABS in particular likes to warp and cool unevenly. The surrounding environment has a huge effect on the end quality of a print, and learning to adhere parts properly to the bed is one of the more difficult skills to learn for 3d printing.

Ttoch:

If you could print a single dot then I would think you would be able to build up a picture by printing all the dots for one color and then changing colors and printing the next color.

You could. This would probably literally take you decades and look less than ideal though.

Ttoch:

Plastic Questions

Do you get any plastic when you get the printer?

The plastic is sold in Kilogram but I am interested in how that relates back to how much printing you could actually do. How long is 1Kg of plastic? How long would it take to a printer running none stop to print 1Kg of plastic? And will these answers change for different types of plastic/materials? For example will the same print in ABS take longer or use more plastic than it would if printer with PLA? Will properties like melting point change with different colors or with different batches of plastic?

A 1KG roll is about 2.1lb if I remember right. You could theoretically run through that with a .35mm nozzle in about 4 days or so printing non stop 100% infill giant cubes I suppose. But you generally are printing smaller items with only a percentage of infill. (the more infill, the more solid the object is, but the more plastic it needs) I find a 5lb lasts me about a month or so of intermittent printing. Different materials and applications will change that, but ABS and PLA will both use about the same amount of plastic to print a given object. Some filaments like ninja flex are uniquely useful and expensive so the cost per print would be higher, but amount of material to occupy a given volume of space is going to be fairly constant

Ttoch:

Changing color or materials, do you need to clean the nozzle when changing from one color or material to another? Or can you change them quickly during a print?

Is cleaning the nozzle something easy to do or a big task? What do you have to do?

Changing color, you usually need to extrude about 15-20mm worth of material before the new color actually starts coming out of the nozzle.
Changing materials is somewhat of a big deal because the materials print at different temperatures. Going from ABS to PLA is the big troublemaker, because PLA prints at a lower temperature, so if there is any ABS left in the printer bore, it will not extrude and block your printer nozzle until you raise the temperature and clean the bits of filament you just ground out of the extruder and push it through. Other considerations are ABS sticks to different bed coatings than PLA does.

Cleaning the nozzle is almost never needed. You can clean the surface to keep it from depositing charred leftover printer filament into your pristine thing you just printed, and occasionally, very very rarely you will get an actual foreign object jam (I’ve never seen one). In that case its kind of a pain but you basically just heat the hot end up enough that you can undo the nozzle without risking damage to the threads, unscrew the nozzle, then carefully remove the blockage and re-attach. The assembly process is here if you are interested: http://ohai-kit.alephobjects.com/project/9af024c0-56d9-4d05-b7b3-45974b401f01/

Ttoch:

More printer hardware questions

I am also interested in seeing what else you could use the printer for.

So if I attach a pen (or paint brush) to the printer could I use it as a plotter and draw on paper? (has anyone done this already?)

Could you attach a small drill and turn it into a CNC machine?

Yes, you can do that. you just have to write the gcode to have it do what you want. There are a bunch of existing pen holders on thingiverse you may want to check out. You could also attach a drill and use it as a CNC. I recommend against that particular approach because sawdust and metal filings don’t mix well with 3d printing plastics. You really want two separate devices for that, though I know at least one company is trying to invent a combo printer mill.

Ttoch:

I think it could be interesting to setup a chess board and have the printer move the pieces around, or make a different tool for it so it could be used as a pick and place machine. I think there are lots of other things the printer could do, (rake small desk zen garden, type on keyboard, play a piano, play guitar, draw, paint) but a lot would depend on how much force the printer can put out to be able to push on objects or to lift objects.

It’s an airduino based robot. You can pretty much make it do anything a robot can do. You could technically make your 3d printer into a quadcopter and fly it around town printing parts as it goes if you really wanted to. Flight time might be a little low.

Ttoch:

Software (Programming)

I am a software developer and I am interested in trying to write software to use the 3D printer as a plotter or for playing chess. So I would like to know how you can communicate with the printer from a computer to tell it to move. Is it just a usb to comm port and you can just send text strings, or is there a drive and an api used for communication with the 3D printer?

Where is a good place to get started with trying to program for the 3D printer?

Look up the Airduno (sp?) robotics groups. All the code for the printers is open source, and can be adapted to other purposes. There are purpose built robot arm servo control packages that might be more useful for that particular approach. The source files for the firmware are all on github.

Ttoch:

Purchasing and postage

I live in Australia and would be really interested in hearing from anyone else in Australia that has brought a 3D printer and what your experience was like getting it through customs? And if you had to pay import tax on the printer?

I am also interested in finding out where the printer is shipped from because that also affects weather I would need to pay an import tax on the printer or not? (I am interested in the KITTAZ printer)

Lulzbot has international warehouses, but I don’t know if they have one in Australia. You can fill out the order profile online without purchasing and see what the shipping is that way. I’d e-mail them directly and ask what they have available near you. I do know they have distribution centers in the UK if that helps at all.

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