What is a RepRap?
Common Questions

We've read some great questions from new RepRapper's so we thought it could help everyone if we put them online.

Is it possible to print directly to glass?
It's easily possible to reliably print on a glass surface. Try this:
  • Make sure the glass is perfectly clean and keep it clean. Use isopropyl and use caution, that stuff is toxic. You shouldn't need to clean it that often as long as you don't touch it. I clean mine about once per month.
  • Before each print (before preheat), spray witch hazel (astringent [~14% alcohol]) onto the glass with a fine mist sprayer.
  • Set your heatbed to 53c for the first layer and 49c for each additional layer.
  • Set your hotend to 190c for the first layer and 186c for each additional layer.
  • If you continue to have trouble, try micro adjusting the distance between the glass and the nozzle.

What's an easy way to solder surface mount components?
This can be tricky. It may help if you have a magnifying glass. Watch these videos for tips:

Is PLA better than ABS?
This can be controversial. Here is our opinion on the topic. PLA is better than ABS for a lot of reasons. Here are a few:
  • ABS gives off toxic fumes while printing.
  • ABS is derived from oil which is bad for the environment.
  • ABS makes softer parts versus more rigid parts which is bad for gears.
  • ABS is more difficult to print.
    • It doesn't adhere well to the print bed.
    • It doesn't adhere well between layers which can cause splitting.
    • It shrinks.
  • ABS causes more wear on the printer.
  • ABS requires higher temperatures.
  • ABS requires more electricity.
PLA has a nice, safe, sweet smell while it prints because it's made from corn starch. PLA is also FDA approved which means you can use it for food stuffs like cookie cutters or you could use it in an aquarium.

Here's a video which demonstrates the strength of PLA versus ABS:

What size objects will I be able to print on the Prusa Mendel Iteration 2?
The Prusa 2 has an effective printing area of 180mm x 180mm x 130mm (7" x 7" x 5.25"). It's possible to modify the Prusa to get more printing area but our kit is pretty standard.

Can I use standard files produced from SolidWorks to work the RepRap printer?
The RepRap uses G-code files. You'll need to use a program such as Slic3r or Skeinforge to convert an STL file into the G-code file the RepRap needs. Some versions of Solidworks can export STL files. You might want to check your export options to see if your version supports it. If you'd like to try the RepRap software, you can download it on our software page for free.

Will I need to purchase any software to use the RepRap?
No. The RepRap community is awesome! Very cool people such as kliment and alexjr have created free open source software you can use for your RepRap. If you're interested in designing 3D models, there is even free software for that such as Google's Sketchup and OpenSCAD. You can download the software you need from our software page.

How long does it take to build a RepRap Prusa Mendel Iteration 2?
This depends on a lot of factors. Inexperienced RepRapper's have reported taking 2 weeks to build a RepRap. RepRapper's who have built RepRap's in the past can build them in 8 hours or less. Our assembly videos demonstrate the entire assembly process and they account for about 8 hours of video. If you're mechanically inclined, detail oriented and good with tools, it shouldn't take longer than a weekend. Once it's constructed, it could take time to fine tune the printer.

How accurate are the printed parts?
All of our printers print with a 0.5mm nozzle and a 0.3mm layer height. The X, Y and Z axis' on our parts are accurate to 0.02mm or 20 microns. With patience, proper configuration, and calibration, you can achieve the same. It's also possible to achieve a 100 micron layer height and that is adjustable in the software. A 100 micron layer height might work better with a 0.35mm nozzle. You could purchase this separately and swap the hot end. Note that when you decrease the layer height, you decrease the speed and it's fairly proportionate. Half the height equals twice the time.

What makes a great hobbed bolt?
It's all about the grip. A great hobbed bolt can push filament into a hotend without slipping. The bolt needs to contact as much of the filament as possible and dig into the filament to keep hold. It can't dig too deep though or it will damage the filament by kicking out little pieces, which reduces traction. This can be achieved by having a good ratio of teeth which are sharp and which wrap around the sides of the filament. We've tried a variety of hobbed bolts. Some were useless and some were fantastic. The most reliable and readily available hobbed bolts which we prefer to use in our production printers are the Hyena hobbed bolts made by Arcol and the Concentric hobbed bolts made by Airwolf 3D.

Do I need to adjust the stepper drivers/motors?
Yes. It's essential to properly adjust the stepper drivers. Whether you have Ramps or Printrboard electronics, you'll see potentiometers on each stepper driver. There are a couple of ways to adjust these. The most common method is to turn down (counter-clockwise) the stepper driver until just before the stepper motor stops working. This can be done by using the following steps:
  1. Connect power to the printer and connect to the printer in Pronterface.
  2. Activate one motor.
  3. If the motor operates smoothly, disconnect from the printer and disconnect power to the printer.
  4. Turn down the stepper driver by using a plastic screwdriver. (turn counter-clockwise)
  5. Repeat the above steps until the stepper motor does not move when you activate it.
  6. Now you can turn up the stepper driver to it's previous position. This is the most efficient setting for the motor.
Another method is to measure the temperature of the stepper motor and adjust the stepper driver until the stepper motor is operating under 40 degrees celsius. If you can, tune it to operate at around 35 degrees celsius.