Frequently Asked Questions - 3D Printing

3D printing is the process of creating physical objects from a three dimensional digital model. This technology has been around for awhile, but typically used by engineers and industry designers. 3D printing technology is quickly evolving and therefore public printing is becoming more common.

Cura is the software developed by Ultimaker to make 3D printing as easy and streamlined as possible. It includes everything you need to prepare a 3D file for printing and to print it. Cura is fully preconfigured to work on the Ultimaker. This is the software that speaks to the Ultimaker printre and converts the .stl files into .gcode (which is what the printer reads)

The printer is for use by current McMaster students, staff and faculty. If you are a visiting researcher and would like to use the printer, please contact the manager of the Lyons New Media Centre (Rhonda Moore - to see if special arrangements can be made

How long will my print job take to print?

Printing a 3D object is not the same as printing something on paper. It is not an immediate process. As a 3D print starts with a bottom layer and works it's way up layer by layer, an average object can take between 4-5 hours to complete. If you download Cura, the free software used to prepare files for the Ultimaker2 3D printer, it will give an estimated printing time based on the size of your object.

Beyond this, it is difficult to estimate a time due to a number of factors:

  • number of requests in the queue
  • number of prioritized requests in the queue
  • processing time
  • size of individual print jobs
  • hours the Centre is open (we cannot print outside of regular hours)
  • unforeseen technical issues and repairs

You can always email Lyons ( about your request. While an estimated time cannot be given, you may find out how large the backlog is at the current time.

What happens after I submit my request?

Your request submission is placed in the processing queue. When your request reaches the top of the queue, staff will open the .STL file in Cura to examine the object. Staff look at different criteria including, but not limited to:

  • requested size of object
  • the printing time required for that sized object
  • the type of object
  • whether or not it is a viable print (does it have a solid base to build from or is it rounded on all edges; does it have any 'overhang' that would necessitate printing with support structures, etc.)If there are any issues wiht the request, staff will contact you via email for clarification or to deny the object if its' just not a viable object for printing. If there are no issues, the request goes into the printing queue.

Once in the printing queue, it's just a matter of getting to your print request in sequence and making the print attempt. Should it fail, you will be notified via email of the failure and what happened. At that point, you can choose to submit another request for a different object, if you wish.

It the print job succeeds, you will be notified via email that it is ready for pick up. You will be asked to bring your valid McMaster ID card with you. 

The 3D printer prints objects from the bottom up, layer by layer.  Here are a few things to keep in mind when looking at an object:

  • Does the object has a flat solid base?
    • a good design will have a flat base to build up from. The base has to be wide enough to balance the rest of the object
  • Are there overhanging sections?
    • Objects such as arms that stick out from the model cannot be printed in mid air. There has to be some type of support built up from it in order to print.  Look for these overhangs and add supports if necessary
  • Does the object have a top/lid?
    • The printer cannot print in mid air and therefore printing a lid for a box or other type of object will not work too well. The filament will fall down into the object as there is nothing to support it underneath.  If you are printing a box type object, think about separating out the two pieces to print separately

Due to the large number of print requests that we receive, we cannot hold onto a finished object indefinitely.  You will receive an email once your print job is complete with a deadline date for pick up (typically a month). Staff will send out a reminder email if the object has not been picked up in a few weeks time with a final date.

If an object has not been picked up by the deadline, we will recycle the object.

If for some reason, you cannot make it into the Centre to pick up your item within the designed time, feel free to email us to let us know.  We will do our best to hold your item for you.

I notice there are different materials such as PLA and ABS.  Can I choose the material to use for my print?

We only use PLA in our 3D printers at this time.

I would like a specific colour for my 3D print. Can I choose the colour I want?

No, sorry.  Once a colour spool is installed, it remains on the printer until it is finished.  With the number of print requests, it would take too much time to change the colours for every print job.

It is not recommended that you use anything printed on the Lyons 3D printer for food or drink. The PLA we use is a porous material, so bacteria can easily get trapped inside the material, which would be bad for anything you are going to ingest.


I don't know anything about creating a 3D model. Is there somewhere I can just download a model to print, that someone else created? 

That's ok! There are a few sites from which you can download pre-designed models (and the creator has given permission for use) including YouMagine and Thingiverse

YouMagine is geared more toward the capabilities of the Ultimaker2.  Thingiverse is geared more toward the Makerbot printer, but many models will work on the Ultimaker2.  Keep in mind, however, that not all models that are on these sites have been tested. Some might work and some might not. Check the comments box on the website for that model to see if others have actually printed the model in question.  Have a proper look at the model in Cura to see if it looks like a printable object.