A lot of people when I tell them that I can 3d print items say ‘ that must be expensive to do!’
Now I don’t know whether that is due to the perceived newness of the technology or due to the fact that they know heat is involved so it must use a ton of electricity, but I would like to put down on paper the facts about how much does 3d printing cost.
What are we going to print?
What I would like to use as a benchmark is a 1in (25mm) cube. 20% infill.
For those who don’t know what infill means, it is the fact that inside a 3d print the piece may not be solid. You can set the software up to only print a certain amount , in this case if you melted all of the inside material down it would fill
only 1/5 or 20% of the total volume. This is a way of saving material along with the fact that most models don’t need to be completely filled to look good or need the strength.
The printer will print a lattice for structural strength along with weight saving and material saving.
If you do need to fill it in completely then a simple adjustment in software is all that is needed.
What is the printer?
I am using a Prusa I3 diy kit as my printer, a lot of people would not contemplate building their own printer, and to some degree I cannot blame them.
There are printers on the market now at the same price as my diy kit, these are fully assembled, or at least as close as possible to printing
As time goes on, in the next couple of years, I can see these printers getting even cheaper, along with the fact that schools are now using these as teaching aids.
A person I completed a job for , they had a young girl come round and state ‘ I didn’t know you had a 3d printer’ before they could explain that the letters they had were 3d printed, so it is becoming better known in schools and will be needed when people go to university and beyond.
What type of filament?
The plastic filament I am using is PLA- a plastic made from starch, typically corn starch but can be made from other plants. It is a biodegradable plastic and not the only one to choose from. I tend to use it for the first models and depending on the environment it will
be going into as the final model choice.
There are a lot of materials coming onto the market which can range from looking like wood, metal and glass to flexible materials.
The main ones which are used with the 3d printers are PLA, and ABS, like used for your car bumper. PLA tends to be a little more brittle and dependent on how it is printed will become more brittle, left in water for a number of years it will revert back to it’s former state, hence the biodegradability of the material.
ABS on the other hand is made from petroleum products and will not biodegrade. This material is more flexible and can withstand a few knocks. Other than the fact you need a heated bed and the smell I would use this for all of my prints.
Designing your model
To design a 3d print model you need to have a cad ( computer aided design) program. Or you can just print out someone else’s design by downloading the model from the internet. A lot of the models now are becoming customisable so you can add your own touch.
When starting from scratch, you roughly sketch something down on paper – or keep it in your mind’s eye. The latter has the ability to morph as time goes on, so I tend to sketch down what I originally intended to draw.
Learning cad is not really that difficult – it just takes time. A lot of people say ‘ i’d never be able to do that’ but once you start learning that most models are made up of basic shapes put together then smoothed out, the concept of cad becomes easier. It is not for everyone and there are design houses willing to draw up what you want to see printed out.
The cad programs themselves can be very cheap or very expensive
. The very cheap ones start at free, they can be online, like Tinkercad, or offline like sketchup or freecad. If you want to go for a professional cad system there are very few, if any dedicated cad programs for 3d printing. You need to be aware of things like overhangs, bed adhesion, detail size and physical dimensions. I hope that within a year this wil lbe addressed, I did find one program, Cubify Invent that was written for 3d printing, but I was three years too late – or they were three years too early!!
It has now been taken off the market and not replaced with anything.
Sorting out the costs
So we know which printer, the type of filament. How to draw the model and we are using the free cad. So lets get started on calculating how much does 3d printing cost.
The printer – Prusa I3 £120
Filament – PLA 1.75mm 1kg reel £12.50
Cad – free £0.00 ( or download model)
Electric (2017 prices) £0.12/kwh
Repairs ( parts) £10.00
Maintenance (time)
Failed prints (10%)
Running the 1in cube through the slicing program Cura, it tells me how much material I will use along with how long it will take.
In this case a low quality (0.2mm layer resolution 20% infill) it will take 34 minutes and consume 2.26m – or 7grams – of material.
Decreasing the layer height to give a high quality print takes 1hr 50 minutes and takes 2.28m of material.
So you can see going from low to high quality normally only increases the length of time it takes to print.
I ran my printer on this print with a power meter inline and got an average of 150W.
Let’s take the average life of this printer to be 3 years, is this before I need to upgrade or until it totally breaks.
So a yearly price is £120/3 = £40.
The day rate is £40/365 = £0.11
The repairs are taken over the 3 years so £10/3 = £3.33
the day repair rate is £3.33/365 = £0.01
The filament cost is £12.50/1000 *7 = £0.09
For the low quality we are running the machine for 34 minutes, which is 34/60 hours = 0.57 hours
The total power consumed is 0.57 * 150 = 85.5watt hours
The price of electric is 12p per 1000watt hour
The price of the electric used is 85.5/1000 *£0.12 = £0.01
For the high quality the print takes longer, 1hr 50 minutes or 1.833 hours
so for the high quality the cost goes up to
1.83*150 = 274 watt hours
the electric used = 274/1000*£0.12 = £0.03
As the standing charge is there we can calculate this over the time the printer is being used, not strictly necessary as this will be there whether the printer is used or not.
Standing charge per year = £80/365 to give the daily standing charge = £2.13
for 0.57 hours use we have £2.13/24 *0.57 = £0.05
We now have all of the information required to calculate the total
Printer = £0.11
Repairs = £0.01
Filament = £0.09
electric low quality = £0.01
electric high quality = £0.03
standing charge = £0.05
So how much does 3d printing cost?
The low quality print would cost £0.27, with the high quality being an increase of £0.02 above at £0.29.
This costing doesn’t take into account the time of an operative setting up the machine or cad time.
But you can see how much does 3d printing cost, an in my opinion it is not a great deal.
Even when you add onto this a couple of failed prints you are talking less than £1.00 for a fully custom part made within your home in a few hours.
After finding out how much does 3d printing cost, are you going to be buying a printer or printing lots more, leave a comment in the box below.
