How to choose a FFF/FDM 3D printer – How much money can I spend on my printer

You are the only one capable of answering that question.
Also, your current state of mind might make you go for a very small model because you want to test the technology, or you might want to go directly for the big ones, with in mind “the bigger the best” or “the big one can also do the job of the small one”.

To be honest, if you want to start with a big DIY printer make sure you have a certain experience in 3D printing.
You will experience for sure all the issues you will get with a small printer and you might experience them all at once!.
Make sure to focus on 1 issue at a time.
With big DIY 3D printers, each detail is very important. It can really becomes the butterfly effect, where you have 1 part of the printer causing another side to go crazy.

Also adjusting stepper motor power can be challenging, and might require you to spend a few hours playing with it.

Also if you are impatient to play with a 3D printer, consider the “out of the box” printers. You will avoid the frustration of having to fix all the problems before doing some good prints.

If in another end you want to save money and gain a great deal of experience with your 3D printer, go for the DIY kit!
First because you will known your printer as it’s part of you. You will be able to quickly diagnose and fix any possible issues that comes during the lifespan of your machine.
You will also be more able to increase the life span of your printer by evolving it on you own and taking the last advancement in 3D printing.
It will also save you a lot of money in maintenance, as you will fix yourself your printer.
It will also increase your creativity, as you will look for many solutions, and find a lot of different answers on the Internet or by your own. People are very creative when it comes to DIY, and we can very quickly learn from their ideas!

How to choose a FFF/FDM 3D printer – What mechanical precision do i want

This questions mainly relies on the mechanical parts of the printer.
If you are using belt driven axes you will find this article answering the main aspect:

https://nutz95.wordpress.com/2014/12/02/reprap-how-to-choose-your-pulleys-for-your-3d-printer/

To make it quick, here is the conclusion for a 16 micro stepping setup on your stepper driver:
Teeth | Steps/mm | Resolution (microns) | Torque required (%)|Speed (%)
16 teeth | 100 steps/mm |10 microns| 100% | 100%
20 teeth | 80 steps/mm |12.5 microns| 125% | 120%
25 teeth | 64 steps/mm |15.625 microns| 156% | 136%

Use a calculator to get more specific details

If you want more details about a specific setup look for some reprap calculators such as :

It should fit 80/90% of your needs.

Resolution is only 1 aspect

Indeed you will quickly see that even a printer with a great resolution can make crappy prints.
You also need to find a proper chassis and find a good ration between speed/quality.
This is where you will have the most effect on the quality of a print.

Stepper micro stepping are to be taken into consideration

If you look at this article: you will find that the more micro step you setup, the less torque you will get from the couple motor/driver.

If you need to drive a heavy heat bed, you might consider reducing a little bit the micro steps on this axis to avoid or reduce magnetic backlash.

How to choose a FFF/FDM 3D printer – What hot end to choose

What hot end to choose

About hot ends you will find at least 3 types of hot ends:

• Plastic
• Semi-metal
• Full-Metal

Plastic

The most commonly known is the JHEAD. (see the photo).
It comes with different version (MKI-> MK 8) see wiki for more details()
The main body is in PEEK plastic that support a maximum of 248°C.
So you will still be able to use PLA and ABS with those hot ends.
Also they are very cheap, so it can be a good idea to start with those cheap hot ends.
You can find some standard and some bowden version of this hot end, and different nozzle size can be available.

Semi Metal

The semi metal hot end has the appearance of a full metal hot end but has a liner inside the nozzle to avoid the PLA plastic to expand when cooling down.
The well known AluHotEnd from 3D-Industries is a good example.

http://3d-industries.myshopify.com/collections/hotends/products/aluhotendv6

The price here is a little bit more expansive but you have aluminum parts + a PTFE liner in the nozzle.
The maximum temperature is about 245°C and you can print PLA and ABS with it.
It’s also a good choice for the beginning as it’s very easy to use.
Notice however that the slim metal barrier part is very fragile and this is often the part that breaks first when holding by hand the hot end.

Full metal hot ends

 

The well known E3D and Prometheus hot ends:
http://www.dta-labs.com/products/prometheus-hot-end-v1-1

http://e3d-online.com/E3D-v6

The idea here is that all parts are made of metal.
Pros:
You can reach more than 300°C if you change the thermistor by a thermocouple (normal thermistor can hold 285°C)
Cons:
The price: it’s nearly twice as expensive as a semi-metal hot end.
You can get some issues with PLA as it can expand and get stuck inside the hot end.
Personally i sometimes have the issue with the E3D hot ends, but never got it with Prometheus hot end.
Often it happens when the retraction is too high, the hot plastic is cooling down too fast, and it expands.
You can avoid this issue by retracting only 2 or 3mm of filament.

How to choose a FFF/FDM 3D printer – What type of extruder do i need

The extruder is the part of the printer that pushes the plastic into the hot end.
You will find different types/sizes/geometries of extruders.

Each have their pros and cons but the main goal stays the same: push the plastic into the hot end!

They can use different kind of Hobbed bolt to grab the filament and to push it to either the hot end, or through a PTFE tubing.

Greg’s Extruder

This extruder exists for both 3mm and 1.75mm filament diameter.

However you will need to choose the one according to your filament diameter.
Note that what changes is mainly the internal hole size that fits the filament diameter.

They uses what is called Hobbed Bolt. It’s a machined screws with teeth on the flange that allows a good grip on the filament.

Look very closely at this part as the quality of the hobbed bolt is critical to have a proper extrusion!
The original greg’s extruder was purposed to push the plastic directly into the hot end.

• Pros:

The advantage of this is that you limit the nozzle dripping effect. You can also retract the filament slightly and the retraction effect is immediately taken into account.

• Cons:

This setup requires the extruder to be on top of the hot end, and therefore you will have the driving motor on top as well. This leads in having a big weight to move and so it reduces the overall speed of the axis where it belongs.

Bowden Extruder

You also have some variant of this extruder that pushes the plastic into a tube. This setup is called Bowden extruder.
The PTFE tubing has the following characteristics and is adapted for each filament diameter:

• For 3mm filaments:

Inner diameter (ID): 4mm
Outter Diameter (OD): 6mm
Lenght: often 1meter but can vary depending on your setup. The shorter, the better!

• For 1.75mm filament:

Inner diameter (ID): 2mm
Outter Diameter (OD): 4mm
Lenght: often 1meter but can vary depending on your setup. The shorter, the better!

The Pros:

• You can achieve very high speed with this setup because you have a limited amount of weight to move.

The Cons:

• The Hysteresis effect:

As the plastic filament is pushed through the PTFE tube, the tube will get into pressure. When you stop pushing the filament, the residual pressure inside the tube will continue to push the plastic into the tube.

You will therefore have a small dripping/leakage on the nozzle side.
To reduce this effect you will need to retract your filament enough to reduce the pressure inside the PTFE tube to avoid dripping.
This amount of retraction differ a lot from 1 printer to another one, and you might spend some time to figure out the proper amount.
Along with retraction you will have to figure out the retraction speed. The more the better, but your driving motor might be limited to a certain speed/acceleration couple.

Possibles troubles:

You might have different troubles with this kind of setup:

• Your hot end is too cold
• Your PTFE tube is too tight
• Your PTFE tube is too long
• Your PTFE tube is too curled
• Your filament quality is bad, and the diameter exceed the Hot end filament hole tolerance
• Your Hobbed bolt is filled with plastic and cannot push it anymore
• Your nozzle is stuffed

In all those case here what can happen and what you can do:

1. Try to increase slightly your hot end temperature, often a few degrees can make the difference.
2. Try to check your cooling fan, and make sure it doesn’t cool the hot end too much (check your Hot end temperature when this happens)
3. The driving motor will need to push more!
4. If you get motor making a lot of noise, you can try to increase current into the motor
5. If your extruder screws are not tighten enough, you will hear some “click”, in that case try to tighten them a little bit.
6. If your extruder screws are too tight, your motor might struggle to push the filament and thus make some noise.
7. Your filament pneumatic connector holding the PTFE tubing might release the PTFE Tube.
   This often means that the filament is either stuck inside the PTFE tube, or that the nozzle is stuffed with something, or your pneumatic connector is broken (some internal teeth might brake when this happens too often).
8. If your hobbed bolt is filled with plastic, your hobbed bolt will sweep over the plastic, resulting in the motor not pushing the plastic. Clean up your hobbed bolt and try again.

Direct Drive Extruder

Here the goal is to drive directly the filament into the hot end, or the PTFE tube for the bowden version.
The Pros:
Very compact, as you only need a hobbed gear (MK7/MK8/Hobbed shafts, etc…)

The Cons:
You can only use 1.75mm filament, as 3mm filament will require more torque.

Different kind of Direct drive gears

From this nice benchmark :

http://airtripper.com/1676/3d-printer-extruder-filament-drive-gear-review-benchmark/
Here is the result by order of performance:
MK8:

The MK8 Drive Gear provides a good balance of grip and torque to push the filament with force that easily exceeds 4kg.

MK7:

It has excellent grip on the filament and the idler tension is easy to set-up. However, the gears’ large effective diameter may not provide enough torque when nozzle and filament troubles occur. If you’re looking for serious pushing power from a geared stepper motor, the MK7 should be first choice.

Plain Insert drive gear:

Good pushing power. However, the gear can be difficult to set-up without the help of the filament force sensor. If you have good experience with 3d printing and have a well oiled machine, you might get some good performance out of this cheap drive gear.

Raptor drive gear:

As proved with the MK7 Drive Gear, bigger gear teeth don’t mean better grip. However, the Raptor Drive Gear might perform better on a geared extruder where idler tension can be increased, but at the expense of causing more damage to the filament.

How to choose a FFF/FDM 3D printer – Do i need a heat bed

You might better understand why you would need a heat bed if you take into account the different material characteristics.
To summarize, the main goals are:

• Keep your plastic parts stuck on the print surface
• Avoid warping
• For ABS it can help you build chamber to stay hot, so you won’t require any additional heating element to heat up the chamber.

Heat beds models

You have several models of Heat beds. (see details here: )

PCB based:

• Single power: MK2, MK2a (8″)
• Dual power: MK2b (8″)
• MK2 A4 (A4 size)
• 200×300 mm
• MK3 : Aluminum 8″ heat bed

Nichrome

Aluminium Clad Resistors

TO220 Resistors

Clothes Iron

Silicone Heater

Polyamide film heater

Peltier Element

 

What are people using?

The most commonly used are PCB heat beds.
They are cheap and easy to get.
They work with 12 or 24V DC and use about 200W for a 8″ surface.
THis means that you will require at least 360W power supply if you want to use a heat bed on your 3D printer. The hot end of 3D printers will use about 25 to 40W, and the stepper motors will use about the same when working.
For more details about what how much electricity is using a standard 3D printer, please look at this article:

My own preference goes for Silicone Heaters,because they can run on either 12 or 230V. The 230V version is very nice because you don’t need any additional power supply and they heat very fast!
They can go up to 1W/cm2 and their price is decreasing. It’s still at least twice the price of a PCB heater but you won’t need any power full Power supply. So the money you put on your heat bed, you’ll get it back on the power supply side.
You will require to use a AC Static relay for the 230 AC models however.
The relay reference is SSR25-DA
It costs extra dollars but you will save your main electronic MOSFET lifespan.
SSR relay life span is at least 20 years, so it’s likely that you are already dead before the relay breaks.

You will also need to take some extra precautions due to the use of 230V.

How to choose a FFF/FDM 3D printer – What type of material do i plan to use

For FFF printer you have a lot of printing materials wit different caracteristics such as:

PLA

(plastic based on corn)
heating temperature: 175-210°C
Note: will deform if left on direct sunlight on inside a car during summer.
Mandatory: You will need a fan to cool down the part when printing in order for the PLA to keep it’s shape.

ABS

(plastic based on petroleum)
heating temperature: 230-245°C
Note: will handle higher ambient temperature than PLA
Note: Don’t use fan as it will prevent each layer to melt on one another
Mandatory: You need to close your printing area to prevent your plastic part from cooling during the print as it will deform the plastic part.
Strongly Advised: You will need a Heat bed that heat up to 110°C if you want your plastic part to properly stick to the print surface. Otherwise the plastic part will likely curl during the print.

Taulman Nylon

There are several kind/quality of Nylon filament.
The main manufacturer will be Taullman
He can provide at least 5 types of nylon filament:

• 618:

See details here: http://www.taulman3d.com/618-features.html
Print temperature: 235C – 265C

• 645:

see details here: http://www.taulman3d.com/645-features.html
Print temperature: 230C – 265C

• 680 FDA:

Mostly used for medial application (bones

• Bridge:

See details here: http://www.taulman3d.com/bridge-features.html
Print temperature: 235C – 265C

• T-Glase:

see details here: http://www.taulman3d.com/t-glase-features.html
Print temperature: 212C – 248C; ideal 235 to 245°C

Note: Here are some special advice when using nylon:

• Nylon must be dried.

Nylon is very hygroscopic. That means it readily absorbs water from the air. Nylon can absorb more than 10% of its weight in water in less than 24 hours. Successful printing with nylon requires dry filament. When you print with nylon that isn’t dry, the water in the filament explodes causing air bubbles during printing that prevents good layer adhesion and greatly weakens the part. It also ruins the surface finish.
Dry nylon prints buttery smooth and has a glossy finish.
To dry nylon, place it in an oven at 180-200°F (82-93°C)  for 6-8 hours. After drying, store in an airtight container, preferably with desiccant.

• Nylon requires temperatures above 240C to extrude.

Most printers come standard with hot ends that use PEEK and PTFE. Both PEEK and PTFE begin to breakdown above 240C and will burn and emit noxious fumes.
Most printers can easily be upgraded with an all-metal hot end in order to print at temperatures above 240C.
E3D hot ends seems to get good results!

• Nylon can warp.

We’ve found it to warp about as much as ABS.
When printing on glass, a heated bed is required with nylon. A PVA based glue stick applied to the bed is the best method of bed adhesion. Elmer’s or Scotch permanent glue sticks are inexpensive and easily found.
We’ve found that a bed heated to 75C, with thin layer of glue applied in a cross-hatch pattern works best.
Do not use layer cooling fans.
Avoid drafty or cool rooms for best results.

Recommend print settings:
240-260C Extrusion Temperature (find the propre temperature depending on your own setup: hot-end Nylon manufacturer etc…)
70-80C Bed Temperature with PVA based glue (UHU stick glue seems to be nice)
Speed: 30-60mm/s
.20mm-.4mm layer heights

Laybrick

Print temperature: 165°C to 190°C
Filament based on super-fine milled chalk (more information here: http://www.3ders.org/articles/20130527-laybrick-a-new-rough-3d-printer-filament-near-zero-warp.html)

Laywood

It is a wood/polymer composite – the filament contains 40% recycled wood and harmless binding polymers. The material has similar thermal durability as PLA and can be printed between 175°C and 250°C.
More information:http://3dprintingforbeginners.com/3d-printing-materials-bendlay-laywood-laybrick/

No heat bed is needed, but adhesive such as blue tape is recommended

Do i need a heat bed

Hot beds are not always needed but it all depends on the material you are printing with.
First, Why a heat bed?
When you print plastic , you want to make sure that the plastic stick properly to the print platform.
If it doesn’t stick to it, your plastic part will move or detach during the print. All you want is to prevent from that!.

Most people are using PLA, and in that case you won’t need heat bed to print. Even if it’s strongly advised, the PLA can stick on specific print surfaces.

How to choose a FFF/FDM 3D printer – How big do I want to print

For Cartesian printers you will find many sizes of print surface. They are often expressed in inches.
For example:

• 4″ x 4″ x 4″ (101.6 x 101.6 x 101.6mm) (printrBot Simple)

• 6″ x 6″ x 6″ (152.4 x 152.4 x 152.mm) (printrBot Simple Metal)

• 120 x 120 x 115 mm (ultimaker go)

• 8″ x 8″x8″ (Makerfarm 8″)

• 230 x 225 x 205mm (Ultimaker 2)

• 10″ x 10″ x 10″ (printrbot Metal Plus and makerfarm 10″)

 

• 12″ x 12″ x 13.5″ (makerfarm 12″)

• 24″ x 12″ x 12″ (Printrbot Go Large)

You can find some that are the size of a man or a building.

Of course each time the price will vary depending on the printing size.

For delta printers you will also find a wide range of sizes, but Delta printers will be taller than Cartesian printers due to their geometry.

 

How to choose a FFF/FDM 3D printer – What type of printer geometry do i want

For the FFF technology, you will find at least 2 main types of geometry with sub declination:

Cartesian

Standard: the print platform will move on Y axis and the print head will move on X and Z axis, with 1 motor for each axis and often 2 motors for Z axis.
Cubed shape printer: the print platform will move up and down and the print head will move on X and Y axis with 1 motor for each axis.
CoreXY: the print head will also move on x and Y axis but 2 coupled motors driving both X and Y axis and 1 or 2 dedicated motor for Z axis.

CoreXY principle

CoreXZ: same principle as CoreXY but with 2 coupled motors driving both X and Z axis at the same time.

Delta

On delta 3d printers,the 3 motors will move on separate Z axis. The movement of each motor will affect the print head position depending on the other motors positions.

Cartesian/delta illustration

How to make a 3D Printer for cheap / less than 400€

Description

After looking around for some time trying to figure out how to build a 3D printer for cheaper than 500€  i ended up on this design posted on Thingiverse:

http://www.thingiverse.com/thing:441143

It’s a Prusa i3 like orthogonal 3D printer:

This slideshow requires JavaScript.

– To make the size of the printer more explicit we placed a 2Liters bottle of water on top of the build surface. this thing is huge compared to a standard 8” 3d printer.

– The BOM is quickly provided on the thingiverse link.

Main Features

To me , the main features this design are:

1.  First the cost of the printer is more related to electronics and motors than anything else. For a general idea, on this 16” build size, the aluminium frame cost about 80€ including screws etc..
2. If you go down to 8” aluminium frame you only get up to 20€ back (around 60-70€) wich is nothing if you consider that you doubled the build surface!
3. It’s very easy and fast to assemble the frame, as you mainly use T-nuts for aluminium profiles.
4. The frame is made of 7 aluminium profiles, all of the same size (about 45 cm for 8” and 66cm for 16”)
5. 30x30mm Aluminium profiles makes the whole struture very rigid
6. If you need to disassemble your printer the screws are properly located on the aluminium profile so that the screws are not locked in inside the frame. For example you can freely remove the Y axis rods supports, they will glide inside the profile and the T-Nuts will exit properly the profiles.
7. Plastic parts are for Y axis are located on top of the aluminium profile, so it’s very easy to mount/unmount and the build plate can freely move freely on top of the profiles.
8. Plastic parts are very limited and mostly small, so it’s fast to print, and easy to mount.
9. The different idlers(X and Y) have built in belt tensioners so it’s very easy to adjust belt tension with a single screw diver.
10. It’s using standard smooth and thread rods (M5 threaded rods and M8 smooth rods for all axis)
11. A limited amount of screws are required compared to builds such as OpenBeans 1.4 or equivalents

Cost

The total cost of this build  : 16” Build area + 1 extruder + 1 heat bed, is near 400€  including 1Kg of PLA plastic, electronics, (power supply is excluded as you can use an old ATX 350W power supply).

Most of the electronic components have been ordered on ebay (china).

The price may vary depending on many factors: the hot end model, the heat bed model, the electronic type (here it’s standard Arduino Mega + Ramps 1.4 board) and the motors you are using.

For this price we made sure the stepper motors were properly sized and didn’t want to take cheaper/smaller motors are it’s the core of everything when the printer is running.

Final Note

If required i can provide a more detailed  list of components with prices in front so that everyone can clearly see that making a 3D printer is Easy, Fun and Cheap

How much electricity cost a 3D print?

Well this is a question everyone i know ask me and i quickly ended up to the conclusion that i didn’t know ^^.

So in the end I decided to take a watt meter and measure.

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In order that everyone understand here is my setup:

Printer: Makerfarm i3 8” (previous model)

Electronic: Ramps 1.4 + Arduino Mega 2560

Stepper sticks: 4 x A4988

LCD:  Reprap smart RAMPS1.4 LCD2004 display controller

Hot end: AluHotEndV5 0.4mm 3mm filament

Heat Bed: MK2B 8”

Stepper motors:

Z Axis: 2 *  42BHH48-050-24A

X Axis : 1 * 42BHH48-050-24A

Y Axis: 1 * 42BYGHW804

Extruder: 1 * 42BYGHW804

42BYGHW804 : Wantai Nema17 Stepper Motor 64oz-in 48mm 1.2A 4-Lead)

42BHH48-050-24A: (cannot find the datasheet)

 Power supply: ATX 380W

80mm Fans: 3 => 2 for Z axis and 1 for Ramps 1.4 board

40mm Fans: 3 => 2 for hot end and 1 for Ramps 1.4 board

Style: Bowden

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 Print Configuration

Plastic: 3mm white PLA (from IGo3D => ino3D filament)

Print temperature:  200°C

Heat bed temperature: 70°C for first layer then 60°C for other layers.

Estimated print data : 2h21 minutes, 1.36 meters, 12 grams.

Real print duration: 2h47 min

Starting ambiant temperature: head= 30°C and bed = 30°C

First layer speed: 20mm/s

outer shell speed: 25mm/s

Inner shell speed: 40mm/s

infill speed:  70mm/s

Print resolution: 0.1mm

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Actual print data

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Print Analyses

 Overall duration: 2 h 47 instead of 2h 21 predicted (this may mainly be dure to hardware accelerations neglected by slicer).

Overall power consumption: 0.27 KW

Price per KW (france EDF no discount): 0.17€ / KW (taxes included)

Idle Power: 20W

Average auto homing power: 37 W

Average auto bed leveling power: 55W

Average print power: 59W

Peak power: 220W

If we analyze the raw data we clearly see :

• The heat bed is consuming most of the power.
• Most of the power is used when powering the heat elements to target temperature
• The Idle power seems to be high (20W) and may be caused by a lot of factors such as the presence of 3 x 80mm fans, power supply stand by consomption ( a few watts at least). I believe that the arduino and the LCD in stand by mode is not consuming that much of power. I’ll try to post some update on the stand by power usage of my ATX power supply . It’s an old power supply so it’s not rated as efficient power supply.
• Both temperature (head + bed) vary very slightly over time which is expected by a few °C but remains in average stable wich is what we want for a good print.
• Power usage is slightly increasing after the first layer (starting at 14 minutes or so) because the speed of the motor increase.
• Electrical cost of the whole print (2h47 min) = 0.17€/KW * 0.27 KW =0.0459€
• Electrical cost estimation per print hour: 0.0459 / 2.78h = 0.0165€/h
• Electrical cost estimation per year: if you print 24/7 : 365 days/year * 24h/day * 0.0165€/h =  144, 54€/year
• Plastic cost if i consider slicer weight estimation: 12 grams  => 25€/kg *0.012 = 0.3€ for this print.
• Total cost 0.3+0.0459 = 0.3459€
• Electrical cost over plastic cost: 0.0459 * 100 / 0.3459 = 13.27%

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  Summary

Those data should vary a little bit depending on your 3D printer:

• stepper motor
• hot end
• heat bed
• print speed
• plastic type/manufacturer/density
• plastic quality
• nozzle size
• filament size
• bowden/non bowden/direct drive
• extruder type
• etc…).

In the end you should have some variation due to all those factors but this demonstration is only intended to give a general idea on the cost of a print and to know if electricity cost is significant over plastic cost.

What i can say is that:

1. Electrical print cost (considering french fares): 0.0165€/hour (0.02$ for 1€ = 1.32$ estimated the 27th August 2014)
2. On this print electrical cost is 13.27% of the overall print cost. (excluded maintenance cost)
3. However we can clearly feel that on longer prints the electrical cost over plastic cost will decrease greatly and that electrical cost will become negligible over plastic and additional maintenance cost.
4. A printer with no heat bed would need a power supply higher than 60W. if you consider peak current you might want to take a 90W+ power supply.
5. A printer with heat bed will need more than 220W. So you might consider using 300/350W+ power supply to avoid possible peak current issues.