Print a 5 mm diameter 0.5 modulus and 5 mm gear with an inner hole

[NL4 0]

Halo, 

I need to print a gear with 5 mm diameter, 5 mm height and 0.5 module with a hole of 1.9 mm diameter that will be used in a normal printer using Ultimaker 2+. I have realized somme pieces with PLA after long time research but it got broken in the machine. Can somebody give me idea on how to do a solid gear? 

Presently I have PLA,  Nylon and ABS in stock.

Thanks.

[gr5 2,069]

What does "0.5 modulus" mean?  I am familiar with that term as a measure of flexibility of materials.  It's usually in pascals or psi.

 

This is very small so I'd print it with a 0.25mm nozzle.

 

PLA is probably the best material for this.  Nylon is tougher but it's also more flexible so if there was much torque on this gear the teeth would probably flex right out of position.  But you could try nylon.

 

ABS is great because it withstands higher temperature and friction can raise the temperature fast.  So ABS might be better than PLA only for the temp reasons.  PLA turns to a clay-like softness around 52C.

 

PEEK, Ultem, carbon fill nylon - those materials would be better.  I'd look at the tensile strength and tensile modulus compared to PLA and find something quite strong and stiff (highest possible values) such as nylforce CF.   PEEK and Ultem need a special printer - UM printers can't print those as you need 160C bed and 80C air temps (will destroy stepper motors).

 

[NL4 0]

The module of the gear is given by the pitch diameter divided by the number of teeths. Can you please propose me some parameters I can use in Cura 3.3.1, concerning ABS with a .25 nozzle ?

[gr5 2,069]

I would print in PLA first and try it but if you want to jump to ABS which is more difficult...

 

In cura just select ABS as the material and 0.25mm for the nozzle size.  Set all the printing speeds to be 30mm/sec.    The rest of the parameters should be okay in cura.  If your part is small enough you can skip the brim and if the teeth are on the glass maybe set "initial layer horizontal expansion" to -0.1mm or so to get rid of some of the elephants foot on the bottom layer.  Look at this in layer view so you can see what it is doing.

 

On the printer make sure the ABS material settings have the bed at 110C and the fan at 30%.  This will not likely be default.  Also since you are using a small nozzle and small layer heights you are printing slower so you can lower the default temp by 5C.  ABS clogs easily if you leave the nozzle at temperature without printing.  Within a few minutes it turns to a clog.  So keep things moving.

 

Put some gluestick on the bed and then spread it around with a wet tissue so it is super thin.  Or even better use abs juice (google it) on the glass.

 

Finally cover the top and front of the printer.  You won't be able to get to 110C bed temp anyway without covering the top of the printer.  100C is not hot enough most likely and your part will come loose from the bed.  105C is probably hot enough but 110C is safer.

 

For the front I usually use a 1 gallon zip lock bag or some saran wrap and blue tape.

 

For the top I usually use a large box.  The boxes that hold photocopier paper are perfect for um2.  It fits on top perfectly with no cutting needed and no tape needed to hold it on.

 

After you are on the 5th layer or higher - double check the fan speed in the tune menu or just look at it.  It should be very quiet but still spinning a little.  If ALL sides of the part are vertical you might be able to get away with 0% fan but probably not.  If you have any overhangs or bridging or if your parts is smaller than 2cm you will probably need a tiny bit of fan.