I have used almost all types of 3d printing gears many times in the projects i have made so far.
Quick question- Which one is the best? hmmm
We actually can't say that this is the best between them. Because each one has its own
advantages and disadvantages. We can't even put them all in the same bag and compare. So the
comparison we'll make today will be between these first three gears: Spur, helical and herringbone
gear and we'll test them out in many ways and find out which gear we should choose in a gearbox or
any mechanical project we'll make. So first of all let's take a closer look at the super gear. As you
can see in a spool gear the teeth are parallel to the gear axis and as a result of this straightness
the engagement of the gear with the other gear occurs suddenly and across the entire tooth width.
So during the engagement this entire surface here suddenly hits the other gear
and impact effect occurs when the gears are working and a more vibrating
noise operation of course compared to the helical gear. Spur gears have such a disadvantaged though
it's the easiest and cheapest gear type to manufacturing compared to the other gears.
Because it's not complicated like helical gears and therefore it's usually preferred...
However when we look at the helical gears as you can see the teeth of the helical gear are
inclined at a particular angle with relative to the gear axis. by the way this is called
helix angle and thanks to these inclined teeth the engagement doesn't occur suddenly across
the entire tooth width but gradually and if you have noticed although the front of this tooth is
in contact with the other gear but the back of tooth is still not touching. So at this moment
the engagement here is only at that point not a close to tooth width and the engagement starts
from here and will continue gradually as the gear rotates will not suddenly like spur gears. thanks
to this difference the impact effect of helical gear is much less than super gears. Therefore
helical gears can wear quieter less vibrating and more smoothly than spur gears especially at high
speeds. that's really cool and this advantage of helical gears is one of the main reasons I use
helical gears instead of spur gears. by the way if you really want to hear what i'm talking about,
you can listen to the sound of the transmission in your car. when you go forward with the car
you hear a normal sound from the transmission but if you shift into reverse and go backward
you'll hear the sun change it will be noisier the only reason for that is the forward gears in the
transmission are helical gears and the reverse gear are spur gears. we can also see that in
the sound test i did. since the reduction ratio is low here there is not that much difference in the
sound but as you can see the sound of the helical gears is still lower. before talking about the
inevitable disadvantage of helical gears i'd like to introduce pcb way that sponsor of this video
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So back to the video... and let's continue with the inevitable disadvantage of helical gears.
helical gears can work quieter and more smoothly than spur gears but there's a problem with that
which is the inclined teeth create an extra axial force.
this force is not that small and not something to be underestimated and as the helix angle increases
the formed axial force also increases. therefore it's recommended that the helix angle should not
exceed 25 degrees but if we still need to use high helix angle then as a solution we
can use herringbone gears but more about them later. by the way even if we design everything
perfectly in practice sometimes we may not make gears shafts or bearings aligned perfectly
and as you can see here although there is no axial movement in the spur gears
sometimes such an axial movements can occur. after all we are not machines and this is quite normal
but this is a disadvantage for spur gears and one of the reasons i don't use them. although
theoretically spur gears have slightly higher efficiency than helical gears that's because
helical gears always want to slide sideways and this creates more heat and causes more power loss,
as you already see when I compared the efficiency of these two gears the results were very close to
each other as i expected. and for this test to be meaningful i painted all gears with
the same material, same layer height, same infill everything is same. If you ask me
using spool gears in 3d printing especially at high speeds is not very correct decision. It
better use at least a low angle helical gears instead of spur gears. For example in this
project I used low angle helical gears instead of spur gears. the helix angle was also 23 degrees
and even at high torque, the axial movement did not cause any problems, it worked very well...
alright well so far we have chosen the helical gear between these two gears however we can use
helical gears within a certain limit though, the helix angle will be low or will fix it somehow.
but this is still not enough for us and here are the herringbone gears as a solution. frankly
when we look closely at the herringbone gears we see two opposite helical gears
right helix and left helix. thanks to these opposing teeth like this, the axial force that
occurs in helical gears doesn't occur in these include. actually the axial force created by this
left helix is eliminated by the right helix and as a result there is no axial force and by the way as
you can see when the herringbone gears engage each other the teeth actually lock together.
this is great because these herringbone gears work as quietly and smoothly as helical gear
and there is no extra movement that is the weakness of helical gears. this is the reason
why I've used herringbone gears in the most projects that require high torque until now.
the only fly can say for these gears is that they are sometimes difficult to assemble. these gears
can't slip over each other like spur gears and using them in a planetary gearbox for example
can be quite difficult. but if you ask me the herringbone gear may be the best, most useful
gear type we can use for parallel axis shafts on 3d printing. by the way the design and production
of herringbone gear in a mystery is more difficult and expensive than the other two gears
but there's not much difference in 3d printing both are easy and for the design I first create
a helical gear then mirror it relative to the top or bottom surface and get the herringbone gear.
herringbone gears are very similar to double helical gears but there's a slight difference
between them there's a small gap in the middle of the double helical gears however there is not such
a gap in the herringbone and therefore as you can imagine the herringbone gear is easier to print
there is no need any support material or something. so I never used double helical
gear until now. as a result, I believe that the most efficient and useful gear in 3d printing is
herringbone gear but of course if the gears are parallel axis and to give an idea
I generally use 1.5 millimeter module in the gears I printed with PLA. this module
lasted up to 100 kilogram in the linear servo I made. so it's good enough with high infill.
so there's more to tell about the gears though that's all for now.
thanks for watching hope you guys enjoyed this video and useful. DontforgettoSUBSCRIBE.