Fix your Z axis with Oldham couplings, dual z screws & thrust bearings!
Summary
TLDRこのビデオでは、Ender 3のZ軸を完全に再構築し、象の足、Zバンディング、不規則な最初の層などの一般的な問題を解決する方法を紹介します。ダイヤルゲージを使用して、元の状態と改造後のZ軸を比較し、定量的な結果を示します。具体的には、ガントリーの片側のサポート不足、リードスクリューの固定方法、Z軸モーターの取り付け方が原因で発生する問題に焦点を当て、BLVキットの微調整、AliExpressからのZ軸剛性キットの使用、二重Zキットの応用を通じて、これらの問題を一掃します。しかし、新しいステッパードライバーの誤接続によるトラブルに遭遇し、次回のビデオで修正後のプリンターのテスト結果を共有する予定です。
Takeaways
- 👣 The Ender 3 has several issues with its z-axis that lead to inconsistent layer heights
- 🔧 Using a dial gauge reveals significant inaccuracies in z-axis movements
- 📏 The unsupported side of the gantry has much more inconsistent z-axis movement
- ⚙️ A rigid z-axis kit helps square and reinforce the vertical rails
- 🛠 Dual z-axis kits can help align the lead screws and reduce binding
- 🧰 Special couplings allow lead screw misalignment without affecting prints
- 🆕 A thrust bearing handles the gantry weight instead of the stepper motor
- 🚧 Swapped stepper motor wires caused driver failures requiring board replacement
- ♻️ Larger z-axis pulleys provide better resolution but required longer belt
- 👀 Further testing coming after replacement mainboard delivery
Q & A
Ender 3のZ軸を再構築する目的は何ですか?
-Z軸の問題、特に象の足、Zバンディング、一貫性のない最初の層などを解決するためです。
Ender 3の元の状態における主な問題点は何ですか?
-ガントリーの片側にサポートがないこと、リードスクリューとガントリーの不適切なアライメント、Z軸モーターへの過剰な軸負荷です。
Z軸の問題を解決するためにダイヤルゲージを使用する理由は何ですか?
-元の状態と改造後の状態を比較して、定量的な結果を示すためです。
BLVキットで遭遇した小さな問題とは何ですか?
-ナットスロット間の間隔が非常に狭かったため、Dremelを使用して調整する必要がありました。
Z軸剛性キットを使用する主な目的は何ですか?
-Z軸を正方形に引っ張り、固定して将来的に動かないようにするためです。
デュアルZキットを使用する利点は何ですか?
-Z軸のアライメントを向上させ、軸の負荷を分散させることで、印刷品質を向上させます。
オールドハムカップリングの使用目的は何ですか?
-スクリューとナットのわずかな不整合を吸収し、印刷に伝達されるウォブルを最小限に抑えるためです。
Z軸モーターの問題を解決するために設計された装置とは何ですか?
-モーターをリードスクリューの上に固定し、ベルト駆動を使用することで、内部のばねワッシャーによる問題とアライメントの問題を解決する装置です。
なぜZ軸のステッパードライバーが焼損したのですか?
-新しいケーブルをプラグアンドプレイと仮定し、中間の二つのケーブルが入れ替わっていることに気づかずに接続したためです。
改造後のEnder 3をテストできなかったのはなぜですか?
-Z軸ステッパードライバーが焼損し、交換用のボードが届くまで時間がかかるため、テストを実施できませんでした。
Outlines
🛠 Ender 3のZ軸問題とその解決策
このビデオでは、Ender 3のZ軸に関する一般的な問題、特に象の足、Zバンディング、そして最初の層の不一致などに焦点を当てています。原因として、ガントリーの片側のサポート不足、リードスクリューの不適切な取り付け、モーターへの過剰な軸負荷、そして柔軟または硬直な結合の使用が挙げられます。これらの問題は、印刷品質に影響を及ぼし、特にZ軸の精度に悪影響を与えます。対策として、ダイアルゲージを用いたオリジナルと改造後のZ軸の比較により、問題の解決と改善が可能であることを示しています。
🔧 Z軸改良キットの取り付け
この段階では、Z軸の剛性キットの取り付けに焦点を当て、AliExpressから購入したキットを使用してZ軸を正方形に整え、将来的に動かないように固定します。さらに、デュアルZキットの利用、軸受けブロックの取り付け、そしてリードスクリューの適切な配置により、Z軸の精度と整合性を向上させる方法を説明します。加えて、旧式のカップリングを利用してZ軸の究極のビルドを目指し、プリントの精度を向上させるための詳細な手順を提供しています。
⚠️ ケーブル接続の失敗とその対応策
Ender 3のステッパーモーターケーブルの誤接続により、Z軸とX軸のステッパードライバーが焼損してしまいました。この問題は、新しいケーブルがプラグアンドプレイ対応であると誤って仮定したことに起因します。ケーブルの修正は単純で、中間の二本のケーブルを交換するだけですが、ステッパードライバーは基板に直接はんだ付けされているため交換ができません。結果として、新しい基板を注文する必要があり、それが届くまでプリンターのテストを続行できなくなりました。次のビデオでは、改造されたプリンターのテストを続け、修正前後の結果を共有する予定です。
Mindmap
Keywords
💡エンダー3
💡Zバンディング
💡ダイヤルゲージ
💡リードスクリュー
💡ステッパーモーター
💡フレキシブルカップリング
💡オールドハムカップリング
💡スラストベアリング
💡プリロード
Highlights
The Ender 3 has several issues with its z-axis that contribute to problems like elephant's foot and z-banding.
Using a dial gauge reveals significant inconsistency in z-axis movements, especially on the unsupported side.
A rigid z-axis kit helps square and reinforce the vertical frame.
Dual z-axis kits can improve alignment, but thrust bearings are needed to handle axial loads.
Flexible couplings allow for minor misalignments between screw and nut while restricting play.
Hanging the gantry from the couplings applies beneficial preload.
Transcripts
have you tried everything but can't get
rid of elephant's foot
are your prince plagued with z-banding
is your first layer inconsistent
these problems plague many of us with
enter three style machines
but fear not
in this video I completely rebuild the
z-axis of my Ender 3 and solve all these
problems
by using a dial gauge and comparing the
original with the modified I will show
you quantifiable results and fix the
z-axis once and for all
so stick around to find out more
[Music]
before we begin consider subscribing to
the channel and leave a like if you
learned something new
let's start by taking a look at the
Ender 3 in its original condition and
try to understand what we are trying to
fix
the obvious is the lack of support on
one side of the Gantry because there is
only one lead screw this results in two
main problems
first the Gantry will sag on the
unsupported side and you will need to
compensate for this by leveling the bed
second is more Troublesome and not so
easy to fix
if you have any tight spots be it due to
the condition of the rollers or the
extrusions the layer height will be
inconsistent and this will result in the
dreaded Z banding
the next set of problems is a result of
the way the lead screw is fixed to the
gantry
for some printers the aluminum plate
that holds the nut Is Not Bent properly
so the lead screw is not aligned and in
some cases the lead screw itself is
slightly bent so again some misalignment
is present this causes the lead screw to
bind and wobble this in turn transfers
the wobble pattern onto the print
finally the last set of problems are
related to the way the z-axis motor is
mounted the entire weight of the Gantry
rests on the stepper motor and when
moving the Gantry up the lead screw
pushes down on the stepper motor
these motors are not designed to take
axial loads meaning parallel to the
shaft there is a spring washer inside
the stepper that will compress if any
downward force is applied to it not only
is this additional stress pad for the
motor because of the inconsistent
compression of the spring the layer
height will again be inconsistent
further contributing to z-banding
artifacts
finally the coupling for the lead screw
if you are using a flexible coupling to
correct the misalignment the springy
nature of the coupling will affect the
layer height consistency and if you are
using a rigid type coupling the motor
and Lead screw will bind even if there
is a slight alignment problem
a combination of all these factors
results in what I am going to show next
I am going to bolt the dial gauge
directly to the x-axis Extrusion this
ensures the dial gauge connection is
rigid and we get maximum accuracy
so let's take a look at the original end
of three without any modifications to
the z-axis I am going to start by moving
the z-axis down to zero position to
simulate the condition the printer will
be in after homing
then I will move the z-axis up in 0.1
millimeter increments but the actual
movement is half of what it is supposed
to be and this only improves slowly
even at a height of five millimeters we
are still not getting perfect 0.1
movements this is why it can be very
difficult to get rid of elephant's foot
then I will bring down the z-axis again
and this time move it up in one
millimeter increments in the first
millimeter you can see we are off our
Target but more than 0.3 and in the
second millimeter by 0.2 in simple words
if your layer height is 0.2 you have
squished more than two whole layers in
the first two millimeters only then does
it start getting better but still not
perfect
what we have seen is the result on the
supported side next I will shift the
dial gauge to the unsupported side and
here things are much worse
again I will start by moving the z-axis
down then move up in 0.1 millimeter
increments and the result is far from
what it should be
and looking at one millimeter increments
we can see that on this side we are
missing almost 0.8 from the two
millimeters
that's almost 50 percent
so it's safe to conclude that while both
sides are inconsistent the unsupported
side is much more so and it's lagging
behind the supported side
moving on here we can see how flimsy the
2040 y-axis Extrusion is and how much
deflection I can achieve with my hand
and here I am pushing on the z-axis
pillars with my hand
so let's start fixing these problems
I had a small problem with my blv kit
the spacing between the nut slots was
very tight so I had to get out my trusty
old Dremel
I will use one of these engraving bits
that I got from banggood
I used an A4 paper to protect the rails
from the metal shavings but it would be
much better to do this before assembling
the printer
[Music]
unfortunately the dust got everywhere
finally it was done
so now we can move on
this is the z-axis rigidity kit from
AliExpress
I am going to use the rods to pull the
z-axis into square
and then lock it in place
now we have a rigid z-axis that is
perfectly aligned and it won't shift
around in the future next I am going to
make use of this type of dual Z kit
I am going to start by installing the
bearing block taking care to keep the
bearing side on the bottom
the blocks are 45 millimeters wide so
they need to be out by 2.5 millimeters
as designed the pulley is supposed to
sit directly on the bearing block but
that's not good it will increase
friction and wear out the block and
pulley the entire weight of the Gantry
will rest on the blocks so I am going to
put in a Thrust bearing you can use any
thrust bearing with an eight millimeter
internal diameter this will take care of
the axial load and the ball bearing
inside the bearing block will bear the
radial loads
then I am going to use a caliper to
align the bearing blocks they need to be
perfectly leveled because even a small
tilt in the block will make a big
difference in the lead screw alignment
over its full length
after putting in the lead screws it is
evident that they are not centered this
is why I went through the trouble of
grinding down the slots now I can move
the nut to align it with the screw
but before fixing the nuts let's take a
look at these old and couplings and how
they can help us in building the
ultimate z-axis
this coupling allows the nut to move in
the X and Y plane but restricts any
movement in the Z this helps us in two
ways first there will always be some
misalignment in the screw and nut so the
coupling will shift the nut into the
perfect position and second if the screw
is bent even slightly the coupling will
absorb the wobble so it does not
transfer to the print
however because of the clearances
required for proper functioning there
will inevitably be some play in the Z
Direction and also some rotational
movement to minimize this effect we need
to apply some preload to the dovetails
we can achieve this by hanging the
Gantry from the coupling as opposed to
the Gantry resting on the coupling let's
see how we can achieve that
I went ahead and fixed the nut to the
old M coupling so we can install it on
the printer
after centering the nut on the lead
screw we need to fix it with M3 nuts
then if you have aligned everything
properly any minor misalignment will be
absorbed by the old en coupling and the
lead screw should slide in like a hot
knife and butter if there is even a
slight hint of binding then you need to
go through the alignment steps again
the same needs to be repeated on the
other side as well
we are then presented with our next
challenge
when the Gantry is moving up it pulls
against the bearing block and all is
good because of our thrust bearing
however when the Gantry moves down there
is nothing holding the lead screw in
place well except gravity
so there is a high likelihood that the
leaves crew will occasionally shift up
and this will affect our accuracy
so to solve the problem I designed and
printed this piece I tried to use off
the shelf metal Parts but space was
pretty tight on the other side so I had
to design this instead this piece has a
ball bearing to take the radio loads and
I will add in a Thrust bearing for the
axial loads similar to the design on top
then I will use this pulley to lock
everything in place you could use
something else but this pulley was most
readily available and the perfect size
finally to solve all the problems
related to the motor like the spring
washer inside and the issues caused by
the coupling I came up with this
contraption this allows me to fix the
motor on top with the lead screws sink
belt granted the teeth engagement of the
pulley is not ideal but it works and
gets the job done I also changed the
driven pulleys to a bigger size to get a
better resolution but the belt length
was not sufficient I had to extend it
and meanwhile I ordered a new belt 650
millimeters
and I use this longer cable to connect
to the z-axis motor
turned on the printer
and move the z-axis
then disaster stride
if you look at the original Ender three
stepper cables you will notice that the
middle two cables are swapped that would
be the green and blue in this case
I assume the new cable was plug and play
and because of that I burnt the z-axis
stepper driver as I was not sure what
had happened I tried using the x-axis
with the same cable and guess what I
burnt the x-axis stepper driver as well
fixing the cable is simple you need to
remove the green and blue cables which
can be done with the small flat
screwdriver and swap their positions the
board however is a different case
because the stepper drivers are soldered
in place they cannot be replaced so I
had to order a new board
unfortunately the delivery time is quite
long I had to cut this video short as I
am unable to run my printer for further
testing in the next video I will
hopefully have received the replacement
board so I will continue testing the
modified printer and share the before
and after results
thanks for watching and see you in the
next one
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