ON Development IVS uStepper User manual

uStepper - Robot Arm
Assembly instructions
By ON Development IVS
Microcontroller, stepper driver and encoder in an ultra-compact design!
© 2016 ON Development IVS All Rights Reserved

Assembly notes
The parts are 3D printed, meaning that they do not have the quality and toughness as mold injection
parts. Please bear this in mind while assembling and using the uStepper Robot Arm. Avoid using exces-
sive force while assembling the Arm. When tightening bolts and screws, please take care not to overtight-
en, since this could cause the plastic parts to brake.
ON Development IVS can not be held responsible for damage occurring during assembly.
The design is still a Work in Progress. Files, instructions, and other stuff might change!
Attribution
The nut cover design used with the uStepper Robotic Arm is made by Gyrobot, published under a CC BY-SA licen-
se on December 24 2012. www.thingiverse.com/thing:39113
When the glue symbol is shown, glue could improve the assembly quality in the appropri-
ate step. This is in general true for plastic/aluminum assembly, i.e. the rods. Care must
be taken before adding glue, since the parts are permanently fixed afterwards. We recom-
mend that the arm is first assembled and glue is added when the functionality of the arm
is validated.

Specifications
The uStepper Robot Arm has the following specifications in its standard configuration
(when using uStepper Premium kits as actuators):
Weight (including uSteppers) 1475 g
Material PLA plastic and Alumi-
num (tubes)
No. of axes 3
Maximum lift (close to base / fur-
thest from base)* 700 g / 350 g
Gear ratios
Main gear 4.09:1
Second gear 4.09:1
Stepper motor torque 0.42 Nm
Micro servo torque 0.15 Nm @ 5 V
*With 24V supply, maximum current limit setting and motor in brake mode. This rating is an absolute maximum, and continuous
operation in this area should not be carried out!

Specifications — Range of Motion

Bill Of Materials
Bearings:
 4 pcs. 608Z
 12 pcs. 624Z
Bolts:
 1 pc. M8 x 40 mm
 1 pc. M8 x 70 mm
 4 pcs. M4 x 20 mm
 4 pcs. M4 x 35 mm
 19 pcs. M3 x 10 mm
 3 pcs. M3 x 16 mm
 9 pcs. M3 x 20 mm
 9 pcs. M3 x 25 mm
Nuts:
 21 pcs. M3
 7 pcs. M3 SL
 8 pcs. M4 SL
 2 pcs. M8 SL
Washers:
 2 pcs. M8, OD: 15.8 mm
 2 pcs. M4, OD: 8.8 mm
Rods:
The length of the rods can be
varied to fit your needs.
 1 pc. 15 mm x 200 mm
 1 pc. 15 mm x 150 mm
 2 pcs. 6 mm x 169 mm
 1 pc. 6 mm x 164 mm
Actuators:
 3 pcs. uStepper premium
 1 pc. Micro Servo
Tools:
 Adjustable wrench
 Hex Keys
 Philips screwdriver
Optional:
 Super glue
 Hard stops:
 1 pc. M3 x 20mm
 1 pc. M3 x 10mm
 1 pc. M3 nut SL

Bill Of Materials
1 1 pc. Base
2 1 pc. Base gear
3 1 pc. Secondary gear
4 1 pc. Main gear
5 1 pc. Main gear bracket
6 1 pc. Secondary gear arm
7 1 pc. Main joint bracket left
8 1 pc. Main joint bracket right
9 1 pc. Triangle
10 3 pcs. Rod end left
11 3 pcs. Rod end right
12 6 pcs. Link end

Bill Of Materials
13 1 pc. Bottom plate
14 1 pc. Left side plate
15 1 pc. Right side plate
16 1 pc. End triangle right
17 1 pc. End triangle left
18 1 pc. Gripper main brack-
19 1 pc. End bracket
20 1 pc. Gripper gear
21 1 pc. Gripper servo gear
22 1 pc. Gripper left
23 1 pc. Gripper right
24 4 pcs. Gripper link

Bill Of Materials
25 1 pc. M8 nut cover
26 4 pcs. M4 nut cover short
27 1 pc. M4 nut cover long
28 6 pcs. M3 nut cover
29 1 pc. M4 spacer long
30 1 pc. M4 spacer short
31 2 pcs. M8 spacer long
32 1 pc. M8 spacer short

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.1: Fit a 608Z bearing in the base
gear 2 .
Fig.3: The base should look like this
from above.
Fig.5: Press the left side plate 14 into
the bottom plate 13 without using
excessive force. Secure it using 2
M3x10 bolts.
Fig.2: Assemble base 1 and base
gear 2 using 5 M3x25 mm bolts and
5 M3 nuts.
Fig.4: Fit a 608Z bearing in the bot-
tom plate 13 , a 624Z bearing and
two M3 nuts in the side left plate 14 .
Fig.6: The bottom plate 13 and left
side plate 14 assembly should look
like this.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.7: Insert the M8x40 bolt in the
bottom plate 13 , and add a washer.
Place an M8 SL nut in the base 1
(not visible here, see fig. 11)
Fig.9: The assembly should now
look like this.
Fig.11: Mount the motor and motor
gear 2 . Secure the motor to the bot-
tom plate 13 using 4 M3x10 mm
bolts.
Fig.8: Tighten the bolt ensuring a
smooth rotation of the bottom/base
assembly.
Fig.10: Insert an M3 nut and an
M3x8 mm bolt into the base motor
gear 2 .
Fig.12: Tighten the M3x8 mm bolt in
the motor gear 2 . (Do not over-
tighten!)
Be careful not to
overtighten the
motor gear bolts!

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.13: The assembly should now
look like this.
Fig.15: Mount the motor gear 4 on
the motor (without tightening the
bolt).
Fig.17: Fit the main gear 4 with a
608Z bearing and slide it on the
M8x70 mm bolt. Insert the motor,
adjust the motor gear 4 and secure
the motor using 4 M3x10 mm bolts.
Fig.14: Insert an M3 nut and M3x8
mm bolt in the main motor gear 4 .
Fig.16: Insert the M8x70 mm bolt in
the left side plate 14 and add the
short M8 spacer 32 .
Fig.18: Insert nut and M3x8 mm bolt
in the secondary motor gear 3 .
Be careful not to
overtighten the
motor gear bolts!

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.19: Insert 2 M3 nuts in the right
side plate 15 .
Fig.21: Fit a 624Z bearing in the sec-
ond gear arm 6 , and attach it to the
secondary gear 3 using 2 M3x10
mm and 2 M3 nuts
Fig.23: This is how the assembly
should look by now. With the gear
and M8 bolt removed.
Fig.20: Mount the motor loosely
(with 4 M3x10 mm) and slide in the
M8x70 mm bolt (removed from the
side plate Fig. 17), add a washer.
Fig.22: Slide the gear 3 onto the M8
bolt (pressing up against the washer)
and align the motor gear. Tighten
the motor and motor gear bolts.
Fig.24: Now gently press the right
side plate 15 into place and tighten
the 2 M3x10 mm bolts.
Be careful not to
overtighten the
motor gear bolts!

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.25: Bottom view showing the
bolt heads, and access hole in the
bottom gear 2 .
Fig.27: The 624Z bearings are
pushed in the rod ends 10 and 11 .
Fig.29: Insert the servo cable prior to
insertion of the rod ends 10 and 11
into the tube.
Fig.26: The Robot Arm base is now
complete.
Fig.28: The rod ends 10 and 11 are
equipped with a path for the servo
cable.
Fig.30: The rod ends 10 and 11
mounted with the servo.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.31: Assemble the rods as shown
here.
Fig.33: Slide in the M8x70 mm bolt
and add the short M8 spacer 32 (see
fig. 16) and main gear. Keep the ser-
vo cable accessible.
Fig.35: Add an M8 SL nut on the
right side and tighten the bolt. (Do
not overtighten)
Fig.32: Slide the short 15 mm tube
into the main gear 4 and secure it
with the bracket 5 using 2 M3x20
mm bolts and 2 M3 nuts.
Fig.34: Slide the two long M8 spac-
ers 31 onto the bolt with the chamfer
facing the bearings. Slide the sec-
ondary gear and washer on the bolt.
Fig.36: Add 4 M3 nuts and 1 M4 SL
nut to the main joint bracket 7 and
8 as shown. Prepare 4 M3x25 mm
bolts for assembly.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.37: Mount the main joint bracket
7 and 8 on the longer tube. The
position of the tube in the bracket is
adjusted in the final step.
Fig.39: Tighten the M4 bolt till there
is no slack but free movement of the
parts.
Fig.41: Mount the link ends 12 to the
linkage arms.
Fig.38: Add 3 624Z bearings to the
triangle 9 , add an M4x35 mm bolt
and the short M4 spacer 30 .
Fig.40: The Robot Arm should look
like this by now.
Fig.42: Mount one of the two 169
mm arms (tube length) as shown.
Requires 1 M4x20 mm and 1 M4x35
mm bolt and 2 M4 SL nuts.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.43: Mount the other 169 mm link
arm from side plate to triangle and
the 164 mm link arm as shown. Use
3 M4x20mm bolts and 3 M4 SL nuts.
Fig.45: Add the M8 nut cover 25 and
the longer M4 nut cover 27 as
shown.
Fig.47: For the gripper assembly the
gripper main bracket 18 and the end
bracket 19 are needed.
Fig.44: The arm should look like this
now.
Fig.46: Add the 4 M4 nut covers 26
as shown.
Fig.48: Press them gently together
and secure with an M3x10 mm bolt
and an M3 nut.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.49: Next these parts are needed
20 21 22 23 24 .
Fig.51: Mount the gear to the brack-
et from fig. 48 as shown, using an
M3x20 mm bolt and an M3 SL nut.
(Make sure the parts move freely)
Fig.53: The gripper should look like
this by now.
Fig.50: Use 4 M3x20 mm bolts and 4
M3 SL nuts to assemble the parts as
shown above. (Make sure the parts
move freely)
Fig.52: Use 2 M3x20 mm bolts and 2
M3 SL nuts for the assembly shown
here. (Make sure the parts move
freely)
Fig.54: Add M3 nut covers 28 to all
nuts but the one holding the gear, as
shown here.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.55: The gripper is now ready for
mount of the micro servo.
Fig.57: Insert the servo horn as
shown and tighten the small center
screw carefully.
Fig.59: Press the gripper assembly
and the end triangles 16 and 17 to-
gether. Insert the M4x35 mm bolt
and add a M4 washer as shown.
Fig.56: Use the two longer screws
from the servo accessories bag to
mount the servo.
Fig.58: Add a 624Z bearing to the
left end triangle 17 and an M4 SL nut
to the right 16 .
Fig.60: Add a washer to the right
side also, and tighten the bolt while
ensuring that there is free movement
of the parts.
Note:
You should
power on the
servo to move it
to neutral prior
to installing the
servo horn.

Assembly
Follow the steps below to assemble the uStepper Robot Arm.
Fig.61: Insert an M4x35 mm bolt in-
to the link end 12 and add the long
M4 spacer 29 as shown.
Fig.63: The assembly of the end ef-
fector should look like this.
Fig.62: Connect the link to the end
triangle 17 as shown, and tighten the
bolt. An M4 SL nut is used here.
Fig.64: Adjust the position of the
tube as mentioned in fig. 37 so that
the gripper is level with the base.

Finished Robot Arm
You have now assembled the uStepper Robot Arm, and your result should be similar to
what is shown on the following two pictures.