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LOWER ARM V2 CABLING

CAD DESIGN

Let's have an overview of the mechanical CAD from different view angles and their specific names on CAD assembly.

Left Forearm V2 Right Forearm V2
in CAD repository (maybe CREO): RC_TLR_007_A_001_LEFT_FOREARM.ASM + RC_TLR_012_A_001_LEFT_HAND.ASM in CAD repository (maybe CREO): RC_TLR_010_A_001_RIGHT_FOREARM.ASM + RC_TLR_011_A_001_RIGHT_HAND.ASM

1 WHAT DO I NEED TO CABLE

Here you will find the overall tables describing the necessary parts needed when routing the cables onto the 11 motors (12 motors inside the Lower Arm but just 11 are cabled) and the mandatory sheaths to be used in the correct place.

1.1 Finger sheaths

IITCODE Alias Description
2375 SHEATH Open spiral spring, inox steel AISI302, D ext= 1.6mm, D wire= 0.25mm, L = 500 mm
13963 MAZZONI_0_3-0_8-250_SS_SHEATH Rectangular section sheath 0.3x0.8, L = 250 mm
2386 TEFLON_SHEATH Insulating sheath, AWG22, inner dia 0,709 -0/+0,102 mm, material thickness 0,152 -0/+0,102mm, Teflon, transparent

Danger

inside sheath 13963 please DO NOT (NEVER) USE Teflon sheath!!!

1.1.1 Sheaths length & labelling

Please refer to this table to find out which sheath you need to install at the right place and the correct label to add on top of it:

Finger Typology Label Length (mm) IITCODE - sheath
Thumb Proximal 6+ 185 13963
Thumb Proximal 6- 185 13963
Thumb Short Prox + pict. above 9 2375
Thumb Short Prox - pict. above 11 2375
Thumb Distal N4 57 2375 (+Teflon)
Thumb Short Dist pict. above 11.5 2375
Thumb oppose S0 50 13963
Thumb oppose S2 57 13963
Index Proximal 8+ 224 13963
Index Proximal 8- 224 13963
Index Distal N5 105 2375 (+Teflon)
Middle Proximal 7+ 224 13963
Middle Proximal 7- 224 13963
Middle Distal N3 105 2375 (+Teflon)
Ring Distal N2 95 2375 (+Teflon)
Pinkie Distal N9 95 2375 (+Teflon)
Fingers abduct T0 90 (1) 2375
Fingers abduct T2 27 2375
Fingers abduct T4 44 2375

(+Teflon) refers to the IITCODE 2386

Note

(1) the length 90 mm of T0 comes from the previous version where there was: T0+T3+tensioner (38+38+14 mm).

Warning

For the proximal sheath, please label BOTH the start of the sheath (base of the motor at the level of the elbow) and at the end of it.

1.2 Finger & hand cables

IITCODE Alias Description
1815 CG077063 Stainless steel micro-cable, cable construction 7x7mm, nom. diameter 0,63mm, not coated, AISI 316
2391 U7194561 Stainless steel micro-cable, cable construction 7x19mm, nom. diameter 0.45mm, outer diameter 0.61mm, Polyamide coated, AISI 316 - CARL STAHL GMBH

1.2.1 Cables length

Please refer to this table to find out which cable you need to install at the right place:

Finger Typology Length (cm) IITCODE - cable
Thumb oppose 50 1815
Thumb Proximal 100 1815
Index Proximal 100 1815
Middle Proximal 100 1815
Thumb Distal 40 2391
Index Distal 40 2391
Middle Distal 40 2391
Ring Distal 40 2391
Pinkie Distal 40 2391
Fingers Abduction 50/60 1815

2 HOW TO CABLE - FINGERS & HAND

2.1 Proximal joints

The 3 proximal joints :

  • Thumb
  • Index
  • Middle

located here:

LEFT FOREARM RIGHT FOREARM

are all wired with the cable 0.63mm uncoated from CARLSTAHL GmbH as per the following table:

IITCODE Alias Description
1815 CG077063 Stainless steel micro-cable, cable construction 7x7mm, nom. diameter 0,63mm, not coated, AISI 316

Every sheath in which the cable pass through (+ and - ) is made of:

IITCODE Alias Description
13963 MAZZONI_0_3-0_8-250_SS_SHEATH Rectangular section sheath 0.3x0.8, L = 250 mm

Danger

inside sheath 13963 please DO NOT USE Teflon sheath!!!

Note

IITCODE 13963 is alternative to the 4545 (old one - not in use ANYMORE) and it was introduced only for cost efficiency.

Please follow this link for an extended HOWTO route the cable.

2.1.1 THUMB peculiarity

The THUMB is a finger a bit particular in the wiring compared to the index and the middle because - as it is the finger with the most degrees of freedom- it needs to pass a series of pulleys at the base of it in order to add also the thumb oppose joint movement inside the articulation.

The IITCODE 2375 as specification described below :

IITCODE Alias Description
2375 SHEATH Open spiral spring, inox steel AISI302, D ext= 1.6mm, D wire= 0.25mm, L = 500 mm

Is needed for the 3 pieces circled in red on the picture above. Here are the specs for each one of them:

Number Type Length (mm)
1 distal short 11.5
2 prox short (-) 11
3 prox short (+) 9

Please follow this link for an extended HOWTO route the cable.

Once the 3 proximal joints are cabled, the lateral view of the forearm should look like the picture below. The 6 sheaths are pointed by the red arrows.

2.2 Distal joints

The 5 proximal joints (theoretically 5 but in practice just 4 motors need to be wired):

  • Thumb
  • Index
  • Middle
  • Ring and Pinkie

Located here:

RIGHT FOREARM LEFT FOREARM

Are all wired with the cable 0.61mm coated from CARLSTAHL GmbH as per the following table:

IITCODE Alias Description
2391 U7194561 Stainless steel micro-cable, cable construction 7x19mm, nom. dia 0.45mm, outer dia 0.61mm, Polyamide coated, AISI 316 - CARL STAHL GMBH

Every sheath is made of both the following pieces:

IITCODE Alias Description
2375 SHEATH Open spiral spring, inox steel AISI302, D ext= 1.6mm, D wire= 0.25mm, L = 500 mm
2386 TEFLON_SHEATH Insulating sheath, AWG22, inner dia 0,709 -0/+0,102 mm, material thickness 0,152 -0/+0,102mm, Teflon, transparent

Please follow this link for an extended HOWTO route the cable.

2.3 Thumb Oppose

To build the thumb oppose you just need 2 pieces of the sheath IITCODE 13963

Label Dimension (mm) IITCODE - SHEATH
S0 50 13963
S2 57 13963

Danger

inside sheath 13963 please DO NOT USE Teflon sheath!!!

And approximatively 50cm of IITCODE 1815 to route it.

IITCODE Alias Description
1815 CG077063 Stainless steel microcable, cable construction 7x7mm, nom. dia 0,63mm, not coated, AISI 316
13963 MAZZONI_0_3-0_8-250_SS_SHEATH Rectangular section sheath 0.3x0.8, L = 250 mm

Here is a more detail specification of where to find the 2 pieces:

Left Hand Right Hand

Please follow this link for an extended HOWTO route the cable.

2.4 Fingers Abduction

To build the fingers abduction you just need 3 pieces of the sheath IITCODE 2375

Label Dimension(mm) IITCODE - SHEATH
T0 90 2375
T2 27 2375
T4 44 2375

Danger

inside sheath 2375 please DO NOT USE Teflon sheath!!!

and approximatively 50cm of IITCODE 1815 to route it.

IITCODE Alias Description
1815 CG077063 Stainless steel micro-cable, cable construction 7x7mm, nom. diameter 0,63mm, not coated, AISI 316
2375 SHEATH Open spiral spring, inox steel AISI302, D ext= 1.6mm, D wire= 0.25mm, L = 500 mm

Here is a more detail specification of where to find the 3 pieces:

Left Hand Right Hand

Please follow this link for an extended HOWTO route the cable.

3 HOW TO CABLE - WRIST

3.1 Wrist tendons length

Here is the list of the 10 tendons needed to build the wrist movements:

Tendon IITCODE Length Alias
1 6400 72 mm RC_IIT_019_G_019
2 6402 84 mm RC_IIT_019_G_020
3 6404 101 mm RC_IIT_019_G_021
4 6413 124 mm RC_IIT_019_G_022
5 6414 107 mm RC_IIT_019_G_023
6 6415 113 mm RC_IIT_019_G_024
7 6416 112 mm RC_IIT_019_G_025
8 6417 107mm RC_IIT_019_G_026
9 6418 51 mm RC_IIT_019_G_027
10 6419 43 mm RC_IIT_019_G_028

3.2 Construction table

The overall cables of the wrist are all build from IITCODE 4482 (of Length defined in the table above) and 2 crimps IITCODE 4722, here is the table reporting the specifics of those pieces:

IITCODE Number of pieces Alias/Provider Code Description
4482 1 CG077081 Stainless steel microcable, cable construction 7x7mm, nom. dia 0,81mm, not coated, AISI 304
4722 2 RC_TLR_010_P_100 THIMBLE FOR CABLE 0.8mm

3.3 Right Forearm - Wrist motor tendons

From the pictures below you will be able to locate and identify the 8 tendons inside the Right Forearm building the active part of the wrist tendons.

To get a more details on how to rewire them, please follow this link

3.4 Left Forearm - Wrist motor tendons

From the pictures below you will be able to locate and identify the 8 tendons inside the Left Forearm building the active part of the wrist tendons.

To get a more details on how to rewire them, please follow this link

3.5 Tensioner - IITCODE 3514

To properly tense the 8 tendons of the Forearm it is mandatory to add the tensioner IITCODE 3514 - alias CAD of the assembly: RC_TLR_010_G014 - it is made by the following pieces:

IITCODE Revision Alias Description
3559 A3 RC_TLR_010_P_050 TENSIONER BODY
3560 A1 RC_TLR_010_P_046 TENSIONER SCREW
3561 RC_TLR_010_P_049 LOCK NUT
3562 A1 RC_TLR_010_P_048 TENSIONER SCREW
3563 RC_TLR_010_P_047 LOCK NUT

3.6 Wrist - Passive tendons

From the pictures below you will be able to locate and identify the 2 tendons inside both the Right Wrist and Left Wrist building the passive part of the wrist movements.

RIGHT WRIST LEFT WRIST

To get more details on how to rewire them, please follow this link.

3.7 TEST - MOTION

Every single motor listed below needs to be tested at the end of the cabling to ensure the perfect motion.

MOTOR LABEL MOTOR FUNCTION volt to open volts to close
2M0 pronosuppination 0.5V-1.5V 0.5V-1.5V
2M1 inside wrist motor 0.5V-1.5V 0.5V-1.5V
2M2 outside wrist motor 0.5V-1.5V 0.5V-1.5V
2M3 hand fingers 1.5-2V  1.5-2V
3M0 thumb oppose 0.5-1V(0)  2.5Vmax(90)
3M1 thum prox 0.5V-1V 0.5V-1V
3M2 thumb distal 2V-2.5V 2V-2.5V
3M3 index prox 0.5V-1.5V 0.5V-1.5V
4M0 index distal 1.5-2V 1.5-2V
4M1 midlle prox 0.5V-1.5V 0.5V-1.5V
4M2 middle distal 1-1.5V 1-1.5V
4M3 pinkie and ring 1V-1.5V 1V-1.5V