Hello, I have a Kawasaki which apparently is an FS003N or RS003N, the joint 3 is damaged the gears and does not move. I wonder if there is any manual with exchange demonstration or a drawing with exploded view of the robot to facilitate the disassembly and exchange of the gear. Grateful
JOINT 3 Damaged
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Caldeira_4616 -
November 10, 2022 at 4:09 PM -
Thread is Unresolved
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Which is it and FS or an RS, they use different controllers and harnessing, therefore any documentation available is relative to the arm model.
- FS003N - xxxx
- RS003N - xxxx
Are you sure it's the gear that is causing the issue and not the brake on the motor, have you tested it using a brake release box?
Is there any error being reported when you try and move JT3 in teach mode using joint interpolation?
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Attached is a document for the removal/replacement of motors for FS02/FS03 series.
Same procedure can be applied to RS03 Series.
Check out the harness (behind joint 3 cover) for signs of friction damage, if damaged then JT3 - JT6 motor/encoder/brake problems can occur.
Really you should carry out as much testing as you can do, to prove fault with JTx motor/gearbox before removal as you can introduce further problems by not disassembling correctly as procedure is very intrusive, especially for JT3.
What I mean by this is:
- JT4, JT5 and JT6 motors require removing first to allow JT3 to be removed.
- Therefore all 4 joints must be re-zero afterwards.
- The retaining bolts for motors are monkey metal and are easily damaged - so have spares available.
- Use long reach T bar hex and make sure end is not damaged and fits perfectly before turning.
- Attention must be made to the harnessing securing location around JT3 before disconnection.
- Make pictures and markings on configuration before removing.
- Is possible this harness can be damaged by internal friction over years to cause problems
I have disassembled many FS02/FS03 and RS03 arms previously, and I can warn you from experience, it is not as simple as larger arms due to the compact nature.
With time, attention, spares and correct tooling it is 100% achievable for full strip down to empty shell and full rebuild.
Good luck with your journey...........
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Thank you very much for the file, it will help a lot
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In order for me to repair the joint 3, do I have to remove the other engines and even the structural parts of the arm together?
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As per my post and as stipulated clearly in the manual.
In order to remove JT3 motor, JT4, JT5 and JT6 motors need to be removed first.
JT3 motor is attached to a motor plate which is bolted to the internal structure
The harmonic wave generator is attached to the shaft on the other side of the plate.
Therefore, the complete assembly requires to be removed and requires full clearance to withdraw it and cannot be removed without removing JT4, JT5 and JT6 first.
You will see this when you open the top cover and JT3 cover.
The manual highlights the 4 bolts that need removing in order to withdraw JT3 motor, these 4 bolts ARE NOT the motor bolts, but the bolts that attach the motor plate to the structure.
When these are removed (including the harness), you can withdraw JT3 motor assembly out and have access to the wave generator ring and bearing for JT3 and can be inspected for damage.
You will probably require some loctite and also some liquid gasket (three bond usually) #1206D and/or #1212.
Kawasaki arms always have this liquid gasket plastered around everything for extra adhesion.
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Thanks for the clarification, sorry for the inconvenience
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sorry for the inconvenience
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No inconvenience at all and nothing to apologise for.
I'm just pointing out that this information about JT3 has already been mentioned.
Check your conversation out, this may assist you further.
The main advice I can give you is 100% satisfy yourself that there is a problem with JT3 first:
- Cross reference errors with manual and try non-intrusive counter measures to diagnose further.
- Not doing this, may direct you to remove un-necessary components.
- The servo board or power block (controller side) could be the problem and not arm side.
If you can confirm electronics are good, then arm side checking needs to take place:
- Position arm in suitable posture for brake checking.
- Make sure suitable safety arrest measures are in place to prevent joint falling when brake released.
- Brake release to check motor brake - you should hear the motor click.
- When brake is released, rotate JT3 joint and check for free rotation and not stiff.
- When rotating JT3 joint, check encoder values are being updated.
- Use Teach and joint interpolation to check manual control is possible.
- Remove JT3 cover and inspect the main harness routing for damage and friction wear evidence.
If any of the above arm checks fail, then further investigation is required.
Unfortunately, with these arms, to further investigate JT3, requires intrusive measures to access.
Due to this there is a risk of introducing problems on the known good joints you have to remove.
Accidental damage to components and harnessing, rezeroing required etc.
Position the arm into the posture indicated in the manual, so that the top cover can be accessed.
- Remove the top cover and JT3 side cover (if not already removed).
- Inspect, check and note position of internal harness routing around JT3 area (take pictures/red pen).
- Disconnect JT3, JT4, JT5, JT6 motor/brake and encoder harnesses.
- Withdraw harness from top cover through JT3 side entry.
- Remove harness routing plate with harness still attached and allow to drop.
- Personally, I would remove the harness from the routing plate to allow full harness inspection.
- You then have full access to remove JT4, JT5, JT6 and JT3.
- After removal of all joints, you just have a 'shell' and further investigation mechanically can be done.
The things to be mindful of when stripping down an aged arm is:
- If possible, have the spares available to replace.
- Damage occurring to monkey metal bolts - you should have a full set of spares available.
- Using the correct tools (indicated in the manual).
- Lots of grease will be present around the harness (this is there to reduce internal harness friction).
- JT4, JT5 and JT6 motors are identical.
- Accidently swapping JT5 and JT6 motors when refitting is possible - but have different gears attached.
- Place a mark on the top encoder housing of JT5 and JT6 motors identifying them to assist if needed.
- JT4 has a completely different gear attached, so cannot be mixed up with JT5, JT6.
If you follow the manual, stripping down and rebuilding is not a problem, just don't ever assume you can strip something down without using the manual as guidance - that information is provided for a reason.
Known JT3 issues with aged arms are:
- Servo board or power block electronic failure
- Motor brake.
- Encoder failure.
- Internal Harness friction damage.
- Wave generator and shell damage.
- Bearing seizure.