LewanSoul LeArm 6DOF Full Metal Robotic Arm with Servo, Controller, Wireless Handle, Free PC Software and APP, Video Tutorials for Arduino Starter

BUEN PRODUCTO

When I received the LeArm kit from Amazon, I was amazed at the quality of the arm, from the heavy metal base, industrial quality ball-bearing, good servos and the very clear assembly instruction videos on the Internet. It assembles easily in a few hours. I would recommend this arm over any other robot arm for robot experimenters as it will last. I intended to write about it in my monthly column in a robotics magazine and was waiting for their version of the 5-DOF hands, another manufacturer's version of which is shown in the photo. I never received those hands from LeWanSoul. I did receive their X-Arm shown to the right in the photo and found it to also be of excellent quality. However, after a year of experimentation and demonstrations for others, I have found both of these robot arms far higher quality than any of the other robot arm kits is have tested. The LeArm uses separate 'standard' servos, each of which must be connected to a controller or Raspberry Pi or Arduino board. Depending on the position of the arm, I could manipulate almost a pound. Programming of the LeArm is fairly simple as you are dealing with standard servos that require basic pulse-width signal inputs. The X-Arm has very similar construction but you can look at both robot arms at the Amazon site and see the physical similarities and differences in the two arms. Both use the same quality ball bearing base, though the metal structure is a bit different and the gripper/claw is identical to the other. This arm uses their LX-15D intelligent serial bus servos that can be 'daisy-chained' and the final end of the three wires of the daisy chain transfers the servo's address (each servo has a number of 1 to 6) and power through the three wires. (You can see the small connector on the end of the white cable in my photo) Your microcontroller addresses each servo independently through that cable, very similar to the Robotis Dynamixel servos. The higher cost is due to the cost of the high-cost intelligent servos. I had a bit of trouble programming the arm with a RaspberryPi but soon got the hang of it. I ended up writing a bit of code to use it with Python, directly. The only issue I might say is using the tiny metric screws that were all in one bag. I found some that were too long so I used washers in mounting them to the small aluminum cylinders between the servos. One of the threaded holes in the long cylinder was a few degrees off 90 degrees so I just left the screw off. The video instructions were fine though I would have preferred a written manual. I found myself 'rewinding' the video to listen again 'what the girl really said.' I also would have liked to test their two hand models as theirs seems so much better made than the other company's hands shown in my photo. I also have their 6, 16, 24 and 32 channel servo controllers that have extensively come into use with my demonstrations. The LSC-6 controller is furnished with the LeArm and is used with the hand controller (they call it a "handle") to control the arm wirelessly. Note the receiver board in the photo of their photo of the arm. I would highly recommend the LewanSoul robotic arms and controllers and servo testers for students from high school to advanced university instruction, as well as home experimenters. Either of their servo models are well made with metal gears and have yet to fail for me. Their web site offers much material on their products, and they have been around long enough for one to find all sorts of articles about uses of the LewanSoul robot arms and controllers.

I'm surprised more people haven't reviewed this robotic arm kit. I found the kit extremely well thought out. The parts machining and anodizing are just beautiful. A very important aspect of this design is the turntable that the arm sits on. It is built using a large diameter industrial quality bearing which provides a very solid base for the arm to operate on and provide servo-controlled rotation. The servos are top quality, very smooth operation and very powerful. The gripper is pre-assembled, a nice touch, and the joint design is quite clever. LewanSoul provides excellent tutorial videos, and an extremely helpful assembly video using 3D modeling to show how things go together in sequence. Another reviewer noted the importance of sorting out all the fastener hardware, that really helped smooth the build for me. The Bluetooth connection to the free iPhone app worked great, another impressive feature of this kit, especially for the money. The PS2 controller worked fine, though I prefer the iPhone app. There is also PC interface software that is provided although I have not tried that. I'm particularly interested in connecting an Arduino to the arm and writing sketches for controlling LeArm, and Aaron at LewanSoul showed me where to find the necessary information for that. LewanSoul has been very responsive answering my questions. Oh, and check out the video for LeHand on the LewanSoul website.

Assembly takes about 3 or 4 hours ... very well designed and manufactured. Extra screws in case you drop one (or two). Be sure to remove separate all the fasteners first ... you'll save a lot of time. Watch the video VERY carefully ... be sure to align all parts as indicated in the video. Works great via Mobile App / Bluetooth, PC App (not really graphical, but a good way to set up "Action Groups". The instructional videos are pretty entertaining ... Once assembled, the unit worked well. This is more of an instructional / hobbyist device, but it is a great introduction to automation and robotics.

I was very impressed with the overall quality. The aluminum pieces are all beautifully made with no burrs or improper shapes or bends. I found out that all parts were present and even a few extra screws were included. One servos connector was pinched a little, making it difficult to get the cable plugged in. The other similar servos connector was tight but not pinched. This was simply an inconvenience. I initially put the arm together as exactly as I could, following the instruction video. Here there was one real problem making assembly impossible. At the point of installing the servo that turns the wrist there was not enough room. I had to lift the servo by putting an additional layer of nuts between the servo ears and the aluminum bracket. This meant I had to replace the supplied screws ones with 4 that were about 3 mm longer (the thickness of the extra nut, and turn the screws around so the head is below the bracket and the nut is on top of the servo ear The info on what connects where was unclear. It took some experimentation to get everything connected properly and working, and again, this was simply an inconvenience, not a real problem. At this point everything is working with the included controller and remote. Now for the second design issue. I replaced the controller and began developing my own software. This was going well until the gripper fell off. The problem was the plastic shaft on the wrist servo supporting the entire weight of the gripper assembly. The screw into the servos shaft pulled out taking pieces of the shaft plastic with it. I will have to replace this servo with a metal shafted one using a metal connector plate. I do not hold the manufacturer responsible for this failure directly because my software had been abusing the assembly a little. But they should reconsider the use of the tiny plastic connection between these two parts. Update: I set all the servos except the gripper cycling from 500us to 2500us letting it sit for a few seconds at each extreme. It did this flawlessly for about 1-2 hours, then something went wrong in at least one servo. The base stopped rotating correctly and I think one of the arm servos is also misbehaving. I'll have to take it all apart and test each servo in detail to discover exactly what went wrong. With the original issues and now this short lived failure, I'm taking another star. At this point this kit is nothing more than a starting point for upgrades and improvement. Will update again once I get more information on the failure. Final Update: After checking things out, It looks like there was something going on with the base servo, but it has resolved itself. I resolved the wrist servo issue with a much longer screw - it seems that the one supplied was barely connecting. So after re-assembling completely, I'm happy to say everything is working perfectly, but this only happened after traveling a somewhat bumpy road.