LA Robotics Club Message Board › Intro, meetings and CNC cutting suggestions

Intro, meetings and CNC cutting suggestions

Chris J.
user 11772561
Marina del Rey, CA
Post #: 2
I'm looking for a local company that can cut and bend sheetmetal. I've found a few but they've been pretty flaky about getting quotes back to me.

I don't remember if I did an intro on here before but I'm working on punching robot. Hoping to start mass producing by April. Here's a video of our early prototype. http://www.youtube.co...­

Should have a much faster more vicious version available to demo in the next month if anyone is interested. It's being built on a custom Arduino based board. The board is based on a 2560 mega with an added dual motor driver (15A motors) and a single (5A motor), ethernet, hardware debouncing for 5 buttons and easy pin hookups for a 1.8" LCD screen and an accelerometer. I may considering selling it at close to cost to help get my volume up for manufacturing. For someone who needs all those functions it might be something to consider.

I live in Marina del Rey in a large condo complex. We've got plenty of space for meetings. I'll need to check with management but I may be able to host some meetups.

- Chris
Alex56782
user 17722901
Los Angeles, CA
Post #: 21
looking good,.... I like how the robot moves its arm position for a diffirent style punch.
have you thought of adding some pressure sensors or buttons to the robot face and/or torso?
your project looks geat, keep at it.
Chris J.
user 11772561
Marina del Rey, CA
Post #: 3
There are going to be 4 pressure sensors in the chest, possibly 1 or 2 in the legs and an accelerometer in the head. Lights will turn on associated with each sensor and we'll log the reaction time to hit it.

For now the data is being logged to SD card but the plan is to upload it to our website and graph and store the data for the user.
Homan C.
user 32599832
San Gabriel, CA
Post #: 1
This is AWESOME. I'm a martial artist and I would love to use this for basic drills. Some improvements would be to randomize the timing of the punches so it's not as predictable/cyclic. What do you use to generate the punching motion? Servo?
Chris J.
user 11772561
Marina del Rey, CA
Post #: 4
It's a low speed high torque motor driving a cam pulling cables attached to the arm. No servos.

I'm just now starting to play with code to mess with the timing. There are going to be different settings, beginner will have a very basic pattern and advanced will throw lots of weird combinations.

In the video we had 40W motors, I'm waiting to test 140W motors. The big advantage isn't just faster punches when it's going but the ability to start, stop and restart in reverse smoothly and quickly.

I've got an ethernet connection almost working that will make it easier to download log files from it than popping out the SD card like I was going to do before.
Homan C.
user 32599832
San Gabriel, CA
Post #: 2
Have you considered using the kinect to give the robot "eyes"? Possible applications are shadow-boxing mode, or record and playback motion, or predictive intelligence to allow the robot to bob & weave as well.
Brian P.
user 13999900
Los Angeles, CA
Post #: 1
Cool bot! For any custom metal cutting I use Charisma Design Studio in Burbank. They do a lot of work for the entertainment industry so they're real good with tight deadlines and clients needing their parts yesterday. Friendly too. Hope this helps.
Chris J.
user 11772561
Marina del Rey, CA
Post #: 5
I'll check out Charisma Design, thanks.

The problem with the Kinect is the placement of it. If I put it on the head/neck of the robot it's too close to the user and is subject to being bounced around and losing focus as you hit it. I tried putting it behind the robot pointing down but the head obstructs the view. From the side doesn't work and neither does behind the user.

I may try playing with the new Kinect for Windows which works at a closer range but I'm not optimistic. I don't think it'll be that necessary either, with the faster motors you'll have your hands full either way.

I would like to put some type of cheap video camera in it and sync the sensor data to a video so that you can see what you're doing. The trouble is controlling and syncing it up with the limited processing on the Arduino.

Lots of fun options. Hope to have something to show off soon.
Alex56782
user 17722901
Los Angeles, CA
Post #: 25
Have you tried the Robotvision software from RoboRealms?
A CPU USB Camera, is smaller and can fit right next to the head, in a seperate stable setup.

Here's the tutorial page
http://www.roborealm....­

I like the dice counting demo...
http://www.roborealm....­

I haven't tryied all the fetures out, just played around with it; but seems possible with an arduino (theres demo code for it I belive).... the next thing might be mixing it with ROS or MSRD.

Your project looks fun with lots of potential, keep at it.
Charles
user 13611753
Marina del Rey, CA
Post #: 1
You said you want a sheetmetal case and are having trouble finding a vendor.
Have you considered using a thicker plastic case that can be 3D printed with reinforcing where needed?

A plastic case should be available from many local or distant vendors.
Many manufactures and contract labor jobs shops will have booths at Westec 2012 March 27-28th at the LA Convention Center.
One plus to contract labor vendors is you may try using different plastic grades to see which stands up better. Another plus to plastic design is shells can have thicker rib like strips. In airplanes the thicker rib strips are called bulkheads and longerons to provide more stiffness at right angles to each other. The downside of thick plastic to not punch through after several hits in one spot over time is added weight for inexpensive acrylics, or other plastic shell to stand the stress. But weight may prevent falling over for a more exciting fight where they can punch each other longer. A knockdown is necessary, but if they fall over to easy it may not be realistic. It may take 3-5 iterations to find out thickness that holds up without pricing it high to limit sales.
If you have a prototype in 30 days that may be good to be more prepared for Christmas sales.

If you find out what plastic grades 3D machines used can print. Then you can ask a plastic supply company for a sample to see if their sample material works for the project. This may minimize what you pay for prototype development. A company I worked for sent out free samples of electric connectors for prototypes. Ask for the tech rep or sales person for your area or sales office. Then your vendor will not charge for material - some may charge a handling charge. I'd have it delivered to you so you can bring it to the vendor to eliminate receiving/inventory steps. An advantage of using samples is the plastic supplier may have structural grades the job shop does not carry they will pay for. You may need to set up machines to punch each other nonstop to see which material sample holds up longer. And mount camera to take a timed photo say every 10, 20 or 30 minutes to find out how many punches it takes to break. Like flexing a wing on an airplane to see how long it takes to break. I'm guessing 4,000 to 5,000 punches is affordable and lasts long enough.

I'm going to Westec to find out what is available from 3D printers. I'd like to have a annual 3D printer show to display what they can make where several manufacturers or vendors with all machines are there. Putting all vendor and service company display booths next to each other at future Westec shows may work.

You didn't ask for it but there is a free Vision magazine that may help to keep current about vision issues.

Let me know what happens.
Charles
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