Boston Dynamics' Stretch at MODEX!

 I had a chance to attend the MODEX show this week and was pleased to see that Boston Dynamics was in attendance with their Stretch platform on full display.  I love seeing robotic products going from the prototype (work in progress) stage to the production model phase and boy is this thing a beauty.  The gray and white color choice is clean and non-threatening.  The simple geometries of the turret base and the main body are simple yet elegant.  I also love the wide and flat appearance of the turret mast that houses the vision systems.  All in all, I'm very impressed at the way the design came out and would enjoy picking the brain of the head designer(s) that produced it.  Unfortunately, I wasn't able to stay at the Boston Dynamics booth for long and I did not take enough pictures.  Here are the two shots that I snapped and you can watch an older video of Stretch in action below. 

Hopefully I'll be able to share some more goodies from the MODEX trip.  Stay tuned!

Never use gloves with rotating equipment - PSA

    Well, I was told this before and I agreed with the statement, but it's not until now that I'm determined to implement it.  You see, during my past employment, I've worked along side several very skill machinists and from time to time they would impart nuggets of wisdom to me.  One of those nuggets was not to wear gloves while using a lathe.  I tend to wear gloves often while working in the shop and I normally don't remove them when I use the milling machine or lathe.  Usually, I'm aware that I have them on and keep my hands away from anything spinning, but last week I made a careless mistake.  I was in a hurry to get a freshly printed part installed and needed to drill some holes quickly.  No big deal, right? As I was drilling the holes, I decided that it was a good idea to brush the chips, that were being created, away with my gloved hand.  I did it twice.  The first time, no problem.  On the second time, the drill bit snagged the glove at the tip of my pointer finger and began to wind it up.  It quickly pulled my finger and therefore my hand into the bit.  I immediately began to pull away, but I could not free myself.  The glove ripped and the digit of the glove became like a tourniquet, tightening more and more as each second went by.  I grunted in panic, eventually realizing that I could not pull away, I tried to turn off the mill.  I overturned the three position switch, making it temporarily go in reverse and then I finally switch it to the middle, cutting the mill off.  At this point the drill bit stopped and I was able to remove the glove and therefore my hand from the mill.  There was no blood just soreness.  Thank the Lord that the glove took all of the cutting from the edge of the drill bit.  I am so thankful that there wasn't any permanent damage done and that this serves as a reminder to adhere to safe practices around machinery.  

Shower valve repair - The Engineer vs. Life

Well let me tell you what happened on yesterday. The shower head in the master bathroom has been steady dripping over the last month or so and I have been planning to set aside some time to repair it.

Well life determined that I would be repairing it sooner rather than later, because the drip almost became a steady stream the night before.  Thankfully, I had done my research on the valve so I knew what to get and where to get it.  I also knew that there was a high probability that the valve would be stuck in the pipe requiring the use of a valve puller tool to get it out.  

Upon purchasing the replacement valve I saw that they included  a plastic twisting adapter that was to be used to "twist" the valve out of the pipe. After several hopeless attempts it had become apparent that this adapter was useless in this situation, I needed a valve puller.

The valve puller was only $15 at the local hardware store, but me being the Engineer type that I am, I thought, "surely I could come up with something that would work".  So after pondering on exactly how the valve puller works, I began to search the shop for something that could fit the bill. Eureka!  I remembered that I have a set of hole saws in my shop and they have a mandrel.  Surely there is some way to adapt the mandrel so that it will operate as a valve puller, I thought.  So I conducted a mini scavenger hunt around my shop to find what parts I would need.  First, I needed a screw to be inserted into the stem of the valve.  Also this screw would need to be able to attach to the mandrel in some fashion.  Secondly, I needed some material that the mandrel would be able to push against that had a large enough diameter to be able to be braced against the pipe the valves was in.  Lastly, I needed some sort of handle in order to hold the make shift valve puller when I go to rotate the knurl wheel.   Thankfully I found a 10-32 socket head screw, an old Delrin wheel hub that I had made, and an adjustable wrench.

To make this all work I needed to turn the head of the screw in order to allow it to be inserted into the end of the mandrel.  I needed to lop off the large diameter portion on the delrin hub, and I also needed to increase the size of the through hole in the delrin hub.  So as I began the work, the first stop was the bench lathe.  Thankfully, I was able to make short work of turning down the screw's head diameter.  Next I needed to lop off the large diameter on the delrin hub adapter.  The cut off tool that I was using wasn't quite set up long enough to reach the inner bore on the delrin without crashing into the workpiece, so I had to improvise with a hacksaw.  After making that cut, I cleaned up the face of the delrin and increased the inner bore diameter to go over the valve stem.  

At this point, I'm ready to give my mandrel valve puller a shot at the stuck valve.  So I go to the shower and install the delrin mandrel combo, add an adjustable wrench and plyers, and start turning the knurled ring.  So far things are looking okay.  The pins in the mandrel are pushing on the delrin and the delrin is pushing on the pipe, but then I come to the end of the screw travel on the mandrel and the valve is still stuck!  Well it turns out that the delrin is pushing on the pipe and on the valve at the same time.  I come to the realization that there is supposed to be a notch in the valve facing end of the delrin so that it doesn't press against the valve while it's pushing against the pipe.  Back to the shop to make a quick notch with the milling machine.  I found the closest end mill to 9/16" and made a cut about 1/2" deep through the approximate center of the delrin part.  Now quickly back to the shower for the second attempt and voila!  This time when I start to turn the knurled ring I see the valve start to move.  I turn the ring until It's gone the full travel on the mandrel and then try to pull out the once stuck valve.  Success!  The valve comes out and I now have access to the pipe. 

The replacement of the valve went smooth from this point on and there is no more drippy shower head!  Would I recommend doing it this way?  No, not unless you just happen to already have these tools at your disposal or can not locate the valve puller from your local hardware store.  With my time, tools, and materials cost, I've greatly exceeded the $16 that was being charged for the valve puller at the store, but it's good to know what can be accomplished with the resources you already have at home.  

XBOX Design Lab inspired R/C Transmitter

 This has been forever in the making.  I'm in the process of designing and building my first 15 - 17 channel RC radio transmitter! I've always been fascinated with all types of control surfaces, but specifically remote control car controllers.  I have a growing assortment of all types of radio controls and video game controllers.  Now, I'm combining what I see as the best of both worlds into my very own personal radio.  Be sure to tune into my new livestream where I'm designing the radio in real time and going over the why and the how of what I'm doing.