Saturday, April 20, 2013

DAY 39 - Back to Form

It was a good day of building today.  Started at 8:00 and hung up the tools at midnight.

I began the day trying to identify the electrical gremlin that has been plaguing me for the past couple of weeks.  I am thinking I have a power supply problem in the dome now that I have all kinds of new goodies in it.  It seems as though when a DC motor is introduced to a circuit, even though it does not consume over 1.5 amps, it can wreak havoc on the other kids in the electronic neighborhood.... I will have to brush up on some reading by some guy named Ohm.  Apparently, he knew a thing or two about electricity ;-)   If anything - his knowledge is directly inverse of mine.  I am like Schultz from Hogan's Heroes, "I know Nothing !"

All in all - I made some progress with the dome lights and periscope.  First up was installing a remote relay that reverses polarity.  I  tried to wire up the 12 channel relay to perform this task, and tried a few other remotes - and the results were the same every time... not good.  This relay is dedicated to moving the periscope up and down - and it just plain works.

I also separated the power for the periscope lift mechanism from the dome logic displays and lights.  Additionally, I installed some uber BRIGHT LEDs in the holo-prokectors.  These also run on their own power.


Front skin removed, and top electronics bay shaping up.  12 channel wireless relay in the center used for turning on the Periscope lights.  Certainly overkill, but I could not figure out how to program a 6 or even a 2 channel wireless relay that I had in waiting.  Apparently, when you purchase something off Ebay for $5 from a seller in China, instructions are not included...

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Periscope chillin' waiting to raise and lower.  the rear electronic panel was opened to try to clean up a number of wayward wires, and to allow access to the body, as I had to reinstall a bunch of parts that I cooked pretty well last week.  


View of the completed electronics panel in the dome.  Separate switches to power up the Dome Logics, The Holo-Projector lights and the Periscope.


Speaking of Periscope, here is a shot of how tight the tolerances are for the periscope nestled inside the dome.  Not sure if the photo shows it properly, but there is about an 1/8 of an inch clearance all the way around.


Shiny - and I mean SHINY new aluminum radar eye.  Mirror like finish - it will be a shame to paint this part.....


A little better look at the Radar Eye.  Of course, the mounting holes do not align with the ones I drilled for the resin Radar Eye, so I will have to drill some more holes in poor R2's noggin.


Happy mistake # 42 - The lighted switches I used in the dome throw off a good amount of ambient light inside the head.


When the lights are low - the effect is really COOL.  Looks like R2 is floating on a bed of neon... Hmmmmm... makes me think this would be cool to put it on a car ...... or not.


Looking really cool when the front PSI turns red and the logo on the PSI mount is red against the blue light inside the dome.


R2 : total Mack-Daddy.


Here are the three switched responsible for all of the interior light.  There are two blue, and one green switch.  The blue light pretty much drowns out the green switch (in the center).


Large Data Port and aluminum utility arms installed.  (Again - the Radar Eye is not in it's final resting place)


Come give us a hug....


The arms installed in minutes - really a great fit, and they swing in and out effortlessly.  Perhaps I need to automate them.  Perhaps, I need another hole in my head as well.


Another pic of the arms with the skins attached.


Dad and I had a good time assembling the all aluminum legs.  That is correct - all aluminum from head to toe now !


Mounting the new legs.  (New to me at least - these were purchased second-hand from a member of the Astromech.net boards.


"Diet" Aluminum Horseshoes from Guy Vardman's recent run.  Many of the parts being made these days are called "diet" because they are routed out to weigh less than a solid piece of aluminum.


Alluminum Center ankle and steel center foot.  This took a while to get together, but the existing caster brackets fit in like a glove.


R2 "Airing it out".


In case you wanted to see more.


A little video of the lights in action.

You can see the periscope acting a little erratic, and at the end - the front PBI panel "locks up".  That nasty gremlin is still in there somewhere.  Oh ye, I will find him, and when I do, it will be "time to exercise the demon".  I can't wait to say "This Droid is clean"....






Cool blue hue with the lights off.  Even if he did nothing else, it would be satisfying to use him as a glorified mood lamp.  I am building an .... ahem .... something - something dollar ... lava lamp.  Congratulations, me.


"Because mine says Desert Eagle five point 0, and your's says 'replica'".... love that movie.

This is a single input and output power distribution board with a digital display of the input and output voltage.  12 V in 5 V out to power the holo-projector lights.


One last parting shot of the inside of the dome.


Next week will involve getting the little guy moving around again.  His legs are mounted, but the motor mounts need to be installed.  (Didn't I do this a few weeks back ?????)

Also, the center ankle will be mounted.  Once that is done - I foresee video of the new legs and feet in action.   That is, if the motors can still move his tubby butt around.

Sunday, April 14, 2013

DAY 38 - WIN, WIN, WIN.... and FAIL.....

First off - the good news.  I recently purchased a set of Aluminum Legs from a member of Astromech.net.  FULL legs - all pieces parts aluminum.  There are a number of parts that I already have, but there were some key pieces that I did not have.

What I did not have :

   - Aluminum Legs
   - Aluminum Booster Covers
   - Aluminum Battery Boxes
   - Aluminum Center Ankle
   - Aluminum Radar Eye
   - Aluminum Utility Arms


Yes, so I am comletely jazzed that the parts have arrived - I received one box last week, another on Saturday... and one more is on the way and will be here on Monday.  The box that did not arrive was the one with the actual legs in it.  Quite literally, the center of all things in the leg universe.  Unfortunately, I can not take off R2's current PVC legs until I get the third box.  Patience......

I believe the seller said the droid that these parts came from was about 10 years old, so these parts are from the old-school runs.  The "non-diet" versions.  All solid aluminum, and heavy.  If ever a row breaks out at a gathering, the booster covers alone will suffice as clubs - they are rock solid, and weigh a ton.

Here are a couple of photos of what I did get :

Aluminum Center Ankle.  Again, this guy was used, so there will be a little reworking involved.  It is interesting to see how some of the newer parts have "evolved" as other members offing part runs put their own tweaks and improvements into the design.


Aluminum Booster Covers.  I think these things weigh as much as the PVC legs alone.


Steel Outer Feet.  NWT on these guys, a little sandpaper and a repaint, and they will be good as new.


Left : New "diet" Horseshoes from Guy Vardman's recent run.
Right : Old School solid horseshoes.


Flip the horseshoe over to see what makes these parts "diet".  You can see that the excess material is milled out to save weight.  Reminds me of an old mountain biking article that I read years back, it quoted a Public Enemy song :

Everybody sayin' it
Everybody playin' it rollin on the scales
'Cause everybody's weighin' it

They were comparing the weight savings of lightened components on the overall weight of a bike at the time.  Back in the 90's, it was all the rage to produce the lightest bike ever known to man.... I assume it is the same now, but I have been absent from that game for a good long while now.

I can see the weight savings on these parts, and all told, I am sure the overall weight savings may add up to quite a bit.... but when you are rolling around a astromech, what is the difference in 210 and 230 pounds total weight ?  :-D

 

Another shot of the new horseshoes, cause they are just too pretty.


Center foot assembly complete with caster mounting bracket.  I am happy to to be able to review the wear and tear on the Uniball casters.  In a previous post, I replaced these Uniballs with regular swivel casters on my center and outer foot mounts.  After seeing these used parts, I know that was a good decision.  These casters simply do not wear well.  One of the casters below is stuck - it would not roll even without a load on it.  I will most likely use this mounting plate with the swivel casters.


My current nemesis.  On Friday, I got the periscope riser all assembled and running without a hitch.  I ran the small board to switch the lighting modes outside of the periscope housing, and then all heck broke loose.  When I put everything back together, including the dome and dome lights.... something went horribly, horribly wrong.

A little blue smoke, and then the Electro-Gremlin set in for a long winter's nap.  I have no idea what is going on, but certain things started dropping out on the body when I enabled the periscope riser.  I would lose 1/2 of the dome lights, or the lights on the Data Port on the front of the body would go out.  No consistency to the problems at all.  Resetting the power on the entire droid would resolve the issue..... for a moment, then things would start dropping off.  Now, one of the power distribution boards is dead to the world.  The input shows a good 12 volt signal, but all of the outputs are disabled.  Damn - that is the whole reason for the board : distribute power.

Back to the drawing board for this one... as I am at a loss.  I will have to check each of the components, along with the continuity of the wiring to see where the problem lives.  I know this is a setback, and I have to deal with it.  My inexperience with this is truly showing at this point.  I think dumb luck has been with me up to this point - as everything I have hooked up in the electric supply realm has worked without a hitch.  Ultimately, I know that this will further my understanding of the power scheme, but I am bummed that it worked well for a day.... then nothing.




Friday, April 12, 2013

DAY 35/37/37 ... ????

It has been a while since I have posted up, due to the fact that I felt like I was getting nowhere fast with the current project.

R2's periscope is a part that comes out of the dome and retracts back in - seen a couple of times in the movies, most notably on Dagobah, as R2 "swims" through the swamp after he falls off of Luke's X-Wing.

So - is this part "necessary" to the build - NO.  Is it a very cool piece that will enhance the viewer's (and user's) experience - YES.   It is nothing but droid-bling.  Something to look at when you are tired or watching a white and blue trashcan drive around the room.

Why did this take so long ?  There ware a lot of parts to make myself in this assembly.  After the Periscope lighting was finished, it then came to mounting the Linear Actuator.  The Linear Actuator was purchased from a member of Astromech.net second hand, and was the correct size and had an appropriate amount of travel for this application.  This is one of those parts that one can buy "off the shelf" and modify to work for a specific R2 related project .... with a little work.  There is talk on the boards of a couple of members working up kits for periscope lifters, but nothing has become reality in the past 6 months.

This particular linear actuator can be found here :

http://www.firgelliauto.com/product_info.php?cPath=118&products_id=257

Firgelli Automation is the company, and they make track actuators and tube actuators.  The tube actuators are the more familiar units - think of a lift gate on a truck bed or trunk lift mechanism on a car.  The tube actuators are more like pistons or hydraulic actuators.  These would be great for this project IF there was enough room inside the dome for the unit.  The track actuator has a screw lift that moves a mount up and down the shaft.  Even this unit is quite large.  It stands 10" tall but only offers 5" of travel.

I won't bore you with all of the details and trial and error that went into mounting this on the dome plate, but it was not easy.  The alignment of the mechanism is critical, as the periscope "head" needs to travel in and out of one of the pie panels on top of R2's dome.  Little to no clearance and less margin of error mean that the actuator needs to be positioned perfectly in order for the unit to raise and lower without getting caught up on the dome opening.

Here are a few shots of the mounting of the actuator and the periscope.

The periscope is mounted on a piece of 1-1/4" PVC pipe to add a little height, and to get the cool posts exposed after it has been lifted out of the dome.


As I stated before, the glide path of the actuator has to be exact every time it is raised or lowered.  The dome plate is rather flexible, and this caused the periscope to wobble and lean as it made it's short 5" trip.  I used some 80-20 aluminum (basically uber-cool erector set like material for big boys) to create a stabilizer mount for the actuator.


Here is a pretty good shot of the stabilizer attached to the top of the actuator.  You will notice that the top edges of the arch are rounded off, this allows the top of the dome to clear the assembly.


Here is the motor on the actuator.  The mount for the riser is shown here as well.  The periscope will mount on the aluminum spire.


Periscope and PVC riser being glued together with JB Weld.  No more craptastic tape to hold the two pieces together.


Yet another hacked-up cutting board was installed on the arch to offer mounting points for the electronic goodies inside the dome.

In the picture below, bottom center is the slip ring connector board.  This was previously mounted on one of the spokes of the dome plate.  On the right of the board is a 12 channel RF receiver.  This allows 12 channels of relays to be triggered by a wireless remote.

The idea was to have a single button used to raise the periscope and another to lower the periscope, as this particular RF board did not offer reverse polarity within a single relay pot.  A little searching on the interwebs showed how to hook up one of these unite to achieve the forward and reverse motion with separate buttons.  OK - it was a LOT of searching, and more trial and error... and some blue smoke here and there before I got it hooked up properly.  Most of the "help" available on the internet is written as if the reader has some kind of knowledge about the unit.  Unfortunately, I am not that guy.  Terms like Comm, Normal Open, Normal Closed, Latched Mode, Toggle Mode and Momentary Mode were all but unknown to me before I read up on the topic.


The individual relays correspond to buttons on the remote, but were not numbered in any way.  A little multimeter probing allowed me to identify the correct numbers.   Relays #1 and #2 are hooked up, but the final working scheme is on relays #7 and #8.  Basically, the relays are wired with shared positive and negative wire leads from the main power - BUT the poles are reversed to pass a reverse polarity signal based on two buttons.  The center pole is used to attach the positive and negative lead of the actuator motor.  Pressing button #7 sends a positive signal to the actuator, causing it to raise.  Pressing button #8 sends a negative (or reversed polarity signal) to the motor which sends it down.  the linear actuator has built in limit switches that stop the signal when it reaches the top and bottom of the travel.


All of these relays will require their own power, so I set up a distribution strip to split out the 12V signal from the slip ring board.


Here is a video of the unit in action - sans Dome.



All in all, the frustration over the past couple of weeks is well worth it.

Tomorrow, I plan on re-installing the lights within the periscope and get the lights wired to a button on the remote.  I will also finalize the position of the actuator with the dome on, so it will clear the opening in the pie panel.

I have to get some pictures up of some of the new aluminum goodies I received last week as well !