Sunday, December 23, 2012


DAY 16 - Lots of sanding - even more dust

Here we go - time to undertake the task of cutting out the dome panels for the carbon fiber doors.

I figured I would take one last photo of the dome in good shape, in case I monkeyed it up in this little process.



The roll of tape in the photo above is for reference purposes only.  It is suggested that the area to be cut out be masked off for reference and to prevent marring of the surface should the rotary tool wander.
I find that I am better cutting things out free-hand, as I pay a whole lot more attention to where the cut is going.  Not to mention, I am not as mad when I cut into the line that I was supposed to follow.  I figure I have some acceptable skills with the Dremel with a number of costumes I have worked on over the years, so I got right to it.
For the vertical cuts, I used the Dremel Multimax tool.  Awesome piece of machinery here, I highly recommend this tool for any workshop.  The flat wood cutting blade went through the fiberglass like a hot knife through butter.... only louder, slower and more dusty.  I did use the diamond cut-off wheel for the round sections on the top and bottom of the pie panels, as the Multimax tool has some issues with cutting curves.  Like any saw blade, it tends to bind if it is cutting at an angle that it does not like.


After I cut out the first panel, I got smart and jammed the shop-vac hose into the dome.  This worked really well, keeping the dust at bay.  There was enough suction that it pulled all of the dust into the dome, and away from the area that I was cutting, which came in real handy for the next process....


With the panel openings cut, the next step was to create a lip for the panel to sit on.  I have this router attachment for the Dremel that I outfitted with a quick cut rasp.  The bottom of the rasp was even with the foot of the router attachment.  The curve of the dome allowed the rasp to cut about 1/16" of material away.

This took a steady hand, but after a while, I got to know the sound and feel of the proper depth.  Yep, sound.... the blade would labor, and the motor would bog down a bit if I was cutting too deep.  The important thing when using a rotary tool is : never forget which was the blade is rotating.  If you know that, you are much more conscious on where the blade may/will go in case of a slip.  When you work against this rotation (which wants to pull the blade OUT of whatever you are working on) you gain two benefits.  A. You are aware that the blade will jump and make you sad.  B. you tend to slow the cut down a whole bunch, and let the tool do the work.


Another photo - I think this one shows the recessed areas a little better.  I went back and hit the little shelves with all manner of material removal devices.  Sandpaper, Files, Sanding drums, Razor Blades - heck, I think I even but a few pieces off.

I only wish I would have snapped a couple of photos of the finished product, as I finished all of the inside edges to the same dimensions.  (more filing, sanding, biting, etc)


Test fit.  Looks like a winner.  The carbon fiber has a really cool reaction to the flash - the silver part of the weave really reflects the light through the resin.


SPECIAL NOTICE:  If you want to cut out the hole for the holo-projector - be VERY careful with a drill press.  Don't wait until the 4th time it binds just before the drill bit passes through the bottom, causing the piece to get stuck on the bit.  When this happens, it yanks the piece out of your hand and then slams it back into whatever finger you still have on the table.

I did this not once, but 4 times... After the first time, I figured I had a goofy angle on the piece.  After the fourth time, I thought... "Hey, maybe this is NOT the tool to use".  Forgive me, I have been hunched over a fiberglass salad-bowl for a good part of the morning.


As bad as the drill press was, the Dremel diamond cutoff wheel worked wonders on the carbon fiber.  Once the piece was rough cut, I then used the drum sander to get the edge more defined in a circular shape.  In case you have not seen them, Dremel now has a quick release chuck for the little drum sanders - no more screwing and unscrewing the arbor.  Simply push a button, putt the arbor out, and the drum falls off.  Brilliant move on Dremel's behalf.  I never used to use these drums because they were such a P.I.T.A. to change out.  Now that they are so easy to change, I feel like changing them every 3 minutes.  Again - way to go Dremel Marketing Staff ! 


After I got the hole pretty much to the correct size, I then switched over to a well used 120 grit flap wheel.  I never throw these old flap wheels away.  When I need precision, the older the wheel, the better.  It does not remove as much material as a new wheel, so it can be controlled a little better.  (As long as you don't get anxious and try to force the issue - that is when mistakes happen)

You can see the results of the drill press on my index finger.  A couple of holes never hurt anyone.  There are a few drops of my DNA inside the dome as well.   The unfortunate thing is that with this injury, I am down to typing with one finger.... haha


Test fit with the Holo-projector.  Holla !!!


Closer sans annoying tape roll.  Since it did not get used, it wanted to get some .jpeg blog-time.  


All of the pretty pieces in place.  They sit really nice, although they are resting on the bottom edge.  Eventually, they will be mounted with the same reveal around the entire perimeter.


I am ready for my close-up Mr. DeMille.


One last parting shot of the entire top.  I decided to call it a day after these panels were cut out.  I felt that my confidence in my skills would lead to making mistakes on the remaining panels.


Coming soon - more of the same, except for on the side panels !




Saturday, December 22, 2012

DAY 15 - Slow to start, but finished STRONG.

Another week away from home, then off to the workshop for the weekend.  Saturday welcomed me with numerous boxes of goodies that I had ordered over the pat week.

Last week during the tear down of all of the pieces-parts, I was really concerned about how the skins were fitting on the frame.  I have read about a number of builders saying that they have a gap on the sides of the skins that they fill in, in one manner or another.  I was happy to find that I did not have this particular issue..... Until I realized that my gap was at the bottom of the back door.  Not a small gap, mind you - about 1/2 inch.  The gap could be closed if you REALLY wrapped the skins tight, but there was no way that the skins were going to stay in an acceptable position without someone holding them..

Out came the grinding wheel.  I imagine a good number of builders will cringe, but I took the grinding wheel to the outside of a classic JAG V4 frame, working ever so gently to remove a bit of the O.D.  I figured if I removed too much material, the skins could always be shimmed from the inside.  After 4 grinding sessions, and about 3 hours - the skins fit really nice.  (And wouldn't you know it - no photos of the results.....

Here is a photo of everything broken down.  What a pile of crapola.....

Onwards to what I REALLY set out to do today.  I spent the last two weeks working over ideas on how to make a manual 2-3-2 droid.  Over the past month, I bought a number of items that I thought would work, including various sizes of square aluminum tubing that would telescope up and down.  Of all the ideas I tried, none of them allowed for the amount of travel I needed within the limited space inside the body.

That is, until I came up with this - linear slides and pillow blocks :


In my search for anything and everything linear / sliding / actuating, I decided to give these a try.  These are rails used in CNC and router tables.  The bearings inside the pillow blocks can withstand 600 lbs of weight - so I feel confident that they will be adequate for my weight unconscious friend here.
In my little melon, I devised a number of mounting plates for the center foot.  Some using 80-20 aluminum, others various flanges and brackets.  Thankfully - simplicity ruled the day and I could not be happier with the results.

As I have decided to run the scooter motors and dome drive at a whopping 24 volts, the first thing I needed to do was make sure the batteries would fit inside the body and still allow for retracting the center leg.  The twin batteries sit nicely on the outer rim of the lower body.  I plan on using some Velcro straps around the lower uprights to hold the batteries in place.

You can see the beginnings of the top and bottom aluminum plates that will be used to mount the linear slides below.  The aluminum bar crossing the back near the batteries (along with the associated front bracket) needed to be notched so they would allow : A. the center foot to travel into the body.  B. sit flush and double as a battery mount.


Flash forward to the completed project.  The 2 screws in close proximity are for the vertical braces of the JAG frame and the others are to hold the aluminum mounting plates in place.  You can't tell from this angle, but the center foot has plenty of clearance to pull into the body.  (And no, the batteries were removed in this inverted state in an effort to save my toes)



Looks like someone is happy to have their new center leg installed.  Either that - or he's doing his best Tricky Dick impersonation.


With the help of rudimentary photoshop rotation skills, I inverted this photo to show how the leg sits in it's retracted mode.  In this state, the quick disconnect doohickeys will hold the leg in the "up" position for those two-legged glamor shots.


Here is a closeup of the disconnect.  The actual part description from Amazon.com is 

Ruland QCL-12-A Quick Clamping Shaft Collar, Anodized Aluminum, Metric, .750" Bore, 50mm OD, 13mm Width

I found two on EBay - and picked up the others from Amazon.  Apparently, I got the last two in stock.. as they are now sold out.  There are four of these collars used - two in front and two in back.  One to hold the leg up and the other to hold the leg in the down position for 3 wheeling.



Here is the upper bracket across the middle of the frame.  The risers are used so the slide can allow enough travel into the body and have the center foot clear the bottom of the skirt.  In this top bracket, I drilled 3/4" holes to allow the rail to pass through the bracket.  In my online searches - I knew I wanted to use aluminum, and ordered 1/2" stock..... the frame is closer to 1/4".... if you plan on doing something like this - use 1/4" aluminum.  Working with the 1/2" material was a bear.


Another angle showing the top bracket, including the 3/4" holes drilled for the rails.  I have a drill press and all, but day-um - that was not fun drilling those holes.  My lack of metalworking tools (and skills) really showed in this little project.


Here is the bottom bracket.  The rails have tapped holes in the ends, so the bottoms of the rails are screwed into the bottom mounting plates.  Here the bottom collar is left open, and the top collar locked to hold the leg in position.  I like the option of having adjustable height in the "leg down" position. This was not planned, mind you, just one of those happy mistakes you run into when you have n idea what you are doing.

You can also see the notches so the mounting plate fits inside the uprights of the frame.  Dad made one, I made the other.  As we switched from drilling, sawing, grinding and test fitting, we passed each other 32 times between the droid and the workshop.  Each and every time, the person going into the workshop muttered an inappropriate word and fired up another tool.  Like I said - we have limited metalworking tools... but we make up for it with colorful language !


The bracket that is used to hold the center foot was made from a couple of 90 degree angles and a 4" X 6" aluminum plate.   The angles allowed me to drop the leg below the two cross bars.  I will probably reinforce the brackets across each other and from front to back, as I think this mount will take some wear and tear as he is tooling around town.


And, yes, you do have to suffer through 30 more photos of this project.  It has been in my head for WAY too long, and now that it is a reality, i must share. And share. And share....


Here is a photo of the entire setup, soup to nuts.  I will get a video of this in action up soon.  Bad had and a questionable outfit made me think that I should wait to get in front of the camera for a demo.


A view of the entire frame with 3rd leg extended.


A view of the entire frame with 3rd leg extended... minus 12 degrees.


Another photo of the mounting bracket in case you scrolled past the previous photos when I said I was going to show this 30 more times.


Turn to the right.


Turn to the right, hold the camera straight and minus 12 degrees.


Parked in the corner, standing guard of his boxes of bolts and bits.


... And last but not least: my dome panels arrived this week.  The R2 Builder's club resident master-of-all-things-resin, Crash made these beautiful Carbon Fiber dome panels.  


Each of these weighs less than a potato chip, and will be placed in the appropriate place within the dome.  (The thing on the floor)


 Like so.


And so.  


I have my work cut out for me uhhhhh, cutting out the existing panels and allowing the correct recess so the panels sit flush with the rest of the dome.  Crash has posted an excellent tutorial on the Astromech boards, and I have a few ideas up my sleeve on how to accomplish this task.  Ultimately, these dome panels will then open and shut.... someday.

It will be sad to paint these beauties.  I plan on leaving the underside unpainted to show off a little BLING when they are opened.  Alas, that day is a LONG way off, so the plan may change.   Wish me luck, as tomorrow, I tear into a perfectly good looking dome... expletives included at no extra charge.



Sunday, December 16, 2012

DAY 14 - More stuff and a complete tear down.

(for those who only want the bling - scroll down for a video without all the "blah, blah")

OK, so here is the reason for the complete tear down.... actually a couple of reasons.  First, I was not too pleased with the fit of the skins.  Although they looked OK in the photos, there was a gap on the lower portion of the back door that would not stay closed without a good amount of effort.  In order to get the skins off, pretty much everything else has to come off.  Surprisingly, the entire droid breaks down into Frame, Dome, Legs, Feet and Skins in about 15 minutes.

Now that I have the frame alone on a bench, I can work on getting the skins to fit better.  I looked for any obstructions on the inside that may be holding the skin away from the frame, but could not find any.  I (SHUDDER) think that a little grinding of the O.D. of the back of the frame will allow the skin to sit in the correct position.  Some builders have left a gap at the sides of their units, and others have filled the gap with a strip of aluminum or ABS.  I have gained enough confidence in this build that I will remove some of the material from the frame itself to achieve the correct fit.

If I make a major mistake, all I have to so is shim the skin.  I sound all confident now - the results will be coming in future posts.

Reason #2 for the complete tear down:  The center leg.  After getting a lot of really great constructive criticism from the Astromech boards, I found that my center leg was, indeed, short.  I was also reminded that I needed to add the skirt at the bottom of the center foot shell.  This was something I knew I had to do, as during initial assembly, I really struck out on this part of the build.  The skirt is on the foot, but it is simply too high.  I used CA glue to hold the foot shells together which pretty much equates to scratch building a new skirt.  No problems there.... here is a photo of what it should look like (courtesy of Thomas' R2D2 Build Blog).

The reveal under the vented panels along the bottom is where my problem lies... I have no reveal.


Reason 2(a) of the tear down: Center foot mobility.  I am under the impression that I can have a manual 2-3-2 droid.  Meaning, I can convert him from a 3 leg mode (used for driving around) to a two leg mode (for glamour shots with Alex in his 3P0).   He has such a distinct look in both positions, I want to be able to have the options of converting him.  This will not be an automated system.... yet - that may come in the future.

I toyed around with about 30 different ideas on how to make the center leg mobile.  The ideas ranged from drawer slide (not beefy enough) to nested square aluminum tubing (not enough height inside the frame to accomplish the move).  While researching linear actuators,  I came across linear slides.  These linear slides are used in router tables and CNC machines.

Below is what I received last week.  15" long x 3/4" diameter linear slide with 4 pillow block bearings.
Mmmmmmm.... Pillow blocks.  Each of the bearings is rated at 600 lbs, so I think that they will do the trick.  The idea is to mount these linear slides on either the sides, or the front and back of the leg within the frame.  The leg then rides up into the body on the rails below.  The problem is all of the additional hardware that I need to mount these inside the frame and the flange that will mount to the foot.  All of those goodies are on their way this week.

I can't wait to get this together and functioning.  It works like a charm in my little brain - now all I have to do is get it all together in the real world.  I am excited as this will be my first scratch built assembly, and it will test my mettle as a builder.  I plan on documenting this well, so stay tuned for the results.



Now to the really scary part of the build.  Something I have less than zero experience with, the electronics.  Watts, Volts, Amps, Receivers, Transmitters, Motor Controllers, Dip switches, mixed modes, binding, wire gauges .... and so much more are items that are not part of my collection of useless knowledge that I have accrued over the years.

I did a BUNCH of research on the Astromech boards, YouTube and various RC boards.  As with anything on the inter web, you have to take the results with a grain of salt, because rarely do you get the EXACT answer for your application.  Without boring you with the details of how many setting I went through and how many dip switches I threw.... here are the results.

I will document the setting here for (mostly) my reference and to assist any other user who may need the help of someone who (almost) thinks he knows what he is doing.

Here is my little bench test setup.  I wanted to get the receiver talking to the motors outside of the droid.  These motors are much smaller than the ones used to drive R2, but are used for testing purposes.  The theory is that if the setup works on the bench - all you have to do is hook up the motors in the droid, and everything should work just like it did in these tests....  theories .... Hopefully next weekend, I will have a "proof of concept" moment, and we will see a little droid moving about the house.

For the uninitiated (like I was about 8 hours ago) here are the parts in the photo below:

- Upper left hand corner Spektrum Dx6i RC transmitter radio
- Center left - battery pack for the RC Receiver
- Center right - RC Receiver (this picks up the signal from the remote) tiny....
- Bottom center - Sabertooth 2X25 motor controller.  This unit accepts the signals from the receiver and converts it into power for the individual motors.
- Bottom left and right - Test motors


Here is a close up of the Sabertooth Motor Controller.  Notice the green light.. green is good.  The main power comes in from the bottom in the middle and is output on the left and right to the individual motors.  The two white leads in the upper left are from the RC receiver.  They are from two individual channels - basically the up/down and left/right motion of the joystick on the transmitter.



A wider shot showing the bench power source in the upper left that I am very proud of.  It supplies from 0 - 24 volts of juice to test setups like these without having to connect it to the batteries.  Necessary ?  Probably not, but dang - it makes me feel like I may know what I am doing.


So, here is a closeup of the receiver for my own reference.  When I hook this up again in a week - I hope to recreate the results that I had today.  You may notice the channel markings on the receiver... this particular radio is designed for use with a plane or a helicopter.  That is why there are many settings to tweak in order to make is usable as a tank-style motor driver thingy.


Here is a video of my WIN this afternoon.  Again - if all goes as planned, all I have to do is hook up the batteries and motors in the R2 unit - and I should have a droid that moves about the room.



For those who care (and for my reference throughout the build) here are the specs on my setup:

Spektrum Dx6i Transmitter settings:

AERO Mode

Mix 1

Elev -> Aile ACT
Rate  L 0%   R 0%
SW ON    TRIM ACT

SETUP menu / REVERSE

THRO - N     AILE   -  R
ELEV  - R     RUDD - N
GEAR - N     FLAP  -  N


Receiver Settings:

Aux 1 : Battery / power supply (brown wire on top / orange wire on bottom)

Elev : Black Wire on Top / White Wire on Bottom - White Wire output to Sabertooth S1

Aile : Black Wire on Top / White Wire on Bottom - White Wire output to Sabertooth S2

Both Black wires from Receiver are tied together and input on Sabertooth 0V input.

Sabertooth 5V input is NOT used and both Red wires from receiver are capped and unused.


Sabertooth output :

Left Motor - M1A Red wire    M1B Black Wire

Right Motor - M2A Red wire    M2B Black Wire






Sunday, December 9, 2012

DAY 13 - Not as productive as I had hoped.

Well, I had all intentions of getting some power to the little guy today.  Jet-lag from last week's west coast visit caught up with me today, and it was difficult to find motivation.

As posted yesterday, I received the aluminum holo-projectors.  These are the lenses that project Leia's "Help me Obi-Wan Kenobi" speech.   From what I understand, these are one of the only "found parts" on R2-D2.  "Found Parts" refer to parts used in prop making that come straight from a source - unaltered.

For example - IG-88's head is made from a Rolls Royce Derwent engine flame tube.  (Of course, anyone would be able to pick that one out.....hahaha



Another shot of the original piece.  This same part was used in the Cantina scene, behind the bar as part of a distillery assembly.


Stay on Target.... so back to the Holo-projectors.  These parts come directly from a Vickers Viscount Jet - they are the reading lights from the overhead bays.

Here is a link to Jerry Green's page that shows the original part.  VICKERS VISCOUNT READING LIGHT

These parts are incredibly detailed and very heavy.


I love the little details put in these parts - the things many people will never see - like the R2-D2 Builders Club logo on the back of the holo-projector.



OK - so back to the build.  The Fiberglass done that I received has grooves in between the panels.  Due to the molding process, some of the grooves are not uniform in their depth and definition.  In a number of places, there are little "boogers" - probably from air bubbles in the mold where excess resin has built up.

So begins the process of sanding and filing these grooves to achieve higher definition and uniform "grooviness".  A set of Testor's Needle files works wonders for this process.


You can see the ring at the bottom of the dome has been worked on, and the groove is consistent, and clean.  in the photo below, the groove to the right of the file has been worked on, to the left, the original groove.  A little pressure with the knife-shaped file really adds dimension and definition to the groove.


Another semi-ok photo of the groove.  Unfortunately, the camera i used does not have a macro setting, so it had difficulty focusing up close.


 I spent a good amount of time sanding the inside of the dome where the various light assemblies will poke through.  In the photo below, you can see some of the parts in their final location.  These parts are held in with tape... not the best solution, but good for a snapshot.  You can also see the definition achieved from the filing of the grooves.  I did not want to go crazy with the filing, as many of the panels will be replaced with Carbon Fiber panels.

Wait... wha ?!?!?!? Did he say "Carbon Fiber" ?!?!?!? Indeed, there is a panel kit on it's way.  This kit will allow various panels on the dome to open and close.  After all, he's got to have the ability to raise and lower his periscope and life-form scanner from the dome.

The front PSI is rotated 90 degrees in this shot, once it is assembled properly, it will cycle through a red/blue pattern.  Dang - I am bummed that I did not put the main eye back on....


Close up of the front logic display.  These lights blink in a random pattern.   The reflection off of the aluminum bezel is really something to see in person.  Hypnotic - you can stare at these lights for a good long time.  I am still amazed by the skills of our fellow Astromech builders, someone actually put the programming together for these lights - and they share it openly with the rest of the club.


Here is a shot of the side - showing two of the three holo-projectors.  Major fail on the placement of the PSI here... This eye toggles between yellow and green lights.  I still have to drill the holes out above the lights and insert the "dome bumps".


Rear logic display all lit up for Christmas.  I am not sure if I have the bezel in upside down or not.  This is an interesting piece, as it has to fit inside the dome that is getting smaller in circumference as is nears the top.  Like the front logic displays, these lights cycle in a pattern.  


Shiny, reflective goodness from the aluminum bezel.  P.S. - notice the incredible holo-projector to the left....


And, of course the obligatory full body shot.  Still bummed that I did not have his main eye on.... You can also see that the weight of the holo-projector is working against the painters tape used to hold it in.  It has sunk into the dome a little.


So, all of the pieces parts have been removed from the dome, and I wait another week to touch him, as work calls, and takes me 2,460 miles form home.

Hopefully next weekend, I will muster enough courage to put some volts through his system and get him moving.  Scary, scary proposition - 12 Volt batteries, RC Receivers, RC transmitters, Motors and Motor Controllers, 24 volt to 12 volt converters, 12 volt to 5 volt converters PCB boards..... you know, your every day project.....  There is just so much that can go wrong.

Wish me luck - I have all of my batteries charged and ready to go.