Sunday, February 26, 2012

Pocket Vent installed

A few weeks back the pocket vents arrived and it was time to install it.

Usually, most parts built from the R2 Builders blueprints slip right in.  But for some reason, this piece was too big for the opening in the skin.

I'll be honest...that sort of thing annoys me.  The fix is to remove some material from the inner skin.  Since the skins have already been painted and bonded together, its very tricky to do this without damaging what you have already worked on.

The next step was to put some protective Blue Painter's Tape to the edges of the skin, so that the debris flying off the Dremel did not damage the paint.

With the area marked off, it was time to slowly...and awkwardly...cut this out.

First we put the THIN cutting disc on the Dremel...

 And despite that looking really scary ...its on the line and what isn't precisely cut can be filed off.

The part comes with a back plate and when screwed into the front piece, they work like a clamp to pull and hold the piece snug...

And now the final results...til paint!


Sunday, February 19, 2012

Repairing the Rockler Bearing

As I did for my first R2-D2, I devoted some time to repairing the Rockler Bearing for the second R2.

I didn't have all the tools to do a thorough job as I did the first.  I wanted to see how much of an improvement there was just cleaning, replacing the bearings with acetal ones....and teflon lubricant.

First up, get everything together...a pencil to label the rocklers, a flathead screwdriver and 2 packages of acetal bearings.  You won't need to worry about not having enough bearings, you will only use about a bag and a half.

 After removing the dome plate, I label each ring "top".  It sounds silly but when things are apart, you can quickly second guess the basics!

Now to remove the plug using the flathead screwdriver.  Notice how the end of the plug looks!

 Now have a container ready and start letting the ball bearings fall out.  You'll have to turn the rockler bearing slowly to get all of the bearings out.  As you turn the bearing, the rockler will start to come apart, so be ready for that.  

And now you can see what a mess the rockler bearing tracks have become.  Grease, debris and metal filings...the later probably from not covering the track when drilling out the mounting holes!

 The "booger cloth" after wiping all the gooey junk out...and the inner ring is nasty too...

 All I did next was use an old towel to again wipe away any residue I missed the first time...then sprayed the Teflon silicone on and wiped it again.  The results were pretty nice, visually...

Next up was to piece the rockler back together and, awkwardly, hold it together while filling it with the acetal bearings.  Once filled, it was time to re-insert the plug, making sure the alignment is correct.

Note the white acetal balls visible ...
 While spinning the bearing, I applied more teflon solicone, making sure it has an adequate amount in there.  With this done, the bearing moves considerably better but there is still a lot of chattering going on.  This means the track insisted very smooth and should be sanded and polished.  We'll do that next!

Saturday, February 18, 2012

Aluminum Utility Arms installed

Finally some time to work on the second R2!

Tonight I wanted to get those beautiful, light-weight utility arms installed.

First, the shafts have to be sanded and filed down a bit so that they will fit thru the opening in the utility arm.  Some people have access to something as elaborate as a lathe to remove some material...I do not, so I used some 60 grit sand paper, a file and attached the shaft to my power drill..

With each shaft now fitting inside the utility arm, I found that I had to add a small washer to the top of each arm.  Otherwise the arm would sag and tip downward.

The addition of the washer will make enclosing them inside the frame's utility arm carrier very snug.  While the arms will still pivot in and out, they won't do so very freely.  If I decide to add servos to these later, I'll have to put some graphite in there.

When it is time to install the vent frame  rails to the bottom of the utility arm carrier, I use hex-head screws.  Why?  I've learned from my first R2 build that if you need to adjust the vent rails, you will not be able to get a screw driver in there at all.  

 I also do the same to where the vent rails attach to the frame ring.

Before I tighten these up I place the center vents in.  There are 10-24 thread holes on the sides of the vent rails to allow 4 machine screws (or set screws) to hold them in place.

And here's how R2-D2 looks now...