construction

Fixing a wobbly leg

Hurrying a build will always come back to bite you later!

When I originally built my R2, I was in a building frenzy. In a way, it was almost therapeutic for me, as I needed to get my mind off things, and really focused as much as I could into the build.

The legs was one of those first things I made, and I did not let the fact that I did not have a drill press stop me!

So, instead of .. I don’t know .. ask any of my friends if any of they had access to one, I basically drilled the holes in my ankles freehand. I know for a fact, that these holes have not been straight.

The symptoms of this, has been that my R2 always drifts towards the left when I drive him, and even though I can compensate, as soon as the drive power stops, and he rolls a few decimeters, he always steers off to the left. This has really been a pet peeve of mine, even though it is something only I was aware of, but isn’t that the definition of a pet peeve anyway, more or less? 😉

So, armed with a plan, I took R2’s legs to my friend Anton’s work (where they have a proper drill press) and got to work.

This is the problem area: (and no it isn’t dirty. It is only painted that way)

A few years ago, I did have the foresight to protect the existing ankle holes, so I had drilled the holes slightly larger and inserted a piece of aluminum tube to not let the threaded bolt eat into the plastic. When the foot was removed, I got proof that my ‘protection plan’ had worked as it should: The threads from the bolt had really eaten into the aluminium bolt! Just imagine what could have happened if it had gone straight into the plastic ankle?

So, the force has been strong enough to not only impress the threads into the aluminium tube, but also to slightly deform the hole!

My plan was to make a new hole, a straight hole this time, and rather than the existing tubes, I would insert some sort of bushings into the hole.

I had these linear ball bearings that will do just fine for the job at hand:

First step was to affix the leg to the drill press… and slowly drill through both ankle and the existing aluminium tube to straighten up the hole..

Since the aluminium tube was only fixed with E-6000 inside, it soon pushed out the other end, while the drill made a straight hole through..

My friend Anton did the first one:

.. and I drilled the second hole. Scary but a VERY quick fix in the end. The new bushings were pushed in to place …

A much better solution, and a more solid contact area towards the plastic!

I also took the opportunity to attach the new motor holders (as seen in “Fixing a hobbled droid” and “Fixing a hobbled droid, part II”). Yes, even though I had made these new motor holders way back, I had to abandon them due to a motor dying on me, but this has since been fixed, and this seemed like a great opportunity to put them in action!

Since fixing this, I have not yet had time to do a proper event with R2, but I’ve got a two day event in September that will be a perfect test. I will bring along my backup motor holders just in case… you never now.

By micke|2016-12-06T00:00:14+01:00August 25th, 2015|R2-D2|Comments Off

Mini update!

My original plan was to do a 40% scale version of my R2.

Well .. This plan has changed. The new plan is to make a 50% scale version of R2-D2.

Why the new format, you may ask? –Well, the slightly larger scale makes the details really pop out from the printer.

I can’t print the entire dome in one go, but I might as well split it in several parts. The first proper dome print was splitting the dome in half, and printing it in halves. It came out really well.

It is quite thin at this point, but once ready, the parts really look good.

It also means I need to print a complete new set of greeblies for the dome, and of course, the old 40% leg struts and parts done, needs to be remade as well.

I just think this is so cute.. 😉

The second dome I made much thicker, and split in 4 parts. The main dome is in thirds, but I also cut off the top to print as one single part as well.

Much sturdier…

However, still fragile..

Fortunately, this is an easy fix, and once I have acetone coated the insides, it should be sturdy and have no issues at all.

By micke|2016-12-06T00:00:17+01:00August 24th, 2015|Mini-R2|Comments Off

Side speaker mount done!

Quick update.

I drilled the metal brackets holding the new speakers, coated the inside of the “pockets” where the speakers will reside with black felt..

.. and hot glued the perforated aluminium backplates in place.

I might need a little more hot glue, but that is a minor issue, as I can always add that later on.

Finally I decided to hot glue the metal brackets in place as well, as I really don’t need to bolt them in to place at this point just yet. It is difficult to drill through inside the body, and the industrial strength hot glue is good enough to hold them in place. If not, I’ll just gently pry them lose and replace the hot glue with E-6000 once I get a new fresh tube.

After trying to fasten the missing hatch in the front, I needed to adjust the hinge somewhat, si I snapped it lose (it was only superglued into place after all), tampered with it slightly, and glued it back in place with the last of my E-6000. That should hold it firmly in place!

As a final thing, I had to test it, and naturally, I can get quite a lot of volume out of the droid. I could still do with more bass, so who knows… Maybe it’ll be a low end speaker or subwoofer inside at some point.. make sure everything inside rattles lose 😉

Once the tests were done, I also had to try out the freshly made driving sound. I recoded this over Christmas at work from one of my colleagues electrical re-positionable desk and worked with the sound file late last night.

Now off for an early evening. Last night of building for this time around tomorrow. Who knows, Maybe I’ll get around to switching the drive train to the one I fixed a few weeks ago. I’m still driving around with my old scooter motors, rather than my newer, fancy twin Jaycar direct drive system…

By micke|2016-12-06T00:00:19+01:00May 12th, 2015|R2-D2|Comments Off