upgrade

/Tag: upgrade

A working Computer Interface Arm…

For a while, I’ve really wanted to make a working “computer interface arm”. I had one made in aluminium a while ago, but this proved to be way too heavy for my styrene droid, so I decided to sell it.

When looking at the movie, R2 “flips up” his arm, then the tip extends, and it rotates as it is inserted into the computer interface.

r2_interface_arm

Image from starwarsscreencaps.com. (c) LucasFilm / Disney.

Most likely, this is accomplished by some sort of magnet lock, and it is actually the wall panel that rotates, and the tip of the interface arm only “tags along”. It is a hundred times easier to make, and this was after all done in 1976, so most likely, That is what happened.

That is not what I’m planning. I’m planning to make a computer interface arm that can both extend AND rotate!

I plan to accomplish this through a simple method:

The thick part of the interface arm is a hollow plastic tube. The tip is 3D printed and mounted on an aluminium tube.

This tube is inserted into a smaller aluminium tube that is fixed within the hollow plastic tube with 3D printed parts.

Inside the aluminium tube, I mount a stiff cable on a holder from a tackle shop, that can rotate as much as it wants.

The stiff cable goes through the assembly to the back end, where a servo can either push out the tip, or retract it. Pretty much the same way an electric car antenna works.

The tube in which the cable resides, has gears glued on to it, and can through a 360 degree servo rotate in either direction. The stiff cable inside, which controls the extension/retraction movement is still in place, and the small tube with the tip attached to it, rotates around it.

Sounds complicated, and to some degree it is: Have a look at these images and see if it makes more sense:

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These pictures have the rear servo taken out for clarity, and also the inside tube removed for clarity. The inside tube would have slots cut out to make contact with the outer gears.

Now that my 3D printer is upgraded and make better parts than ever, it is time to set this all into action! 😀 Stay tuned!

By |2016-12-06T00:00:13+02:00August 25th, 2015|R2-D2|Comments Off on A working Computer Interface Arm…

My Makergear M2 3D printer upgraded!

One of the best tools I’ve purchased in the last few years has hands down been my 3D printer.

It is a Makergear M2 and I really must say it is a great piece of machinery!

The Makergear M2

Back in the day when I did my research for a 3D printer, I mainly looked at two things: Build volume and quality. Well, I also wanted something that looked sturdy and not an assortment of threaded rods held together with a few 3d parts. I got it all.

The M2 has an 8 x 10 x 8 build area, which is large enough for me to do most of the parts I would need. At the time I also saw it listed as being able to print down to 20 microns (0.02 mm thick layers). That sounded good. In reality I had no idea what it really meant. I chose this over other printers with similar build volume due to them not supporting under 100 microns (0.1 mm thick layers).

After having it for 2.5 years, I still rarely print anything with higher resolution than 0.15 mm per layer, so what on earth did I need all that extra quality for? =)

It did, however, get me a great machine. Steel frame and built like a tank. No need to constantly recalibrate.

In fact, I can pick it up, carry it to my car, put it in the front seat, drive to a new location and simply plug it in and print immediately without recalibrating the machine.

I have, however, done a few upgrades that really has increased quality and made it a bliss printing on it:

  1. The VIKI LCD Display! To have its own display and no need for a computer stationed next to it really helped a lot!
  2. Putting up a Raspberry Pi with Octoprint installed! Full control (and time lapses) of my prints!
  3. I upgraded to the new v4 extruder, which really works great. In addition that also meant I needed to upgrade the power supply to a 24V power supply, and this has caused the heat plate to warm up MUCH faster! 😀
  4. I invested in BuildTak, which is a printing surface. It is a bit pricy, and you really have to tweak around to find the sweet spot where it sticks enough to not warp, but not hard enough so you can get the model off. A Japanese putty knife really helps with removing the prints. Before I found this, I used razor blades from my break blade knife. It got the model off alright, but it also damaged the build surface, so I went through a few rather quickly until I found the preferred way of working with it!
  5. Thew new upgrade of Simplify3D! The software I’ve been using to slice the models for printing on and off just got a LOT better! Now, this one kicks them all out of the pond, and makes the prints look better a lot quicker!
  6. Replaced the fans for quiet ones! I changed out the 40mm 12V  fans for Noctua fans. Extremely quiet! 😀
  7. Nema dampers! As most 3D printers, this printer runs on Nema 17 stepper motors. My fiancée has complained that she hears them when I run a print over night, and it has had a characteristic whining noise, but adding these dampers has made ALL the difference!

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Now, I can run the prints over night and you can’t hear it even though it is in the next room!

So, at this moment, the only thing that I can really still hear that bothers me, is the PSU fan, but I am exchanging that this week as well as I’ve ordered a Noctua fan for the PSU as well.

Forthcoming updates will be:

  1. Changing out my laser cut electronics enclosure for a metal one. My plastic laser cut one has had a tab or two break on it, and is at this moment held together by duct tape. A metal enclosure would also help in acting as an active heat sink!
  2. Also changing out the PSU enclosure for a metal one. Also to act as a heat sink.
  3. VIKI 2.0 LCD display – updating the VIKI LCD Display for a newer version. I actually already got this, but no time to do the work.
  4. Auto Calibration! I have purchased a inductance sensor that I will add on to the machine that will automatically deal with the levelling of the print bed. It won’t actually level it, but it will sense how it is tilted, and compensate automatically.
  5. (STILL WANT): A MIC-6 6mm thick machined aluminium tooling bed! This will make the print surface totally straight and not have any small discrepancies due to thinner print beds.

So what is all this to do with my building?

Well.. I do build things… I help friends with making parts… and there is one thing .. which I am absolutely not building, but more on that in a later post!

By |2016-12-06T00:00:14+02:00August 25th, 2015|Building|Comments Off on My Makergear M2 3D printer upgraded!

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)

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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?

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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:

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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..

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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:

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

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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 |2016-12-06T00:00:14+02:00August 25th, 2015|R2-D2|Comments Off on Fixing a wobbly leg