Periscope Installed

I’ve been tardy posting updates this last week – been busy trying to get stuff back together for the new Clone Wars movie.

I finally got my periscope installed and functioning. Here’s a short video of it in action

There’s still some small quirks I need to iron out, but I’m pretty close to being done with it (for now). One of the big issues is that everything has to be align perfectly, and taking the dome on and off isn’t as simple as it used to be. What I’ve quickly realized is that with every gadget I add maintenance goes up exponentially.

I repainted the periscope housing after tweaking the curve at the top to match my dome. While I was at it I clean up some spot that I wasn’t happy with

Right now the dome pie panel velcro’s on top of the periscope, but it’s hard to get it to sit flush with so much spring in the velcro. It also very hard to align things perfectly and to get it to stay put. I’m probably going to use magnets instead or even use the small side screws I added. Right now they’re just for show to mimic the ROTJ periscope.

I’m not convinced that the clear lenses look correct either, it’s hard to tell but I suspect the original had a slight frosting to it.

I really need to document the wiring and micro-controller setup for this, but here’s a few overview shots of the periscope installed and there are more in the gallery.

Right now, up/down is manually controlled by the Futaba transmitter, at some point I’ll probably automate this. I also have a small 08M Picaxe micro-controller dedicated to automatically rotating the periscope when it’s fully extended. In addition I have to route 12VDC from the main dome power board back down to the periscope light circuit. The Picaxe and the small mini-servo that rotates everything runs on 5VDC and just taps off of the power for the lift servo.

There are two small micro switches, the first trigger the micro-controller to start randomly turning the periscope when it reaches the top

The second turns on/off the lights when the periscope is raised/lowered

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Posted by Chris on August 12th, 2008 in Dome, Electronics | 2 Comments

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More Periscope Work

I’m still fiddling with the periscope, I added some LEDs, a servo to make it turn and something to mount it to the lift mechanism.

But first I had to adjust the dome pie panel cut out to give more clearance. I marked off the area I wanted to cut and Dremeled in a few slots to start things off and finished it with a small hacksaw blade.

The main periscope assemble is mounted atop PVC tube to add more height.

I wanted to easily remove it for maintenance and also allow some height adjustment at the same time. This little tube is fixed to the lift mech

And the main PVC riser tube slips over and locks into place with a couple of screws

I installed a small HiTec HS-55 servo into the top of the PVC tube to turn the periscope side to side when it’s extended. Attached is a round plate the aluminum based of the periscope will screw into.

I’ve also add the LEDs to the main periscope housing. On the front is an array of 6 rectangular LEDs. These are very close to one’s used on the original ROTJ periscope

They’re glowing orange in the photo but they’re deep red in person. Power is 12V and no resistors needed as they’re in series

Here’s the block of LEDs soldered together before I installed them

I’ve wired in some bright white LEDs inside and some colored one’s on the back of the housing, I also re-appropriated one of my old PSI boards to blink a couple of LEDs to add a bit of variety.

Getting closer 🙂

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Posted by Chris on August 1st, 2008 in Body, Dome, Electronics, Feet | 3 Comments

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Life Form Scanner – The search for a short antenna

Well I’m almost done with the mechanics of my dome periscope, and I’m turning my attention to the life form scanner, in particular the antenna to raise and lower it.

Just like with the periscope the limitation will be the height of the dome. I can’t extend the antenna into the body because of the slip ring cross bar on the top of the body – so anything I come up with has to remain within the 9-10 inches of the dome.

Everyone has a different approach to things. I plan on making my own radar screen and body/cap assembly. My rough sizing calculations have it coming out around 6″, maybe a little shorter, from the top of the radar screen to the bottom of the body.

From studying photos of what other people have done, most seem extend the antenna into the body, but as I said – I don’t have that luxury. But what they also do is un-attach the antenna from the spool/motor housing. This allows you to rotate the antenna 90 degrees saving some space, rather than having the motor adding to the height.

A couple of weeks ago I bought the shortest antenna I could find on eBay hoping it could get it to work, the jury is still out but I suspect I’ll need to find something even shorter.

It’s a Harada MX-1 and once I removed some housing and un-attached the mast from the body this is what I was left with

Unfortunately, the mast was still too long, collapsed it’s close to 7″, and once I stick the LFS assembly on top that’s still too tall.

This is a rough drawing on what the plan is

So I’m still looking for a short (and cheap) antenna. I did find this one (a Metra 44-PW32) which is meant for old school Minis, but the cheapest I’ve found it is $73 – which is more than I want to pay at this point.

The mast is approx. 5 1/2 inches when collapsed which should work if I extend the body of the LFS assembly over it

So if anyone has a lead on something please let me know.

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Posted by Chris on July 26th, 2008 in Dome, Electronics | No Comments

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Lift Mech Support Bracket

I replaced the original drawer slider bracket with something a little bigger. It’s cut from a piece of alu angle and makes the whole setup a lot more solid. You can see the original bracket in the background.

The slots make it easy to align on the dome ring

I still need to work on the riser below the periscope assembly and fix it to the lifter.

Posted by Chris on July 24th, 2008 in Dome | 1 Comment

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New Periscope Lift Mech Prototype

I’ve been busy prototyping a new periscope lift mechanism for Artoo.

Some of you may remember my earlier posts and videos demonstrating a mechanism I’d purchased from Daniel, unfortunately I gave up on it a very long time ago. In my opinion the design was flawed from the start and I never did get it to work well, but not for the lack of trying on my part.

Now that I’ve finished adding servos to the dome I was anxious to get the periscope working. I remembered seeing photos of Wayne Orr’s lift mech and thought I’d try and do something similar. Rather than fabricate something new he uses a drawer slide as the basis for the design and a small motor to hoist the periscope up on a platform.

The only catch with Wayne’s implementation is that the periscope and life form scanner mechanisms extend deep into the droids body. I don’t have this luxury as I’ve left the top ring cross bar in place to support the slip ring. So anything I come up with would have to fit within the approximate 10″ height restriction of the dome. The periscope assembly itself is around 6″ tall, so that would be the minimum requirement but if I could get more height that would be a plus as I could add an additional riser or have room for a servo to rotate the periscope once extended.

I’d shopped around and bought a selection of drawer slides, but couldn’t find anything shorter than 16 inches locally. Once I had them on the workbench I realized that it really didn’t matter because whatever extended out would need to be hacked off anyway. In the end I picked a 20 inch slider made by KV because it’s two sliding components worked in lock step, which was important to my design.

I removed the stops and hacked it down to just over 10 inches and cut a small section of the inner slider that would run up and down on the sliding bearing, which itself ran inside main track.

This is the start point with the slider on the right

And it extended all the way to the left. Notice the two part slider has moved and not just one piece.

http://www.artoo-detoo.net/gallery/v/build/gadgets/IMG_1339.JPG.html?g2_imageViewsIndex=3

Unfortunately I have to jump a few steps as I didn’t take many photos of my late night tinkering with the lift platform and various iterations of how I tried to move it.

I’d originally added a roller to the top (similar to Wayne’s) which would guide the rope, but in the final design it wasn’t really needed – and currently acts as the end stop.

Right now I have a fixed motor on the lift platform that pulls itself up with a piece of string attached to the top of the slider. It uses gravity to lower itself back down as the motor unwinds the string.

I’m using a small Vex motor, but basically it’s a servo that can continuously rotate, so I can plug it directly into my receiver without the need for a speed controller.

It looks like the platform is sloping in this photo, but I’m hoping it’s just the angle of the shot 🙂

Here’s a short video of it in action

I have a lot more work to do on this and not sure how well it will work inside Artoo, especially at an angle. My short list of things to work are:

  • Add support to help stop the drawer slide shaking.
  • Extra weight to the platform to help it lower.
  • Make sure it’s all level
  • Limit switches to stop the motor
  • Possibly automate with the PICAXE micro-controller, rather than control it manually via the Futaba transmitter.

In closing I also wanted to mention that I’d experimenting with having a spring loaded wheel on the motor (same position as it is now) that would run along the side of the drawer slide to pull the platform along. I still like the idea and may give it another try later. It definitely had a smoother action and having a wheel on the motor made the lift a little faster – Unfortunately I couldn’t get the spring mechanism to work right.

Posted by Chris on July 22nd, 2008 in Dome, Electronics | 10 Comments

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Life Form Scanner Screen Material

I’ve finished re-installing the pie panels using hinges and servos, so now I’m starting to think again about the gadgets that pop out, like the Life Form Scanner as seen in ESB.

Yesterday at Ace, I found some perforated brass sheet that’s close to the screen material used in the movie. It was $25 and probably big enough to make at least 6 screens. According to the label the product is distributed by K&S Engineering, Stock No. 6412, UPC 6 76116 06412 2.

I’ll have to paint it silver, and the perforated design is not totally accurate but it’s close enough for me.

I’ve also been researching mini/compact power antennas for the Life Form Scanner lift mechanism.

Posted by Chris on July 12th, 2008 in Dome, Electronics | 3 Comments

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