Project Otto Session 5

Hello Folks!

Shooting:

For the past week I have been shooting a flowering Drosera Capensis, and a new pitcher on a Nepenthes Alta.  It is a simple setup, 2 plants, 2 cameras, no motion on these. Just selective camera angles to give them the appearance of being outdoors. The Drosera timelapse is going fantastic, I don’t know if I will bother finishing the pitcher plant though.

Z-Axis.

I have settled and committed on the telescoping design.  The Aluminum extrusion has arrived. The system will comprise of a 8x8x12 aluminum square tube with 4 sets of the heavy duty drawer bearings that are used to raise and lower a 4x4x12 square aluminum tube.  At the most compact it will be about 12.5 inches long, and when fully extended 37 inches long allowing for plenty of travel and a comfortable top height.

I spent some time last night getting the bearings attached together, and with any luck the remaining aluminum stock needed to fit should arrive tomorrow.  I already picked up all the machined bolts, washers, and nuts, which ran a total of 27 bucks. Not cheap, but i want high quality parts 🙂

I am considering having the 8 and 4 inch metal square tubes annodized. But i may just prime them and paint them with a good enamel. I cant paint the bearings, they will remain black. I might look into creating some sort off a shroud or something that will cover those when extended.

The Frame

IT HAS SHIPPED! I am so excited! It should show up tomorrow. It took about 24 days from the time to the order to time of shipping, but most of the parts were custom cut and anodized black to help keep any reflections down.

I already have the Pan/Tilt/Roll, the hardware for the telescoping Z axis, the linear bearings and ball-screws, the motors, cabling, just about everything to get this shit up and running 🙂

Almost….

There are several fairly critical design considerations that still need to be done. Right now I have a good idea how this will all go together, but the final method of attaching various things together is still undetermined. Sometimes these things are far easier to figure out when you have all the parts. You can line things up and see whatever leftover brackets are needed.  The most critical aspect is connecting the telescoping unit to the brackets, and figuring out where to run the Chronos rail, and when/where/size of pulley to use and how to mount it.  I also need to figure out where to mount the motors for the X and Y axis, and figure out how to attach everything.

These are all very critical connection points. But I am confidant that once I have the rest together that it will make sense and sort of work itself out.

Visitor

Last weekend I had a visitor to the studio. He is a Canadian photographer by the name of Scott Portingale.  That was a very interesting visit, Scott is a pretty cool guy!  It is fun to be able to talk to somebody about this sort of work without their eyes glazing over and brain shutting down. If you have not heard of him, be sure to check out his film Infinitude. It really is a brilliant bit of film making. I don’t know how to describe it, other than it really strikes its own path and is fairly unique.  He has some BTS videos that are certainly worth checking out.

 

How much to Blog?

This is a pretty tough question. There is a part of me that sort of wants to clamp up until Project Otto is complete. It would be fun to put out a neat BTS video and keep some of the design aspects, or at least images of the design sort of under wraps until it is finished.  I may just keep the imagery out until the system is complete. Of course that will be at least another month out at the earliest.

Things left to do

  1. Build the frame
  2. Finish the telescoping unit and mount it
  3. Setup the control center and power system
  4. Wire the connections and run all the cables to the motors
  5. Wire the enable switches on the front of the power system
  6. Tweak/ Optimize the drivers for the motors
  7. Install limit switches
  8. Possibly shorten the arms on the Roll assembly
  9. Run the camera connections
  10. Test all 8 degrees of movement.
    1. X
    2. Y
    3. X
    4. Pan
    5. Tilt
    6. Roll
    7. Focus
    8. 3D Stereoscopic slider
  11. Test runs
  12. Troubleshoot and debug any problems with the system

I really do have my hands full.

Z-Axis problem

The Z axis problem.

This one has been a tough nut to crack, but I believe I am finally on the right track.

I want the camera to move up and down. This means I have to have a mechanical solution to solve this.  If I go a traditional Z axis setup like on a CNC machine, the equipment I need to raise or lower the camera a specific distance must equal that distance + room for motors and frame.

Let me try to unpack that a bit. Lets say I want the camera to raise/lower a maximum of 20 inches.  This means to use a leadscrew or ballscrew (think our chronos rails) the system to raise/lower the camera must be at LEAST 20 inches. You have to have room for the motor and frame, putting that closer to 24 inches.

In the image below, on the very top is a motor that turns a ball screw, or lead screw. Think of these as highly accurate and very well made threaded rods. There is a carriage with a nut that the rod goes through. As the motor turns, it lifts and lowers the assembly with the cutter.  These sorts of systems allow for VERY accurate motion and they can lift a LOT of weight.


So if I wanted to use a traditional Z axis and get 20 inches of travel, the Z axis assembly would be at LEAST 20 inches. I could Probably make it 24 inches.

The pan/tilt system is about 18 inches itself (rough guestimate).  since it would have to attach to the carriage and hang BELOW the Z axis assembly, that would mean at MAX HEIGHT the camera would be somewhere around 42  inches from the ceiling. When the ceiling in my studio is 86 inches, you can start to see the problem.

The shooting envelop is the area in which the camera can be moved. My goal is an area 5ft x 5ft by 20-30 inches.

This means the set SHOULD sit roughly on the low end around inches above the ground, and when the camera is fully retracted up, it would only be around 3.5 feet off the ground.

no good.

So that means the traditional Z axis is no good for this project. I have to find a way to maximize the travel, keep the accuracy, and have enough vertical travel for my proposes.

So I played around with several ideas. One was an idea of a scissor jack style setup.

Image result for scissor jack

If I could flip that upside down and attach it to the X/Y gantry, and attach a motor to the screw that would allow maybe 18-20 inches of travel with only needing 6-8 inches of space for overhead. Thats not too bad. However these are heavy duty systems developed to lift cars, not high precision devices used for motion control. I am skeptical it would be an easy modification, and then there is the fact that the motion would not be linear. When it is just slighty extended moving 4 threads would drop the camera much father than when nearly fully extended.  This is still a possibility but I am not really excited about trying to integrate it.

So then I moved onto an idea of creating some sort of a telescoping rig. And I THINK I may be onto something.

I found some heavy duty drawer bearings. They collapse from about 25 Inches to 12 inches, and are intended for drawers that hold up to 500lbs. They are very heavily duty and have virtually no slop or play in them.  Click Here 

If i get 4 sets, and double up so i have 1 set attached together, for a total of 4 sets, and get the right framework, i can build a telescoping system that is 12 inchs when closed, and about 38 inches when fully extended. This gives 26 inches of vertical travel and keeps the camera much higher when retracted. The camera would sit about 30 inches from the ceiling at full retracted height. That puts the camera at about 53 inches from the ground, close to 4.5 feet up.

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How to raise / lower?

Easy enough. I plan to attach one of my Chronos HD rails to the main carriage overhead, and use a teflon belt attached to the carriage of the rail which will hit a pulley at the end and go to the base of this telescoping structure. As the carriage on the chronos rail moves out, the system drops down, as the carriage moves in, it will lift the system

Z axis explained

I think this is going to work out fairly well. The parts have just been ordered, I am excited to get this up and running 🙂

Biolapsing

Ok so its been forever since I put a video BTS up.  This is a bit long, but if you are into this stuff you will probably find it interesting. It covers the start of a shoot, plus 8 days into it. It highlights the Dragonframe software and shows some pretty killer functionality. Of course you cant just buy dragonframe and get shit to work, you have to build some stuff. I spend a little time going over the Driver/Power supply box and what its used for, as well as some time on the Pan Tilt from Servo City.

Hope you enjoy

 

Project Otto Session 4

Its been a busy but awesome weekend. 🙂

 

New Lens Ring

First off, I am really excited about this thing. A while back Kyle had printed up some lens collars for me. The idea was to mount the lens to the 15mm system instead of the camera body.

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Focusing is a bitch to do. One of the main reasons is there is always SOME degree of slop or play in a lens mount. when tugging the focus ring back and forth the lens will shift ever so slightly but it is MORE than enough to show up on a timelapse.  I have several macro lenses that I timelapse with and the focus ring is very stuff. So to combat the lens shift the lens itself is mounted to the 15mm system, and the camera attaches to the back. That worked pretty well, but still was not perfect.

When playing around with the 6D, eMotimo, lens apparatus, dragonframe, I had set it up as such. In order to lock in a very tight fit i used some copper wire and a eye-screw and wired it down so the lens apparatus had a very tight lock. But seriously, it looks stupid. But it worked like a champ for my focusing testing.

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I ended up sending Kyle a sketch to see if he could modify the design and reprint. And Kyle that glorious bastard did it in Safety-Orange, which I think looks absolutely badass.

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He had actually added the 15mm support on the wrong side, but after installation it will work out fine.  The Lens apparatus has an amazing level of contact with the lens now. There is no perceivable give between the gear and the lens ring.

 

 

 

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Using a fairly short 15mm rod. Everything is a nice compact form.

 

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And to top it off, Kyle put a window in the lens ring so you can see the focusing scale.

Another great thing about this is is that since all the hardware is on the lens itself, I don’t have to deal with the added height of 15mm rod system under the camera. I really would not want to deal with that extra height on this rig. This really made my day!

 

THE POWER BOX

Beware this is getting geeky.

Managed to put the power box together.  First off lets explain what this is and why I need it.

For this setup to work you have to power the motors, and you have to be able to chop that current into various patterns to get the desired response from the motors. If you just apply power they motors will get damaged.  These are not like DC motors that just spin when you apply power, rather you instruct them as to what you want its position to be. For this to happen you have to use whats called a “driver”, which is basically hardware designed to manipulate stepper motors.

So thats what this box will be used for. It comprises of a pair of 36 volt 16 amp power supplies, which power the 10 Stepper Drivers. Each driver can control a single motor.

So the Laptop is used to build the movements out in some pretty awesome stop-motion software from Dragonframe. . That plugs via USB into the Dragonframe DMC-16. That piece of hardware is what is responsible for lighting control and motion. On the motion side it can send signals to up to 16 stepper drivers, and one motor per driver.  It uses RJ45 (ethernet) cables to connect to this new power device to send the step(move)/direction signals to the Drivers.

Laptop –> DMC-16 –> Driver –>Motor.

The Build.

It went surprisingly well.  I had picked up a server chassis to use to house the power supplies and drivers. It was a bit bigger than I expected but it has great ventilation and a solid build for about 80 bucks.

I had to play around a bit to figure out how this was going to be laid out. I kept the drivers in parallel and behind the fans on the front of the chassis to help cool them.P1770047

 

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I had picked up some wall plays for RJ45 connectors and they would fit fine right behind the slots, a few cuts later and a little file work…

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Next I needed to be able to mount the jacks for the motors.  Using some 2 inch aluminum stock Measured it up, marked it out, and had to drive to Ace Hardware because I did not have a 5/8th bit. Damn thing cost me 20 bucks. That was Trip 4 I think.

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PRO TIP. Put painters tape on the aluminum and make your markings on the tape to keep the plate looking nice.

The aluminum stock was also purchased at Ace Hardware on my 2nd trip. P1770054

The plate measured, cut and drilled. After I got all the plugs attached in I used this fantastic glue called GOOP.  I seriously love this glue, it sticks to damn near anything and is like a super sticky rubber cement. It never hardens brittle and has some crazy grip.  I used it on both RJ45 panels and the aluminum panel.

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Next I went in and drilled and tapped the sub-bottom after marking various spots so I could mount the stepper drivers and the power supplies with screws. That bottom panel comes off making it easy to modify it as needed

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Once everything was installed and bolted in it was time to start dealing with the wiring. That was a real pain in the ass. This shitty 4 wire telephone cable I got from Ace Hardware it did not want to strip and the copper was pretty brittle. It was a real bitch to deal with. I probably spend close to 4 hours just wiring.

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The voltage regulator is basically just used as a super simple fan speed control. It just takes a 36v feed off one of the power supplies and reduces it to 7 volts to keep the fans running.

You cant really see it in the pic, but each of the drivers is numbered,  and I split them across two power supplies. Even numbers on one, Odd on the other. If needed down the road the thing is rigged up for 12 drivers. I am only using 10, but if i need to expand later I can virtually just pop them in.

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The back end looking pretty good to me. Not huge on  the plastic ethernet panels, but they will certainly work and are very secure.

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Finally done wiring the damn thing and it was time to turn it on. I checked the voltage and everything looked in spec, so I wired up the first row of drivers, turned it on, and nothing exploded. I powered up the other side and got to testing.

During testing I discovered I could drive a motor off all off them but 3, 5, and 7. Checked the wiring and that shitty house telephone cable had a couple leads that broke. I had to re-terminate them but everything checked out after that. A few min later and all 10 are working as expected

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Now that everything is tested, I closed it back up and started experimenting with the stepper to see what sorts of speeds i could reach. Everything seems to be working well!

Here it is in all its glory, closed up and ready to make some awesome shit happen. I really could not be happier with how well this went together.

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Next its time to address the systems frame, figure out to mount the PTR,  how to get the z axis going.

One thing at a time.

 

 

 

 

 

 

TImelapse Life

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