ps the 6 axis looks like fun.
the dolly 'needs' to tilt or boom up for the dorrway shot - showing that 1 axis is often not enough. also the dolly shows wobble as the camera is far from the track, a 2mm raise in track gives a 20mm (or so) dutch of camera - this is why my track is up high (ie a slider) to try and keep the camera near the track so deviations in the track are not multiplied by a (large) distance.
Thread: SMM moco
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06-04-2020 09:45 PM
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06-05-2020 08:24 AM
Hey Austin,
That six axis arm is something a lot of us over at the Timescapes forum have been looking at making, and here you have done it! Has Gerald seen it? Thought I’d ask since you are part of the Mantis crowd. Very cool. Sam is right about the tripod but what I found over the years is weight in the right place is your friend. If your motors and drivers can handle it add some to the base of the rig then maybe play with the key points in Mantis and also the jog settings. I built a huge rig using the same small motors of my mini Volo crane and found that buy adding some weight here and there and adjusting the jog settings and key frames I got it to dolly in and out smoothly and with the HVX200 way out on the end of the boom mounted to the 3 axis head! The hardest thing to over come are those pesky jitter moves.
And if you have ever wondered whether or not the people who made and used the original rigs back in the seventies had these problems, yes they did! One of the rigs used at iLM back in the eighties was called “The Moose” due to the weird noises it made while moving back to start. I would love to see some bts footage from those days. Too bad everyone was busy creating those iconic shots. No one had the time.
Cheers.
Doug K.
MDKfilms - Sound & Film production
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06-05-2020 08:35 AM
Deviations in the track! Ah! Sorry Sam, thought you wrote something else. Me old eyes.
Hey Austin, a very usable and pre-built track can be made from extension ladders you can get at HD or Lowe’s or just about any hardware store. These things are pretty accurate along their length with mine being out by 1 to 2 millimetres from end to end. But wait you say, that is a lot. Well there are ways around that.
By using the ladder as a base then getting some aluminum U channel, 1/2” maybe 3/4” cut to the same length, then on top of that you get 1.5 or maybe less, round alu tube, which lays perfectly in that trough. By using this method you can adjust the rails all the way down the track so that they are perfect. Oh and you are mounting them as you go down the track with the most accurate ruler you can find. One with metric works best.
Drilling holes in the U channel and through the ladder. I found the ladders to be about 1/2” to 3/4” wide. Perfect for the U channel. If you drill an oversized hole, say 5/16th, and then use a 1/4” bolt, you have the wiggle room needed to adjust things as you go.
After that you lay the aluminum tube on top and you can use heavy duty construction adhesive to hold it in place OR, by carefully drilling small holes along the side of the tube that won’t interfere with the dolly wheel, you can use Zip ties. That’s what I used. Worked a charm. And cheap!
Ya notice a motif here? Save money where you can! Spend it when there is no alternative.
A 12’ foot track is enough for a lot of shots. And if you buy two ladders you can make 24 feet of moco goodness. Best of all the materials are cheap ish and readily available. I looked into real bearing and rails sets like the pros use and man oh man that stuff is pricey.
Cheers again.
Doug KLast edited by MDKfilms; 06-05-2020 at 08:43 AM.
MDKfilms - Sound & Film production
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07-18-2020 09:30 AM
Gerald has seen it and mentioned about the possibilty of adding inverse kinetics for a 6 axis arm. In fact I saw he waiting on one to arrive to start playing with it. He also told me to check out the maya plugin mimic which may help a bit. Hoping to get back to the project soon, though started working on some pan tilt head and pneumatic rigs for some other projects first .
Florida Based Photographer & Cinematographer
http://www.austinburke.photography/
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09-08-2020 11:16 AM
Very dull. Particularly dull due to the white background.
Nikon AF, pan amount is generated by subject distance from rails and camera distance along rails .. which is pretty hardcore maths
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09-08-2020 11:46 PM
Yep nikon af. I’m far from convinced but it’s kind of amazing
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09-20-2020 08:58 PM
So finally got around to some tweaks and testing out the 6 axis arm. Shot this quick little piece before i had to pack up gear for a shoot. All shot static on a tripod with the arm doing all the movements.
https://www.instagram.com/p/CFXjehXBXWK/
Next up will be learning how to add encoders properly to the motors and relaying the info to manits.Florida Based Photographer & Cinematographer
http://www.austinburke.photography/
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10-20-2020 03:25 PM
Cant remember if I ever posted this - watching it back it is quite a move and I would struggle without the robot..
(manual focus remote tilta, GH4)