Adding a selectable, rotating scanglass effects wheel

It's time for another construction project! For a long time, I've been toying with the idea of adding a modified rotating gobo wheel to my existing projectors. I'm starting out with one to test. About 6 years ago (jeez, has it been that long) I bought a rotating gobo wheel on ebay that was in an intelligent light. I thought it would be perfect for adding rotating scanglass to a projector. Unfortunately, this was missing the center gear and other projects put this on the back burner for a very long time. I finally got some time and resources to make this a reality.

The first thing I needed to do was buy or make the center gear. Since I have no idea what light this wheel came out of (I suspect it's from a Design Spot 575E but I'm not sure), I didn't know where I could get parts for it. I decided to just make one. I contemplated 3d printing it and decided it would be better to cut one from acrylic. I must say, I absolutely love the gear creation tool in Fusion 360. Making this thing was a snap. I also needed to make the center spindle hub. That, I decided to 3d print out of tough resin. After that, I mounted the whole thing to a 6mm shaft coupler. DONE!

Next, I needed to design the mount for it. After designing the mount, I had my Taz 6 build it. Once everything was fabricated, I knocked it together. The selector is a NEMA 17 stepper that's driven, in servo mode, by a DMX Stepper controller found here: https://shop.dmx4all.de/en/dmx-stepper-control.html. These things are pretty cool. Very configurable.

This wheel is going to sit right in front of my scanner pair since the useable area of each effect is about 20mm dia.

The effects I'll be running are:
Straight (no effect)
Lenticular line optic (thanks Displaser!)
6 point star filter
Fuzz Glass (acrylic disc with a dusting of clear coat. Thanks to Laserist for the idea!) this effect will not need to rotate
fresnel lens (this will also not need to rotate)
grid diffraction grating
2x grid diffraction gratings, one fixed and one rotating.

Here are the pics of what I have done so far and also a video showing the operation of the wheel and the review of the DMX boards. For the record, in the video, it looks like the wheel alignment shifts, it doesn't, the temporary laser I was using was moving around a bit. The effect selection stays true and accurate.
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https://www.youtube.com/watch?v=xET0cqOkZro

That's all I have for now. More to come.

The motion looks nice and smooth. The first production rotator I ran into at laserium used a thin wall aircraft bearing that I had to press out and use emery paper to slip fit to avoid a really gritty motion due to the press fit distorting the bearing. Nice job with the gear!

WOW! That thing is awesome. Great job on the construction and performance. I really like the design and layout. Thanks for describing the effects in the wheel. I have seen the star effect but did not realize there was a star filter available - now it makes sense.

P.S. you got some great tools as well.

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Originally Posted by laserist

The motion looks nice and smooth. The first production rotator I ran into at laserium used a thin wall aircraft bearing that I had to press out and use emery paper to slip fit to avoid a really gritty motion due to the press fit distorting the bearing. Nice job with the gear!

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Thanks, man! The bearings on this wheel were surprisingly smooth. Not sure if grease was used in these to begin with though I kind of doubt it. Regardless, they were filthy and had gunk in them when I first got the wheel. Since this wheel came from a moving light, I'm sure it was in a club with fog machines and I'm thinking they were gummed up from a collection of dust, glycol residue, and maybe even cigarette residue. I had to take each one apart and clean really well. The motion is super smooth now.

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Originally Posted by Kevint

WOW! That thing is awesome. Great job on the construction and performance. I really like the design and layout. Thanks for describing the effects in the wheel. I have seen the star effect but did not realize there was a star filter available - now it makes sense.

P.S. you got some great tools as well.

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Thanks! The star filter I'm using is a Cokin star filter for an SLR camera. They're acrylic, so I just cut one out in the same 27mm diameter of the effects wheel bearing. The Cokin filters work but I don't like the look of the stars and they are not very consistent. I'm going to try my hand at making one. I need to find an accurate and repeatable way to gently score grooves into a blank disc.

About the tools, my first 3D printer started out as a hobby, just seeing what the hype about these new fangled printers was all about. After printing novelties, I started printing stuff for my Halloween setup, which is extensive. I then got a small 40W co2 cutter and soon after, needed something bigger and a bit more powerful. I ended up with an 80W co2 cutter with a large cutting area. I never dreamed I would have so many uses for it. I have knocked out quite a few projects using those tools. It's made fabrication a lot more fun and possible. Design it, prototype it, build it... all at home. Convincing the wife it was all needed... that took some doing! She uses the cutter quite a bit too now. Of course, I have to take a little time to playfully rub it in her face that I "don't need something like that!" :D

Nice Job. I have a semi-custom Commercial unit that does the same thing, but bolts onto (or Velcros to) my projector in front of the scanners. I sorta like yours better, due to the much nicer drivers. Plus it has the home made touch.

Steve

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Originally Posted by mixedgas

Nice Job. I have a semi-custom Commercial unit that does the same thing, but bolts onto (or Velcros to) my projector in front of the scanners. I sorta like yours better, due to the much nicer drivers. Plus it has the home made touch.

Steve

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Thanks! Those drivers are nice. Easy to program, too. You can set how many steps, how many positions (divided equally), the rotation direction, if you have a limit/0 switch, even ramp up/down, a lot more... So many attributes, and that's just for the servo functions. The only downside is, they are not cheap. Over $100usd each and that's not including shipping to the US from Germany which was also not cheap.

Nice work!
I built one from a HES studio spot 250 gobo wheel. The whole gobo wheel+motors were available as a catalog item in the HES replacement part list and I lucked out and found an inexpensive one. The apertures on these are huge, so I use mine as a sort of external targetable scan-thru box. Can confirm they're lots of fun! :cool:*retardo

Attachment 61102https://vimeo.com/938790819

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Originally Posted by absolom7691

Lenticular line optic (thanks Displaser!)

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Quite welcome and good to see this material incorporated into your effects wheel. Wow, tremendous work - congrats on the progress! I love seeing the yellow! I too found the DMX4all site, but had yet to order anything to play around with yet. Yes, expensive, but good to see your implementation of their boards.

Thanks for posting this!

Greg S. (Displaser)

i recently got one from john at technological artisans and did some ugly hackery so i could control it from my stream deck:

https://www.youtube.com/watch?v=9saE-sXSa4A

You probably can chop the DMX 00,00 padding to 16 bytes or less.
The standard allows for short streams.

I have a few devices that just send 12 bytes.

Advantage of doing this is strictly update speed.

I have the same Unit from Technological Artisans. I love it.

Steve

that's true, but the limiting factor is really the speed of the steppers. it does run a lot quieter when you're using buttons to bop wheel positions and rotation speed instead of using sliders.

i'm in communication with technological artisans about some firmware changes that would optimize how the unit works, but it's a great unit and is going to be a lot of fun now that i can drive it from the same controller i'm driving radiators.

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Originally Posted by mixedgas

You probably can chop the DMX 00,00 padding to 16 bytes or less.
The standard allows for short streams.

I have a few devices that just send 12 bytes.

Advantage of doing this is strictly update speed.

I have the same Unit from Technological Artisans. I love it.

Steve

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Traveling salesman or nearest neighbor for the disk movement, and hitting the freeze on the microstepping driver for slightly less noise?"

Steve

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Originally Posted by mixedgas

Traveling salesman or nearest neighbor for the disk movement, and hitting the freeze on the microstepping driver for slightly less noise?"

Steve

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yes, i think nearest neighbor is very good approach. it's simple and could result in quite a time save. it would also be cool to have a routine to dip the laser to black while the disk is rotating to the new position and then fade it back up when it's in position.

....etc

I 3D printed one of these a while back - still haven't done anything with it though...

Attachment 61108

Quote:

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Originally Posted by mixedgas

Nice Job. I have a semi-custom Commercial unit that does the same thing, but bolts onto (or Velcros to) my projector in front of the scanners. I sorta like yours better, due to the much nicer drivers. Plus it has the home made touch.

Steve

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We are looking at maybe opening in a second Planetarium and putting a second (grass roots) laser system together. OPT lasers has a "grating disk" box for sale, but I was wondering where you might have purchased your commercial unit? Thanks in advance.

Quote:

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Originally Posted by mixedgas

Nice Job. I have a semi-custom Commercial unit that does the same thing, but bolts onto (or Velcros to) my projector in front of the scanners. I sorta like yours better, due to the much nicer drivers. Plus it has the home made touch.

Steve

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Found the answer to your commercial unit below this post. Technological Artisans, Thanks