Spinning mirror to make cone. Help

[dsli_jon]

...Here is ...Genesis,

Pfff, oh, only Genesis, huh? Sheesh.. Zeppelin, Genesis, the Olympics... wish the heyl u weren't retiring and I could afford to hire ya.. I think I'd pay to just sit and listen to yer stories.

...on adjustable hub. It needs to spin at least 1200 RPM

..Nice, simple hub, I like.. Here's a 'honker' of a hub / adjustable-yoke I designed-up a while back..

..pretty easy for a 'DIYer' to, well, DIY... from flat / tube stock, with minimal machining.. the 'Mount-plate' can either be a single bar, or the 'cross' (band-sawed from a square-plate..) and you can use the 3M 'VHB' mounting tape, stuff will just not let go, even at hi-rpms, once-set.. You can find the round-mirror (albeit, not FS, but.. usually 'good enough' and cheap to replace, if-broken..) at hobby / craft shops..

...Most-importantly, nets fairly-decent results..

...Speaking of Red... PM, incoming..

fwiw..
j

[CountFunkula]

I vaguely remember an old AVI-manufactured (...I think) remote cone scanner that had an adjustable bounce mirror as part of its input port and an internal safety shutter before the also-adjustible (cone size/angle) spinning mirror section. The shutter operated such that it would snap closed if the motor or power failed, thus avoiding potential "random beam of doom" scenarios.

When the shutter was closed, you were left with a very nicely self-terminating bounce mirror!

It seemed heavy for its size (QUALITY construction) and was NOT quiet...especially when that shutter fired! Never used it outside of a studio setting, but would have definitely trusted it to operate reliably while clamped (and safety-cabled) above a stage.

The secret is not to use a small mirror, the glass is too thin and subject to breakage from vibration. Small mirrors then become a pain in the neck to hit from any distance.

+10 for that, MixedGas!!! Totally agree.

This particular piece of gear had some substantial mirrors that made targeting easier and most definitely helped keep it from self-destructing. Interestingly, the spinning mirror was rectangular. Some extremely clever engineering clearly went into that thing because I don't remember it vibrating all that much!

There will be plenty of time to speculate as to how it worked internally while driving up to SELEM

[Photonbeam]

Sounds like you are describing the ones I remember from the '80's made by Image Engineering. Very well made (expensive).

I vaguely remember an old AVI-manufactured (...I think) remote cone scanner that had an adjustable bounce mirror as part of its input port and an internal safety shutter before the also-adjustible (cone size/angle) spinning mirror section. The shutter operated such that it would snap closed if the motor or power failed, thus avoiding potential "random beam of doom" scenarios.

When the shutter was closed, you were left with a very nicely self-terminating bounce mirror!

It seemed heavy for its size (QUALITY construction) and was NOT quiet...especially when that shutter fired! Never used it outside of a studio setting, but would have definitely trusted it to operate reliably while clamped (and safety-cabled) above a stage.


+10 for that, MixedGas!!! Totally agree.

This particular piece of gear had some substantial mirrors that made targeting easier and most definitely helped keep it from self-destructing. Interestingly, the spinning mirror was rectangular. Some extremely clever engineering clearly went into that thing because I don't remember it vibrating all that much!

There will be plenty of time to speculate as to how it worked internally while driving up to SELEM

[CountFunkula]

Sounds like you are describing the ones I remember from the '80's made by Image Engineering. Very well made (expensive).

YES!!! Image Engineering!!!

I KNEW it was one of those back-in-the-day production companies that had some combo-sortment of the words laser/image(s)/engineering/fantasy/light for a name!

I'm so glad at least one other soul around here knows those cone projectors! They were (and still are ) VERY cool!

That same company (NOT the Image Engineering based in Baltimore) also made some REALLY NICE spinning mirror barrels which were lovingly referred to as "the trash cans." The speed controller box even had a padded wrist rest!

When done right (and safely), moving-mirror bounce effects can be breathtaking! They really need to make a comeback in a big (and safe) way! I have a feeling it'll start here