need big mirror scanners, speed is least of concerns

[rns0504]

Please tell me if I angled the mirrors right.
（X）12X14X1mm （Y）10X20X1mm



If its right then with 7mm it barely fits on the Y mirror and with 6.5mm you get only few degrees before overspilling.

For an orthogonal mount, both mirrors will be at "45 degrees" while at rest. Kind of hard to tell from the image, but it appears to be right

[catalanjo]

No, its not quite any size "scanner can handle any size mirror if you slow down enough..."
!......A G330 can throw beams around the whole room, with mega mirror and mega angle, but most clients these days want something much faster then 200-300 Hertz max small angle.. I do keep a pair of 330s for the day I have to do a gig where I need to wrap beams around the room, ...... A good reason to own a 330DT with a CX660 amp is to pan a whole scan from an existing projector around a room, or to have a movable "beam bounce" mirror downstage...Steve

x2 They definitely bridge the gap between fast scanners and rotary optical switches, although as Victor has already pointed out, if you want to get your hands dirty the stepper motors certainly get a look in.

That way your cute little high-speed 506 set, deals with projector screens & complicated small range scans just stealing as much of the beam they can handle.

.....2 cents moar (low budget) : http://www.ebay.com/itm/C128452-Lot-...YAAOSwbYZXX032

Cheers
PS. Ryan ....... @"text is a rather cold medium" = no offense taken..., (my post was just to straighten up the flag pole a bit),.....I will probably hit on you further upstream, (concerning your extra long/large mirror sets) if and when I have enough "money talks" resource to be able to explain myself more clearly.

PPS.
NIL ......@ "For an orthogonal mount" this careful qualification, refers to the "set back" difference, which would allow you to thin down the Y mirror.

[rns0504]

You can just use the equation

MINIMUM X MIRROR WIDTH = (Beam Diameter) * secant (45deg + (desired mechanical degrees past nominal))

So say you want to scan, say, 40 degrees optical (20 degrees optical in either direction from resting position of 45 degrees).

40 degrees optical is 20 degrees mechanical. So + and - 10 degrees mechanical from rest position of 45 degrees.

Right now we're interested in the PLUS direction as this is where the overspill will occur

So we use the equation MIN X MIRROR WIDTH = 6.5mm * secant (45deg + 10deg) = 11.33mm wide is the minimum width of the X mirror. Should be a bit bigger, say at least 11.5mm, as no mirror is perfect and there will be chipping around the edges.

So if you want 60 degrees optical, thats 30 mechanical, or + and - 15 degrees.

MIN X MIRROR WIDTH = 6.5mm * secant (45 + 15) = 13 mm wide


Alternately, to just calculate the minimum width of the X mirror at rest position of 45 degrees, just multiply the beam diameter by 1.41, to determine the minimum X mirror width, just to capture the beam

[mixedgas]

Bill does cover magnifying angle with multiple scanners in his book, its just that in most cases the software is not set up for it. So you have to do something like DMX out controls the course scanner and your show software drives the primaries. That is, unless you have more then one show card addressed by your software.
I'd just use one course scanner for expanding the X axis, I'd never ask a beginner to use two scan pairs in series.

!
Heck, I cant think of a time where I've ever came close to needing that except one "theatre in the round" and one outdoor show. That is because at that point I'd be using the beam table.
When I worked for SWO they had multiple scan heads on beam table positions to answer the "wrap beams around the stadium" problem. With a 50/50 beamsplitter on the first position, that got you drive for two scan heads... However, more angle is always good, especially for things like Pink Floyd Tribute Bands.
!
The Kindle E-book from Pangolin is worth far more then the 99 cents..
!
!
Steve

[rns0504]

CONSTANTS FOR MINIMUM X MIRROR WIDTH

For 40 Degree Scan angle, Multiply beam diameter by 1.743
For 45 Degree Scan angle, Multiply beam diameter by 1.8
For 50 Degree Scan angle, Multiply beam diameter by 1.861
For 55 Degree Scan angle, Multiply beam diameter by 1.928
For 60 Degree Scan angle, Multiply beam diameter by 2
For 65 Degree Scan angle, Multiply beam diameter by 2.079
For 70 Degree Scan angle, Multiply beam diameter by 2.166
For 75 Degree Scan angle, Multiply beam diameter by 2.261
For 80 Degree Scan angle, Multiply beam diameter by 2.366

You can see from the image that the width of the mirror grows tangentially instead of linearly

The case becomes worse in terms of length of the Y mirror

[catalanjo]

@ "I'd never ask a beginner to use two scan pairs in series."

IMHO if you don't mind a vertical shadow stripe and X scans across two parallel Y mirrors with inverted signals, the signal input is not so much of the problem as getting a beam into the scanner setup elegantly.
Cheers
PS. @ "The case becomes worse in terms of length of the Y mirror"...... since you seem willing to take the effort ....why not post the Y curve which would be really quite useful.

[Nii]

http://www.ebay.com/itm/C128452-Lot-...YAAOSwbYZXX032

I'd buy that in a heartbeat for 2x the price if it came with amps and didn't have corroded mirrors even though aluminum should only oxidize (and was tested of course).
It's fast enough to project at least 8 points at full angle right? I could use it for all my testing even if it wouldn't be useful for this specific build. But no amps and untested condition...

[catalanjo]

Try pestering Steve for a source of amps. !
Mirrors are replaceable and allow YOU to choose the size /quality/colour etc,
Cheers
PS. @"(and was tested of course)" ....... ask seller to test coil continuity (these scanners are difficult to break) ... any way I think it is a good gamble and occasionally you have to live dangerously!
PPS. @"It's fast enough to project at least 8 points at full angle right?" .......... only with noticeable flicker! but U did say "speed not a problem".

[Nii]

Thanks. But still, untested condition... $50 not much money for a spare scanner but noticeable sum to just throw away.

[catalanjo]

Maybe you should scan across beam steering mirrors if you need a specific 8 beam effect !
Cheers
PS. You could always resell them to me if they don't work out (at an even lower price ), if we could sort reasonable postage costs !