Rob's Homebrew - Magmounts the next generation

[steve-o]

Crank up the factory, man!
Looks like production orders are coming in

[stanwax]

Very good question andy...though I think for what you wanna use that mirror for you need something a little less sophisticated. I will post some pix later of what I use to turn a DVD diodes beam through 90 degrees before the cube - cis im assuming thats where you are using it. If not tell me where you wanna put the mirror and I will offer up a suggestion or 2

Rob

[andy_con]

yes a duel red set up mate

[buffo]

This is a little off-topic, but since Andy_Con mentioned a dual-red setup I thought I'd share my experience with my dual Maxyz module alignment.

I used some large MM2 mounts when I set up my two Maxyz modules. One holds a mirror to bounce the vertically polarized beam 90 degrees into the side of the PBS cube, while the other MM2 holds the cube itself to accept the horizontally polarized beam coming out of the second Maxyz module.

Some people say that you don't need a fully adjustable kinematic mount for that bounce mirror, but trust me, you want it! With two fully-adjustable mounts like that you don't need to have any movement available on the lasers themselves. You can get the two beams to line up perfectly (both near and far field) by using just the two mounts - one on the mirror and one on the cube. The adjustment doesn't take very long at all either!

Set up the lasers and use the mirror mount adjustments to get the two beams on top of one another just as they exit the PBS cube. Then use the mount on the cube itself to get the far-field adjustment back into line. With any luck, you won't have to go back and fourth, though if you're really picky about the alignment you might want to play with it some more just to convince yourself that you're truely 100% aligned.

But seriously, the whole process takes less than a minute, assuming that you have *good* mounts on both the mirror and the PBS cube, and that you have a throw of at least 30 feet with which to test your far-field alignment.

Works like a charm...

Adam

[steve-o]

I just used a "L" shaped piece of aluminum bolted to a plate with a screw. Glued the mirror on it. Maybe I just got lucky, but that worked 4 me..
Adjustable mounts are far superior though I'm sure..
The important thing was to follow Marconi's instructions and adjust the mirror near-field and the cube far-field. Made it pretty easy. (I believe I got that right-- or vice-versa )
OH-- and with power reduced to just a few mW, to avoid accidental incidents (like i had )

[buffo]

Steve-o;

Did you kill one of your maxyz modules from back-reflection?

Yeah, I always dial the power way down when I playing with the alignment. It's easy to screw up and send the beam back towards the diodes. Of course, I'm probably a little more paranoid than most people anyway, but I haven't killed a Maxyz module yet! (I have killed other red diodes though.)

If you get lucky with your L bracket for your first mirror, or if you have enough adjustment in the mounts for your lasers themselves, then you can get away without the kinetic mount for the first mirror. But having a mount for the mirror and a mount for the PBS cube just makes it easier.

In my case, each Maxyz module is on it's own floating table, so it was difficult to ensure that they were both at exactly the same height and slant. But it didn't really matter since I had the second mount on the mirror. I could get it aligned no matter how far off the lasers were with respect to each other. (If you mount them both on the same plate then this isn't nearly as big of an issue.)

And yeah, you got the alignment right. You use the mirror to get the near-field in line, and then adjust the PBS cube to get the far-field dialed in.

Adam

[steve-o]

Adam, I killed both Maxys with the final output mirror (where the galvos are going to go) I had the power dialed way down during the set-up on the BS cube/ mirror for the red/red combiner.
One of them brain-fart stupid mistakes I make sometimes . When I put the scanners in this time I will have the power way down on the reds..
Steve Roberts was kind enough to send me 2 G124 galvos. THANKS, STEVE
I'm working on that project now. Does anyone know the operating voltage of a General Scanning G124? He sent me a schematic for the amp-driver; it's +/-18V but I don't think that would be the nominal V for those
Thanks

[buffo]

Adam, I killed both Maxys with the final output mirror (where the galvos are going to go)

D'oh! That would have made me cry... I know you had to be pissed!

I had the power dialed way down during the set-up on the BS cube/ mirror for the red/red combiner.

Well, at least you were careful for the most dangerous part... Too bad you lost it at the very end. I take it this failure was some time ago, right? I mean, your dual maxyz were kicking ass at SELEM... (BTW, did you get a chance to check out the beamshow video clips? You can see your red and green lasers coming off the mirrored ball... I like that effect so much I've already decided to buy my own ball!)

Steve Roberts was kind enough to send me 2 G124 galvos. THANKS, STEVE

Damn - what a guy! 3 cheers for Mixed Gas!

I'm working on that project now. Does anyone know the operating voltage of a General Scanning G124? He sent me a schematic for the amp-driver; it's +/-18V but I don't think that would be the nominal V for those

Actually, that sounds about right. Normally galvos need a dual-polarity power supply at either +/- 18 volts or +/- 24 volts. Figure at least 2 amps minimum. (The PSU I selected for my DT-40 pro's is capable of a little over 5 amps... Overkill, I know, but I wanted to be safe.)

Adam

[stanwax]

Andy

Sorry about the delay getting back to you on this - my projector has taken over my life this last week - anyway here is the info about how I turned the beam to direct it into the PBS cube. I made a little L bracket - cut from aluminium L section from B&Q - and to this I added a 15mm strip of ally (onto which the mirror is fitted) which has 2 hacksaw cuts near one edge (about 1/4 of the way along), one long cut from the top and one short cut from the bottom that get to within a few mm of each other. This keeps stiffness but allows for some flexing. The narrow bit to one side of the cuts is screwed to the L bracket by a single screw - or you can use 2 - and then 2 screws are placed diagonally through the L bracket to act on the remaining 3/4 of the strip to provide adjustment. The Idea is that you place the whole bracket reasonably accurately pointing the beam at the cube and fix it down. Then use the small ammount of adjustment in the screws to get the far field aligned. I know this may not make sense so here are a few images of my setup which hopefully will make the text make sense.

Its not exactly refined bt it really gets the job done.

Rob

[steve-o]

Damn we got some contenders now!!!hehehehe
Nobody needs to go buy new***ts now