Betsy - my first RGB projector

[blowfly]

Betsy was the name of my first real girlfriend so it makes sense to name my first real projector after her. While I still have a long ways to go, I thought posting some pics would be a nice diversion from aligning laser beams. Speaking of alignment, I have new found respect for everyone that's ever completed a projector.

I couldn't have gotten very far without a ton of assistance and parts from so many people on this forum. Lasers and scanners are from gottaluvlasers, enclosure from Edison, micromirror mounts from Laserman532, GM-20 from DZ, and sound card correction amp from DrLava built using Electrofreak's tutorial.

Specs:
600mw 532nm
450mm 640nm
250mw 473nm
DT-40 Pro Wide
Sound card DAC

On to the pics!



When drawing straight lines along the extents of the projection area, the DT-40 wides at full angle seem to curve the lines quite a bit. This doesn't happen when the projection angle is reduced below 50%. I see now why the wide scanner is good for beams but not so much for graphics.



Some obvious alignment issues. Besides the gaps, the green isn't hitting all the scanner mirrors. This is makes for a cool ghosting effect shown in this video: http://www.blip.tv/file/3776919



The next thing to do is reduce the complexity of the beam path. The two mirrors on the left aren't doing much but make it harder to hit the scanners.



The current setup. Quite a bit of wrangling left to do.


This is circuit board is basically an direct implementation of Buffo's interlock schematic. It's the first PCB I ever made and learning Eagle CAD was fun. The next version will be more compat and add some bells and whistles including a power-on time delay and more safe guards and status indicators. I'm trying to stay with 5v instead of 12v, though it remains to be seen if I can get the GM-20 open far enough with 5v.



This is a side shot. It's weird that a quite a bit of light is going straight up through the Y galvo mirror. Not sure if this is normal.



It's clear now that I'm going to need a hazer if I want to get decent beam pics. Damn you Gordon Gould, I'll be broke before I'm through here!

Mike

[Dr Laser]

Betsy was the name of my first real girlfriend so it makes sense to name my first real projector after her.

So in the beginning it will work fine and then slowly it will start drifting away and one day it will break.

[stanwax]

Mike if its not too late for you checkout the alignment guide for free download off my website - also my scan angle chart which may be of use
www.stanwaxlaser.co.uk

Rob

[dream beamz]

I obtained a car really cheap last year and i fixed it up for a really bad off friend. the car was named Betsy

[gottaluvlasers]

Looks good Mike!!

And yeah, definitely need to try and ease up the beam paths. A few suggestions-

1- the 40 Wides are *not* designed to scan graphics at those extreme angles. Keep the angles to the standard 8-12 degrees. Beams and aerial effects, go crazy wide. graphics, keep at standard angles.

2- Worry about your near field alignemtn FIRST. dont even look at your converged beams down field. It's a psychological thing. the minute you start seeing un converged beams down field you automatically want to start tweaking things to get a good convergence. however, if your near field is not aligned, you far field will NEVER EVER EVER be aligned. get those dots *perfectly* aligned on your dichros. get the white beam perfect into your scanners. THEN- tweak your dichros for your far field.

3- You might want to rethink your blue bounce. Most people dont like doing that becasue every mW of blue is treasured. Hoever, this is your setup. if this is how you want it, all the power to ya.

Other than that, everything looks great!

-Marc

[Phredy1]

It's clear now that I'm going to need a hazer if I want to get decent beam pics.

Mike

I have a mini fogger you can borrow if you want.

Gene

[blowfly]

Good feedback guys. I read through Stan's alignment guide a dozen times. The whole near field/far field thing is starting to make sense now. I had heard those terms before but I can see now how getting the gross alignment done by positioning the laser modules to hit the dichros perfectly, followed by the fine adjustment using the dichro kinematic knobs.

I'm not sure how to mount the lasers to be adjustable so I'm going to try to just get it right.

One thing that bugs me is the DT-40 galvos have this bare aluminum cylinder that I keep reflecting off of while trying to align on the X mirror. I think I'm going to get some black paint tomorrow and idiot proof this!



Mike

[blowfly]

Ok, alignment isn't all that bad... when I follow the directions. It's when skipping ahead that alignment gets tricky. Best things I figured out tonight 1) unplug the galvos during near field alignment, they just distract you 2) how to turn the color intensity down in LFI Player so I'm not working with full strength beams. I have safety glass but I keep having to lift them to double check results. Perhaps there is a happy medium with beam intensity where I don't have to lift the glasses so much.

Got green and blue aligned pretty well! Red is more tricky because the beam seems to be coming in a little lower than the green and blue. Also I have two sets of safety glasses, one for green/blue and another red.




Thanks again for the helpful tips!

Mike

[gottaluvlasers]

looking good mike-

you *did* do your near filed alignment first though right? remember, if your near field is not perfect, you will never get your far field aligned and consequently your overall alignment will suffer also.

You need to align you RGB near field first dont even project an image or worry about your scanners until you get the near field down.

Look

Look

Look

Once you get these aligned, project (IMO, the easiest way) a white square or circle. *NOW* adjust your far field. i also shoot a straight beam and reflect it off of a mirror at the far end of my office and then back to the other so that i get a long beam throw. i adjust the alignment this way sometimes also.

Chances are, if you think you have your B/G aligned, they are going to have to be changed once you get the red in there.

-Marc

[blowfly]

46 M4 & M5 holes, drilled and tapped! Now what am I going to do with this drill press?

Next steps:
Wire up ILDA connector
Power connections
Safety features
Variance application!

Mike