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!


first pic from new projector.jpg
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.


photo1.jpg
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


photo6.jpg
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.


photo2.jpg
The current setup. Quite a bit of wrangling left to do.

photo5.jpg
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.

photo7.jpg

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.


photo8.jpg
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!


DT-40 galvo.JPG
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.


photo9.jpg

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]

holeboard.JPG
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

[polishedball]

holeboard.JPG
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

Nice! can;t wait to get started on a case.

[blowfly]

Make that 47 holes. I decided to place the interlock shutter now while I can still get the plate on the drill press... last hole, I promise.

Mike

[DjHeadie]

hah nice! good to see you got those all finished, and good to know you have a drill press! i was scrambling trying to find one last week, ended up solving my issue thank god!


anyways, lookin good mike! i also have a small fogger you can borrow. the amount a decent hazer costs is not worth it just for... beam shots

[blowfly]

Betsy is online! I'm totally psyched. Last night I mounted everything, built this temporary connections board, plugged in my new FB3... and she ran like a champ right out of the gate! Some pics below.

Yeah if anyone area Seattle needs to use a drill press let me know.

IMG_3818.JPG
IMG_3819.JPGIMG_3812.JPGIMG_3815.JPGIMG_3809.JPG
IMG_3798.JPG

Later,
Mike

[dstar]

I think, there is a little much space between the heads and groundplate.
His name is Heatsink.

[ElektroFreak]

Depending on the power of those heads and the duration of the shows the OP will be running they should be fine. Most lower-powered heads have sufficient heatsinking to run for several hours or more in a climate-controlled environment. The TECs in the head keep everything that matters at a constant temperature, but in very hot environments the high temps can cause the TEC control circuitry to run away, overloading the circuit, which usually causes the emergency interlock to shut down the laser to protect it.

[dstar]

I think the BlueHead will work, but produce after xx minutes much more IR and less blue.
Temperature drift at the crystals. Although dual TEC.
The Head has only 1cm² contact with plate, an it is freeair in a nearly closed room.

[ElektroFreak]

Don't get me wrong, having the base of the head in full contact with the baseplate is ideal, but the OP should be able to run like that for the vast majority of shows so long as they're not being run continuously in the heat for hours on end..

[dstar]

The Problem is, to hold this Heads on constant Temperatur. Not over-heating.
The TEC works to, hmm, strong. The crystal temperature varies much.
So you have never the optimum.

Messure the power after a reflecting yellow dichro.
Your original 250mW will be only 120-150mW CW @ 473nm after some minutes.
The diode produce the same power, but the crystal can not convertet IR to blue.

[ElektroFreak]

Disagree. I have a 100mW CNI 473nm IR filtered head here that I just ran 2 nights ago on my wood workbench. No heatsink. After I was done with it it was making pretty much precisely the same amount of blue as it was once it stabilized after powering on. I had it on for about 45 minutes which was enough time for the case to reach a little over ambient temperature. I've run many other lasers on my workbench and have never noticed any abnormal instability other than tiny changes on overall behavior vs. the same lasers on baseplates. The whole point of TEC stabilization is to keep things more-or-less level over as wide a range of ambient temps as possible, heatsinking or not, up to a point at which the TEC drive circuitry is overloaded. While the TEC drive circuit does work harder, in my experience the critical side of the TEC should NOT vary much from the temperature the control circuitry is trying to maintain. Having TEC stabilization is not a cure-all, and not having the module on a heatsink introduces a duty-cycle in hot environments to avoid possible damage, which is why even low-powered modules are best placed on a baseplate. If you have a module that displays large amounts of instability with temp. variations there may be a problem with the module. Of course this is all just my own personal experience and I'm not a scientist, I'm just telling it as I understand things to be.

As I said previously, full contact with the baseplate is ideal and greatly preferred, but one can get away without doing so when using lower-powered lasers in environments that aren't too hot. Outside in summer? Absolutely not.

[blowfly]

Fair point about the heat sink, thanks for the feedback guys. I think it would probably work OK like it is, but at the very least better heat transfer should extend the life of the blue module. I won't pretend to understand all the IR filtering stuff. Originally I intended the washers to be temporary, but I sort of forgot about them. It should easy enough to order a couple plates of the right thickness.

Mike

[Insanity]

Looking good...

But something you might want to keep your eye on is the dichro mounts... I notice the adjustment screws are wound a long way back (of course it might just be the angle of the photograph)

IMG_3812.JPG

I found that after every show, my beams were out of convergence. Whether there was a 60k or 1k sound system providing the vibrations, everything was out of line. After a lot of troubleshooting, swearing and cursing I found that the springs on the Laserwave dichro mounts didn't have enough tension. I found by tapping the corner (the one without the adjuster) of the dichro mount with my finger it went out of bonk... So I now have to wind my dichros forward to stop them moving and just hope and pray that I don't have to disassemble the whole projector and drill new holes to get it back in line... Fingers crossed eh...

Mark

[blowfly]

Betsy is complete!!! The last piece to go in was in the aperture glass. DONE! I am so happy and can't thank the bright bulbs here on PL enough. I'm working on my variance paperwork now and then plan to get deeper into software side of things. In the meantime, here are some pics.


IMG_4796.jpgIMG_4798.JPGIMG_5006.JPGIMG_4807.jpgIMG_5004.JPGIMG_4808.jpgIMG_4803.jpgIMG_5002.JPGIMG_5002.JPGIMG_4795.JPGIMG_5010.JPGIMG_4815.jpgIMG_4812.JPGIMG_4813.jpgIMG_4818.JPG

IMG_4806.jpg

Mike

[masterpj]

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.

wow your harsh XD



Nice projector blowfly

[LaNeK779]

marvellous!!!!!

excellent job sir blowfly!!!