$20 LASER Enlarger Alignment Tool

[jim10219]

Here's a $20 LASER alignment tool I just completed. It's extremely accurate, easy to build, and best of all, cheap! I actually made mine for about $15 in two days (most of that time spent waiting for the epoxy to dry), but I had the mirror already on hand. I'm not the fist person to come up with this idea, but several of the other instructions I saw had much more expensive and elaborate setups, like using 3D printers and such.

Materials List:

$10 adjustable LASER gun sight with picatinny mount from Amazon
$5 angle aluminum 3/4" x 12" x 1/16" x 36" from hardware store
$4 mirror from thrift store.
$1 celebratory beer or soda

Tools List:

JB Weld
File or rough grit sand paper
Clamps
Rotary tool with metal cutting disks
Carpenter's square or framer's square
Rotating circular tray

Basically you just cut angle aluminum with a rotary tool to make each part. The lengths are up to you. I didn't measure anything. Then sand down the parts you want to epoxy (to get rid of the oxidation and provide for a better bond), epoxy and clamp them, and wait over night. I did it over two days because I couldn't fit all of the clamps on the joints all at once.

First you make the base. It's just an "X" with a channel cut out of the lip for the top piece to rest flat on the bottom piece. Now, since the top piece is raised off the ground by the thickness of the bottom piece, you cut two more small pieces of angle aluminum to shim them so it rests flat. Remember to sand down the oxide layer just before applying the Epoxy.

Next you do the vertical post. I had to plunge cut a small slot into short lip side of the vertical post for the laser sight to attach to. You can see it in the pictures. You can also see that the aluminum was a bit too thin to hold the LASER firmly in my case. If that happens to you, drink your celebratory soda or beer prematurely (and wait if you need to because you're going to need sobriety on your side for the rest of these steps) and cut out a small shim of aluminum and wrap it around the vertical post, through the slot you just plunge cut. Epoxy and clamp it down. Align the vertical post 90 degrees from the base using a carpenter's or framer's square, and epoxy and clamp it down. Once the epoxy has all cured, attach the LASER and adjust it. You adjust it by placing the completed alignment tool on the rotating circular tray, place both on level ground, center the LASER over the center of the tray and rotate it while shining the LASER at the ceiling. From there you just use the adjustment screws to align the LASER so that as it rotates around, the point on the ceiling doesn't move.

To use it, just install the small thrift store mirror into the slot where the negative carrier goes, and place the LASER tool on the board below the enlarger head. Adjust the enlarger until the LASER beam bounces off the mirror and perfectly aligns with the hole in the LASER. Now, if you didn't before, drink your celebratory soda/beer!

[Bob Salomon]

Which thrift stores sells front coated mirrors for $4.00?

[Peter De Smidt]

Versalab's device doesn't use a front-coated mirror, and it works just fine.

[jim10219]

Which thrift stores sells front coated mirrors for $4.00?

Yeah, you don't need a front coated mirror for this application. The distance between the LAZER and the reflection surface is irrelevant. Only the angle matters.

[Leigh]

You don't need a first-surface mirror, but...
If you use a regular mirror, the front and back must be accurately parallel.

The reflected images will then be coincident only when perpendicular to the incident beam.
I can think this would be beneficial since it gives you twice the error indication.

- Leigh

[Drew Wiley]

Hmmm. Being someone who borrowed a $3000 laser and employed Starrett machinist's levels and a set of semi-silvered front-surface mirrors to level and
calibrate an enlarger with micrometer-driven yaw adjustments salvaged from a big military device, we both apparently had fun doing this; but the brand of beer I got to celebrate with certainly doesn't come in cans!

[Leigh]

Hmmm. Being someone who borrowed a $3000 laser and employed Starrett machinist's levels and a set of semi-silvered front-surface mirrors to level and calibrate an enlarger with micrometer-driven yaw adjustments salvaged from a big military device...

Throwing money at a problem does NOT imply that one understands the problem or its correct solution.

In fact, just the opposite.

I own several Starrett 199Z precision levels, but I don't use them on enlargers.

- Leigh

[Pere Casals]

$10 adjustable LASER gun sight with picatinny mount from Amazon

Thanks for sharing, I'm to built one.

[Drew Wiley]

Leigh- what on earth makes you think I was "simply throwing money at a problem"????? ... My SMALL enlargers were built by Durst - 138's and L184's, and this was a big one - do you think the machinists at Durst were working with plastic measuring tools bought for a few bucks apiece? Do you imagine one can
just grab any level and assume it's level, or that a square is actually square, or a beam properly aligned, unless you have a serious standard to compare it with? Today I'm finishing a garden enclosure, and the try square I bought fifty years ago for two bucks is plenty adequate. But two weeks ago I was getting
paid for a big teak counter, and it sure wasn't adequate for that. There's a reason every serious cabinet shop owns a drawer full of Starrett. And even my big vac easel is machined flat within a few thousandths. What's wrong with "overkill" when you already either have access to the right gear or outright own it?
Some of us like to work with precise attractive gear in the darkroom itself, as well as have the satisfaction of making it. For
one thing, it's EPA illegal to even market an amateur laser with a tight beam; and such a thing doesn't come cheap anyway.
Some of those cheap things are so far off it borderlines on silly.

[HMG]

https://www.trippingthroughthedark.c...lignment-tool/

I had a 3 3d printed for $18. Haven't tried using yet though. It is necessary to make sure the laser is pointed exactly vertical. Your rotating tray method should work if you are precisely in the center. The other approach is to use a plumb bob from the ceiling to establish a vertical.