Can it stay on topic?

The Lumenlab focal calculator:

http://lumenlab.com/focal_calc.php
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Here's a nice cutting bit for your dremel or rotary saw that makes cutting stainless reflectors a breeze.

http://store.yahoo.com/ehobbies-com/1001-5774.html

With this bit you should be able to cut the lamp recess in your reflector in about 30 seconds.

(You can get the same tool at Home Depot.)

Oh yeah, if you don't wear goggles while doing this, you will be picking metal shavings out of your eyes!

http://www.lumenlab.com/forums/index.php?s...ic=230&hl=tools

I used standard Dremel cutoff wheels to cut my Norpro bowl. If you keep in mind that you can only do straight cuts with a cutoff wheel, you should be able to accomplish it using only a couple wheels. It took me two for the cutout. You can then grind down the jagged edge with a grinding stone. It took 15 minutes.

Thanks,
Zendance

Thanks Rorshack, for this 'tool.' I can't cut straight even with a table saw, so maybe this tool (aka clamped board) will do the trick for me. This should work with Jig/Sabre saws as well, any saw with a base/foot on it.

Here is something that might help some people out.

It's a very small program (78K) that converts from one type of measurment to another. No installation to do, just the executable. Personally I've found it a very handy program to have. This is ver. 4.0 and there is a 5.0 but it has a advertisment kind of theme going on, so I stick w/ 4.0. Here's a quote.

"Unit Converter is a freeware tool that can take care of all your unit conversions even when offline. It has an easy-to-use interface and contains most of the units commonly encountered while solving engineering problems. With more than 400 units, you are likely to find the units you are looking for. Other features include the ability to add user-defined conversions. Everything is built into a single executable file so no uninstaller is necessary. Its small file size makes it easy to distribute among friends and co-workers. "

Give it a try, you'll be glad you did!

-Jay

Here's a pic

For tuning your picture I would like to highly recommend both the AVIA and Digital Video Essentials DVD's for a properly calibrated setup.

You should never tune your settings to any certian movie, as the director has felt that any one particular scene has to set the mood by giving it a certian hue, much like music does. The Matrix comes to mind as it has a green tint to it, so anything you watch after, if you were to adjust to this movie, will have the wrong look to it.

All movies are edited on properly calibrated setups, so make sure your's is too so you can see it how they intended you to see it.

Hope this helps.


peace

I found this wonderful tool to see the different effects of different sized diameters and bulb placement has to do with beam travel in real-time.

Spherical Mirrors

Now that's cool


peace

That is a very neat site. You can actually BUILD a virtual LumenLab projector and see how it works. Great find!!!!

I have just found this lens design software:

SYNOPSYS lens design program (SYNthesis of OPtical SYStems)

I think it is an invaluable tool in adept hands. This is an optical CAD.

There is a "Samples" page where you can view what can this software do.
There is also a "Download" section, where you can get the actual version. You can use it without any restrictions for 90 days. After then, either you pay the $1000 registration fee, or.... download and install it again and you got another 90 days.

Here are some monitor testing and setup tools.

DisplayMate: DisplayMate is an expert software utility program for adjusting, setting up, calibrating,
tuning up, testing, evaluating and improving image and picture quality on any display.

Monitor Calibration Wizard: Monitor Calibration Wizard is an easy-to-use tool for calibrating the colors displayed by your monitor. Most monitors have flaws, they may be too dark, too bright, or they may have a color tint like green or blue. All these problems can be easily fixed through Monitor Calibration Wizard.

MonitorsDirect Calibrator: The MonitorsDirect Calibrator is designed to help evaluate monitor quality, diagnose possible problems, and help properly adjust the display image

Nokia Monitor Test: This Windows program will guide you in setting the parameters, controls and adjustments of the monitor. It will also guide you on how to measure picture quality.

Pixel Persistence Analyzer: Pixel Persistence Analyzer is a truly amazing LCD testing tool, which should make it easier to compare the pixel persistence (streaking or ghosting) of TFT monitors. It includes a few tests (flicker test, readability test, etc.), gamma correction feature, scrolling game, attractive interface, and much more!


peace

just to elaborate on tony's idea for using a board as a straight edge. to improve on this idea a bit glue the straight edge to a wider board (wider than the width of your saw base, scrap MDF is fine) once the glue is dry sit the saw on this jig and trim off the excess on the lower wider board, this leaves you with a straight edge that is the exact width of your saw, and if you cut it straight it will always cut a striaght line. for marking out you just align the edge with your saw cut marks with the lower board and away you go, save having to set the straight edge back from the mark a certain measurment, which can lead to errors or movement. this way you can see at a glance if it's bang on the mark. Once it's made put it away in a safe place and it's always there if you need it again. you can also use this idea to fabricate a jig for jigsaws or for routers, but when used with a router you have to remember to always use the same cutter, as a different diameter cutter will cut a different path.

If you need to convert measurements and don't wan't to run software to do it (or you have a Mac) you can go to this site. It is a great online tool that I use often.

It will convert anything from chemistry to shoe size.

Here is a modal calculator. It will help build a new room or perfectly place speakers and seating positions in an existing room.

http://www.ultimateavmag.com/news/10388/


The AVIA and Digital Video Essentials DVDs can be aided with an inexpensive sound level meter (an analog version is $10 cheaper). It's not the most accurate, but it is better than running around a room while a test signal is playing.

http://www.radioshack.com/product.asp?cata...ct%5Fid=33-2055

A volt meter it can tell you the difference between AC 120v-240v where your black wire is your hot conductor and white is the neutral which is only for your 120v fans and your ballast .
Your volt meter should also tell DC voltage as well make sure before you purchase,in DC voltage its opposite from AC here black is ground,use a car as an example when you look at a car battery RED is hot and BLACK is ground.
If your still confused please ask somebody120-240 should not be played with you can damage your equipment or seriously hurt someone.

here is a file that allows you to test your lcd to fince dead pixels....just hook up the lcd to the pc and this file post different colors to allow you to see the pixel and color of the pixel

Use this method with your Computer/HTPC to see what running a LCD in it's native resolution will get you and the importance of having a scaler: 1:1 pixel mapping

Notice the date, it's nothing new.


peace

Here is a useful tool:

I had my box plans laid out on a piece of paper and knew each pieces dimensions. I took these drawings to Home Depot and they cut the parts to size. The first three cuts were free and it was .25 cents for every cut after this. It was well worth it!

Advantages:

1. Easier to transport in the car versus a 4x8 sheet of MDF
2. No need to purchase a circular saw
3. No need to cut your fingers off trying to cut a 12" X 27" piece out of a 4'X8' piece of MDF.
4. BIGGEST ADVANTAGE: Every cut was square. This means that the box fit together nicely.

Sam

heh that's what I do for all my projects lol

I know that there are two suggestions on this that have already been posted, but if you're looking for a really simple unit conversion, try google.

I have a googe toolbar, so it's even faster, but if you run a search in google for something like "320mm to in" you get the conversion right there in nice bold print. Works for most of the units that I've tried, and is really fast and easy.

Or you could just remember that it's 12.6" and not worry with it too much

I feel I have to second the use of Google calculator, this is the second best thing that google can do

It can convert almost any unit to any other unit, perform many calculations including mathematical constants and hex, binary etc.

Best of all you type sraight into the search bar, try the following:

10.5 feet in meters
11 feet in mm
20mm in inches
seconds in 1 week

you get the picture

full details google calculator

for cutting circular holes, for this project and any others, this works well for me.

Attach a piece of metal strap ~@1cm wide and as long as you need to your jigsaw. You may need to modify the jigsaw base a bit to get the metal to fit and still keep the base of the jigsaw flat, some drilling and or filing may be required. Mount it as close to the sawblade as possible.

Whenever you need to cut a circle, drill a hole in the strap this distance of the radius of the desired circle from the blade (or just predrill the strap with a bunch of holes .5 cm apart before you mount it), drill a starting pilot hole in the wood for the blade to begin (indside the circle obviously) and manually jig-cut until you get on the circumference of the circle. (you may need some sort of compass/pencil here to find a small arc of the circumference to target)

nail the strap to the target wood at the desired centre of the circle and let it guide you around, cutting a perfect circle.

I have seen people use string instead of a metal strap, but the you are responsible for angling the jigsaw correctly. Imo, the string method is inferior to just compassing a line and following it manually.

I used this method to make some really nice speakers, cutting holes that look perfectly machined.

This works well for the fan openings, and perhaps for the lens opening, but there is a limit to how small a circle you can cut with this method.

Make sure and use a scrolling blade in the saw also (less that .5 cm wide)

hope this helps!

sg.

Helpful tips for anyone cutting plastics:

1. Always always always go slow. Plastics melt very easily, and will cause you quite a bit of headache if you don't have patience.

2. Always use a backer. What this means is to put a piece of scrap wood behind the plastic. The reasoning for this is that you do not want the drill bit to accelerate once it has cleared the back side of the plastic you are cutting. This acceleration often cracks the plastic, or rips out little chunks that you did not intend.

3. Buy some cheap drill bits. The reason for this is because you want drill bits that are NOT titanium. Take these drill bits and drag them on the concrete out side your apartment until the top edges are no longer sharp. These sharp edges are responsible for cracking plastics just as you are exiting the back side.

These are all good tips. Having drilled through a lot of plexi and lexan, I will offer one more suggestion that you may try if you like: Use a high-speed drill at max speed with a steel bit IN REVERSE. This makes it impossible for the bit to "bite" and crack the plexi. Note: This works well for up to 3/8" substrates, but anything thicker might melt and bind to your bit. Also, like anything, it takes a few tries before you get a feel for how much pressure to use when drilling plexi in reverse, so try it on a piece of scrap and see what you think.

This is a simple monitor calibration tool like Video essentials but it is free.It works great.Praxissoft

Searching tip.

Finding things can be made easier if you use an outside search engine like Google or whatever else one you prefer.

For example, if you want to find every time a word like "HTPC" is mentioned type this in:
htpc site:lumenlab.com

Hope this helps.


peace

some tips on grinding drills to cut acrylic

http://www.plasticsmag.com/features.asp?fIssue=Sep/Oct-01

need a table saw ?
got a circular saw ?
then build a improvised table saw


i used this to cut groves to mount my fresnels
BUT PLEASE BE CAREFULL YOU WONT ENJOY YOUR NEW PROJECTOR WITH NO FINGERS !

An addition to this setup would be to screw a piece of hard board to the bottom of the board, then make one cut with your saw using the board as a guide like you normally would. Now you can just line up the hard board edge to the cut marks on the piece you are cutting so you no longer have to measure back to place the board. I made an 8 footer and a 4 footer.

I don't know if you could consider the following a tool, more like a callibration screen:
http://www.diybeamer.ch/portal/downloads.php
It may help if you want compare standard screen pics as opposed to movie clips (which I must say look fantastic on the projectors here)

This suggestion is the most important thing in the world! I have made such a "slide" for my cirular saw and beleive me! the cuts that are made from such a tool are amazing( no kidding) and set up time is cut in third!

some people might like to try the Frink programming language
http://futureboy.homeip.net/frinkdocs/#Conversions

as noted in the above link, enter 38 feet -> meters in the shell and it will return 11.5824, I find it useful when I have a bunch of calculations to run.

Not to overdo a great idea, but here are a few more tricks to making a strait-edge for a skil saw:




Insted of making the strait edge out of a board, since even the best board can be warped, make the whole thing out of plywood. The mill cut edge of a piece of plywood is VERY strait, and will not warp over time like even the best board can.

Make the first cut about 3-4" wide and as strait as possible. The next cut will be as wide as your saw base + the width of the first cut. Lay the first cut strip on top of the wider strip with the factory edge oriented as to be used as the guide. Glue and screw the two pieces together, as mentioned before, and when dry lay your saw on the guide edge and cut the final edge. This will ensure that you have an uber strait cut, that won't warp with time.

Other tips:

-If you find that clamps get in the way of your saw, and one side of your project will be hidden (i.e. the inside of your pj), drill a few pilot holes the length of the board about 1ft apart in the guide section. This way you can use 1-1/4" drywall screws to secure the guide to the workpiece, without them getting in the way.

-You can cut the pieces out of the plywood either lengthwise or widthwise to make different sized guides.

-Use pre-laminated shelving (the kind that has a plastic like laminate) to make your guide. The laminate will make your saw slide as if it were on Teflon!

Good luck, and I hope this helps.

-Dave

I find these to be incredibly handy.

Click to view attachment

Do those work well with norpo reflectors? Or are they only good with flat surfaces?

I have never had a norpro in my hands but these will work with non-planar surfaces to some extent. I've used them on stuff that's a bit curved. You'd want to attack something curved from the convex side. I see no reason you couldn't nibble something very convex. They just take teeny little nibbles out of the metal so can be somewhat tedious to use.

An easy way to calculate screen dimensions when you know the diagonal. This method works for every ratio 16:9, 5:4, 4:3, etc.

This doesn't take a math wiz to derive, but it's good to keep handy

To solve the equation, use the following calculator http://www.hostsrv.com/webmab/app1/MSP/qui...ve&s3=basic

enter:

screen size = sqrt( (x^2) + ((x*ratio)^2))


when solved for X, you have the verticle dimension of the screen. multiple this value by the ratio to get the horozontal value.

Example

a 100" 4:3 screen. enter 100 = sqrt( (x^2) + ((x*4/3)^2))

the result will be x = 60. multiple 60 by 4/3 and you get 80. the dimensions of a 100" 4:3 screen are 80x60"

The same thing can be done with a router. Take a piece of metal (or wood might work, I never tried) about 1/4" thick, as wide as the base plate on your router, and as long as the radius of your router's base plate plus the radius of the largest hole you plan to cut, plus a few extra inches to accomodate the nail and added width of the router bit.

Next, remove the base plate of your router and place it on top of the end of your piece of metal. Trace the screw holes and the center hole (for the router bit) from the base onto the metal. Drill out the holes and attach your router. Then drill the holes for the nails, put in a small straight router bit, and you are ready to go.

This way you don't have to worry about anything but spinning the router around the nail, and it should be faster than a jig saw. I never tried making a small hole with this. It may be tricky.

Tips:
The smaller the bit (diameter) the better.
If possible, use a plunge router.
DON'T FORGET THE SIZE OF THE ROUTER BIT WHEN FIGURING OUT THE RADIUS OF THE CUT!!!

For measuring the front and back focal lengths of large projection lenses.

Get a crosshatch or cross beam laser level (very handy in any case for alignment)
Using a front surface mirror align the laser level and mirror such that the reflection of the projected cross is centered on the laser output of the level.
Now place the lens in between the mirror and the level with the front facing the laser. Center and level the lens so that the reflection of the cross is once again centered on the laser emmitter. Now slide the lens until the cross pattern focuses to the smallest point possible. The distance between the lens and the laser is the front focal length for the lens. Reverse the lens and repeat the process for the back focal length.

a quick easy conversion to remember is 1"=25.4mm

(edited by dazzzla)

The price of a non-contact thermometer has finally hit my price range. Harbor Freight is selling a Cen-Tech unit for $9.99 right now. Item 93983-1CJB (later you may want to try 93983-1VGA). I think I'll pick one up. Here it be:
Click to view attachment

A square or a T square work good too.you cn get one at a picture frame store with a stop adj.. for about 10.00 at Micheals or at an art store..