eagleeyedjoe
Active Member
Great idea, i personaly use a bell and howell vintage projector lens, looking through it from front to back, it works superb and the needle point looks huge through it, even shows dirt embeded into the needle surface.
What Do You Need?
The following basic things are needed to duplicate the instrument in this project. All of these items are covered in detail below. Some will have to built.
1. A basic laboratory microscope.
2. A set of the proper eyepieces.
3. The correct objective lens.
4. A good and appropriate lighting fixture.
5. A mount for your cartridge, head shell, or arm wand.
No special tools are needed other than normal shop tools. Nothing complicated.
The Microscope
I started with an Olympus CH binocular student laboratory scope. This instrument is serious overkill but it was what I had on hand. A binocular scope is not necessary. If you have one, it will not be used with both eyes at the same time. But a binocular scope does have some advantages. I mount the 5X and 20X eyepieces at the same time. This lets me position the stylus in the view field using the 5X and then move to the 20X for critical examination. It’s very easy to use but not absolutely necessary. A single tube scope would work just fine and is much cheaper. You would simply switch out the eyepieces.
My Olympus scope has a variety of objective lenses on its four lens turret which included a 10X. The 10X is the basis for the projects optical system. With the 5X and 20X eyepieces, magnifications of 50X and 200X are available which are perfect for this job.
Do not discount the micro-adjustable stage. I consider this to not be optional. Most modern microscopes are provided with one. If not, you can buy one at microscope suppliers like Edmonds Scientific. Do it! This is a bad place to economize.
Since the cartridge or stylus must be positioned directly under the 10X objective, you must find a way to cover the hole in the stage through which the normal scope illuminator provides light. I just use a sample glass slide with which the slide clamp works perfectly. I then set the cartridge on top of the slide. Of course, the normal illuminator is not needed and is turned off.
The Eyepieces
Searching on Google to find a zoom eyepiece, I found nothing. I thought this was strange because I was sure I had seen them in the past. I gave up on finding a zoom eyepiece. I settled for using a combination of low and high magnification eyepieces. This is probably not a bad situation because the eyepieces are inexpensive. If I insisted on Olympus brand lenses, it would have cost hundreds of dollars. Olympus lenses would have been optically faster and better but, for this project, what I bought are perfectly adequate. If you can find a better solution, go for it and let us know. The only constraints are the size and magnification of the lenses. Do not be tempted to go to higher magnification. It will not work as well. Links are provided below to purchase the eyepieces I used.
Be careful when buying eyepieces. The diameter of the stock 10X Olympus scope eyepieces is 23mm which is pretty standard but there are other diameters. Measure yours and buy the proper one. On my Olympus, the eyepieces can be interchanged by simply pulling the eyepiece out of the tube and slipping in a replacement. Be sure to check that your scope can interchange eyepieces.
Here is an ebay link to the 5X eyepiece (Brand Name: AmScope Model No: EP5X23-S):
http://cgi.ebay.com/ONE-COMPOUND-MI...5|66:2|65:12|39:1|240:1318|301:0|293:1|294:50
Price: $29.99
And here is the ebay link to the 20X eyepiece (Brand Name: AmScope Model No: EP20X23-S):
http://cgi.ebay.com/ONE-WF20X-EYEPI...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
Price: $24.99
CONTINUED
HI,
I'm no expert when it comes to examining grooves. The best examples I have seen use laboratory electron microscopes which are usually way beyond the means of most amatuers.
The scope you linked me to will be very tricky to use because there is no mounting or lighting system. You will not be able to hold it steady to get any meaningful results. Additionally, the inexpensive computer based scopes I have seen are totally inadequate for stylus examination. For grooves, well, I am very skeptical.
If you do purchase it, you should report back with your results, either good or bad.
One more thing. Why are you going after the groove when stylus examination offers the shortest route to knowledge? Build the stylus microscope then worry about the groove.
Sparky
wtaylorbasil said:My fault. I was not clear enough. I want it purely for stylus inspection. I did have a look at som microscopes on the link provided on this thread. It was confusing that they talk about eye piece and then the microscope body etc. I thought I could use the USB scope so I could even take snap-shots of the views. I could make a holding mechanism to be able to rotate the stylus head to get the angle of the tip. About the lighting I am uncertain what I would do. May be someone in the forum could suggest. I did want to know if the
2Mp resolution would be sufficient and the range 50X to 200X seems to fit what is required for a good examination.
Would you have any more comments to add to your already good response?
Regards
William