microscope on lathe

[chuck foster]

hi guys:
a few days ago i read an article in home shop machinist magazine about jerry kieffer and the way he uses a stereo microscope to make his incredibly small models.
so after reading this i thought i had to have one. i bought one from a guy on ebay, and i mounted it on my 9" south bend lathe.
now i know jerry and those other microscopic machinists have small sherline lathes, but i can't afford one right now!!
so the old south bend will have to do.
after mounting it to the lathe (first pic)

i tried to make an intake valve for my 1/4" x 1/4" engine. the valve has a .093" head and the stem is .032" x .300" long.
using the microscope makes seeing the part easy but it sure showed me that i need to learn how to sharpen tool bits.
looking at the part with just my eyes it looked shiny and smooth but under the scope it looked as rough as a plowed field

i will have to do some experimenting with the tool sharpening to get a better finish.

just to give you an idea of how much bigger things look under the scope here is a picture of a 0000-160 tap, the tap is .020" in diameter and 160 threads per inch. the picture shows the tap the same size as you would see it when looking through the scope.

if anyone has ideas or experience with using a scope on their lathe or mill i would like to chat with them about some ideas and questions i have.

cheers
chuck

 

[Loose nut]

Very cool!

 

[gilessim]

I love that set up, how on earth did you manage to cut 160 tpi?

Giles

 

[chuck foster]

i should have mentioned that the tap is manufactured, if all goes well i will be trying to make my own taps.

this tap is made by a company called j.i. morris and they want $80 to $90 bucks apiece, and i'm sure i will need more than one.

if i get to making one i will try to post some pics or a video if you guys would like.

as always take care and play safe.
chuck

 

[tattoomike68]

Thats the ticket for the small parts, no other way. Thats as good as an optical comparator on the cross slide. the smallest part I ever made was a bushing that was .030"ID .040" long and .050" OD it was made to replace a bearing in a lathes travel dial indicator.

other than a $25,000 optical comparator in a fancy shop the olny microscope we had in the shop was one of the cheapo units, An Illuminated Microscope , its the type we can all afford and is worth having around for $10.99. Its better than nothing.

http://www.radioshack.com/product/i...kw=microscope&kw=microscope&parentPage=search

In my shack of a shop I can drop a 5/16 -18 tap and lose it , i better clean up that thing soon, it has been a catch-all all winter and is full of crap. ;D

 

[PolskiFran]

We used to have microscopes mounted above our Levin watchmakers lathes at work. I used to use these for drilling 1/32 vacuum holes through 3/32" dia. Elkonite 1" deep. Using the microscope it was like plowing a 1/2" pilot hole on an 18" swing lathe. The key was watching the chip and adjusting your "feel" for the feed on the tailstock handwheel.

Frank

 

[GailInNM]

I have machined under a microscope, but am not currently doing so. I still use a microscope for inspection and small printed circuit work.

One suggestion is to protect the objective lens from cutting fluids, smoke and swarf. Typically the objectives are recesses in a threaded cavity so a reducing lens or a filter can be added when necessary. Mine is a 50mm x1mm thread. I use a disk of 0.06 to 0.09 acrylic made up to slid inside the threads with a ring made of thin foam slightly larger glued to one surface so the foam sticks over the edge of the disk will hold it in place as the foam makes a friction fit on the internal threads. Just slide it up under the objectives. A short length of string glued to the foam makes removal easy. On a stereo microscope a slight amount of distortion and a slight shift in focal length will be noticed as the objective lens are not perpendicular to the acrylic, but it is very minor. I use these for soldering work to protect form the smoke and splatter of flux and solder. Make up several for replacement as they are quicker to make than to clean.

For inspection I have made up several custom reticles than fit in the bottom of the eyepiece using foam to hold them the same way. On many eyepieces the focal point is the bottom of the retainer that holds in the lens in the bottom. I cut a ring of thin acrylic with the ID about 0.14 smaller than the OD. I use 0.004 wire EDM wire to form the desired pattern. I groove the ring, really just a scratch will do, where I want the wire to go. For a simple cross hair, 2 wires 90 degrees apart. For inspecting thread cutting tools, make the wires 60 degrees apart. The one I use the most has a single wire across and them 2 wires spaced 0.040 across. This goes in a 10X eyepiece. Used on a zoom microscope with the zoom set at 4X and combined with the 10X eyepiece for 40 power the 0.004 wire shows up as 0.001 wide and the apparent spacing of the 2 wires is 0.010 inch. At an objective zoom of 1, the wires appear 0.1 mm thick and spaced at 1mm

Gail in NM,USA

 

[Swede]

I bought a Meiji stereo microscope for engraving, and they are incredible devices. A scope with good optics gives you capabilities you'd never have dreamed of before, and best of all, they are wonderful for removing splinters!! ;D

I haven't mounted it on a machine tool yet, but these scopes are set up to ride on a standard diameter boom, so it should be no problem to adapt one to almost any machine.

Their normal magnification is TOO great, and like Gail mentioned, a 0.5 or 0.4 Barlow (objective) lens will do two things... it'll increase the FOV while reducing the magnification, AND it'll protect the native, built-in objective lens from splash and crud. Since the add-on barlows are relatively inexpensive, I'd put one on even if it is a 1.0.

 

[BobWarfield]

Swede, that one's got a fancy anti-eye-poker-outter protection device too!

I gotta look for one of these 'scopes. I always like microscopes anyway.

Best,

BW

 

[JimM]

I've just purchased an 8" rotary table but never really considered the weight of the item before I bought it. It's weighs in at 34Kg and I'm, planning on using it on an Elliott Juniormill, the modern day equivalent would be something like a VMC or the Grizzly G3102.

Don't think the 34Kg will be an issue but does anyone know what the maximum recommended table weight is for this sort of machine ? Guess by the time you have a chuck etc added to this you'll be getting on for 40Kg

Cheers

Jim