Cutting your own mirrors

[allthatwhichis]

I say everyone make a video and we can all vote... Best, best cheap, worst, and, worstest... I know an pld school glass cutter sucks.

[OSLS]

So for the most part I wish to encourage this information because when you get a 4' to 6' circle of dielectric 1mm glass (or an 8' by 12' piece of BM glass) that very first ruin your day nerve raking cut will make you perspire like a $2.00 w*ore on nickel night. Well to say the very least.

I much rather teach or show others how to cut bulk stock rather than cut it myself by hand. This in turn will save the end user money and at the same time reduce the offerings that I will be forced to submit to the glass god. (More Later)

Now for the Toyo cutter... You need to score the glass on the coated side to accomplish the most perfect looking (To the untrained eye) pieces of mirror.

Let me define what I just said...

Picture 1... A raw piece of mirror.

Picture 2... A score on the front surface of the mirror stock... Don't press so hard that the outside edges of the cutter actually scratch the surface.

Picture 3... If you score very carefully on the front surface of the mirror so that when you break it (Well hopefully) most of the time it will snap right down the score line. But this is very important at this point because you actually have no control if it goes straight down (LOL YEAH Right) or if it offshoots at an angle. But if you listened and cut on the front surface the glass whether it be a mirror, dichroic, or beam splitter it will appear to have nice square edges.

Ok now just imagine making this same cut on the backside... Great you eliminated your chance of not very likely scratching the surface coating but now more than ever increased your chances of acquiring the most customized mirror that you never wished to have owned the first place. (Picture 4)

If you continue to cut on the back side of your optics then you are taking the many undesirable chances with the glass breaking gods and if enough blood hasn't already been spilled on that particular day then all your mirrors will be ruined.

I say this because even though I am well trained in cutting all kinds of mirror stock (Well glass) for some reason or another on certain days no matter what I do the glass well it quite frankly refuse's to break cleanly at all. So I chalk up these rare days to the glass gods being extremely angry due to the lack of quality blood offered while we tried to do our best to satisfy the many orders that keep arriving daily.


Now you want to cut your own glass and are completely new to the Toyo cutter, ok fine here is some advise...

When using the Toyo cutter (The newer oil filled carbide tip) you will FEEL a little (Will say 1mm - 2mm) give in the tip. Now that the tip is firmly pressed against the glass (Also try to keep the cutter completely vertical with very little angle) with the same amount of pressure it took to compress the spring score the glass until about a millimeter of the edge on both sides. I say this because with any amount of real force when you reach the edge and accidentally slide off the glass exerting the same amount of pressure on the glass will tend to shatter the product leaving you feeling like the glass gods have frowned on your less than desired offering of little to no blood. Also when saying this BY ALL MEANS don't go north and south repeatably on the score you just made!!! This will increase your chances of spider cracking throughout the glass when you attempt to break it.

[allthatwhichis]

the toyo cutter is the old school one I was speaking of correct? I used one a few times and had to have made all the mistakes you mentioned. With very similar results to the pictures you provided...

[The_Doctor]

The Toyo cutters seem to improve the old idea in a few ways. Main ones being a spring to help you regulate the pressure accurately, and an oil reservoir to help prevent a grating cut. I guess the cutting wheel and axle might be better formed than most cheap cutters too, which is important to help you regulate the cutting speed.

My main problem is that when you start the cut across a narrow strip to form small square mirrors, how do you make sure the cut starts cleanly from one edge and smoothly crosses the surface and exits cleanly on the other side. The poise and practise to acheive that in situations where you really want a fine corner or edge on a small scale might mean a LOT of work and waste. More than in making a nice, unattended threadsaw, probably. Unless you're going to be cutting glass as a major part of your chosen career, it might be easier to devise a machine for the small accurate stuff.

If you look at small mirrors in many optical assemblies you won't see much that looks like it was cut by a glasscutter. Even if it was, a lot of grinding has happened since. On the same principle that a good bandsaw beats a handsaw and a lot of careful filing, a threadsaw or wiresaw of some kind seems to be the most efficient way to cut small bits of glass accurately with straight cuts.

So again, anyone know where I can get some diamond powder? I think the threadsaw idea is worth exploring even if borks as thoroughly as my plotter-for-PCB wheeze. Still hoping someone has something cool to add about water knives, too...


Edit:
http://dove.eng.sunysb.edu/~kao/wiresaw/
http://dove.eng.sunysb.edu/~kao/Wiresaw/NSF-99.pdf

Those guys obviously wouldn't think my wiresaw wheeze is nuts.
Diamond powder? Got to be some somewhere...

[steve-o]

I just used a regular hand-file instead of the dremel to score a mirror and it broke ratherly cleanly, but I think I'll stop at 'One-Stop' for future needs.. Y'all sell galvo mirrors?
I'm also looking for simple (meaning cheap ) optics for collimating a 7 degree x 40 degree LD. Edmund gave me pricey-wisey-shivvers
Sam sez use pointer optics, edmund sez cylindrical and anamorphic pairs..uhhh.. :/

[whitcher88]

I have used fel-pro clover compound ( valve grinding,lapping compound,)
found at auto-parts store, a dremel and small dia. brass tubing, to bore a hole in a glass globe.You use the tubing as a drill bit,and just drizzle the compound on the tip,and use just alittle pressure. the abrasive will eat awawy the glass. in the mold bizz we also use a diamond paste of various grits to polish molds to a mirror finish. might try GESSWIN.

BILL