I have that laser unit on my project list. I just watched it again. Very cool tool. For those who haven't seen it, check out
http://www.youtube.com/watch?v=otSjut1iGGk&feature=youtu.be
I haven't seen any plans, but it doesn't look too difficult to design. You'll need some way to hold the laser pointer and to hold the whole unit firmly to your chuck or spindle. (Don't want that dropping off at full speed.) Maybe a separate battery in the body, if you don't want to keep replacing those button cells. I might make the body out of plastic, but aluminum is also a possibility. You will want to keep the whole thing fairly well balanced.
You will need a laser beam that is perfectly central to the casing . I made a simple holder with six small screw in adjusters to try and set up a simple £10 ( $ 15 ?) pointing laser .
The turning was easy , trying to get it aligned was not.
The beam came out at about 18 degrees from parallel with the sides and unless I managed to re site it perfectly every time in the same axis of alignment ( impossible ) it was taken off and put back I was on to a loser .
Now if you could aim the beam with mirrors and set it through a cross hair slit things might be different but do any of us have the required skills to do this ?
The footprint of the beam was also problematic , for over a length of 42 inches you could see that the dot of the beam looked like four sausages side by side and covered almost 1/8 th of an inch by x 9 /64 ths of highly reflected light . Even at a distance of only 12 inches the dot was far bigger than my dot punched scribed cross lines .
As for finding an edge , due to the beam spliting in half on the edge and one half of it being reflected back at all angles it's a similar problem to be solved
I found that using a decent fixed centre Morse taper in the tail stock and putting into the dot punched hole was far quicker & easier to align things.
I think it was " British Steel " on this site who suggested using the method employed by Rolls Royce precision engineers by using a ball bearing tipped rod in the tool post to centralise round bar in a stopped work piece to the best limits before turning thing up . Put piece in gently lightly tightened chuck jaws , for as you advance the feed on a hand rotated chuck the bearing presses the work piece into alignment , Then tighten the chuck and re check for accuracy .
For my centre finder I've turned up a six inch long 1/4 stainless bar to a good point and set this in the small Jacobs lathe tail stock chuck , smear the face of the work piece with some engineers blue or similar and gently advance the point onto the smeared face ,then gently hand rotate the chuck . You'll soon see if you have the centre accurate and in any case can you can see where it is if it's not central so you can then dot punch in the centre of the scraped clean circle .
Whoops ..... I do apologise , I took the laser indicator to be for lathe use . . twas only when I looked a the link and managed to get the connection I saw the error of my words . though if I have comprehended things correctly first time I would have taken on board that you did say " mill " in your opening lines.
I think you'll still need to have a real good quality fine point laser for the best results though , something out of a CD player perhaps ?
