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PSD KEN
02-07-2005, 06:37 PM
This might save some squinting.http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=83191

pgmrdan
02-07-2005, 07:39 PM
$59.95??? Then you have to align it before you can use it!!!

I'd like to find one of the little pointers and make my own for less than $10.

wierdscience
02-07-2005, 08:41 PM
http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=83191

JCHannum
02-07-2005, 08:47 PM
I have an optical center finder that operates on the same principle. I forget the magnification, but it is more accurate than the laser dot.

It also has to be aligned each time. This is necessary as it has to be aligned to the center of rotation. Otherwise, inaccuracies from runout in the chuck or collet will throw it off.

wierdscience
02-07-2005, 08:48 PM
Thats neat.But,like said save some money and buy a laser pointer.The one I have has a screw in cap on the back end,all you would need do is turn the same metric thread on a homemade arbor and presto.

I would use the lathe as an adjusting feature.Clamp a thin piece of black painted sheet metal to the toolpost and chuck an 1/8" drill,drill a hole in the sheetmetal using the carrage feed.Then chuck the new pointer into the tailstock at the far end of the lathe,adjust it till the beam passes through the hole.
Okay,I gotta try it http://bbs.homeshopmachinist.net//biggrin.gif

precisionworks
02-07-2005, 09:29 PM
Reply to JC --

>>>inaccuracies in the...collet will throw it out<<<

Now just suppose you're using an ER-40 collet system, guaranteed concentric to no more than 0.0005", measured 2.50" from collet face. I can understand your concern if the holding device is a keyed chuck with 0.0025 TIR, but would an accurate collet introduce measureable error?

------------------
Barry Milton

JCHannum
02-07-2005, 09:38 PM
Since the manufacturer has no control of the means used to install, or the machine it is used in, it is adjustable to compensate for any potential mounting errors. The more accurate the installation, the less adjusting needed.

I just looked it up, the unit I have is an SPI, 45X magnification, optical position accuracy of 0.0001".

Lyndex Precision ER collets tolerance is guaranteed to be 0.0004" at 4 X diameter. So the centerscope is 4 X the accuracy of a quality ER collet.

[This message has been edited by JCHannum (edited 02-07-2005).]

PSD KEN
02-07-2005, 09:47 PM
Laser pointers that I have seen have a large (relativly speaking) beam.
I was hoping someone would jump on it as a Beta tester.

nheng
02-07-2005, 09:50 PM
The word that catches my eye in that ad is "projector".

I suspect that it has a tiny aperture that is projected onto your work the same way that a slide is projected onto a screen.

The resultant dot size can be as small as the designers wanted it to be ... and well worth $59.95 by the time you finish with the aperture, optics, adjustable cell and ... time, if it works properly.

Den

dvk
02-07-2005, 10:12 PM
I remember HSM had an article (forrests) about using wigglers and in the reply part someone asked why not just use a straight shank with a point in the chuck and line it up with the punched mark, and forrest gave a very good explanation of why a wiggler is more accurate, he said something like if the shaft or the chuck is out a little than the awl would be off when the spindle is spinning, However when using a wiggler you have the spindle spinning so any descrepancy in the chuck would be eliminated because the wiggler would be set perfectly concentric with the center of the spindle, giving the most accurate center finding. After I read that I myself stopped using a tiny carbide scribe as a finder and always now use my wiggler, so if the spindle is not spining how can the laser be assured perfect alignment if the chuck would have runout, to me it seems like the laser is just a hightech means of using a solid pointer in a non rotating spindle, which cannot be all that accurate as the make up of how a wiggler works..
That's just my theory,....

Ryobiguy
02-07-2005, 10:36 PM
Well I think it's meant to be turned at least by hand to adjust it, and preferably to use it. I'd certainly get the dot centered with a full rotation of the spindle, and re-adjust it if I changed the distance between the work and the pointer thingy.

dsergison
02-07-2005, 10:45 PM
ohh. shiny. gotta have that.

IT"S REDICULUS

look at the stickout from that bitsy jacobs chuck. sheesh that little mill probably doesn't have that much quill travel! so you pull that pos out of the little jacobs chuck and put in your tinsy wensie drill bit, and then what? raise the knee you don't have? lower the head?

WHY? to sell stuff.

zl1byz
02-07-2005, 10:47 PM
I see it has adjusting screws. Maybe if you adjusted it so that when spinning the laser dot doesnt move, would eliminate runout errors. Of course unless using collets the adjustment process would have to be run each time it was mounted. I think another part about this devise that would annoy me is it relatively long and needs distance between the end and the work. I can see a lot of frigging around each time you want to line up a mark.
Interesting toy though.

John.

Rex
02-08-2005, 10:20 AM
I bought a couple laser pointers lately for just this purpose. Fry's has some nice small ones, about 5/16" diameter X 2" long, machined brass with some sort of silver coating. Also bought a cheapie with replaceable lenses. It's about 3/8" by 2" brass, and the end is threaded for the lense. Both have the disadvantage that the switch is momentary.
I also have a "Torpedo Boy" laser level from HF that has a on/off clicker switch, but the body is a 6" level. No apparent way to get a cylinder out of it.
Somewhere I have seen a website with a DIY boresight made from a cheap laser. Well illustrated.

mayfieldtm
02-08-2005, 10:55 AM
I notice that they do not spec the size of the Dot.
If you need 0.001" accuracy then I would think the Dot size would need to be in the 0.001" Dia. range.
That would require some very nice optics that would cost more than $59.95.
I'd like a Permanently mounted "Line Generator" that I could align a mill vice or whatever, in 1 step.

Tom M.

hoffman
02-08-2005, 09:17 PM
I use a centerpunch and hammer. I'll bet it's as accurate as that rig...

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Hoffman in Warner Robins Ga

hoffman
02-08-2005, 09:19 PM
Of course I'd be screwed if the batteries in my hammer died http://bbs.homeshopmachinist.net//eek.gif

wierdscience
02-08-2005, 10:10 PM
I was gonna make one today,but didn't have a thread change for a .9mm pitch.Then it hit me,it would in no way be anywhere near as accurate as the common wiggler center finder that costs a whopping $6.95,so I said screw it and drank another cup of coffee at lunch instead http://bbs.homeshopmachinist.net//biggrin.gif

ibewgypsie
02-09-2005, 12:27 AM
Didja say laser plumb bob?

My machine has a hollow spindle, the added distance will help. Now to find a old pistol scope, a periscope off a submarine, a brass plumb bob, ten feet of old rusty conduit and some stainless steel tapered machine screws and two 30 watt lasers.

What? too many beers and not enough sleep? maybe ya ain't looked around my shop lately. Dr Demento has came to visit. (been doing carpenter work on the house and the dog is running the shop)

He sure plays hell with the air lines thou. I keep catching him shaking them. Ever seen a pit bulldogs lips flutter at 100 psi?

David http://bbs.homeshopmachinist.net//biggrin.gif

Gary Helmick
02-09-2005, 04:23 PM
Here is the site of the sightin laser that someone built. www.homemetalshopclub.org/news/feb02/feb02.html (http://www.homemetalshopclub.org/news/feb02/feb02.html)
Page down about 3/4 the way down and you will see the plans and pictures.
I thought about building this just for the fun of it. Maybe next week http://bbs.homeshopmachinist.net//wink.gif
Gary Helmick
p.s.
how do you put a link in the text and so you can just click on it?
GH

Gary Helmick
02-09-2005, 04:24 PM
I guess I answered my on question about the link.
Gary Helmick