The Shop > Tools
Anybody build Dan Gelbart angled laser centre finder?
Andrew Wildman:
Pekka,
I have not had much of a chance to fiddle about with it yet, but it appears to produce a stable circle and the laser can be focussed to a fairly fine point.
I think these devices are most useful when centering a cylindrical object that is normal to the table. The angle of the laser to the surface of the object means that it can be quite sensitive in this mode. The shallower the angle of the beam to the surface of the cylinder is the more sensitive it will be. Accuracy is determined by how well you can judge how parallel the laser line is to the bed. Just using it projected on to a flat surface means sensitivity is limited to how well you can determine the edge of the laser. I am treating this as a rough positioning device for non critical applications though. If any accuracy is required it is time to get the dti or edge finder out!
I used £3 focusable laser module from ebay. This was good as the spot can be focussed. I also found out that the case of the device is bonded to the positive input. The module is at one end of a 12mm hole, two cells stacked up to the case and then the negative is connected to the other side of the cells with a screw in a threaded hole, to act as a crude but effective switch. There is also scope to convert this to centripetally operated switch arrangement in the future.
AussieJimG:
This thread just keeps getting better and better. Very interesting. Thanks to all of you.
Jim
BaronJ:
--- Quote from: Andrew Wildman on May 02, 2015, 03:13:28 PM ---Here is a laser centre finder that I put together. Most parts were 3d printed.
It looks a bit like a laser guided toilet seat for mice but the strange shape is allow it to be used on a number of different machines with different spindle sizes. The centre finder is fixed to the spindle with magnets and is very stable when running, even on the drill where it looks a bit precarious!
--- End quote ---
Hi Andrew,
Look very futuristic :beer: I like your description though, I can imagine a mouse sat on there. :bugeye:
vtsteam:
Any concerns about magnetizing spindles and chucks?
It may not be a problem for everyone, but I've been on a concerted effort to reduce super magnet usage in the shop, since I find more and more tools and fixtures attracting iron and steel filings and grit. True, a degausser can help, but it isn't always possible to use those on hidden and internal parts. And magenetism seems to get transferred from tool to tool if you aren't diligent in demagnetizing. Magnets are a nice convenience, but in many cases a simple clamp will work in their place without the assocated magnetc field. I believe Gelbart's laser finder used a clamp.
Arbalist:
Dan's original design is very elegant with just a couple of pieces of spring steel to hold it in place.
Most folks that have built these have used a spindle design for use in various fixtures instead though.
I'm torn between the two concepts but will probably go the spindle mounted route as most others have as it's easier for me to make and more economical on materials. We shall see though! No progress from me on this lately as I've not been too well recently. The hospital ED say it's nothing life threatening though so it's just finding a way to deal with the symptoms.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version