Appropriate Laser for Hollow Form Woodturning?

I am a woodturner - basically, I mount a piece of wood to a lathe that spins it at high speed as I carve it. I've recently gotten into doing hollow forms, which is an urn-style wood vessel. I blew through the side of a gorgeous piece this past weekend and want to make something that will help ensure this does not happen again.

Basically, my intention is to build an arm that clamps to the shaft of my hollowing tool, comes up ~8", and then out ~12" so it's directly above the cutter head. A laser would be held there and aimed at the cutting edge of my tool. (When in use, the cutter is inside the wood and hidden from view, so you're pretty much cutting blind, hence the problems cutting too thin and destroying the piece of wood.) Since the laser would move the same as the cutter as I move the tool, it should show me on the outside of the wood where the cutter is located on the inside. See at about 1:30-1:50 in the video at https://www.youtube.com/watch?v=YA--jAhrKkU (not my video) for something similar to what I want the laser for.

Making a system to hold the laser and aim it at the correct spot isn't a problem - a little metal fabrication and it'll be done in short order. The problem I'm having is trying to determine what specific laser I should get for this purpose. I do NOT want the laser to mess with pets, burn matches/balloons/etc, cut anything, take down airplanes, perform amateur DIY eye surgery, or any of the other things I've read about since starting to look at laser stuff online; I ONLY want it as an aid to allow me to see on the outside of a piece of wood where the cutter head is located on the inside when it's hidden from view. I know next to nothing about lasers (as you can probably guess by reading this ;-) ) and am hoping somebody here will be able to help.

The ideal laser for this would:

- Have an on/off switch rather than a button you need to hold down.
- Be able to run for long periods of time - up to an hour or more - without problems.
- Last a long time.
- Not suck down batteries too quickly.
- Take standard (AA, AAA) batteries.
- Be lightweight. (Combined with the last item, maybe take 1 AAA? I could also wire to a remote battery pack.)
- Be safe to look at when bounced off a wood surface for long periods of time at close range. (I'm maybe 14-18" away.)
- Not harm wood, whether bare or finished.
- Have a well-defined dot at 18" away or less. (Too large and it won't accurately show where the cutter is located.)
- Be inexpensive, yet functional. (I'm hoping to be able to get a suitable laser for $5 or less.)

I do have a box of old computer CD/DVD drives in the basement and am very handy with computers. If there's a safe way of taking the laser out of a drive and simply running power to it from batteries, it'd be ideal as long as it fits the other above criteria.

Anybody have advice for me? I've been reading about lasers for hours and honestly, don't understand half of what I'm reading.

All you need is a weak <5mw red module. You want to stay with <5mw for safety.

650nm 5mW 3.2VDC 8x13mm, AixiZ

Then you can run it off of 2 AA or 2 AAA. Just wire a switch in series with them and you'll be good. This only draws ~30mA so you shouldn't be draining batteries fast, and it really needs barely if any heatsinking.

Feel free to PM me if you need anymore help or need something made.

Mrcrouse said:

All you need is a weak <5mw red module. You want to stay with <5mw for safety.

650nm 5mW 3.2VDC 8x13mm, AixiZ

Then you can run it off of 2 AA or 2 AAA. Just wire a switch in series with them and you'll be good. This only draws ~30mA so you shouldn't be draining batteries fast, and it really needs barely if any heatsinking.

Feel free to PM me if you need anymore help or need something made.

Click to expand...

Agreed. One other bonus to the Aixiz one is that it is focusable, so you can make the dot as small as you desire.

Thanks for the help guys. I have a couple more questions, both about the lasers available on that specific site and some I've found since.

The one you linked to is 5mW. They also have a 1mW of what appears to be the same thing otherwise at 650nm 1mW 8x13mm Laser Module with Focusable Lens, AixiZ for basically the same price. Would that be better? (I'm thinking safety and battery drain versus being able to see the dot.) Could either/both be safely run from 2 AA or AAA batteries? Does anybody know where I could find one of those plastic battery holding thingies with the wire leads coming off? (Yeah, that's the technical term for em. )

Also, does the brand of the laser matter much? I've seen some chinese import sites that have lasers with similar specs as the 5mW above for $5 for 4 of em, but also understand that there may well be internal differences that make the ones referenced above better. I've found some of the chinese direct-import stuff to be the same as the name brand and some is absolute crap. For example, the button-cell batteries for my digital calipers are the same price for a pack of 50 as a single battery is bought locally.

I also found the following gizmo that shows as being in stock locally - any thoughts on it? Laser Marker (It's probably not focusable and would be MUCH bigger/heavier, but it is local so I could start using it right away.)

Finally, does anyone have any coupons for Aixiz, maybe free shipping? ($4 for a laser and $3 to ship it seems silly.)

If you feel safer with 1mw you can go with it. Not exactly sure on how bright it is, but should be bright enough for you to see it.

They both take 3.2V input, so you'll be fine.

You can easily pick up battery holders at Radioshack, or you could find them online with a simple search.

At this power, the brand is irrelevant. With chinese suppliers the lasers in this power range could easily be overspec as well.

Looks like it'd work. No need to have it focusable really as long as it is focused on infinity. Only draw-back is that it uses button cells.

Both lasers will take very little current, I would not worry about battery life. You can also go for regulated power source.
If you use good lighting, as I would expect .. like for example 100W lightbulb from rather close .. I think 1mW might not be all that well visible.
For the money, get both.

Thanks for all the advice guys. I posted on a woodworking forum, asking about what power lasers are used in the professional captive rig hollowing systems. There were several replies which indicated they knew by my question what I wanted to make. One suggested a laser marketed as a pet toy at the dollar store. Stopped on my way home & got a <1mW laser pointer that takes 3 LR44 button cell batteries for a buck. Threads on the battery cover are crap, but I just taped it shut and am good to go. (So much easier than what I was planning with the lasers referenced above...)

Thanks again for all the input.