mod eliminates parallax error

[Ljohnsaw]

Thanks!

[burlybee]

If you got the focusable laser, you will want to focus it to get a strong fine line.  Turn the lens until the line is as fine as possible on your scale.  Then put a drop of locktite on the lens threads.  Then loosen the laser holder and rotate the laser until it makes a level line on your scale.  Lock it down.  Done.

[burlybee]

This laser scale has been working flawlessly for 2 years now.  I was expecting the laser module to fail, so I bought spares to switch it out quickly.  That hasn't been needed.  I also had some custom scales printed at one of those places that makes the big magnetic signs for cars and vans.  I wasn't sure if they would come back accurate, but they did.  Now I just slap on whatever scale fits the job at hand.  Unused scales stick to the sawmill out of the way.  Another thing that has turned out to be real handy is that I can slide the magnetic scale to wherever the laser is currently pointing and then make my next cut off of that.  Just drop it on a line and move the mill to the next line.  It is so fast and simple.  I used a spreadsheet to calculate the kerf and shrinkage for the woods I cut here.  I can use one scale for Douglas Fir and another for Oak.  I'm having fun!

[burlybee]

When I wrote this post, I suggested using a 7805 voltage regulator.  Those are common on circuit boards, and it is what I used.  Since I probably have a lot more circuit board experience than most people who would be adding a laser to the sawmill scale, I would suggest a buck converter instead.  The cost is about $12 instead of $6.  The advantage is that it is a little box with screw tabs on the ends and four labeled wires sticking out.  You can attach it with plain old nut screws.  Two wires go the the battery and two wires go to the laser.  Just be sure to put the 12 volt wires on the battery and the 5 volt wires on the laser. :D


 

[burlybee]

Here is a picture of the quick magnetic scales.  I think that they came out looking really good. 

 Enjoy.

[Nebraska]

I think you could market them.  The scale looks awesome. 

[Ianab]

The buck converter is a much tidier solution, and more power efficient. The 7805 style  regulator is a linear regulator, and simply steps down the voltage while keeping the current draw the same. The difference goes as heat, hence the heatsink tab on the chip. The buck converter uses high frequency switching MOSFETS and inductance / capacitance filtering to achieve a similar result, but can be maybe 90% power efficient. So 1 Amp output at 5V should only need 0.5 Amp input at 12 volts, and very little heat wasted in the conversion. 

Probably not an issue in a sawmill application, but this sort of circuit is widely used in computers / cellphones etc to produce the various voltage rails the different chips need, without wasting battery power and making excess heat. 

[Ljohnsaw]

Here is a picture of the quick magnetic scales.

Printed or vinyl stencil?  Are the scales coated with anything?  Assuming waterproof but wondering about fading in the sun, too.

[burlybee]

It is printed vinyl magnetic sign stuff.  The same stuff the magnetic signs on cars are made of.  Since it is made to be in the weather and sun it has weathered well on my sawmill.  I think it is printed with a plastic coating over everything.

I generated the graduated measurements in a spreadsheet and then did the layout in CAD.  I printed to PDF at 100% scale and emailed it to one of those companies that makes magnetic signs for cars.  I wasn't sure it would come out printed to scale well, but it did.  I laid out 6 of them in the PDF and separated them with a razor knife and straight edge.  They have lasted very well so far.  Each is just over 36" (limit of my mill) tall.

[never finished]

 I finely did it. And now I'm kicking myself for not doing it sooner. Not really. It's how I do everything. But truly it works as good as advertised. It improved my sawing considerably. I love this place.

[Ljohnsaw]

So I've been using my laser guide for 3 years without issues. Then one day last week, nothing.

I used spade connectors so I easily pulled it out. Put it on a battery to test it. Nope, not working. Checked the regulator output, 0. Then I started smelling something hot. The regulator was cooking. I might have hooked it up wrong. Figured it was toast.

When I bought my supplies, I got 3 lasers and 10 regulators. I wired up a new regulator and tested the old laser, dead. I think the laser died and I killed the regulator.

Anyhow, built up a new set to install whenever the rain stops in the next day or two.