Need instructions on how to calibrate a dwo77 dewalt laser

Contact DeWALT directly to request the manual.

An arc, as in low on both extreme's and high in the middle, would be caused by a deformity in the lens or protect glass.
If you mean low on one side, and high on the other, than it's a calibration issue.
Either way, these are not repairable units, and you should contact Dewalt and they will likely tell you how to go about getting a replacement.

Set it up and shoot 4 level points around the laser . Like at 12 -3-6and 9 o clock. Move the laser 15 or 20 ft from where it is now and re-shoot those 4 points again .if they don't read level then your laser needs calibrated

You have to remove the module from the instrument

You can not calibrate the Laser in the field it needs to be sent to a dewalt service center however you can check the calibration to see if it is off

download the manual here with instructions on how to check it

No unless you got the calibrating tool.

Here is a link for the owners manual for that particular laser. http://www.dewaltservicenet.com/documents/English/Instruction%20Manual/593338-00,DW086.pdf
In there are the instructions for a Field Calibration Test. These units should be sent to DeWalt Factory Service for Calibration. If the unit is less than 1 year old they should calibrate it for free under their "1 Year Free Service" warranty.

Hi,
To find a service center near you please click on the link below. When you get to the Dewalt site enter your info in the search pane on the right.

http://www.dewalt.com/us/service/center_finder.asp

Hope this helps,
RSMITH972278
P.S. PLEASE RATE MY ASSISTANCE

this unit does not have any replaceable parts, if the unis is covered by warranty, it would be exchange, if not then check with your local servicenter the max rate program to do so.

Sounds like you figured this out on your own. I calibrate my own DW073 regularly without any fancy gadgets. I use the calibration check procedure in which the unit is placed about midway between fixed objects 100' apart.

These have a front and back and sides, so first you mark where the laser hits facing front to back at your targets. Then turn it 180 deg. relevel and resite. If the difference between the new and old marks is not the same then I turn the adjuster to halve the inconsistency and once that is accomplished, tweek the adjusting screw at the end of the level vial. (Because if you have adjusted more than the tiniest bit, the bubble will no longer display as level. So having established level, or closer to it, the adjustment here is actually to bring the relevant bubble vial back to level rather than assume they are level and adjust the physical beam mechanism (unlike the old physical sight levels where you adjusted the actual optics -- a little more like adjusting a rifle scope). Then you repeat for the side to side vial.

Anyway sounds like you are set so I posted this for anyone who happens to find this thread and is looking to field calibrate their DW073, e.g. don't have time or money to get it done in some shop.

I also wanted to post an add on question. Did you figure out how to adjust the "cone error", i.e. the accuracy of alignment of the twin lasers. They appear to have allen set screws that lock their adjustment, and maybe they are then reaimed by using a slotted screwdriver on the brass ring surrounding the laser. Maybe these are made eccentrically or slightly beveled so turning the laser reaims.

So far, my cone has stayed within the specs of 3/32" at 25' in the manual. But I'm seeing two lines at maybe 150' out. Probably that is close enough for gvmt. work, and I may find the adjusment so sensitive that I can't really get it any closer. But I'd at least be interested to know the method for adjusting the cone error.

Thanks,

Brian