Tricks for Positioning without rulers?

[Dave Johnson29]

My issue is I normally put something like this against the rulers but the rectangular plaques are rounded on the face and the back edge, so the edge is higher than my ruler and I can't butt it.

Hi Jackie,

May be too little too late but here is what I have. The rulers are at the bottom for flat stuff, then I have spacers (nuts) to support 1-1/2" x 1/16" aluminum angle. The angle is on the spacers so I can get a good draft-through for smoke removal when doing flat stuff. The slots in the aluminum also allow good draft with taller stuff.

I machined up the angle a few months back and it all works well without the need for any adjusting or swapping things out. You can get a better look at the angle in this older posting.
http://www.sawmillcreek.org/showpost...80&postcount=1

When the beam is focused on the bare table top, the bottom of my lens mount is about 1/4" above the top of the angle for clearance.

[Richard Rumancik]

When I am in a hurry and there is only one item I often park a piece of plywood or MDF up to the rulers, plot the plaque or part outline, and set the plaque into place. Many of you seem to be doing something similar.

But when doing several items, and where I can't afford to have an error, I use a different approach. In that case I screw the MDF down to the table so it cannot move. (I drilled four holes into my aluminum table to accomodate screws.) Then I know that movement of the fixture is eliminated.

Then I plot the outline on the MDF from the file. I then attach "stops" right up to the line. They can be wood blocks or acrylic blocks. It can be handy to make them with slots if you want them to be adjustable. Three blocks are adequate (two on the long edge and one on the short edge.) I use a battery powered drill to make a few holes in the MDF for the stops and then screw them down with washers and wood screws.

If there is a chamfer or radius on the underside of the plaque, the block is thick enough so that is not an issue.

In some cases I apply another special block to force the plaque into the "corner" and keep it from moving outwards from the stops.

If I have to set up the same job again, I would not use the old lines. I would move the image on the screen and replot my outline again. If the MDF gets a few too many lines you can spray paint it and keep using it.

By moving the working area out from (0,0) to say (6,6) I find that I can see the work much better.

[Brian Robison]

I made a fixture years ago out of 3/4" ply wood with 2 pieces of wood ( 1 x I think) sticking up about 1" on the top and left sides (0,0 corner). The plywood fits square in the corner. I made sure the wood was up just high enough to clear the rulers. No Math! I bet I've used it thousands of times.

[Shaddy Dedmore]

If you take Martin's idea and raise the tabs you can slide his jig against the rulers and still have the laser's 0-0 point.

Do this, it's pretty easy really, and you don't have to make changes to your 0,0.

Take a 1/2 or 3/4" piece of ply or MDF then butt it up to where your rulers are, then take a thin piece of anything, even more ply would work, 1/8 or 1/4 then staple, nail, glue it to the edges over your rulers. up on it's edge would be best... so...

cut a rectangular piece of wood for a base, 1/2-3/4" that fits your table. then cut some thinner pieces like 1.5" x 12" x 1/4" change the 1.5" to the height needed to match the piece you're needing to position

Put large piece in place, snugged up to rulers, then put smaller pieces in place, on edge, up against the larger piece (covering up a little of the ruler) then affix it somehow, screw, glue, nail, staple.

there you have it.

Shaddy

[Bill Cunningham]

Anything that will butt up against your rulers, but is still higher than your rulers will work.. Scrap wood/mdf, thicker plastic, ..etc..