DIY Laser levelling using webcam and laser level

[John McNamara]

Hi All

Gee who would have thought this thread would have generated so much interest.

I am tempted to bring up the possibility of automating bed machining using software!

The following is just first draft of a possible solution. My plan is to level the surface by milling small sections of the bearing surface in an overlapping grid pattern. When finished the surface would look a little like hand scraping. As each "Peck" was made after aligning the cutting head to the laser or stretched wire. Once the cutting cycle is complete the surface flatness would be equal to any errors in the measurement system that we already know is pretty good from the experiments done so far my a number of testers. A final stoning of the machined surface would remove any high spots. Note the cutting head is aligned to the measurement system not the rail it slides on.

A quite small milling head with a small cutter (5 - 8mm) traversed along the bed using the rails to be later used on the machine itself temporarily fixed to the sides of the in your case 80x80 rail support frame.

I don't plan on using a high speed spindle just a simple Import
https://www.ebay.com/sch/i.html?_fro...motor&_sacat=0

It would need 4 axis.
One controlled by the leveling software

One that rotates the cutter head to vertical (Leveling IC's are cheap) a small stepper. The leveling could be done with 3 steppers for complete control or just one if only levelling transversely across the rail in the x direction. Therefore only one small stepper required.

One to drive the cutter head down and make a peck. Another small stepper and a simple screw drive ball screw not needed just low backlash.

One to move the small cutter across the work. the X axis has very limited travel maybe 50mm maximum.

There would also need to be a longitudinal drive.
Ideally using the timing belts to keep the cost down.
This drive could use the drive motor later to be used in the machine.

So the sequence would be:
Starting with the cutter head in the up position.

Move along the rail to the next cutting "peck"
Level the head

Find the center point with the alignment software to align the attached cutting head.
Move the cutter head down #N steps to engage the work.

Retract the cutter head.

Repeat cycle.

The temporarily fitted rails would only need to be roughly aligned. Within say 2mm Ideally 1mm. Not that hard, it can be done with simple measuring tools.

The accuracy of the system is derived from the measuring system not the supports for the temporary fitted rails.

I imagine that the mounting face of the Box tubes would be coated with a strip of say 5mm thick and wide enough to fit the rails, to be be machined flat with A mixture of epoxy and metal powder.
Easier to machine than steel. Thin box sections are often bowed. You don't want to weaken them.

I posted this a while back. I still run the lathe on the material. Inexpensive to prepare. For non sliding Iron or Aluminium powder alone and epoxy would be fine.
https://www.cnczone.com/forums/epoxy...al-method.html

If a few people are interested I would have a crack at drawing up a design that mainly uses laser cut sheet steel parts ground rod and Asian bearings for the Simple jig needed. Anyone could download the files and send them off for cutting to their local cutting shop. It will be quite small so low cost.

I am not planning a servo driven XY axis just point to point positioning via steppers,
An Arduino or similar processor could easily drive all the above.

Regards
John