DIY Laser levelling using webcam and laser level

[Michael Gilligan]

Good to see you back, John

This design is only a single axis level, not a plumb ... but it might provide some inspiration.
https://www.allaboutcircuits.com/ind...leveling-tool/

MichaelG.

[Mud]

Just wanted to say thanks for the software - I used 0.26mm black fishing line and I would conservatively say I got my reference rail straight to within +/-5% of the line thickness with only manual adjustment (i.e. no fancy cams) without much bother. I did have trouble with reflections on the black line, so could not rely on the red/green/red gauge - I resorted to tape on my screen!

Image attached to show my lazy setup - whilst I wouldn't recommend ABS for metrology (nor my tape on the screen method) the idea clearly is a good one!

[leolfs]

Hi all,
first post.
If a digital output could be made available to indicate a when the wire is centered in the view field, then this would make a fantastic home switch for a variety of projects If coupled to say mach3. Presumably the axis would need to overshoot somewhat so as to detect the slope of the signal, but if this is consistent it would not matter. If all this could run on a RPi it could be a better alternative to any switch or sensor. .As this is beyond my skill level I wonder if the developer might be interested in adding this feature?
Regards....Leo

[John McNamara]

Hi Joe
Hi All

Also see previous post LeoLFS

If you are wondering what we have been doing while holed up due to Covid the following design has occupied us for quite a while. I am also halfway through moving house.

The attached images show the CAD drawings for a machine that uses a microscope and two suspended wires to generate a reference plane. The wires are tensioned by a heavy weight suspended in a container of oil. Gravity will assure that the wires are parallel and coplanar. Music wire is easily obtainable down to about 0.003inches. The thickness is consistent and accurate to sub microns.

A microscope on each side of the carriage is used to position a cutting head that is used to machine a plane surface on the workpiece. It is planned that this is done using software.

The spindle carries a small cutter 2 to 3 mm in diameter. It will have two modes: one a small peck cut, then a re-reference of the wires by the software and a small positioning move of about half the cutter diameter then a cut. This will be the slowest mode however due to the averaging effect of so many small measurements (not unlike hand scraping), it is expected that this will create a very high quality result.

The second mode will create a reset of the carriage on a line by line basis. This will be considerably faster.

The plane of the wire and the cutting plane are aligned. As shown, the moving crossmember carries a platform that is aligned to the wires. The main frame of the machine is 2 x 100mm square tubes. Yes, there are no precision rails: the crossmember rides on ball bearings firmly against the frame tubes. It is certain that the tubes will have a small amount of curvature as delivered by the factory that made them. It certain therefore that there will be a small “tramming” error as the carriage moves up and down the tubes. This has been considered carefully. With the small cutter diameter planned the tilt error will be very small. Remember that the cutter height is aligned to the wires. Commercial tube suppliers in Australia quote a straightness error of about 0.5mm per meter, so with a very large radius - 250m - the error will be very small indeed.

The machine has been designed to use laser cut 5mm steel, assembled by the tab and slot and bolt method. No welding will be used to avoid distortion. This method has proven itself in many past projects. The x across motion is guided by 500mm linear rails - these need to be shimmed straight. Drive is via a 16mm ballscrew. The total travel across is 220mm, however in most cases the machined surface will be between 25 and 50mm. As shown a 100x100mm workpiece is mounted Blue and Red. Using a different clamp tubes up to 200mm square can be accommodated.

The spindle motion in and out is mounted on 300mm linear rails. Travel is 120mm to allow for easy cutter changing. In use the total travel will be a few mm as the spindle moves in and out of a cut. It is driven by a 16mm ballscrew.

The carriage moves up and down the column using a 50:1 Asian worm drive gearbox (Not shown) and counterbalanced 20mm T2.5 synchronised timing belts.

All drives are step motors.
It was not intended to create a general purpose CNC machine. This allows a much-simplified drive system. Only the precision needed to create small overlapping cuts to create a flat surface was considered.

As you can see there are two people contributing to this machine design The CAD by myself and control system design by LeoLFS We have been mates for a decade or two. The machine is made possible by the excellent software developed by Joe,” Devmonkey”

For a single builder some of the parts can be reused in the final machine they build. Or better still a few enthusiasts can team together and share its use.
We are well on the way to assembling a prototype with many parts in hand.

Once the design is finalised I will place the plans on Grabcad.

Regards
John

[Kitwn]

Great to hear from you again John. I have now completed my move to Tasmania and am in the process of reasssembling my own machine on a new, more rigid frame in between all the other jobs that go with a new house and garden. I'll be using the taught wires method inspired by yourself again to get it back in 'reasonable' alignment. I think there's what may be described as a wide margin between your construction methods and mine but I follow your progress with great interest.

That looks like a machine that people might wish to borrow or hire once you have it made and working.

Kit

[John McNamara]

Hi All
I uploaded version 28 to Grabcad replacing version 25
Regards
John

[leolfs]

SOS devmonkey!
I've got together with John McNamara to implement his great mechanical design. I need to level long lengths of RHS for several router?laser projects. We are ready to cut and assemble the first two units for John and myself.(I live several hundred kilometres away) But... where is devmonkey? We are hoping he could make his great (but to me impenetrable) program output the wire zero to a physical output. We are hoping to use his code for 2 cameras on a rPi which could be used as a reference for a simple mach3 controller routine. If you are out there we would really appreciate your help.
I have come across a paper (Oleg Borisov) that uses a cheap slotted photodetector to produce some impressive accuracy that I may be able to reproduce, but the webcam seems to me the best option.
Hope to hear from you devmonkey.

[lmclaren]

Hi leolfs, do you still need help with the sw?

I am not a great coder but might be able to phone a friend...

[John McNamara]

Hi Imclaren

Your timing is good Leolfs and I have been discussing getting the project underway, We have already purchased the ball screws and linear rails. the initial design for the laser cut components is complete.

The need is to connect the machine to devmonkeys software he that he outputs to the screen, fairly simple I guess once we get a handle on the code he posted.

Any contribution will be appreciated.

I do hope devmonkey is well, if anyone knows him personally send him my regards.

Regards
John

[lmclaren]

Hi Imclaren

Your timing is good Leolfs and I have been discussing getting the project underway, We have already purchased the ball screws and linear rails. the initial design for the laser cut components is complete.

The need is to connect the machine to devmonkeys software he that he outputs to the screen, fairly simple I guess once we get a handle on the code he posted.

Any contribution will be appreciated.

I do hope devmonkey is well, if anyone knows him personally send him my regards.

Regards
John

What sort of output would you like?
I am guessing that the error signal that is shown as a bar on the right is what you are after?
Are you running this on specific hardware that has a suitable hardware output or would you like a serial data stream from a comm port with an error value?

What sort of input does your motor controller want? step / dir or error signal?