DIY Laser levelling using webcam and laser level

[John McNamara]

Hi Joe

The measuring system is just a manually driven XYZ platform

Once set up I only move the webcam The light is at this time fixed and non moving. This is wrong! it should move with the webcam sensor although a 0.25mm movement is pretty small slightly less than 0.010 inches. I am going to work on the light next.

And yes I clicked measure after each movement to the next tick on the dial indicator. The straight line is proof that the system is linear. Subject to my possible manual positioning errors as detailed in my previous post.

And the results we are getting are better and better, once the lighting is sorted I am certain the repeatable accuracy can be improved. Once this is done I really want to try a higher resolution webcam.

Regards
John

[John McNamara]

Hi Joe

Just noticed your comment re the catenary sag. Adding this feature to your software will make it exceptional.

The formula is widely cited the Wiki in this case is a good place to start.
https://en.wikipedia.org/wiki/Catenary#Equation

Once your measurement table is filled with points and the user has input a length The catenary sag allowance at each point can be added to the table. The weight of the wire and the tension applied to it need to be added, they do not change so can be stored constants.

Regards
John

[John McNamara]

Hi Joe

Correction this line my post above
"
The weight of the wire and the tension applied to it need to be added, they do not change so can be stored constants.
"

Should read
The weight of the wire does change according to its length.

Roslau are are a world leader in music wire manufacture.

This is where I sourced my wire. https://parkepianostrings.com.au/pia...als-and-tools/
It costs about $40 AUD per coil plus post. they will ship internationally.

Half KG coils of #2 .010" Roslau Blue music wire contain 1250 metres of wire.

Regards
John

[John McNamara]

Hi All

Today I received a nice webcam in the mail, a gift from a forum member,Thank you.

It uses a smaller sensor than mine so it will be interesting to see how it performs. I will have to make a new mount for it.
For the tests I will use a one micron Maher milemess indicator. that should assist in getting an even better idea of achievable accuracy.

For any members who live in Australia I will be at the MSME exhibition.
https://www.msmee.org.au/

Our club has been meeting since 1926 in Melbourne new members are always welcome.
Or just pop in at out next meeting as a visitor and have a chat.

Regards
John

[Kitwn]

John,
I have found a dirt cheap webcam online which is very easy to dismantle which I plan to play with once my more urgent project of working out how to successfully cut wooden gears proves fruitful.

Much as I'd love to come and see you at the MSME I'm afraid it's a bit of a long way from here, even though I don't need to show my passport enroute.

Kit

[cropwell]

Hi Kit,

Inkscape has an add-on that will draw involute toothed gears and gear racks. I have used this to input a dxf into Fusion360 to extrude it to an stl for 3D printing. I haven't yet had the need to cnc cut one though. If you want helical cut teeth you are on your own.

Cheers,

Rob

[Kitwn]

Rob,
Thanks for the information but I use a rather splendid bit of software called 'gearotic' written by Art Fenerty, the creator of MACH3. For anybody interested in creating gears of any kind you can think of, and several kinds you previously couldn't, and especially anyone who wants to design wooden clocks I can heartily recommend it. The program, not unlike Art himself, is a little eccentric and is therefore, in my humble opinion, well suited to many of the regular contributors to MYCNCUK The one-off, minimal license fee entitles you to a lifetime of free upgrades.

Gearotic is brilliant for creating the basic gear design. I then export a DXF file to CamBam for design editing and G-code output.

My problem in cutting wooden gears is that those teeth that have the grain running tangential to the gear wheel tend to chip and break off when cutting. Teeth with the grain running radially are fine. I have managed to successfully cut gears from Jarrah blanks created from six segments with the grain running radially all round but the wastage of timber is criminal. I'm currently experimenting with plain pine blanks stabilised with Cactus Juice resin.

Most wooden clock makers use plywood for the gears but, being me, I want to use various types of better-looking plain timber to produce a more impressive result.

I had thought about starting a new thread asking for help on how to cut these gears if the current experiments don't work. I'd prefer not to hijack this existing discussion.

Kit