Una mierda

Hi! Amazing video! is there a parametric version ??

le feu

What silicone are you using for this? This is great!

Looks gay 👍

This got randomly recommended to me. What's the goal here?

cool 👍

Very useful !!!! thanks

Man this video is the most thorough of all that I seen on this subject. Good job! P.S: your sneezing made me lough so hard lol

I'd say that the version 2.0 should work like a battery as well, so, should comes with at least 3 gears, and the first one and 2nd one to just speed it up enough to grab a momentum and 3rd gear should work like a flywheel. Count the maximum torque and use less to always stay on the go. This way, you'll use less energy than here and can easily charge that iMac ;), or laptop. Plus, if you'd think o removing the friction, you can gain even more ;).

Nice! Great instructable.

code monkey wheel!

I am busy making a F-Theta lens for a laser galvo system. 405nm. The plan is to cover a 200mm x 200mm area with 15 bit resolution (32768 positions). The laser moves at around 200mm per second. This requires custom electronics to measure the galvo feedback at 16 bit resolution and a FPGA as PWM generator. The FPGA runs at 260MHz. At 15 bit resolution the step size is +-25um and it moves at almost 8000 steps per second. The FPGA also takes care of H-bridge dead time. The control loop is done with an ESP32 that runs on a 16kHz cycle. Each cycle both galvo positions are read and the PWM adjustment is calculated and sent via SPI to the FPGA. In the CPU spare time the SDcard is read and the data is queued for the next cycle. It runs nearly asynchronously from the control loop. The laser is from a 405nm 500mW module. The output power is actually much lower as the photographic material I use is quite sensitive. The beam is first collimated/expanded. An expanded beam stays collimated over a longer distance, thus I don't need the laser source that close to the first galvo mirror. The beam expander also controls the final focus of the beam. The laser spot size is around 25um to 30um when it reaches the photographic material. There are other issues to consider. The laser origen is diode based. Thus it looks like a bar/rectangle. Generally that does not matter when engraving but does when small features, like 50um lines, are drawn. I normally orientate the laser diode diagonally so the vertical and horizontal lines have the same width in both directions. It is only thinner in one diagonal direction, which is handled in the software. The next issue is light-bleed in the photographic material. This means if a 25um spot is flashed that the material will be slightly wider exposed to e.g. 30um. This must be handled in the CAM software exactly like additional kerf caused by spindle/tool runout. Now the acrylic lens part. The lens is fairly large and thick. 250mm x 250mm x 20mm. I have written ray tracing software to project a perpendicular beam (from the target surface), though the lens to the galvo mirror surface. At 405nm acrylic has a higher refractive index, so that must be kept in mind as well. The software then runs through all possible projections and figures out what the lens must look like to satisfy the beam requirement. Luckily this only needs to be done in 2D as any rotation of the lens yields the same results. Thus, in the end, I end up with a profile to be cut. I then import that into OpenSCAD and generate a 3D surface spinning the profile 360 degrees. I must do this for both sides of the lens. The model is then exported in STL format that I can then import in a CAM program. I have made smaller test lenses and so far they look and perform quite well. But the method of machining does have an influence. I have used ESTLCam (very nice and cost effective CAM software). However, it cuts the profile using straight lines. I would like to do it in circles and it seems I will have to write my own software to get that to work. But straight lines are not all bad. My CNC uses ball screws but these still have backlash in the order of 30um. You cannot feel it by tugging on the machine but you can see it on the material, under a microscope. Going in circular movements gives a better final smoothing pass but at the cost of many small backlash errors. With straight lines the motors are backed off for a few steps(on the sides) before cutting. This results in the axis nut and first bearing block being preloaded with no backlash artifacts. Moving in the other direction requires either to skip machining(to origen) or subtracting the system backlash value. The Z axis is generally not a problem as the weight of the spindle takes up the slack. To polish the lens I start off with 400 grit sand paper. I also have loose abrasive powder that I use in concave areas. Then I just go up until 1200 grit. 2000 grit paper feels like a waste of time. Above 1200 grit I move over to Brasso. I find that if I use a motorized buffer that it burns/melts the acrylic. Generally it requires a lot of patience. My next abrasive is a product called Silvo (obviously for silverware). It has smaller particles(well, it feel so). This gets me very close to the ideal optical properties. I have also used a coloured car polish that gives a near mirror finish. Some people have suggested that I flame polish the surface. But many others have warned me against it. Sure, the surface will be nice and flat but the heat can cause the refractive index to change in different spots, ruining the lens for this specific application. Lastly, and this I only found out a few years ago, is that there is a huge difference between cast and extruded acrylic. Extruded acrylic is much cheaper. This is normally the type you will find in hardware stores. The problem is that extruded acrylic has a lot of internal stresses. E.g. if you laser cut it and then glue the parts with acrylic glue the parts can actually warp and crack. I assume, for lenses, the same apply for issues in refractive indexes. I don't know if it is possible to relax stresses by heating/annealing the material. So, it is just more convenient to just buy cast acrylic. The one question I regularly get is "why don't you just buy a lens off the shelf? ". Apart from the cost ($1500 to $3000 from a local supplier) the lens is glass based, AR coated, optically near perfect and looks professional...and will work from the start. Well, I would chalk it up as being stubborn. I have the CNC equipment and I am a sucker for punishment. Plus, if I get it to work I can remake those lenses for around $15 material cost. I also build my own galvos for just over $10. This means that if the product is successful I can reproduce the machines at very low cost for my own production lines. Apart from my photographic requirement the lens (slightly altered) will also work with higher powered 450nm and other visible lasers. Then there is also the advantage that I can expose much larger areas than commercial lenses. One last thing. There is a epoxy product a company is selling as a "lens replacement plastic". The idea is to make copies of e.g. obsolete car light fittings using rubber moulds. My question is if one could mould a basic lens (slightly over size), then CNC/polish it...or just cast a functional lens from it?

I guess Stanley Kubrick really was ahead of his time.

Thanks very much dude, nice tutorial! Hope you are better from that coughing !!! :)

Thanks for the knowledge. Your personality and voice are insufferable.

kzbin.info/www/bejne/fKHVd3umj9-ZbMk

Sick video, thanks for sharing this bro.

Супер идея для программистов

"Google, show me a depressing metaphor."

haha!😂😂

Me encantó! Cómo se ensambla la base? Necesito una para mí y para nuestros 26 gatos 😻💞. Saludos desde MTY. México.

Are these purchasable?

"I'm gonna move this back so that it's not proud of it's friends" ..."Wait that's a sad sentence" "EVERYONE SHOULD BE PROUD OF THEIR FRIENDS" I laughed hard

brilliant tutorial!

I learned a lot, especially from all the mistakes! :) great video! (no sarcasm)

Jesus. How many times a month does this prick have his car keyed?

Nice.

I hate that fusss... You could make that silent in editing..

Swag 😩😩

Me switching between female , make , and non-binary : uhm... Shit

Now you just need a water bottle with a metal spout hanging down that you lick the bottom of to get water.

El compañero preciosa hizo realmente encantador. Nuestro amigo Djungario ocupado mueve también linda. El mío es tan lindo como el suyo.🐹🥰

I can see production quality here^^ keep it up

Bring back the cryoscope!

Great idea

Great video. Now a question: how do you transform all the components into one flat surface for cnc milling?

Thank you so much This has helped me a lot!

Great job! Now try the Arabic alphabet!

Thanks!

Great video

If newton could do it with primitive equipment, we should be walking on clouds with our access to tools. 👍🏼👍🏼👍🏼 great video

Bruh I thought I was high I didn't know it moved

Валенки, что тут сказать..

I would add a bicycle brake to manage the speed/stop.

Here is a link to the file. a360.co/2PnbFMe

Made lots of these. Look up 'telescope mirror grinding', for how to hold the blank without distorting it. The polish you are doing is going to look great - until you try and use it as a lens. What you do with plastic polish, and by the way Brasso works as well, is melt the surface a bit. It's shiny, but it's not an optical finish. To be able to focus a really sharp image, look up 'how my spectacles are made..' or whatever. You make a 'lap', use loads of slurry of polish in water, and by hand it will take ages. Acrylic changes it's properties optically when sawn and drilled. Likewise, on the mill or lathe, use coolant. Also make some plaster tools that have the right curve cast into them. Double-side tape the wet and dry paper cut into petal shapes. Etc etc. I admit it's great fun to turn your shed or bedroom or classroom into a camera obscura, with a big plastic lens you made yourself. Even if it isn't perfect.

I like this :3

Robb, Are you planning on building these again? I really like the idea of this project.

WOW! its surprising me... Have any DIYer know about DIY SmartDesk Kit from Autonomous?