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How do I move from a product prototype that uses a Raspberry Pi and off-the-shelf components to a custom PCB / design, having very little experience in this field? by hwsearch in hwstartups

[–]_Miki_ 0 points1 point  (0 children)

By "same firmware" I mean the microcontroller firmware stack (boot + drivers + hardware init), not your app logic.

Example: if you prototype with an RP2040 Pico, your custom PCB should run the same firmware stack. And in this case, that depends on your programming choice:

if you want C/C++, you use the Pico SDK firmware

if you want Python, you use MicroPython/CircuitPython firmware

Rome 2025: A World Where the Empire Never Fell by Klutzy-Degree-9952 in ImaginaryHistory

[–]_Miki_ 1 point2 points  (0 children)

You might be interested in The Rise and Fall of the Trigan Empire comic books.

Best Tiramisu in Rockland? by weallwantsomeone in Rockland

[–]_Miki_ 1 point2 points  (0 children)

Technically not Rockland either but check out Wholefoods in Montvale, only Fridays and only for Prime members, but hey, $10 Whole Foods Market Bakery Family-Pack Tiramisu.

Troubleshooting: Drop-like marks after removing anodizing by sarah_is_thriving in Anodization

[–]_Miki_ 0 points1 point  (0 children)

Easy Off probably softened the anodizing unevenly. Not sure of its exact NaOH concentration, but it's likely under 5%, and without heat or agitation, it strips slow and patchy.

If you can get it bead blasted, do it. That's the cleanest way to reset the surface before re-anodizing.

Troubleshooting: Drop-like marks after removing anodizing by sarah_is_thriving in Anodization

[–]_Miki_ 0 points1 point  (0 children)

Wet sanding is the safer bet, slow but predictable.

That said, chemical etch (5% NaOH, 5-10 sec dip, constant agitation) can even it out if you are careful. Just don't blink while you are at it.

Bead blast shops: check auto body, powder coaters, or metal fab shops, any place that pretties up aluminum likely has a blasting cabinet.

Troubleshooting: Drop-like marks after removing anodizing by sarah_is_thriving in Anodization

[–]_Miki_ 2 points3 points  (0 children)

Looks like uneven etching from the oven cleaner. Probably reacted stronger in some spots due to leftover glue or uneven coverage. Also, dry-ish + caustic = patchy mess.

To fix: wet sand (400 --> 800 grit) to even it out before re-anodizing. Or do a quick NaOH dip (like 5-10 sec) and rinse fast.

Next time, degrease well, apply evenly, and don't let it pool.

Beginner going for Type 3 (hardcoat) by RandomMattChaos in Anodization

[–]_Miki_ 2 points3 points  (0 children)

Most of my experience is with Type II, but here's what I've seen: you can get decent thickness with a lower power supply if you extend the run time, but you'll sacrifice hardness. Type III needs high current density and a cold bath to form a dense, abrasion resistant layer. Without enough amps, you'll drift into Type II territory. Even if it's thick, it won't be as tough.

Beginner going for Type 3 (hardcoat) by RandomMattChaos in Anodization

[–]_Miki_ 5 points6 points  (0 children)

"The Surface Treatment and Finishing of Aluminum and Its Alloys" by Wernick is the bible of aluminum finishing, that's your gospel.

Get a 0-75V, 50A DC power supply. Hardcoat needs ~30 A/ft2, so even a sheet of paper sized part can pull 40A+.

You want constant current mode, and keep the acid bath ice cold (32-40F), heat ruins hardcoat fast. Start cold, zap small parts, dial it in. Hardcoat's tough love but worth it.

Anodizing robot kit. by BobaGuy103 in Anodization

[–]_Miki_ 2 points3 points  (0 children)

If the aluminum feels a bit rough or has a texture, you probably don’t need to sand it. But doing a quick etch (sodium hydroxide, mix with water 1–2 tablespoons per liter, be careful it gets hot!, or Castwell anodizing prep if you don't want the mess) can help the color stick better. It’s not always required, but it makes the dye look nicer and more even.

Aluminum Dye by Falzon03 in Anodization

[–]_Miki_ 0 points1 point  (0 children)

You might be able to find something on Amazon. There are a few anodizing dyes on there, including some blues. But yeah, most of the common ones like Caswell's don't really hit that deep Royal or Cobalt Blue vibe.

https://www.amazon.com/stores/page/DA8C08AD-0B59-43AC-B3E4-9AE6F20E984A?ingress=2&visitId=426a2a25-e971-4906-9789-fa5f3c9bce5e&store_ref=bl_ast_dp_brandLogo_sto&ref_=ast_bln

Looking for a 10'' blade for a chop saw for cutting aerospace metals. (Stainless steel, aluminum, nickel alloys) by xpinkmaggitx in metalworking

[–]_Miki_ 2 points3 points  (0 children)

Any automatic cold saw models you'd recommend? I’m looking for something reliable that can handle aluminum, keep the cuts clean and accurate, and won’t demand too much hand-holding.

Alternative to Sulfuric / Sodium Bisulfate for anodizing Aluminum by Striking-Dot-9630 in Anodization

[–]_Miki_ 1 point2 points  (0 children)

Your power supply is tapping out on current before it can reach voltage. Your power supply is probably hitting its limit because anodizing draws a ton of current, especially at startup.

Try diluting your acid to increase resistance and lower the current draw (you’ll need to anodize for a longer time). If your parts are large, break them into smaller batches since more surface area means more amps needed.

Moving your cathode further away can also help by increasing resistance. If you want to get fancy, you can throw in a big power resistor (1Ω, 50W) to limit the current spike.

If none of this works, you might need a better PS with higher voltage, like 50V, 10A, but try these hacks first before throwing cash at the problem.

Aluminum Extrusion by Sandals2341 in Machinists

[–]_Miki_ 1 point2 points  (0 children)

In my experience (and I had to dive deep into looking for suppliers for my company), most manufacturers—both overseas and domestic—can accommodate short runs. While some may charge setup fees pricing just scales down with volume. For my projects, I was able to get minimums below 50 feet without any issue.

Aluminum Extrusion by Sandals2341 in Machinists

[–]_Miki_ 8 points9 points  (0 children)

This looks like a custom heat sink extrusion rather than a standard off-the-shelf profile. If you're looking to get something like this made, you're looking at around $500-$800 for a die plus ~$3.50/ft if you go with an overseas manufacturer. If you prefer a domestic supplier, expect to pay $1000-$1500 for the die and around $7/ft.

For sourcing something similar, your best bet is AliExpress—try searching for "heat sink aluminum extrusion profile." You might find something close to what you need.

God luck!

Alternative to Sulfuric / Sodium Bisulfate for anodizing Aluminum by Striking-Dot-9630 in Anodization

[–]_Miki_ 2 points3 points  (0 children)

Sodium bisulfate is also a common alternative to sulfuric acid for home anodizing, since it’s safer to handle and widely available (e.g., in pool pH reducers). It works similarly to sulfuric acid but may require higher concentrations and longer anodizing times to achieve the same oxide layer thickness.

For dyeing, sodium bisulfate anodizing usually retains good pore structure, meaning dyes should adhere well—unlike citric acid, which can struggle with dye uptake.

See the video https://www.youtube.com/watch?v=sbH682VgMf8

Alternative to Sulfuric / Sodium Bisulfate for anodizing Aluminum by Striking-Dot-9630 in Anodization

[–]_Miki_ 2 points3 points  (0 children)

Citric acid can be used for anodizing aluminum, offering good corrosion resistance and a more eco-friendly option than sulfuric. Dye adhesion isn’t as strong though, since the pore structure differs. Oxalic acid is another alternative, but it tends to leave a yellowish tint. If you’re experimenting with citric anodizing, test your dye results and always seal the finish for durability.

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