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Project Log 60: DIY Electric Motor³.

A project log for DIY Mech/Exoskeleton suit.

Mechs are not viable, nor cheap, so I will try to design and build one alone anyway.

fulanodetailFulanoDetail 07/10/2023 at 11:530 Comments
Monday, 10/07/2023, 08:52.

Well, sh1t.

Just now I remembered that there is a reaction between iron oxide (rust) and hydrogen gas:

I can use this reaction to make pure iron powder in any grain size I want. In fact, there are tons of tutorials on how to get iron oxide.

Well, this can either be used for the fuel cell or the electric motor.

I asked ChatGPT and it said it could be done with nickel, but I would need to corrode it with muriatic acid (HCL) and hydrogen peroxide (oxygenated water) and then expose it to hydrogen.

But as far this would actually work is questionable, it is not like ChatGPT is a chemist...

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... Which means I just wasted money with that graphite powder and nickel plate for electroplating, huh...

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And I think this video shows a few nice insights on the subject of DIY electric motors:

Well, as you can see in the second video, the soft magnetic core that the guy made was half as good as the basic ferrite core he could find.

Unfortunately, I don't have the fancy tools he has for measuring the specifics of each part, so I would be going in the dark.
Meaning that I have to go absolutely right in the first try.

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Also, I asked to chatGPT some materials with higher resistance that could be used:

"The specific resistivity or resistance value of insulating materials can vary depending on factors such as composition, temperature, and specific grade or formulation of the material. Here are some approximate resistivity values for certain insulating materials, expressed in kiloohms per meter (kΩ·m):

Polyethylene (PE): The resistivity of polyethylene can vary depending on its type and grade. Generally, it ranges from approximately 10^14 to 10^17 kΩ·m.

Polyvinyl Chloride (PVC): The resistivity of PVC typically ranges from around 10^12 to 10^15 kΩ·m.

Cross-Linked Polyethylene (XLPE): XLPE exhibits higher resistivity compared to regular polyethylene. Its resistivity is typically in the range of 10^15 to 10^18 kΩ·m.

Polypropylene (PP): The resistivity of polypropylene is similar to that of polyethylene and can range from approximately 10^14 to 10^17 kΩ·m.

Polytetrafluoroethylene (PTFE): PTFE is known for its exceptional electrical insulation properties. It has a resistivity in the range of approximately 10^18 to 10^21 kΩ·m.

Epoxy Resins: The resistivity of epoxy resins can vary depending on the specific formulation and curing conditions. Typically, it ranges from around 10^12 to 10^15 kΩ·m.

Ceramic Materials: The resistivity of ceramic materials can vary significantly depending on the specific type of ceramic and its composition. Resistivity values for ceramics can range from around 10^9 to 10^15 kΩ·m.

It's important to note that these values are approximate and represent a general range. The actual resistivity of a particular insulating material can vary based on various factors, including temperature, impurities, and manufacturing processes. Additionally, the resistivity is often given in a wide range to account for variations in material properties and applications."

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Now I get why the scientific articles were so focused on using sintering on their soft magnetic composite cores... So all the binder material is burned and extracted from the piece, leaving only the metal structure (that is what sintering is).

I was so focused on what materials I could/should use that I never thought on the concentration of materials that I should use...

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By the way, the question is: how the duck I can use the polymer as a binder of the material since every little thing I just talked about is super viscous and super hard to deal with?

Well, I was kinda thinking in a solution for that before I even realized I needed one.

Basically, since plastic extrusion machines are expensive for the mold casting of the mech/exosuit, I was thinking on using a manual metal pump to forcefully extrude the viscous plastic into the pressure-held molds.
It would like using an hydraulic jack, but spicy. And harder.

Again, I asked chatGPT:

"In a DIY sintering setup, there are several materials you can use as binders to hold the material powder in place during the sintering process. The choice of binder depends on various factors such as the type of material being sintered, the desired final properties, and the temperature and conditions of the sintering process.

Here are a few commonly used binder materials for sintering in a DIY setup:

Organic binders: Organic binders are a popular choice because they can be easily burned out during the sintering process. Some examples of organic binders include starch, cellulose, polyvinyl alcohol (PVA), and various waxes. These binders can provide good green strength and can be removed by heating the material to a temperature where they decompose or burn off.

Inorganic binders: Inorganic binders are another option for sintering. They are often used for materials that require higher sintering temperatures. Examples of inorganic binders include colloidal silica, sodium silicate, and various glasses. These binders can provide good strength and stability during the sintering process.

Water: Water can also be used as a temporary binder for certain materials. It acts as a binding agent by creating a slurry with the powder. Once the desired shape is formed, the water can be allowed to evaporate, leaving the powder compacted. However, this method may not be suitable for all materials and may require careful drying to avoid cracking.

It's important to note that the choice of binder depends on the specific requirements of your DIY sintering setup and the materials you are working with. It's recommended to consult material-specific resources, such as technical data sheets or research papers, to determine the most suitable binder for your particular application. Additionally, it's crucial to follow proper safety precautions and guidelines when working with binders and during the sintering process.

Besides water, there are other liquid binders that can be used in the sintering process. Some common alternatives to water include:

Organic solvents: Organic solvents like acetone, ethanol, methanol, and isopropanol can be used as binders for certain materials. These solvents can dissolve or disperse organic binders or polymers, allowing them to act as temporary binders for the powder. The solvent can be evaporated later, leaving the powder compacted. It's important to note that some solvents are flammable and require proper handling and ventilation.

Organic binders in solvent form: Instead of using a dry organic binder, you can dissolve or suspend an organic binder such as PVA (polyvinyl alcohol) or acrylic-based binders in a suitable solvent. This creates a binder solution that can be applied to the powder, allowing it to hold its shape. The solvent can then be evaporated to leave the binder behind.

Aqueous binders: Besides water, there are specific aqueous binders available for different applications. These binders are typically designed to be water-based and can provide good binding properties. Examples include water-based polymer dispersions and emulsions.

When selecting a binder, it's important to consider its compatibility with the material being sintered, the sintering conditions, and the desired properties of the final product. Some binders may have specific temperature requirements for their removal, and others may leave residues that can affect the properties of the sintered part.

It's recommended to refer to material-specific resources, such as technical data sheets or research papers, or consult experts in the field for guidance on selecting the most appropriate binder for your specific application."

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I think it would be interesting to mix acetone and sodium silicate (assuming sodium silicate solidifies even without the presence of water) to use as the binder for a DIY sintering process.

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Even though I trash-talk ChatGPT most of the time, I don't think I would have half the information I learned without this thing.

Today I'm in a good mood... For the last 20 minutes... It is 1 am.

No, I wasn't researching until 1 am. I just had an eureka moment and I'm studying at 1 am because I like to learn new things.

Holy crap, I'm such a nerd...

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Ok, I'm awoke now and I rethought on some stuff.

The polyethylene mold injection method may not work, but the DIY sintering thingie may have something useful.

Basically, I was thinking on mixing insulation material and iron powder mixed with acetone in different materials, so I would just spray layers of each one in a sequence, creating some kind of lamination without the need of actual laminations.

So, the steps would be:
Make a mold and a pressure mold, spray iron powder suspended in acetone until it makes a layer on the mold, wait for the acetone to evaporate, apply insulation layer, wait if to evaporate, apply pressure using the pressure mold. Rince and repeat.

The thing is that you still need to apply resin on the outside, since everything would just be held together by pressure alone. You could also apply a spray of sodium silicate in acetone after every layer.

PS: I just now found out that there are electric insulation pastes, so all this tedious process may be skipped by simply mixing the iron powder and the paste, lol.

I was also thinking on using that teflon tape used on water pipes, but I don't know how well I would be able to actually cut everything to pieces. And yes, teflon powder is kinda expensive.

Well, I could literally use those insulation tapes used for electronics and so on, but you would need to come up with something to deal with the adesive.
ChatGPT suggested acetone and/or isopropyl alcohol.

Bruh, I will be using so much fricking acetone/alcohol that I will probably turn this project in a fire harzard.

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