Rolive

Does any of you have any experience with this? I'm looking at the Felfil Evo pellet extruder which seems like an acceptable option. One thing I don't understand. Why are the shredder and spooler so ungodly expensive?

I mean, can't you just use an old blender to grind pieces down far enough for the pellet extruder? The finer the better no? Airborne microplastic may be a concern at some point.

Also the spooler. Is that more complicated than a stepper motor that runs at a certain RPM spinning the spool around? With perhaps a mechanism that slows down a bit after X rotations to compensate for the spool getting thicker. Nothing an Arduino can't handle. Also don't grip the spool that tightly so pull strength is more or less equal.

Both the spooler and shredder individually cost more than a pellet extruder does..

This type of battery seems quite easy to DIY. Cheap materials, relatively safe, not flammable.

You can either maken individual cells or make a flow battery which is theoretically infinitely scalable. You'd be limited by the size of the electrode in how much power this battery can deliver.

Has anyone here tried to make a flow battery? And did you have any success with powering something large and energy consuming?

I guess it would also be possible to make a battery out of old buckets, carbon fiber mesh and separator material such as glass fiber.

In a transformer, why are both coils apart from each other? Wouldn't make more sense to have the ferrite core (tube shape), wind the primary coil around that and then wind the secondary coil on top of the primary? So that the magnetic fields are as close to each other as possible?

Hi all

A higher nozzle diameter has the benefit of being able to print faster due to to bigger layer width. There is a tradeoff, you'll have to lower print speed and/or raise temperature to maintain proper layer adhesion. That means that there is an optimal nozzle size for a given print speed/temperature combination. You also don't want temperature too high because it will burn/degrade your filament.

In my experience layer adhesion is quite poor with a nozzle of 0.8mm and it also prevents you from printing finer details (gear teeth for example). The tradeoff versus a 0.4mm nozzle doesn't seem worth it especially if you print overnight.

What are your experiences?

Hi

I'm interested in building my own solar panels mostly for educational purposes. The idea is to use individual solar cells and solder 36 of them in series to get about 18V open circuit voltage. It's what commercial solar panels have as well so its easier to integrate later.

The cells are bonded to the substrate using optically clear silicone or EVA. Not sure which is better. Polyurethane is not good because the mere mention of humidity will cause tons of bubbles.

As for the substrate. Optically clear tempered glass is prohibitively expensive unless bought in bulk. Normal glass is significantly cheaper but could that be a safety hazard? I seriously doubt that thermal shocks are strong enough to break glass sheets unless cold rain falls on it.

Has anyone tried plexiglass/acrylic? It's UV resistant but could bend/warp at higher temperatures breaking the cells.

Perhaps using screen protectors for obsolete phones/tablets could work as well. It's really thin and strong but I don't know it holds up in a hailstorm.

Would love to hear from your experiences in DIY solar panels.

I'm interested in learning how to make a proper PCB rather than perf board with wires all over the place.