Sebastian Köln

Why not a used professional laptop?
You can get a Thinkpad T480 for $200. I already bought a handful for friends who asked for a good laptop, but don't need a new machine.
I could not imagine working without a proper keyboard, but apparently some people can.
While the cooling of a laptop isn't idea, it is still much better than that of a tablet, so you get more performance.

Having used an air filled tire, a foam filled and solid tire, the air tire is by far the best and easiest to handle.
Bicycle tired are getting pretty good at being puncture proof today, I am sure something similar can be done for a wheelbarrow.
You will need an inner tube and some heavy material as a liner that thorns do not make it though.

John, essentially yes. The simple chargers that comes with the Lamp will probably not be able to charge the big battery in a reasonable time.
I would suggest to get a separate charger. They are not expensive and then you can charge one battery and use the other in the lamp.

It took me 10 years to find the right one. And that was a total accident.

That looks beautiful!
You make me want to visit the US.

I looking for a husband for a friend of mine (20). What you write sounds pretty good.
Maybe she will write you.

Jose, how much power does your oxygen concentrator use? And all the other things you need?
Figuring out how much energy you need would be the first step.

It is most likely a scam.
Assuming you need around 1kW of power on total, it will require a fairly large solar installation and batteries to keep that running all the time. Even as a DIY verison, this is not cheap.

I think the only option is a black and white laser printer.
You already mentioned why ink does not work.

We still have a color laser printer that I need to fix … and only yellow is not being detected, so really the stupid thing has no reason to refuse working, but it does.

Nancy Reading wrote:The microphone on the phone I use as a camera appears to be broken :( It records pictures but no sounds.

Does the microphone of your headset work with the phone?
Maybe there is a way to connect a microphone and keep using the phone.

Nancy Reading wrote:We have a Canon EOS 40D

The camera body is not the important part. The lenses are. And you already have lenses for the EOS 40D.
Find a used camera body with the same lens mount that has the video features you need and fits the budget. I am sure you can find that.

No camera has good audio. If you want to record people, then the voice you want to record is in a different place than the camera and the microphone needs to be very close to the person you want to record.

There are handheld microphones ("portable audio recorders") with pretty decent audio quality. And you can plug in a lavaliere microphone if you are in noisy environments. (see "Zoom H1n" for example)
They should all have USB if you don't want to take out the SD card.

That means you will need to synchronize the audio later, but it isn't too difficult.