lowest power printer

I am looking to run a 3d printer off limited solar power. The solar panels produce a small amount of power when overcast and in winter the daylight hours are short.

If you are connected to an electrical grid, you might measure power in kilowatt hours, and not understand where I am coming from. Just understand that saving even 1 watt is an important difference.

Ways to (maybe) reduce power:

1) use most effcient stepper driver tmc2660 even with smaller motors because of lower on resistance.

2) print using PLA, and not using a heated bed. It should also be possible to heat the bed and extruder using a different heat source than electricity

3) insulate extruder with a sock.. Not sure how this works. I would like more details.

4) Use closed-loop stepper motors. Not sure if it's worthwhile, but from what I can tell the stepper motors use more power (about 24 watts) than the extruder (8 watts). I have seen people put heatsinks on the motors so obviously they use a lot of energy. Open loop steppers are notoriously inefficient, and a bldc servo would likely run cooler as well.


5) Could the extruder gear ratio effect efficiency? Can I just use a hobby rc servo continuous here since absolute position is not important, and the rc servo is more efficient and lighter?

5) Use peltiers to heat the extruder. Would this be possible? The peltier makes plenty of heat, but also keeps the other side cold meaning it might not need the fan, and besides, it makes more heat than a resistor since it pumps heat. Why can't the extruder use a ceramic or other material tube to prevent heat traveling away so much? I don't understand why it needs to heat up and also use a fan, it seems like there is room for improvement here.

6) software adjustments? What can I do to reduce power consumption of a print? I don't care if it takes longer to print, as long as I get the same result using less total watt hours. Is this possible?

7) Use the smallest motors possible. Obviously this will have other limitations, like maybe print speed, but if overall power consumption is reduced it could be worth it.

8) use linear ball bearings to reduce friction??


Any other suggestions appreciated.

Edited 1 time(s). Last edit at 09/13/2018 07:50PM by retrosenator.

If Sexy Cyborg can run a printer from a battery you can too.

use a lcd based resin printer. One stepper motor vs 4 or 5
no heaters
only one light + electronics + lcd.

How about using a wind mill instead ? With enough pulleys and gears no need for motor, the wind can cool the Peltier cells to produce heat and electricity for the rest ! In absence of wind, brain farts will do.

---

"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Joking aside...

Power conservation costs money. In order to make this the most efficient possible, you are going to have to trade off, and some things, the only reasonable trade-off is money.

If you do this with small motors and low currents, it won't be fast. That means that you need to keep your hot end hot for longer for a given print. Like a car doesn't get its best fuel economy at very low speeds, even though its hourly fuel consumption is low, we care about how FAR the car goes for the fuel, not how long.

Small motors don't always get the best economy. Going back to cars, I built my Supra engine for ~450 horsepower, and it gets better fuel economy than my winter beater Honda, because it doesn't waste the power that it's got. In your printer, stepper motors do a job, and sizing them properly to do that job quickly and efficiently is going to save you time pumping 35-50W into the hot end heater.

A UV/LCD resin printer is probably the most power efficient, if for no other reason than the lack of a bunch of heaters.

In order to make an FDM printer more efficient, you're going to need to make a lot of compromises, but I would say to first consider that your FIRST concern should be reliability. Most of us can fail a few first layers for a print, or can have prints de-laminate and fail, and we just make another one. each time that happens for you, every watt-hour that print cost you is gone, and you get nothing for it.

Printing by melting thermoplastic filament doesn't seem to be that reliable a technology to me.

As far as choice of filament, I'm personally working on a design for a propane heat chamber (For a vacuum forming table to heat plastic sheet to forming temperatures) which would be arduino controlled. It's basically a small gas oven, but I'd put good odds that I could use the same control mechanism to keep a small metal plate (and/or heated chamber) at temperature. For this, it would then become which plastic has the lowest specific heat.

---

MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.

Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts

You've already listed a few valid things.
The hotend sock will help a lot. Also take care, the part cooling fan doesn't blow on the nozzle.
Small stepper motors, like 0.4A NEMA 17. It works, as long as the extruder motor is strong enough ( geared 3:1 or 5:1 ) you can print at 50mm/s reliable.
It's all about finding a reasonable acceleration for them and you can use travel speeds of 120-150mm/s.

Switch off Z-motors. If you have fine pitched leadscrews and set the driver to fullsteps or 1/4-steps, they won't loose position, when switched off.
Lift Z during retraction is forbidden then.
Switching off XY-motors won't help a lot, only during heatup-time.
I'd propose using a backup battery permanently connected to the solar module. ( You won't print everyday from dusk till dawn, right? )

Why not use a solar collector to heat the bed? A solar powered waterpump pumps hot fluid through a maze below the bed. PWM control regulates the temp.

Quote
o_lampe
You've already listed a few valid things.
The hotend sock will help a lot. Also take care, the part cooling fan doesn't blow on the nozzle.

What type of hotend is best? do the j-head really use ceramics instead of metal to prevent heat from rising out of the nozzel? If so, does this improve efficiency significantly?

can I use 2 or 3 socks?

Quote

Small stepper motors, like 0.4A NEMA 17. It works, as long as the extruder motor is strong enough ( geared 3:1 or 5:1 ) you can print at 50mm/s reliable.

It's all about finding a reasonable acceleration for them and you can use travel speeds of 120-150mm/s.

Switch off Z-motors. If you have fine pitched leadscrews and set the driver to fullsteps or 1/4-steps, they won't loose position, when switched off.

What pitch, 4mm/turn 2mm/turn? 1mm? Why do people use anything but fine pitch for these since z axis movement doesn't need to be fast? Is this only to facilitate:

Quote

Lift Z during retraction is forbidden then.

?

Quote

Switching off XY-motors won't help a lot, only during heatup-time.
I'd propose using a backup battery permanently connected to the solar module. ( You won't print everyday from dusk till dawn, right? )

There is a battery, but it's limited. I might want to print all day, it sure seems like printing can take a long time, and the sun isn't always out.

Quote

Why not use a solar collector to heat the bed? A solar powered waterpump pumps hot fluid through a maze below the bed. PWM control regulates the temp.

I have a solar furnace I use for cooking, distilling sea water, and sewage treatment made from about 400 small mirrors glued in a satellite dish.

This gets hot enough to make stainless steel turn blue. It is significant heat source, approximately equivalent to a stove but the heat is concentrated to an even smaller area of 10-15 sq cm. Piping this heat needs to be some kind of fluid other than water.. molten salt? Not sure how I can pipe it to the printer without losing significant heat..

Quote
SupraGuy
Joking aside...

Power conservation costs money. In order to make this the most efficient possible, you are going to have to trade off, and some things, the only reasonable trade-off is money.

If you do this with small motors and low currents, it won't be fast. That means that you need to keep your hot end hot for longer for a given print. Like a car doesn't get its best fuel economy at very low speeds, even though its hourly fuel consumption is low, we care about how FAR the car goes for the fuel, not how long.

I don't think this analogy extends to 3d printing perfectly.

That is only because the car isn't designed for low speed. If it had a 1 horsepower engine and much lower gears than even 1st gear it would go considerably further on the same amount of fuel going only 2mph. A big factor here is wind resistance, but it's also possible in large engines (for their power) at low rpms because they don't heat up as much so the temperature differences can remain greater better thermal efficiency

But cars aren't designed to be efficient, at all. If they were, they would have larger diameter thinner wheels more like wagon wheels or bicycle wheels, travel much slower than they do, and accelerate very gradually.

Quote

Small motors don't always get the best economy. Going back to cars, I built my Supra engine for ~450 horsepower, and it gets better fuel economy than my winter beater Honda, because it doesn't waste the power that it's got. In your printer, stepper motors do a job, and sizing them properly to do that job quickly and efficiently is going to save you time pumping 35-50W into the hot end heater.

I guess ultimately all the plastic has to get melted which takes a certain amount of heat, and the faster it can do this, probably the less wasted heat. This would mean like you suggest smaller motors could be worse. But larger motors also weigh more and so..

maybe it saves power to put the extruder to the frame and feed the nozzle through a tube like typically on a delta style? This takes a load off the steppers allowing them to be smaller?

Quote

A UV/LCD resin printer is probably the most power efficient, if for no other reason than the lack of a bunch of heaters.

It makes sense, but I believe the parts produced are not useful outdoors since they are not UV tolerant?

Quote

In order to make an FDM printer more efficient, you're going to need to make a lot of compromises, but I would say to first consider that your FIRST concern should be reliability. Most of us can fail a few first layers for a print, or can have prints de-laminate and fail, and we just make another one. each time that happens for you, every watt-hour that print cost you is gone, and you get nothing for it.

Printing by melting thermoplastic filament doesn't seem to be that reliable a technology to me.

I don't see any alternatives.

Quote

As far as choice of filament, I'm personally working on a design for a propane heat chamber (For a vacuum forming table to heat plastic sheet to forming temperatures) which would be arduino controlled. It's basically a small gas oven, but I'd put good odds that I could use the same control mechanism to keep a small metal plate (and/or heated chamber) at temperature. For this, it would then become which plastic has the lowest specific heat.

It may be possible to use propane or some other type of fuel, but it would be very wasteful and bad thing to do.

Edited 5 time(s). Last edit at 09/16/2018 12:20AM by retrosenator.

Quote
retrosenator

Quote
o_lampe
The hotend sock will help a lot. Also take care, the part cooling fan doesn't blow on the nozzle.

What type of hotend is best? do the j-head really use ceramics instead of metal to prevent heat from rising out of the nozzel? If so, does this improve efficiency significantly?
I haven't used j-heads, but AFAIK they use a high temp plastic instead of E3Ds heatbrake and heatsink. They say, it works without hotend cooling fan

can I use 2 or 3 socks? Not neccessary

Quote

If you have fine pitched leadscrews and set the driver to fullsteps or 1/4-steps, they won't loose position, when switched off.

What pitch, 4mm/turn 2mm/turn? 1mm? Why do people use anything but fine pitch for these since z axis movement doesn't need to be fast? Is this only to facilitate:

Quote

Lift Z during retraction is forbidden then.

?
Many printers use M5 leadscrews with 0.8mm pitch. But IMHO 1.5-2mm pitch will also work. Try to use only one stepper with belt and pulleys to drive Z.

I have a solar furnace I use for cooking, distilling sea water, and sewage treatment made from about 400 small mirrors glued in a satellite dish.

This gets hot enough to make stainless steel turn blue. It is significant heat source, approximately equivalent to a stove but the heat is concentrated to an even smaller area of 10-15 sq cm. Piping this heat needs to be some kind of fluid other than water.. molten salt? Not sure how I can pipe it to the printer without losing significant heat..
You'd need a thermal transfer device right at the furnace, like a radiator. Then you can transport the low temp fluid without too many losses. You could also cover the mirror partially or aim it slightly away from the sun to reduce energy.
Another idea: The backside of the dish sure gets pretty hot too, maybe you can get your hot fluid from there?

Edited 1 time(s). Last edit at 09/16/2018 02:15AM by o_lampe.

Put the whole thing in a well insulated box, also stops cold air which is bad for prints.

What pitch, 4mm/turn 2mm/turn? 1mm? Why do people use anything but fine pitch for these since z axis movement doesn't need to be fast? Is this only to

yes it does... you dont want you print time to double just because you use features like z-hop, also some people home to max Z so with a fine pitch that can take minutes


you could probably design a gas powered hot end and or heated bed, depends just how 'silly' you want to go

Edited 1 time(s). Last edit at 09/16/2018 03:09AM by Dust.