why no one use 2d printer technology for 3d printing?

Hi;

I just wonder why we don't use the 2d printer frame like those found on inkjet printer to develop 3d printer? Is dc motor + encoder base design that much more complicated than stepper motor - but it would be a hell cheaper!!

I want to investigate this idea further so if you have any inkjet printer base technology please provide me guidance

A reference design would be nice

Thank

Phonx

Some people are doing it, but it's trading a lot of time and work for a limited money saving, so it's not that popular.

For instance see that post for an extreme salvaging method of building repraps - They mostly use old computers but probably also use or could use 2D printers parts : [forums.reprap.org]

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

There was also some discussion about this topic here: JunkBot (One man's junk is another man's reprap).

I think the main reason that more people do not use a dc motor + encoder approach is because the common printer controllers (RAMPS, Melzi, etc) do not have an easy interface - they are almost all designed for stepper motors. There are, of course, tons of industrial or hobbyist-robotics motor control boards available that will handle dc motor + encoder, but as far as I know none of them have an easy interface to common RepRap firmwares (Marlin, Teacup, etc).

One project on my list of "stuff to do" is to make a small "add on board" that has the same footprint as the widely used Pololu stepper driver board. This board would receive step/direction signals from the Arduino, and then control a dc motor + encoder accordingly, as though it were a stepper motor. I call it a "stepper emulator". I have a working circuit from another project I'd like to use, but the form factor is wrong, so the board needs to be redesigned...

... I've recently reactivated a CNC-mill equipped with servos+encoder with a common stepper-controller, that drives the motors with STEP/DIR-signals.
This could be done with a RAMPS in the same manor, but I had to use one of our own controllers, so it's compatible to our CAD/CAM.

The machine runs much faster and smoother than possible with steppers and the encoder-accuracy is in the sub-micron range, so better accuracy and dynamic than with steppers.

One maybe relevant point is the price - a common industrial microstepping controller for similar powered stepper-motors is around EUR30, while the 'stepper-simulating' servo-controllers were EUR105 each ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I am interested in using the the throw away printer savage parts, I have accumulated more than 10 inkjet printers and some laser printers and a copy machine! Looking through the parts that had dismantled - they all have strip of encoders and pulley driven x-axis and a controller card. Since some of you already started along this idea may be we should create a controller that is suitable for dc motor ( commonly found in cheap inkjet printers) + encoder - or even better reverse engineer the inkjet printer controller - any taker?

Some reverse engineering will be needed, just to power the encoder and pick out the signal. My thinking is that making a custom driver circuit is easier and/or more useful than trying to reverse engineer the whole controller...

Give me a day or two and I will put up what I have on github. If people think there is any value in it, we can use it.

I think this approach only makes sense (outside of academic curiosity) if the controller can be made very cheaply:

Cost of the standard option = Arduino + Ramps (or whatever) + 4X Pololu stepper drivers (4X $8) + 5X stepper motors (5X $9)

Cost of the "salvaged dc motor + encoder" option = Arduino + Ramps (or whatever) + 4X Controller boards (4X $P) + 4X dc motors + encoders (free!)

So, the break-even point is when the cost of the controller board $P = (4X $8 + 5X $9)/4 = $19.25

These numbers are approximate of course!

VDX: Do you have a part number or link to the motor controller you mention above? I am curious about what is already available off-the-shelf.

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MattMoses
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VDX: Do you have a part number or link to the motor controller you mention above? I am curious about what is already available off-the-shelf.

... this are UHU's - developed and assembled by two guys in a German CNC-forum.

Here are two related links:

[www.embeddedtronics.com]

[www.uhu-servo.de]

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

uhmm

It doesn't looks customers like this technology that much or understood its potentials??

[www.kickstarter.com]
only received 19% with less than 3 days to go

"Yes, Rappy uses servo motor and its position feedback system. Right, It is very interesting project
Also, Its encoder is incremental.
Thanks. Stellamove team."

"There is backlash, and we handle this with certain amount of errors and it is not enough at the moment. But it is being improved.
I am very sorry that I can not say the method we do in detail.
But one thing is clear, while backlash is inevitable, we know when it happens and how much it is, and it can be controlled with.
We are trying to handle this software approach and hardware config also.
I can not say this more in detail. This is not a open project yet and still it is developing and improving.
Thanks. Stellamove team."

Quote
phonx
It doesn't looks customers like this technology that much or understood its potentials??

It looks like that particular Kickstarter campaign had a lot of problems that didn't have anything to do with the dc motor concept.

For making a low-cost 3D printer, I don't think using dc motors + encoders will offer much of a performance improvement over stepper motors. For me, the main motivation is the ability to make use of an available resource (salvaged motors).

Totally agree

VDX, thanks for the links. That looks like a really nice system!

Here is the little controller I made (in collaboration with some others): [github.com]

It uses a LMD18200 and a PIC. Unfortunately the LMD18200 alone costs more than the entire budget for a "cheap" board. The PIC is only about $3 however, so that can probably stay...

I am thinking about trimming down the design and using something like a L293D for the motor driver. Remember we're trying for a small, cheap board to run the cheap DC motors dug out of a cheap printer (are you detecting the "cheap" theme yet ) so I think the L293D might be OK.

Does anyone know of any other motor drivers that might work?

... hmm ... remembering my old H-bridge circuits with four Darlingtons driven with two pins of an 8031 in the early 90-ies.

What's the cost of 4 MOSFET's today? -- have some with 3 Milliohms RDSon driving my laserdiodes with 10 Amps continuously or >30 Amps pulsing with prices below 2 Euros each ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

In my experience, it is a bit of work to get a good solid MOSFET H-bridge design, especially if you want to drive it at a few kHz with a PWM signal. You have to worry about shoot-through current and snubber circuits and gate drivers and so on... and by the time all that is factored in, an "all in one" package starts looking better and better. However, if anyone would like to share some schematics I'd like to see what people are using... Maybe it doesn't have to be that hard.

It looks like the UHU controller is using a IR2184 gate driver. They are also using kind of a complicated network on the gate of the MOSFET that I must confess I do not understand completely... I think this is to introduce a delay when the MOSFET turns on, but allow it to turn off quickly - in order to prevent shoot-through during transitions.

A biploar H-bridge might be more forgiving than a MOSFET one, but they can be tricky to bias properly, especially if you want to use a wide range of supply voltages. Maybe some experts in this area could chime in and offer some advice?

There's a nice writeup on a biploar H-bridge design here. Something similar to that circuit might work...

here something to inspire you guy
[justcheckinm8.blogspot.co.nz]


- keep going - love it

I am also interested in doing something like this. I have found this motor controller which is no longer available and a newer version with usb here which I no are out of the price range but seem to offer something similar to what is needed.

This guy is making great progress building a RepStrap with DC motors and encoders. He is using a dedicated arduino pro-mini to read step/dir signals from RAMPS, read the encoder signals, and perform closed loop motor control. One arduino for all the motors. (A separate arduino for the RAMPS controller is also necessary.)

I played around with inkjet printer parts for a while, but found that almost any low cost 3D printer is a better choice than trying to modify inkjets. Most parts in those inkjet printers are highly properitary designed parts which do not meet any industry standards- Just check the gears, belts etc. Hacking the controller is a time consuming dead end, most mechanical parts are mounted on panels that maes it very hard to give the assembly a new function. So all in all it has been said here before, it is just a tradeoff time vs money.
In addition you have to buy many parts anyway, because you wont find them in an inkjet.
Any reworked cheap or fixed used 3D printer is a better choce.

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Blogs:
Meine 3D Druck Abenteuer
[3dptb.blogspot.de]
FLSUN Delta Drucker für Deutschland
[flsun-deutschland.blogspot.com]
Books on 3D patents:
[goo.gl] (english)
[www.amazon.de] (deutsch)

It is possible though! I played around with a linear unit from a hp printer and made it act as a stepper motor using feedback from the optical encoder and the PID_v1 library. In my main loop i set
I'm trying to build a repstrap using stepper-motors on all axis but the X-axis where I'll use this linear unit (just to see if it can be done ). Next step is to merge it with the Teacup firmware.