Beginner advice, Hardware serial ports

Hello, new to the whole 3d printing scene. A buddy of mine just got a 3d printer. It had a hefty price tag, I am looking to build something myself to better understand how it all works. I am getting lost in all the models of printers. What would be a good printer for a beginner such as myself to start off with building? I want to print ABS, so from what I understand i will need a heated bed.

As for the electronics side of things, I see alot of the printers connect to a computer via USB. I have an interest in using a much older computer with serial ports, is there any way to directly drive the printer via a serial port? I do not care about any fancy features on the printer side, things like printing from a sd card or fancy web interfaces, I just want to control the printer directly via a serial port.


Any guidance is much appreciated.

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billy
As for the electronics side of things, I see alot of the printers connect to a computer via USB. I have an interest in using a much older computer with serial ports, is there any way to directly drive the printer via a serial port? I do not care about any fancy features on the printer side, things like printing from a sd card or fancy web interfaces, I just want to control the printer directly via a serial port.

Older as in Pre-Pentium? There is not a single 3D printer board i know of that directly supports RS232 and i have no idea why you would prefer it over USB. You are setting yourself up for a lot of hurt, extra work and utter frustration going this way. Printing from SD card is nothing fancy, it is a simple insurance against communication drops that ruin your hours long print.

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[www.bonkers.de]
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Most 8 bit controllers use serial over usb

So it is already serial in most cases (just RX and TX, no flow control)

eg on a ramps with marlin its easy to move the firmware to another serial port and break that out. (you don't want to remove the usb to serial as you need it to re flash firmware, as boot loader is hard coded to serial 0)

NB this is 5v serial not real -12v/+12v serial. If you want to connect it to real serial port you will need standard converter chips max232 and the like

Edited 1 time(s). Last edit at 04/04/2016 06:48AM by Dust.

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Srek

Older as in Pre-Pentium? There is not a single 3D printer board i know of that directly supports RS232 and i have no idea why you would prefer it over USB. You are setting yourself up for a lot of hurt, extra work and utter frustration going this way. Printing from SD card is nothing fancy, it is a simple insurance against communication drops that ruin your hours long print.

I fully understand that what I am asking is not the usual way of doing things, however that is the way it is going to have to be set up. It is a dedicated purpose computer, communication drops should not be an issue, I understand the concern.


Thanks "Dust" for the sugestion for the ramps board. I have some max232 chips around. That sounds like it will fit my needs.

I think i will start out by buying a ramps board and see if it fits my needs.

Alternatively you could try a 32-bit board like the Duet which includes a webserver on the board for controlling the printer. No dedicated computer necessary. The Duet 0.6 board is available from Replikeo for $50, though there have been some issues with quality in the past and reports of poor communication since the Chinese New Year.

Another option would be running an application like Octoprint on a Rasperry Pi. I was thinking the B+ model was down to $25 and your first post-calibration print could be a custom case for it. Adding a Rasperry Pi camera to the board would also allow for remote monitoring of prints.

You also might consider starting with a kit rather than building something from scratch. I have been seeing things about the Wanhao i3 a lot lately, which I believe includes the RAMPS board for $350ish or so. You might still save a few bucks off sourcing parts yourself, but a kit can be a nice starting point for your first printer, and most people eventually want to build a second or third, so you won't necessarily miss out on the experience in the long run.

What ever you decide, good luck with your project.

I already have a couple of pi boards around here. Thanks for the suggestion. I want to do a tiny self contained printer as well. The design of the pruza I3 was apealing to me with the small lcd display on it. I think i am going to go get a ardunio mega and see if i can get that talking with my machine over serial first. Once i get that sorted out ill buy the rest.

I get it, controling the thing from serial from a mideval machine is not ideal, or even practical, but that is the way i am looking to go. Thanks for the input.

I'm running a TB6560 4-Axis board thru a LPT1 port with Mach3. Once configured and you get the correct gcode output from the slicer, no issues. Manual PID heat controls, powered on/off via spindle control relay.

Fujitsu Lifebook laptop, Intel Pentium 4-M 1.7 GHz, 512mb ram, more than enough to run Mach3 and a TB6560. Even an ancient Intel 486 chipset can handle Mach3.

No hurt or frustration, Chinese TB6560 board requires minimal mods, Timing cap correction, a few transistors to remove, couple of possible sloppy solder points, and bypassing optical isolators. There's a complete tread on these mods if you want a link. It's intended as a CNC controller, but can easily be configured for a printer, and no firmware to deal with, all parameters are set in Mach3. Also controllable in Linux, with LinuxCNC (EMC2)

You an go with a 5-axis board if you want dual extruders, Mach3 will run it, not sure about LinuxCNC (EMC2) for dual extruder.

Only driver board I've used for the past 3 years. Stable enough for 7 day prints, and longer.

Edited 6 time(s). Last edit at 04/05/2016 08:21AM by Dirty Steve.

Those old fujitsu laptops will run till the end of time. I have an older pentium 3 fujitsu lifebook model and it is still running good.

My machine does have a parallel port as well, that might work. that TB6560 4-Axis board looks to fit what i am looking for. Mach3 looks pretty interesting as well. I am on a linux like system, so linux cnc would be of interest to me as well. thanks.

For the price can't beat the 4 axis board.

What would be a good software for converting a model to gcode? Ive boon looking at slic3r,it does everything i need, but im looking for something a little more basic, preferably for linux that is shell based.
I have seen a bunch of old python and shell scripts around on the web, that is more what i am looking for. The ones i found are pretty limited, did not generate support structures, and just flat out did not work, but are more along the lines of what I'm looking for.

If you intend to print ABS, you'll need more than a heated bed. You also need to enclose the printer and warm the build chamber to about 50C. The bed heater may be sufficient to heat the chamber if it is insulated, or you may need to add supplemental heat.

If you don't enclose and warm the print chamber you won't be able to print anything in ABS more than a cm or two high without it warping and delaminating.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Is it a common addition to the mendel model of printer to have a heated chamber? I did not know about a hated chamber being required for abs, thanks for the tip, I am looking into it further now.

No, it isn't common. Most printers are not designed to be enclosed and placement of the electronics is typically an afterthought. If you design the machine to be enclosed, make sure you put the electronics outside of the warm build chamber.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I will do so, thanks for the advice.

Stay away from 40Wt heater cartridges.

Edited 5 time(s). Last edit at 04/08/2016 04:18PM by atagunov.

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atagunov
Stay away from 40Wt heater cartridges.

What else does it tell us than to not use a heating element at 150% of it's rated voltage without any kind of control?
Sorry, but this isn't a worst case scenario but simple exaggeration.
This is what happened to me with a 40W heater and thermal runaway.
[b.bonkers.de]

What else would you use than a heate rcartridge? What is so much safer?

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[merlin-hotend.de]
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Srek
What else would you use than a heate rcartridge? What is so much safer?

Thx for the info Srek. 25Wt heater cartridges?

Edited 5 time(s). Last edit at 04/08/2016 06:14PM by atagunov.

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atagunov
Thx for the info Srek. 25Wt heater cartridges?

Keep in mind that the power consumption is always the result of the voltage and the resistance.
In the example you gave they upped the voltage so they had effectively a ca. 60W cartridge instead of 40W.
In general lower wattage is safer, but ultimately you can reach the same high temperatures depending on what exactly are the circumstances.
The worst situation might be a short in the heating coil of the cartridge, in that case you hahe a fraction of the resitance and a multiple of the wattage. Depending on your PSU
this is a recipe for desaster.

There are a couple of things you can do to lower the risk.
Only use as high a wattage heater cartridge (or other heating element) as you need
Avoid heating elements that make use of running anything beyond specs (the old high wattage resistor heaters)
Use a firmware that supports thermal runaway protection
Use a high temp silicone sleave
Make sure the fuse for your electronics has the correct rating

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]