ORD Bot Hadron Inquiries - Help Appreciated

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ORD Bot Hadron Inquiries - Help Appreciated

Postby JLG » Thu Aug 22, 2013 8:14 pm

Hello Everyone,

I've become interested in the realm of 3D printing, and being a 3D Artist / Electronics hobbyist, it's peaked my interest. I came across this and was immediately amazed at it's solid build and that it could produce 200 microb print resolution at the 200mm/second, especially at it's price point. I'm very interested in trying to get one of these, problem is, I don't know where to begin. I'm very unfamiliar with the components of a 3D printer, and I understand that the low-priced version of this is a mechanical platform. I have been all over the net it seems, and still am very vague on the parts I need besides the mechanical platform, and also have read some stuff about different options as far as heatbeds, heatends, and extruder a go. How do I know what to invest in? Can I buy faster / better motors for faster print speeds, better extruders for higher resolution prints, and better heat beds (I've read on cheaper 3D printers sometimes the material doesn't stick to the base and can ruin a print)?

I'd be very grateful for any advice on getting started, I'd love to learn this stuff. What are the standard options for motors, heat beds, extruders, etc. and what are some high-end options? I'd be interested in investing extra money if it'll increase quality, or speed in any way.

I should mention that I'd be interested in printing out mechanical parts, as well as 3D artistic designs, if that makes any difference.

Thank you in advance,

- Jeff
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby rickmellor » Thu Aug 22, 2013 8:38 pm

I'm not sure if a complete shopping lists exists, but here's an attempt for you based off my rig:

Mechanicals: http://goo.gl/JR2OqK
Controller (add four drivers, the Helios bed and an epcos thermistor on that page): http://goo.gl/nsvPyH
Three limit switches: http://goo.gl/FfxA6c (you can get cheaper ones if you want, but you want this size)
Power supply: http://goo.gl/hYuHCh (I modified mine so only the +12v + GND lines are attached and the enable pin is always closed)
Glass plate for bed: http://goo.gl/nbrTnO (3/16" thick works fine)
Thermal epoxy: http://goo.gl/jBGDn2 (for installing the thermistor in the heated bed)
Extruder / hotend: http://goo.gl/zwoRg2 (this is controversial but mine is great AFTER I did the PTFE mod, others including Bart like theirs just with the spring tension mod)
Filament: http://goo.gl/enyH0q

Then lots of wires, solder, zip ties, etc. to hook everything up. I have molex connectors on everything and spent two days wiring it up. You can get by just fine with less effort ... up to you.

-Rick
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby cvoinescu » Thu Aug 22, 2013 9:32 pm

First, I'd like to say that the ORD Bot is a great choice, if you're at least marginally familiar with electronics and willing to tinker a bit. There are much more expensive ready-assembled 3-D printers out there, and they're great for people not willing to get their hands dirty, or incredibly pressed for time -- but, as Bart says, "if you did not build it, you will never own it".

These days, RepRapDiscount seems to be the best source for ORD Bot kits.

The standard 3-D printer electronics is the RAMPS. It is a shield (add-on board) for an Arduino Mega 2560. It takes up to five Pololu (or compatible) stepper motor driver modules, and it has thermistor inputs and MOSFET outputs to drive a heated bed and up to two extruders. Most driver modules are based on the Allegro A4988 driver IC, but newer versions based on the Texas Instruments DRV8825 chip are now available. Anecdotally, the Texas Instruments chips are more robust. You may also see A4983 drivers, but those are obsolete.

There are many RAMPS derivatives available, some with support for additional stepper drivers, thermistors and MOSFET outputs. Most can take SD card readers and various "controllers" of varying sophistication (modules with LCD displays and buttons or other input devices). With those, it is possible to print "headless", that is, without a PC, reading the machine commands (G-code) from a file on the SD card instead.

There are many sources of RAMPS and derivatives; again, RepRapDiscount is one of them, but it seems that creating a RAMPS clone is a popular passtime, given the number of them.

Stepper motor driver modules are also available from a variety of sources, but I would stay with Pololu or Panucatt Devices. Speaking partly from what I've read on the Internet and partly from experience, the StepStick and other pin-compatible Pololu driver clones (e.g. those from RepRapDiscount) have worse, sometimes much worse thermal dissipation capabilities than those from Pololu and Panucatt Devices. That limits the current they can supply, so you can't squeeze the most out of your motors.

Speaking of which, Panucatt Devices is a company that stands above the rest in 3-D printer and small CNC machine electronics. Their LCD controller and their 3-D printer control boards are beautiful, and their versions of the stepper motor driver modules are very well engineered for thermal dissipation (better than Pololu's).

Good choices of firmware that support the RAMPS and its assorted peripherals are Marlin and Repetier Firmware. On the PC, Pronterface and Repetier Host can be used to send the G-code to the Arduino. To get the G-code given a 3-D file, one uses a slicer: Skeinforge and Slic3r are two examples, but there are several others.

If you are concerned about speed, you should note that the original RAMPS and many other solutions use 12 V for motors (and for the heaters). Stepper motor drivers work better at higher voltages, so I would strongly advise anyone building a new 3-D printer to choose 24 V for the motors, heaters and heated bed. 24 V heated beds are now becoming common, and it's very easy to replace the resistor or heater cartridge in the hot end with a 24 V version.

In my opinion, the best hot end to start with is the J-Head Mk V. The real thing is available from hotends.com and a few authorized resellers, but bad, very bad, and occasionally decent clones abound on eBay. Stay away from them. Also stay away from the QU-BD extruder. It may be cheap, but it's not easy to get to work reliably. You may see a "15-minute mod" on this board, but I'm pretty sure it involves a lathe, and it's on top of two other mods... Definitely not recommended for beginners. PEEK/PTFE thermal barrier hot ends (such as the J-Head) are much more forgiving when working with PLA, compared to all-metal designs. I replaced the resistor supplied with the J-Head with a 25 ohm version from the same range, bought from Digikey, for 24 V compatibility. For the cold end, I use a 3-D printed Greg's Wade Reloaded (see Thingiverse) with 3 mm filament. It may be ugly, but it worked from the first try, and kept working ever since. For 1.75 mm filament, a direct-drive extruder may be a better choice -- just not the QU-BD.

The two materials that are used almost exclusively are PLA and ABS. PLA melts at a lower temperature, does not smell, and sticks to a cold bed (room-temperature glass with blue masking tape, warm glass with Kapton tape, or even wood or plastic with Kapton tape). It needs a gentle breeze (a small fan on low) to help it solidify quickly as it's being extruded. PLA is hard but brittle. ABS melts at a higher temperature, smells strongly of molten plastic, and needs a hot heated bed to stick. It sticks to Kapton tape on glass, and several methods exist to improve adhesion (cheap hair spray being one). ABS does not need a fan to cool the print, and requires less fastidious cooling of the cold end of the extruder. It is more flexible, but very resilient and not brittle at all. However, it shrinks much more as it cools, and large parts can crack and delaminate. A heated chamber can alleviate this problem.

I hope this is enough to get you an idea of where to look.
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby cozmicray » Fri Aug 23, 2013 1:22 am

It is NOT a turnkey item
Building, fixing, tweeking, replacing parts
Models to be made and compatable for 3D printing
Slicing
100's parameters to set
cantankerous extruders PLA, ABS, Nylon

See
3D printer comparison / pricing
http://www.3ders.org/pricecompare/3dprinters/

Take a look at Isis3D
http://www.isis3d.net/pages/isisone

Mendelmax 2.0
http://www.mendelmax.com/

Lutzbot TAZ
http://www.lulzbot.com/

Rigidbot
http://inventapart.com/rigidbot.php
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby JLG » Fri Aug 23, 2013 1:55 am

Thank you everybody, I will take an in-depth look at this as soon as I have done spare time. I appreciate the shopping list greatly, experience is valuable. I know this wont be a turnkey item, I've had experience with electronics (attempted to build a 3D LED cube controlled by and Arduino), and I'm fairly good at building things, just needed a push in the right direction, a foot hold so I could get going. I think I've obtained it. I'll research everything I've been given here, and ask if there's anything else I need. I will try to document the build for a beginning to end tutorial, hopefully. Any further input is always welcome, as well.

Thanks again, Cheers,

- Jeff
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby JLG » Fri Aug 23, 2013 11:59 am

rickmellor wrote:I'm not sure if a complete shopping lists exists, but here's an attempt for you based off my rig:

Mechanicals: http://goo.gl/JR2OqK
Controller (add four drivers, the Helios bed and an epcos thermistor on that page): http://goo.gl/nsvPyH
Three limit switches: http://goo.gl/FfxA6c (you can get cheaper ones if you want, but you want this size)
Power supply: http://goo.gl/hYuHCh (I modified mine so only the +12v + GND lines are attached and the enable pin is always closed)
Glass plate for bed: http://goo.gl/nbrTnO (3/16" thick works fine)
Thermal epoxy: http://goo.gl/jBGDn2 (for installing the thermistor in the heated bed)
Extruder / hotend: http://goo.gl/zwoRg2 (this is controversial but mine is great AFTER I did the PTFE mod, others including Bart like theirs just with the spring tension mod)
Filament: http://goo.gl/enyH0q

Then lots of wires, solder, zip ties, etc. to hook everything up. I have molex connectors on everything and spent two days wiring it up. You can get by just fine with less effort ... up to you.

-Rick



Hi Rick, I took a closer look at your list, is the difference between the Azteeg X3 3DP Reprap Controller w/ ATMEGA2560 and RAMPS 1.4? Is it just a different controller card? I know the AT Mega 2560 is the same processor as the Arduino 2560, but are the advantages to this one? Is the firmware / software better in some way?

Also, since I'm a beginner, should I be buying this extruder and modding it? Are people modding it because it'll produce better quality prints, or is it because it's cheaper? I'll go this route if it will produce better prints. I'm really more interested in quality, just not interested enough to pay $2500 for the known 3D printer brands out there

Another thing I'd like to discuss is speed. cvoinescu mentioned that 24v motors would be good for speed increases, as well as putting in a 24v hotend. Can we get into this in some more detail? What are some potential roadblocks of going to the 24v route? Is it possible that the motors could run too fast? Will I need dual PSUs, I don't recall eber seeing a PSU with a 12v and 24v rail, but then again I'm used to computer PSUs, would I need some sort of voltage converter?
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby cvoinescu » Fri Aug 23, 2013 1:35 pm

Many people run their setup on 12 V, and it's the de facto standard for 3-D printers. I think the only reason for this is historical: in the beginning, many people used a PC power supply, so it had to be 12 V. I am going against the entrenched tradition when recommending 24 V, but it's based on comments from many people who struggled to get their RAMPS etc. to deliver 10-12 A to the heated bed with a reasonable voltage drop. At 24 V, you need to switch and deliver only 5-6 A, which means less voltage drop on the wires, and much less heating of the MOSFET. As for the motors, the drivers can take up to 30-35 V (more for the DRV8825-based modules); they don't heat up more with 24 V, but they work better. Please note that the drivers are current-limited: you set them to deliver the rated current for your motor (typically 1-2 A), and they'll never put out more than that, even though they're supplied with 24 V and your motor's voltage rating is 2.5 V or so. However, having a higher voltage power supply allows more torque at high speeds, and a higher top speed, all with the same driver and the same motor. The only downside of using 24 V is that you'll need a 12 V supply for the fans, or harder to find 24 V fans. A DC-DC converter that takes 24 V and puts out 12 V at 3 A (which could power two dozen fans) costs a few bucks on eBay.

Stepper motors will never run too fast. They simply don't work that way. They step exactly when commanded by the firmware, and a step is always the same size (most commonly one two-hundredth of a revolution, or 1.8 degrees), regardless of the supply voltage. If you send more step pulses per second, the motor will spin faster, but always in sync with the pulses, up to a point where the motor can no longer keep up and stalls. With a higher supply voltage, it simply stalls at a higher speed, so you can configure your firmware to allow faster moves.

The Azteeg X3 integrates an Arduino Mega 2560-like controller and RAPMS-like electronics into one board. The same firmware works with both the Azteeg X3 and the RAPMS 1.4 -- in fact, if memory serves me, the pins are exactly the same, so you set up your firmware as if you had a RAMPS board.

About the QU-BD: people mod it simply because, as shipped, it does not work. It does not work with PLA at all, and often not with ABS either. You may hear reports of success with unmodified QU-BD extruders, but always with ABS, or for a very qualified definition of success. It is still very attractive because it's very cheap, but then bricks are cheap too and they don't extrude either, unless heavily modified... :)

I warmly recommend the J-Head hot end and the Greg's Wade Reloaded extruder because they work as they are, from the first try, with zero headaches. They may not be the cheapest, lightest, smallest and most elegant, but I think reliability trumps that. They definitely aren't the only good solution, but they're what worked for me as a beginner.
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby JLG » Fri Aug 23, 2013 3:29 pm

cvoinescu wrote:Many people run their setup on 12 V, and it's the de facto standard for 3-D printers. I think the only reason for this is historical: in the beginning, many people used a PC power supply, so it had to be 12 V. I am going against the entrenched tradition when recommending 24 V, but it's based on comments from many people who struggled to get their RAMPS etc. to deliver 10-12 A to the heated bed with a reasonable voltage drop. At 24 V, you need to switch and deliver only 5-6 A, which means less voltage drop on the wires, and much less heating of the MOSFET. As for the motors, the drivers can take up to 30-35 V (more for the DRV8825-based modules); they don't heat up more with 24 V, but they work better. Please note that the drivers are current-limited: you set them to deliver the rated current for your motor (typically 1-2 A), and they'll never put out more than that, even though they're supplied with 24 V and your motor's voltage rating is 2.5 V or so. However, having a higher voltage power supply allows more torque at high speeds, and a higher top speed, all with the same driver and the same motor. The only downside of using 24 V is that you'll need a 12 V supply for the fans, or harder to find 24 V fans. A DC-DC converter that takes 24 V and puts out 12 V at 3 A (which could power two dozen fans) costs a few bucks on eBay.

Stepper motors will never run too fast. They simply don't work that way. They step exactly when commanded by the firmware, and a step is always the same size (most commonly one two-hundredth of a revolution, or 1.8 degrees), regardless of the supply voltage. If you send more step pulses per second, the motor will spin faster, but always in sync with the pulses, up to a point where the motor can no longer keep up and stalls. With a higher supply voltage, it simply stalls at a higher speed, so you can configure your firmware to allow faster moves.

The Azteeg X3 integrates an Arduino Mega 2560-like controller and RAPMS-like electronics into one board. The same firmware works with both the Azteeg X3 and the RAPMS 1.4 -- in fact, if memory serves me, the pins are exactly the same, so you set up your firmware as if you had a RAMPS board.

About the QU-BD: people mod it simply because, as shipped, it does not work. It does not work with PLA at all, and often not with ABS either. You may hear reports of success with unmodified QU-BD extruders, but always with ABS, or for a very qualified definition of success. It is still very attractive because it's very cheap, but then bricks are cheap too and they don't extrude either, unless heavily modified... :)

I warmly recommend the J-Head hot end and the Greg's Wade Reloaded extruder because they work as they are, from the first try, with zero headaches. They may not be the cheapest, lightest, smallest and most elegant, but I think reliability trumps that. They definitely aren't the only good solution, but they're what worked for me as a beginner.




Okay, so if I understand properly, the only reason for not using 24v is because it can't get enough Amperage to the heatbed, and you'd need a 24v hotend and heatbed? Would a suitable fix be to use a transistor or relay to allow the Arduino to switch a hard-wired 24v line from the PSU into the heatbed?

I think I'll go with the hotend and extruder you recommend, unless there is something that will produced higher quality prints. As I mention, I'd be interested in looking for quality.

As for the Azteeg X3 3DP Reprap Controller, it's just an upgraded / integrated RAMPS 1.4? So are there any instructions somewhere on how to wire the components into this?

And as for slicers, which have you found to be the best?

A technical question about G-code, how does it work? Is it a series of movements for the controller to send to the stepper motors? Or is it turning the model into a 3-dimensional array of points that the controller interprets and then tells the motors what to do?

PS - I'm grateful for all of your technical advice, thank you very much!
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby cvoinescu » Fri Aug 23, 2013 5:32 pm

JLG wrote:Okay, so if I understand properly, the only reason for not using 24v is because it can't get enough Amperage to the heatbed, and you'd need a 24v hotend and heatbed? Would a suitable fix be to use a transistor or relay to allow the Arduino to switch a hard-wired 24v line from the PSU into the heatbed?

Two reasons for using 24 V: the motor drivers work better (higher top speed, better acceleration), and it's easier to switch and transport half the current, compared to 12 V (no need to wrangle 11 A). There's a version of the popular PCB bed heater that is dual-voltage (12 and 24 V), and adapting the extruder is a simple matter of changing a resistor or choosing a 24 V heater cartridge. What you described is exactly what the RAMPS board is doing with either 12 V or 24 V (using a MOSFET transistor). I think you should head over here and check out the schematic. All 3-D printer electronics follow the same general pattern.

JLG wrote:I think I'll go with the hotend and extruder you recommend, unless there is something that will produced higher quality prints. As I mention, I'd be interested in looking for quality.

There's no compromise on quality with the J-Head. It's one of the best hot ends.

JLG wrote:As for the Azteeg X3 3DP Reprap Controller, it's just an upgraded / integrated RAMPS 1.4? So are there any instructions somewhere on how to wire the components into this?

Yes, there is a hook-up diagram on the Panucatt site. If you get familiar with the RAMPS schematic and connections, the Azteeg X3 will be practically the same, only better made than your average board.

JLG wrote:And as for slicers, which have you found to be the best?

I have used only Skeinforge, and it's a subject that divides opinions. Skeinforge isn't particularly user-friendly, but not in a way that discourages me (I'm a programmer). Many people swear by Slic3r, and yet others are fans of the newer slicers, such as Cura. Hang around here, or search for old discussions -- I can't really give any advice except that I found Skeinforge perfectly satisfactory.

JLG wrote:A technical question about G-code, how does it work? Is it a series of movements for the controller to send to the stepper motors? Or is it turning the model into a 3-dimensional array of points that the controller interprets and then tells the motors what to do?

The G-code is essentially a series of motions for the controller. A motion can move more than one axis at a given time (e.g. it can move X and Y and the extruder motor), and the magic is that the controller keeps the motion coordinated, even if the speed varies during the motion. That means that a straight line stays a straight line, and plastic is extruded proportional to the distance, thus at constant thickness. The slicer generates the G-code required to build an object by "slicing" an object represented as a collection of triangles (a STL file) into thin slices, and contouring and filling each slice in turn, bottom up. The controller dumbly follows the motions prescribed by the G-code; in fact, the same controller with the same firmware, but with different G-code, can also drive a CNC milling machine or a CNC lathe, or even a pick-and-place machine or other stuff like that.

JLG wrote:PS - I'm grateful for all of your technical advice, thank you very much!

You're welcome.
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Re: ORD Bot Hadron Inquiries - Help Appreciated

Postby rickmellor » Fri Aug 23, 2013 8:06 pm

Yeah, I'd really only recommend the qu-bd to someone if they have a lathe handy and know how to use it. Between the PTFE mod and the Mk7 drive gear the qu-bd works great for the money but it's a pretty steep hill to climb to get there. If you're decent with metal working then it could be worth it.

I've used the MkV J-head with 3mm filament and it never missed a beat. I'm in the process of switching to E3D 1.75 hotends with the EZStruder and I expect these to perform really well. Too early to tell though.

For 12 vs. 24 volt... mine works fine at 12v. The bed takes a while to heat up but once it's there it stays where it's supposed be. I also don't have any torque issues with my machine. The Hadron is a great frame, but it's really not stable enough to handle too much jerk. Maybe that's just me, but I don't really care about speed anyway. Waiting an hour or more for a large part is still much faster than I can design it so I don't have any trouble feeding the machine. I'm mostly concerned about precision, not fine details or speed.

-Rick
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