Tri Hotend

[McSlappy]

Not sure where the hate on patents came from. Maybe from companies like Stratasys doing rotten things with them.. Or patent trolls... or Apple v Samsung... In all these cases there are questionable tactics surrounding the ownership of patents. However none of these companies HAD to be dicks about the patents, they just chose to for the pursuit of money...

Let's just say that Generic decides NOT to patent anything (assuming he has anything that can be patented...) and along comes Stratasys (surprise surprise) and says "Hey there's a nice idea, lets implement this into our next product! Oh and lets patent it while we're at it!" Where would that leave the open source community and Generic? Both will lose.
If Generic can patent what he's working on, he can then choose to treat it as open source by not prosecuting anyone who uses it, while at the same time preventing anyone else from taking and locking it down.

It all depends on whether you trust Generic to stick to his word on this.

I don't know Generic, but if I were to wager, I'd bet on it remaining more 'open source' having a patent on it than left to a larger company to do the same. Just look at the recent Stratasys patent trolling (stealing) to see what happens to great open source ideas when a company with a massive budget and team of lawyers gets a hold of it.

Sometimes you need to play the game that the big boys are playing in order to keep the big boys honest.

I give tons of props to Generic for going this route. It shows he's serious about his development and serious about the future. It would be foolish to put a tempting treat on the table, walk away and be mad when the dog steals it. Corporations are psychopaths and they will not respect the open community, we should all be very aware of this.

[astroboy907]

Makes you wonder - we have open source, maybe it's time to start the ball rolling on open patents? Like a group dedicated to the preservation of patents for the "little guy" to make sure that Stratysys doesn't happen.

[bot]

The cost of actually receiving a patent is probably more than it's worth to attempt. I can't foresee how there could really be anything that could be enforced as a patent here. The application might help establish prior art, for when/if startsys decides to "rip off" this idea. But, to be honest, exactly who might be ripping off whom here? This design doesn't actually look that original. Filament paths, nozzles, heat sinks, pretty standard stuff for hot ends.

I don't know the specifics of the cases of patents based off of open-source work, and these cases are obviously unfortunate, but that shouldn't deter people from going the fully open-source route. Patents are expensive and they ultimately represent an obsolete idea of intellectual property. We all build off of each-other's ideas. This is very obvious in the design of this hot end. Our contributions to the open-source community, and our ability to capitalize on them before we release the open source files should be our only reward. Closing off elements of your design to others wishing to build from it, in any way, is absolutely antithetical to the idea of open-source.

A patent, if one were to be given in this case, would likely do little to protect the concept anyway. Unless the one holding the patent has better lawyers than Stratasys, that is. They will just describe it a different way and patent it anyway. Having the technology/idea as pervasive concept in the open source community would be a much greater defense to a Stratsys theft attempt than one designer with one measly patent and no lawyer on retainer, vs. Stratasys' team of lawyers on retainer, eager to pursue an intellectual property battle.

And to be clear, this is not meant as an attack on anything but patents. Patents are evil, and they bankrupt people while convincing them they are protected. They end up being ripped off anyway and are already bankrupt... so what left? The lawyers only win, when patents come into play. The key is to simply execute the idea better than anyone could before they could... and allow others to develop the idea. You then benefit from their developments too, and can incorporate the developments into your commercial product.

[Generic Default]

They also need to include integral wind-up prevention, which would prevent overshoot at startup. Right now the integral error term can drive you to max_pwm.

AHHH that's the term I've always been trying to figure out! The integral accumulates the temperature difference even when it is passing the target, and even when it is inactive. I never knew there was a special word for it though. The code I used to write for helicopter gimbals had a bunch of logic to deal with similar problems.


This thread has taken a path towards patent discussion. I wish more companies would discuss the technical details of their products with transparency, but everyone should understand that there is a lot of risk involved with it. My goal is not, has never been, and will never be to stockpile patents for legal extortion purposes (ie. no trollin'). I want to stay open source and prosper. The patent is just here to decrease my chance of being a startup business failure; if I ever get a demand for licensing, I'll keep any royalties dirt cheap and avoid exclusive contracts.

The benefits from tungsten disulphide (and several of the other improvements) are obvious for 3d printers, and I want everyone to have access to them. It has already taken me longer than I'd like to bring this to market; if I had access to the tools and money earlier this year, progress would have been much faster. So once I start shipping orders (should start late next week) I expect progress to accelerate. I apologize for all of the delays up until now, thanks for being patient everyone!

EDIT; 3 people have posted since I started writing this. Hot topic I guess?


On the performance of the hotend, I've concluded that PLA can still be jammed if the heatsink fan is turned off and the PLA is left to cook in the thermal isolator at excessive temperatures. I let it sit in the hotend at 280 degrees for around 6 minutes, and I couldn't extrude it with the cold end after that. When I let it cool down to room temperature, I was able to pull the filament out of the hotend. It releases once it gets below its rubbery temperature (~55 degrees C). So I guess that the moral of the story is to not burn plastic in a tight space. It didn't leave any residue on the interior of the thermal isolator.

The external nozzle coating had an unusual effect. The ABS and PLA are very hesitant to stick to the nozzle, but bringing them above their typical printing temperature can allow them to stick on the outside. Translucent ABS discolored to a light brown after a few hours at 250-280 degrees, but it never turned into crusty black chunks like it did on an uncoated nozzle. The coated nozzle seems to stay much cleaner than the uncoated one, but not spotless. Keep in mind these tests are not under normal printing conditions. I'm pushing some limits here.

[bdjohns1]

They also need to include integral wind-up prevention, which would prevent overshoot at startup. Right now the integral error term can drive you to max_pwm.

AHHH that's the term I've always been trying to figure out! The integral accumulates the temperature difference even when it is passing the target, and even when it is inactive. I never knew there was a special word for it though. The code I used to write for helicopter gimbals had a bunch of logic to deal with similar problems.

The external nozzle coating had an unusual effect. The ABS and PLA are very hesitant to stick to the nozzle, but bringing them above their typical printing temperature can allow them to stick on the outside. Translucent ABS discolored to a light brown after a few hours at 250-280 degrees, but it never turned into crusty black chunks like it did on an uncoated nozzle. The coated nozzle seems to stay much cleaner than the uncoated one, but not spotless. Keep in mind these tests are not under normal printing conditions. I'm pushing some limits here.

The joys of a degree in chemical engineering - I had to take a course on controls theory. I forgot all of the ugly math to derive transfer functions and crap, but I still do enough PID work in my day job (process engineer/manager at a large food plant) that the practical parts of PID are still front of mind. I'm usually playing in ladder logic on PLCs.

Looking at the code in the Temperaturecontrol module in Smoothie, it looks like it would be easy enough to add the code in - just need an if statement to force the integral term to zero outside the desired control band. I just need to download the toolchain so I can build my own firmware, I guess. I did put in a request in the Smoothie google group, but it might be faster to do it myself.

Back on topic for your hotend, how wear-resistant is the coating? If I do get black crud on it and hit it with a mild brass brush, will that wear away the coating? What about if we ever muck with something exotic like glass-filled filament?

[bdjohns1]

Looking at the code in the Temperaturecontrol module in Smoothie, it looks like it would be easy enough to add the code in - just need an if statement to force the integral term to zero outside the desired control band. I just need to download the toolchain so I can build my own firmware, I guess. I did put in a request in the Smoothie google group, but it might be faster to do it myself.

Turns out it was dirt simple, even for a hack like me who hasn't touched C++ since my undergrad CS requirement. I just tried it out - on my first go (setting the windup limit to 15C from the setpoint), I reduced my overshoot from >13C to <6C.

https://github.com/Smoothieware/Smoothieware/pull/540

One new parameter for your config file (temperature_control.hotend.i_windup). I might try narrowing the windup band further, then see if I can get my temperature rock solid with PID parameter tweaks.

edit: nevermind - they just properly documented i_max instead, which is the other way to prevent integral windup.

[redoverred]

All I want to know is when can I buy one! at only $50-odd bucks over an E3D for a triple extrusion that is lightweight and easy to use, I am sold. All I'd need to do is figure out where to mount a couple more steppers, spools, and how to run more wires now that the printer is all put together already!

On that note, how would I run 3 extruders on the stock board? Is it even possible? I could probably run 3 steppers for the cold end (put one in the 2nd z axis driver) but there are only two extruder power and thermistor connections, IIRC.

[bdjohns1]

You would need an extension board to do this. Fortunately, since the Kraken predates the Tri, one of our fellow users already figured out how to get 4 extruders, even:

http://forum.seemecnc.com/viewtopic.php?f=55&t=4522

Over on the Smoothieboard, you just need to pick three available GPIO pins per stepper. If you're using a graphic LCD, then the following are already used: 1.30, 1.31, 2.11, 3.25, 3.26. I'd probably use 1.23 and 1.22 (next to one of the LCD hookups) and then one of the unused endstop pins. You could probably also commandeer unused i2c pins as another option, since i2c on the Smoothie isn't terribly usable.

[redoverred]

You would need an extension board to do this. Fortunately, since the Kraken predates the Tri, one of our fellow users already figured out how to get 4 extruders, even:

http://forum.seemecnc.com/viewtopic.php?f=55&t=4522

Over on the Smoothieboard, you just need to pick three available GPIO pins per stepper. If you're using a graphic LCD, then the following are already used: 1.30, 1.31, 2.11, 3.25, 3.26. I'd probably use 1.23 and 1.22 (next to one of the LCD hookups) and then one of the unused endstop pins. You could probably also commandeer unused i2c pins as another option, since i2c on the Smoothie isn't terribly usable.

Cool, Thanks!

[Generic Default]

Back on topic for your hotend, how wear-resistant is the coating? If I do get black crud on it and hit it with a mild brass brush, will that wear away the coating? What about if we ever muck with something exotic like glass-filled filament?

WS2 has been used on injection molds for quite a while now, so while my own Tri hotend experiments don't have the benefits of long study times, I know that WS2 lasts for years under the right conditions. It doesn't come off easily, you usually have to scrape off the material under it to remove the stuff. So a wire brush would probably take a lot of it off the outside.
Glass fiber resins will definitely wear it out of the brass nozzles, and they will expand the orifice hole too (over time). Unfortunately I can't buy glass filled filaments right now so I'm unable to test this for at least a few more weeks.

I have plans for producing nozzles that can withstand this for extended periods of time. My experiments showed WS2 to be the best solution for the current filaments being used in 3d printers; I messed around with multiple other coatings and some of them have excellent abrasion resistance. The strongest, stiffest plastics are usually glass filled, so we may have to start viewing nozzles as consumables when it comes to high end plastics. The price of these "super nozzles" that last a long time will be at most a few dollars more than the current brass nozzles. Changing nozzles on the Tri hotend takes ~1-5 minutes.


But for PLA, ABS, nylon, PET, ect. the current nozzles should last a long time. I really have no idea how they will interact with metal powder filaments, but I'm guessing they won't last indefinitely for those either.

[0110-m-p]

So what are you using to control 3 extruders? Can the RAMBo's extra Z-motor be used for a 3rd extruder?

[artexmg]

So what are you using to control 3 extruders? Can the RAMBo's extra Z-motor be used for a 3rd extruder?

The answer just three posts back

http://forum.seemecnc.com/viewtopic.php ... 110#p52458

[0110-m-p]

So what are you using to control 3 extruders? Can the RAMBo's extra Z-motor be used for a 3rd extruder?

The answer just three posts back

http://forum.seemecnc.com/viewtopic.php ... 110#p52458

Thanks, I have been keeping track of that thread as well because I was originally considering a Kraken. Just wasn't sure if that was necessary for 3 extruders or if there was some work around other than adding an auxiliary board. I remember reading something about using various other pins on the RAMBo to make it work.

I've got my printer calibrated and running great with RAMBo and Repetier 0.91 firmware, so I'm just hoping to change as little as possible.

EDIT: Although...I have been thinking about building a second machine and the Azteeg X3 Pro's schematic makes it look pretty badass.....G4 S(time for brain to process)....

[artexmg]

So what are you using to control 3 extruders? Can the RAMBo's extra Z-motor be used for a 3rd extruder?

The answer just three posts back

http://forum.seemecnc.com/viewtopic.php ... 110#p52458

Thanks, I have been keeping track of that thread as well because I was originally considering a Kraken. Just wasn't sure if that was necessary for 3 extruders or if there was some work around other than adding an auxiliary board. I remember reading something about using various other pins on the RAMBo to make it work.

I've got my printer calibrated and running great with RAMBo and Repetier 0.91 firmware, so I'm just hoping to change as little as possible.

EDIT: Although...I have been thinking about building a second machine and the Azteeg X3 Pro's schematic makes it look pretty badass.....G4 S(time for brain to process)....

Well, not sure if I understood correctly, but the solution given in the thread is for a RAMBO, just adding an extra controller for the extra extruder

I am in the same very dilemma of using a Smoothie board (or Azteeg, same thing) or get stick to RAMBO.

Probably will have to have one Rostock with Rambo and other with Smoothie board

Cheers!

[teoman]

Would some one minde sharing gcode of 3riple or double extrusion?

[bdjohns1]

Would some one minde sharing gcode of 3riple or double extrusion?

It's not a gcode thing - your slicer (and the parts you feed into it) need to be set up. All you do in the gcode is tell it to do a tool change. The slicer should do that.

Most common thing today is to use the 2nd extruder for support material (ie HIPS support with ABS prints).

[0110-m-p]

Would some one minde sharing gcode of 3riple or double extrusion?

It's not a gcode thing - your slicer (and the parts you feed into it) need to be set up. All you do in the gcode is tell it to do a tool change. The slicer should do that.

Most common thing today is to use the 2nd extruder for support material (ie HIPS support with ABS prints).

KISSlicer has a really simple way to change materials/extruders. Just add a printer configuration based on what extruder you are using, what kind of material is loaded into that extruder, and where you want that material to go in the slice. I haven't used it yet, but after seeing how easy it is to configure I'm ready to jump on the multi-extruder train...calibration on the other hand is probably going to be a complete PITA.

Here's a screenshot of the Extruder Materials tab...

[teoman]

Yep.

I was planning on rewriting parts of the repetier firmware to pump out the commands to an auxiliary controller card over I2C.
Just need to figure out what are the commands.

[bdjohns1]

I noticed something is finally listed as in stock.

[Jassper]

Other than support material I have no desire to print rainbow vases. So how long until the software allows you to print specific parts of a print in different colors, or at least allows me to print 4 black checker squares along with 4 yellow checker squares on the same plate

Also, I didn't read the entire thread so maybe this was already addressed, but wouldn't the hotend melt the ABS effector plate?

[Generic Default]

I finally got to the point where I'm selling and ready to ship! I'm sorry for all of the delays. I did most of the design work in the first few months of the year, some basic prototyping, I did limited production on some mini CNC machines from June to August, and the machine shop finished the first big batch in October. Then I took the time to get the parts coated, but there were still a lot of delays after that. But I'm shipping the finished product now, and the performance of the thing is excellent. Future products won't take so long.

Jassper,

I don't care about rainbow vases either. I have never even printed a vase, but I think that using multiple extruders has huge benefits. Support material, multi-color, different materials in the same print, and different nozzle sizes are the big ones. And I think that most of the slicers allow you to print those checkers now, you should look up a video on how to do it. Plus this is the only full-metal hotend that can reliably print PLA without special care (as far as I know). The WS2 coating prevents jams.

I have used printed effector plates for over a year now and I haven't melted any yet. As long as there is at least a little gap between the plate and the heated bed you should be fine. The hot part of the Tri hotend never touches anything, and the titanium thermal isolator prevents almost all of the heat from getting to the heat sink anyway. It's about 3x more efficient than the stainless thermal isolators used on other hotends. ABS and trimmer line nylon should work fine for effector plates. PLA is more risky since it gets soft around 50C.

[pkhzor]

I've been keeping an eye out for this thing for a while now and it's finally released. By the time I'll get around to install it I'm sure someone will have written some sort of a tutorial for it. Hope to see it in the mail soon.

[pkhzor]

It arrived today, it looks awesome and the included instructions are very nicely written too. All in all the hotend looks really good, I've yet to purchase rest of the upgrades I need to make it work but at least it's here. Can't wait to print something with it.
Generic was awesome and included a mount for me, thank you for that man.

[TwinTurboGuy]

I am awaiting delivery of my first 3D Printer (Rostock Max V2) and am already considering upgrades for the build process.

I am highly interested in the Tri-Hotend, as it looks fantastic and seems superior to all others out there.

A couple of questions:

1) Can I buy this hotend and simply just run two of the heads off of the Rambo board until I am ready to upgrade to the smoothieboard, leaving the third vacant?

2) I'm also interested in upgrading the arms on my printer and the magnetic ends seemed attractive. Is there a specific kit I can buy or at least a parts list that plays nicely with the effector that was designed for the Tri-Hotend? I also noticed the TrickLaser arm kit which seems to be well thought out. Would the Tri-Hotend mount nicely with that as well?

The magnetic ends appeal to me so I can swap out a dremel, laser head, etc. while also wanting to reduce weight.

Any additional advice on upgrade parts are also appreciated, though I realize it may be off-topic.

Thanks in advance!

[Generic Default]

Yes, the Tri hotend can run one, two or three hotends during the same print. A lot of prints I do don't need support or more than one color/material, so I find myself doing many of my simpler prints in one type of plastic only (usually trimmer line).

With that being said, you can also input more than three types of filament into the Tri hotend with a little merger device I made, although you will need a board that supports more than three extruder stepper motors for that (6+ total)


I love my magnetic arm setup because it makes the smoothest prints out of anything I've tried so far, but you will not be able to mount a dremel to it without modifications. The magnetic force can only hold a few pounds and the force of the dremel will break the connections. No permanent damage if you have a hotend on it, but a dremel may go spinning around the room if it gets loose!

I have a newer design I've been prototyping that works the same as the magnetic arms but without magnets; it's a lot more rigid and it can't get loose. But it is more expensive and I'm still in the designing and iterating process.



As far as mounting goes, I have designed several mounts specifically for the Rostock Max and they are compatible with stock arms, trick Laser arms, and magnetic arms. If you want a custom mount I'll be more than happy to design and print one for you.

Have fun when you get your Rostock! I was in your same position a year and a half ago. You will learn a lot, and having a machine that makes stuff easily is awesome!