Need a hot end . More reliable then J head? Bowden drive

Alright

So im making a mendel max 1.5 that will be dual extruder bowden setup.

Iv been running a few machines pretty hard with the typical J heads running ABS

Having problems with reliability. They either come apart and leak or the threads strip is suspect this is because running ABS at 240C is very close the melting temp of the insulator.

The E3D V4 looks interesting? Is that the way to go?

Arcol looks intresting but very expensive esp for two. SG2-hot End is another option ?

What would you suggest? Ready to spend 250$ for both hot ends if i can get a high level of reliability.

go for the water cooled version of the sg2 called the europa, i have it, i ran 1.75mm filament at 10mm/s through it with no problem, its extremely durable and the water cooling allows you to tune the melting zone of the hot end very effectively, also it doesnt need a fan since its water cooled.

Water cooled closed loop like a computer? Its an option but he only has one in stock .

Any other options?

it runs off a little pump, i have mine hooked up to a reservoir i made from a nalgene bottle, then i printed a lid for the tubes and wires. dont get the qu-bd i had one and it kept jamming and i went crazy. also the SG2 is very good, and the guy that makes them backs his product 100% so if it breaks he will replace it.

Do you run the pump on all the time or do you control the temp of the cold end? I know he was saying that you could set it up to control the melt chamber length by cooling the other side aggressively with things like a TEC dont think i want to get that into this ...

Hi,
have a look at reprap-fab.org V3 this is quite reliable, all metal, exchangable noozle for different orifice ;-)
Only you need to be lucky that they are in stock, but they are worth waiting...

Hi FlyingFreak,

I designed/sell the e3d v4 hotend. I am quite confident that our design would eliminate all the leaking and reliability issues you are having, as well as being able to reach high temperatures happily - the SG2 has a PTFE liner inside that would fail around the 240C mark.

Arcol make a good product, and he puts a lot of effort into his products. I haven't tried his latest hotend personally, but he has a good reputation and everything I have seen out of his shop is good (Hobbed drive shafts etc)

The reason I am chiming in here, is that I have a hotend version with an integrated bowden tube fitting on the way, the hotend would have a pneumatic fit coupling screwed into the top that couples right to the tube. Probably sold complete with 1m of tubing and another pneufit coupler for the other end. So basically a 300C+ capable hotend with an integrated bowden system - seems like something that would suit your needs.

If you are interested I will get more details up rapidly.

ive run my europa up to 300c no problem. it has the ptfe as well. but the e3d v4 hot end is good as well. also ptfe and peek have the same relative working temperature, the ptfe tube in the SG2 is being cooled by the heatsink and its not a structural component of the extruder so strength is not an issue. however because ptfe has a lower coefficient of friction it allow for faster extrusion.

Edited 1 time(s). Last edit at 04/13/2013 03:20PM by aduy.

The issue with running a PTFE liner at 300 C is not an immediate mechanical one. But the fact that if PTFE is over 240 C it is going to be degrading chemically at that temperature. Eventually it will fail when being run at those temps

Both seem interesting i like water cooled as my computer background has shown it to be very reliable and extremely efficient. It could , at a later date also be another parameter i could control (control both hot end heating and cold end cooling).

That being said the e3d design seems much simpler.

Not sure. Anyone have experience with both? Any other designs i should consider? Arcol seems cool but too expensive and from what iv read fragile.

I've considered water cooling, and there is a really nice base of available parts and literature on it. The thing that gets to me is that no computer water cooling system is designed for repetitive flex/motion. I can see a coupler or hose working to failure - and failure in this case is likely catastrophic. The other point is that it is high cost, high complexity. We need to keep in mind that we are killing LESS THAN 10 WATTS this is not an overclocked monster GPU .

The fight is not about removing as much heat as possible, its about carefully placed and controlled heat along with carefully placed cooling of the correct magnitude.

I'm not sure that controlling cooling is a useful variable to manipulate. You are simply looking to maintain plastic below its heat-deflection/glass transition temp until it is in the correct position. As long as the plastic stays below the magic number I cannot see that adding more cooling would result in any kind of performance gain. Reducing cooling would just cause the filament to jam up as it gets hot and sticky in a non-optimal position.

That's how I see matters anyway...

the advantage is, when you make the water running through warmer, you can run plastic through the hot end much faster, when you run cold water through it comes out slower which is better for precision, and also controls oozing. also it uses silicon tubing rated for 500c working temp so running the water is not a problem.

Sanjay, I was/am going to send you a PM about consideration of you producing a water cooled version of your hotend, that would ideally be shorter and lighter without the big aluminum heatsinks. Any possibility of you considering that? I could possibly help with alpha testing/development and feedback.

I have both the SG2 and the Europa hotend, and have been using them for a while. Really well-made hotends, and the guy that makes them stands behind his products, which is awesome. It's the nicest thing on my printer.

atv Wrote:
-------------------------------------------------------
> I have both the SG2 and the Europa hotend, and
> have been using them for a while. Really
> well-made hotends, and the guy that makes them
> stands behind his products, which is awesome.
> It's the nicest thing on my printer.


we should start a club.

I am the maker of the SG2, and Europa. I would NEVER use a forum to sell my products ! A forum is for independent discussion, NOT for chiming in about the wonders of your new hot end, and trying to sell it ! I know who the owners of the Europa hot ends are, since it is a developers hot end. Everybody that owns one is a developer. I would NEVER ask anybody to even write nice things about me, let alone try to make sales on a forum. I don't think much of the sales tactics of E3D ! I have EARNED my following !

As 3D printing becomes more popular, I see more and more feeble products for sale, some at ridiculously high prices. This is not the manner that RepRap was originally inspired, not the spirit of cooperation that has brought 3D printing to the masses. The idea has been corrupted to the point I ask myself if I want to bother with bringing high quality parts to people, at fair prices.

I would NOT recommend any of the hot ends we currently build for high temp prints, HOWEVER, this has inspired me to build a new hot end. It will be capable of handling 650C, AND have a low friction lining. It will not have any issues of getting hung up on seams on the barrel.

Unfortunately my health is not as good as I would like, so releasing it will take more time than I would like, or developers would like.

Thank you to the people that said nice things about our products, and everybody that appreciates high quality and service. Bradley C Fudge

maddox
Would certainly consider it, weight reduction would be the main motivation if understand you? In that case we do have to account for the moving mass of the tubing full of water and some other considerations:

Using 30cm of 5mm ID tubing full of water, makes for about 6g of water in the pipes. Consider than we need an inflow and an outflow pipe that means 12g of water. Plus the weight of the tubing - probably sillicone for heat and flexibility properties - which would come to 2.5g a length, for a total of 5g. That's 17g for the piping and water inside of it. Now add the cooler block, which has a minimum height due to mounting considerations - lets say a 16mm cylinder 30mm tall of aluminium - that's 16g.

12g Water
5g Tubing
16g Cooler block
= 33g

Also you would probably want to use 'proper' fittings for joining the pipe to the cooler block to prevent leaks, which will have some weight too.

Assuming our main objective for decreasing weight is to achieve higher X/Y velocity of the head, we also need to consider that the tubing will require a certain amount of force to bend it.

The part that all the above replaces is the heatsink, fan, and printed fan mount which weighs 52g in the current iteration. So we are saving around 20g in total. But we must also account for hose-bending as mentioned before.

I have already done a minor fat-trimming on our heatsink - the next batch will be around 10-15g lighter I think (need to check the numbers on the CAD model). So the weight saving on water cooling seems nearly eliminated?

I am not trying to rain on your parade! I actually just did the above calcs as I wrote the post, and before I started I honestly didn't know what the answers would be like... But it seems like maybe althought intuitively it makes a lot of sense, when you factor it all in, maybe not as great as it looks?

Just also realised, that although the tubing moves, not all of it moves as far/fast as the head itself, so the equivalent moving mass will be somewhat lower.

Anything I am missing?

Bradley
I don't really buy the assertion that sellers shouldn't be posting in forums, lots of people on here are both selling and contributing to the knowledge base here. It's an ecosystem, not a pool of customers who go elsewhere to find sellers.
The first versions of the E3D hotend were borne out of a collaborative discussion on a thread in these forums quite some time ago, we asked people what they wanted, showed what we had done, got feedback and engineering advice, we modified our designs and engaged in more discussions with the community - sharing everything we had as we went. See here: http://forums.reprap.org/read.php?1,145069

Just so you know, so far I have not made a single penny out of E3D since starting up over a year and a half ago. Every last bit of revenue has gone right back into developing and releasing more stuff, probably made a loss infact to date.

I find it kind of upsetting when you make out like I'm some sort of marketing shill, when if you read my post history, I am on here discussing a wide range of topics and offering opinions and advice across the reprap community. Moreso on G+ than here nowadays, but anyway.

We have never, ever, asked people to write nice things about us. When they do, that's great, but it's only of their own free will that it is done. We have supplied samples to people who might review them on blogs etc, but we always say to them that all we want is an honest review, not biased flattery in exchange for a free part.

I don't quite understand your point about high prices of other peoples products. Your hotend is 150%-200% the price of ours and most others on the market. With regards to the spirit of community, all of our stuff is open-source, drawings and downloads are available at our website. I know of at least one person who is using the files to try and manufacture their own hotend - and many others using the drawings to make mountings or adaptations for weird and wonderful 3D printer varieties which I find really cool. I can't seem to find the engineering drawings or source models for either of the SG2 or Europa models? Do you have a website?

I'd be really interested to hear about your concept for a low friction liner that is good to 650C, what liner material do you plan on using? If you are having issues with filament catching on seams of the barrel we have found that using a steep angled countersink completely eliminates this (using a 60degree centre-drill works really well to machine this). I wish you the best of luck with your health.

Sanjay

Edited 2 time(s). Last edit at 04/17/2013 06:41PM by SanjayM.

SanjayM Wrote:
-------------------------------------------------------
> maddox
> Would certainly consider it, weight reduction
> would be the main motivation if understand you? In
> that case we do have to account for the moving
> mass of the tubing full of water and some other
> considerations:
>
> Using 30cm of 5mm ID tubing full of water, makes
> for about 6g of water in the pipes. Consider than
> we need an inflow and an outflow pipe that means
> 12g of water. Plus the weight of the tubing -
> probably sillicone for heat and flexibility
> properties - which would come to 2.5g a length,
> for a total of 5g. That's 17g for the piping and
> water inside of it. Now add the cooler block,
> which has a minimum height due to mounting
> considerations - lets say a 16mm cylinder 30mm
> tall of aluminium - that's 16g.
>
> 12g Water
> 5g Tubing
> 16g Cooler block
> = 33g
>
> Also you would probably want to use 'proper'
> fittings for joining the pipe to the cooler block
> to prevent leaks, which will have some weight
> too.
>
> Assuming our main objective for decreasing weight
> is to achieve higher X/Y velocity of the head, we
> also need to consider that the tubing will require
> a certain amount of force to bend it.
>
> The part that all the above replaces is the
> heatsink, fan, and printed fan mount which weighs
> 52g in the current iteration. So we are saving
> around 20g in total. But we must also account for
> hose-bending as mentioned before.
>
> I have already done a minor fat-trimming on our
> heatsink - the next batch will be around 10-15g
> lighter I think (need to check the numbers on the
> CAD model). So the weight saving on water cooling
> seems nearly eliminated?
>
> I am not trying to rain on your parade! I actually
> just did the above calcs as I wrote the post, and
> before I started I honestly didn't know what the
> answers would be like... But it seems like maybe
> althought intuitively it makes a lot of sense,
> when you factor it all in, maybe not as great as
> it looks?
>
> Just also realised, that although the tubing
> moves, not all of it moves as far/fast as the head
> itself, so the equivalent moving mass will be
> somewhat lower.
>
> Anything I am missing?
>
> Bradley
> I don't really buy the assertion that sellers
> shouldn't be posting in forums, lots of people on
> here are both selling and contributing to the
> knowledge base here. It's an ecosystem, not a pool
> of customers who go elsewhere to find sellers.
> The first versions of the E3D hotend were borne
> out of a collaborative discussion on a thread in
> these forums quite some time ago, we asked people
> what they wanted, showed what we had done, got
> feedback and engineering advice, we modified our
> designs and engaged in more discussions with the
> community - sharing everything we had as we went.
> See here:
> [forums.reprap.org]
>
> Just so you know, so far I have not made a single
> penny out of E3D since starting up over a year and
> a half ago. Every last bit of revenue has gone
> right back into developing and releasing more
> stuff, probably made a loss infact to date.
>
> I find it kind of upsetting when you make out like
> I'm some sort of marketing shill, when if you read
> my post history, I am on here discussing a wide
> range of topics and offering opinions and advice
> across the reprap community. Moreso on G+ than
> here nowadays, but anyway.
>
> We have never, ever, asked people to write nice
> things about us. When they do, that's great, but
> it's only of their own free will that it is done.
> We have supplied samples to people who might
> review them on blogs etc, but we always say to
> them that all we want is an honest review, not
> biased flattery in exchange for a free part.
>
> I don't quite understand your point about high
> prices of other peoples products. Your hotend is
> 150%-200% the price of ours and most others on the
> market. With regards to the spirit of community,
> all of our stuff is open-source, drawings and
> downloads are available at our website. I know of
> at least one person who is using the files to try
> and manufacture their own hotend - and many others
> using the drawings to make mountings or
> adaptations for weird and wonderful 3D printer
> varieties which I find really cool. I can't seem
> to find the engineering drawings or source models
> for either of the SG2 or Europa models? Do you
> have a website?
>
> I'd be really interested to hear about your
> concept for a low friction liner that is good to
> 650C, what liner material do you plan on using? If
> you are having issues with filament catching on
> seams of the barrel we have found that using a
> steep angled countersink completely eliminates
> this (using a 60degree centre-drill works really
> well to machine this). I wish you the best of luck
> with your health.
>
> Sanjay
I am not picking a fight with you, however you do appear to have ulterior motives. Neither am I going to debate you at ANYTHING !

As for the comment about high prices, that was NOT aimed at you, rather the overall happenings in the community.

You have said that over heating the filament on YOUR hot end causes it to fill in the seam, and hang up. Our hot ends do NOT have any hang up problems what so ever ! As for the lining I am going to use, sorry, I do have trade secrets. You can figure it out, it is not that difficult. It's not like I'm an engineer, thank you !

Good day, and good luck !

^Bradley, why the hostility? Sanjay's response was very courteous, couldn't you have given him the same level of respect?

Hostility ? I think I was as courteous as the statements he made deemed. He is the one that has made assumptions, and criticized a well established, and praised product. I wished him a good day, and good luck. If I was misinterpreted, then I apologize to anybody that took offense ! I wish e3d the best of luck ! I think they have a ways to go in hot end technology, but I have no ill will towards anybody !

SanjayM Wrote:
-------------------------------------------------------
> maddox
> Would certainly consider it, weight reduction
> would be the main motivation if understand you? In
> that case we do have to account for the moving
> mass of the tubing full of water and some other
> considerations:
>
> Using 30cm of 5mm ID tubing full of water, makes
> for about 6g of water in the pipes. Consider than
> we need an inflow and an outflow pipe that means
> 12g of water. Plus the weight of the tubing -
> probably sillicone for heat and flexibility
> properties - which would come to 2.5g a length,
> for a total of 5g. That's 17g for the piping and
> water inside of it. Now add the cooler block,
> which has a minimum height due to mounting
> considerations - lets say a 16mm cylinder 30mm
> tall of aluminium - that's 16g.
>
> 12g Water
> 5g Tubing
> 16g Cooler block
> = 33g
>
> Also you would probably want to use 'proper'
> fittings for joining the pipe to the cooler block
> to prevent leaks, which will have some weight
> too.
>
> Assuming our main objective for decreasing weight
> is to achieve higher X/Y velocity of the head, we
> also need to consider that the tubing will require
> a certain amount of force to bend it.
>
> The part that all the above replaces is the
> heatsink, fan, and printed fan mount which weighs
> 52g in the current iteration. So we are saving
> around 20g in total. But we must also account for
> hose-bending as mentioned before.
>
> I have already done a minor fat-trimming on our
> heatsink - the next batch will be around 10-15g
> lighter I think (need to check the numbers on the
> CAD model). So the weight saving on water cooling
> seems nearly eliminated?
>
> I am not trying to rain on your parade! I actually
> just did the above calcs as I wrote the post, and
> before I started I honestly didn't know what the
> answers would be like... But it seems like maybe
> althought intuitively it makes a lot of sense,
> when you factor it all in, maybe not as great as
> it looks?
>
> Just also realised, that although the tubing
> moves, not all of it moves as far/fast as the head
> itself, so the equivalent moving mass will be
> somewhat lower.
>
> Anything I am missing?
>
-----------------------


I never replied to this. Yes, weight reduction is a primary motivation of considering water cooling, along with effectiveness/efficiency and being able to control the airflow in the build area. Some thoughts:

- Weight reduction -- the weight analysis that you posted adds the weight of a water column and piping as if it were free standing 'unsprung weight' (if you get my relation to the car term). Not the entirety of the water and the tubing (you also mention this at the end of your post), is being accelerated as if it were dead weight hanging solely on the hot end. The further the tubing gets from the head, the less it is accelerating, to the point where the tubing is accelerating zero where it is mounted to the Bowden motors. And regarding the weight calculation, the water and tubing are being supported at two points, not at a single point, so we can't treat it as if it were just a pillar of water on the hotend. Also like you mention , the compliance of the tubing would need to be factored into the resistance that the moving head would feel. The hotend shaft could also likely be shortened, as the watercooled block is likely shorter than your current heatsink, for additional weight savings.

I hadn't/haven't actually gone through any weight calculation with real numbers, as I don't have any of these comparable hotend parts to weigh and to try to make a valid comparison. I was basically just going off of Adrian Bower's comments in the description of his "RepRap water-cooled head" video, where he says, "I made a RepRap extruder with a water-cooled head, instead of a fan. It's more compact, and lighter. It's a variant on Jean-Marc's brilliant design. It seems to work quite nicely." [vimeo.com]

The weight is possibly more of a critical factor for me than it is for others, as I'm planning on running 3-4 heads on a single carriage, and my machine will have a much larger build volume than your average reprap. I'm sure weight is not near as critical for your average reprap machine with a nominal build size and a single tip Wade's extruder or whatever.


- Being able to control the airflow inside the chamber -- So I am going to have an enclosed heated chamber, with likely some with solidly mounted part-cooling blowers and ducting mounted onto the frame of the machine (the Z height of the fans won't need to change, as it is an X-Y cartesian bot with a separate Z-axis for the build platform). The ducting will be similar to the Dimension, as can be seen here: [kisslicer.com]

Ideally, I would be able to control (on/off) whether I want fans cooling the part, and with the heatsink fans dumping to the side, they may cause airflow over the part when I do not want any. I don't see this as a huge deal, just another perk of watercooling over fan cooling.


Are you still possibly considering making a water cooled version instead of air? Obviously, I would be greatly intrigued if so.

Edited 5 time(s). Last edit at 04/29/2013 10:05PM by maddox.

I wonder if we could not use this kind of peltier cooler to create a very sharp controlled transition zone and reduce the heatsink size and weight :

[www.tetech.com]

This particular one is not adapted to high temps but such modules exist.

A peltier ring from china is less than 10€

Maddox:

Agree wholly with your additions to the weight discussion. The only good way I can see to find out what kind of speed increases can be made is by using a good FEA sim. I might well get around to doing this.

For just 1 extruder the extra complexity and cost of water cooling is a little high, for what isn't going to be a massive weight drop. There should be some, but I don't think it will do better than 30-40% off the amount of effort needed to accelerate the head.

However for a multi-extruder system water cooling makes a great deal of sense. Once we have a nice neat integrated bowden system finished the next task is for a 3-4 extruder head. (3 heads is a lot easier than 4, due to planarity issues) Separate heating for each, single heatsink for all. Bowden fed, with nice integrated coupling etc etc.

In this case using water makes a hell of a lot of sense. Heatsinking 3 hotends with air is going to be bulky and awkward. And for the heated chamber issue you really want to be able to not worry about the heat of the chamber affecting convective cooling. I really like the idea of a heated chamber at a heat just a bit below the glass transition of the plastic being printed and a LOT of airflow inside, air blowing on the print directly after extrusion with a good deal of flow, as well as a lot of general ambient airflow. In this way plastic would be extruded, and rapidly cool to just below glass transition temp, making bridging and overhanging perform very well. Once the plastic has solidified after going below glass transition however it would not cool further, so eliminating warping.

This is multi-hotend is very much on the cards, and not a pie-in-the-sky idea, whether it will be water cooled or not isn't certain, but quite likely. I don't know the timeframe with any certainty - hopefully inside of 2013.

Sanjay

Cool, I like your thoughts. My ideas are on a much shorter timeframe than the end of 2013, so maybe once your hotend gets a little more thoroughly tested and the heat level/jamming cases gets worked out, I'll probably be talking to you about possibly buying some of the hotends without the aluminum heatsink, to retrofit my own watercooling prototype on there.

What is the expected timeframe like for the integrated Bowden setup for your current hotend?

Water cooling sounds interesting to me. How do you manage the inlet/outlet water lines on a moving carriage? Do they ever kink or become dislodged? Is it possible for the water lines to come loose during a print?

ive never had mine come loose, they come with little steel clamps, but i switched them out for zipties.

Hello everybody I have made an hot end that can sustain temperatures up to 1050 C the only problem is the thermistor can not go more then 300 C. I am thinking to try a thermocouple type K witch can sustain more then 1200 C. This hotend will be able to melt aluminum at ca 600 C and all plastics materials including PTFE and PEEK.This hop-tend will never ever come apart and leak with plastics materials and is not going to change the characteristics at temperatures ranges of the plastics materials like ABS, PTEF PEEK etc. I did not try at the 1000 C.
Any idea about thermocouple connection to reprap main-board?

You will need a little more circuitry to get it to work and there are specific chips available for this.

Check out the adafruit tutorial, they are always great places to start.
[learn.adafruit.com]

aduy Wrote:
-------------------------------------------------------
> ive never had mine come loose, they come with
> little steel clamps, but i switched them out for
> zipties.


Any pics of your watercooled setup?

this is it [www.befr.ebay.be].