Does the Hotend Make Much of a Difference

I was just wanting to know what other thoughts and experiences were when they upgraded their hotends. What kind is being used and what kind of difference it has had in print quality. Currently I have a chinese j-heah currently and was wanting to know if an upgrade would be worth it.

I bought a $20.00 finned and fanned 1.75mm end with a .4mm nozzle (actually .35mm) from Aliexpress and could not be happier. The best thing I did was add a piece of aluminum tubing to keep the filament straight between the Hob Gear and entry hole. No more flex in the filament as head moves left and right eliminateing filament pushout.

The hot end is one of the single most critical components on your machine, if not the most. The quality of the non name brand imports can be pretty dicey. Get as good a hot end as you can afford.

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elwood127
I bought a $20.00 finned and fanned 1.75mm end with a .4mm nozzle (actually .35mm) from Aliexpress and could not be happier. The best thing I did was add a piece of aluminum tubing to keep the filament straight between the Hob Gear and entry hole. No more flex in the filament as head moves left and right eliminateing filament pushout.

[attachment 58830 DSC00504.jpg]

fyi, what you have there is actually an e3d counterfeit,

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This video made me realize how much to the design of hot ends there really is: E3D at 2015 MidWest Reprap Festival

The video and audio quality is poor, but it's worth watching. If you want to skip the intro to E3D as a company, jump to 3:42.

The hot end is either going to work or it isn't. You won't see any difference in print quality from one to another.

You may see a difference in print quality depending on the nozzle size, layer height, and the object you're printing.

If you have a hot-end that works and you're looking to improve print quality, look elsewhere. Print quality is affected by things like frame and guide rail flex, sloppy bearings, printer speed and acceleration settings, printer calibration, and slicer settings. Notice the last few items in the list are free. Optimize those before you start spending money on new printer parts.

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

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the_digital_dentist
The hot end is either going to work or it isn't. You won't see any difference in print quality from one to another.

Sorry, that is not correct. Depending on the nozzle shape the print can be quite different. Flat nozzles tend to easily brint plane surfaces with little calibration effort, while sharp tipped nozzles require better calbration but deliver better precision and bridges. Most hotends are of the flatter kind.

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I've never seen any comparison of nozzle tip shapes. Do you have a link?

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

Sorry, no. This comes from feedback of testers and users of my Merlin hotend, which has a particular sharp tip.

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A good/bad hotend can be the difference between a reliable good quality machine, and a problem machine. Hotends can fail in a number of ways depending on the model, and these various failure modes can manifest in various ways on the print quality.

Hotends can make all the difference, but wont make up for poor tolerances or build quality on the rest of the machine.

I no longer buy my hotends but instead make and design my own.
After trying varoius types and cofigurations I realised a few things:

1. There is no real need for more than 20W unless you want to try to push the limits of high speed printing with all the problems associated like cooling and drooping.
2. Full metal, teflon lined, or like the J-heads with a PEEK cold end - does not matter if you just want to print PLA or ABS at the lower end of the heating scale.
3. The bst option is to have a dedicated hotend for the filament in use

Having said all that crap, a good all metal hotend is a good investment as it allows to print almost everything, if there is no teflon liner inside.
But even the best hotend is useless if the user is unable to calibrate the printer and use the slicer in the right way.
There is little to no problem getting reall prints using a cheap J-head clone for a few bucks, same for a E3D knock-off.
The real difference for a serious comes into play with tolerance, heat dissipation, binding forces and the shape of the nozzle tip.
A cheap knock off might look god but once you had your filament stuck because it melted in the cold zone or totally blocked because the teflon liner was not cleaned properly you know where you went wrong.
Changing to a really high end hotend like the E3D or other models is only worth the money once you actuall understand your printer and slicer.
I know a few guys that paid top dollars for a really good printer, added some more money for a big collection of hotends but never managed to get a proper print themself.

To cut it down: If you want a new hotend to improve your prints you should be 100% sure you already exhausted the limits of your current hotend.
Bad prints only too often come from using the wrong settings or a bad calibration (not to mention uneven beds).
For me the only reason to invest into a top quality hotend would be to print high temp filaments that require over 300° for proper printing.

A hot end can make a big difference to reliability.... I'm on my 3rd, after having lots of clogs & jams with a Ubis ceramic (installed on my Printrbot when I got it), I tried a Chinese fake E3DV6, and I'm now on a Chinese all-metal J-head.

It turns out that the jams were caused at least partly by the extruder, so I now don't know whether the "E3DV6" was any good, but (now that the extruder is fixed) I haven't had a single clog or jam with the J-Head.

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the_digital_dentist
The hot end is either going to work or it isn't. You won't see any difference in print quality from one to another.

You may see a difference in print quality depending on the nozzle size, layer height, and the object you're printing.

If you have a hot-end that works and you're looking to improve print quality, look elsewhere. Print quality is affected by things like frame and guide rail flex, sloppy bearings, printer speed and acceleration settings, printer calibration, and slicer settings. Notice the last few items in the list are free. Optimize those before you start spending money on new printer parts.

As Srek says, there is more to a hot end than working or not working. To chime in on what frankvdh posted reliability is a big factor as well though long term and under moderate duty cycles the import clones usually don't fair well. A good hot end is a combination of many factors including nozzle, melt zone, thermal break and heat dissipation over the device. The lack of those parts not being able to work together will impede consistent, proper extrusion. On a FDM/FFF machine if you don't have good extrusion it doesn't matter how good the rest of your parts are, your prints aren't going to be very good. Those poorly made clones and counterfeit parts are the cause of many problems with entry level machines. Some (many or most) don't have the right tolerances or materials and combined with poorly copied designs and poor workmanship it's not a recipe for success.

Unfortunately there is no single repository of knowledge to reference for hot end designs. There is quite a bit of info here or on the Google + groups as well as IRC. Guys like Srek (Merlin), jollygrimreaper(aluhead), Reg Pye (Genie) and Sanjay (E3D) are a weath of information (among others) Once one starts printing a great deal, with different materials on a regular basis the differences are much more noticeable.

All those things speak to reliability, not print quality, which is what the OP was asking about. I suppose actually finishing a print can be considered a quality issue, but for me print quality is about the surface finish, and accuracy of size and shape. None of those are affected much by the hot end. I think the drive mechanism that pushes the filament into the hot end is of much more importance to print quality, at least by my definition.

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

Not entirely correct.
A bad hotend with inconsistent friction or being unable to hold a steady temp will ruin all your prints.
The surface finnish depends on material used, print settings and the actual nozzle tip.
I know we could argue about that all day but how do you get your quality if the hotend ruins all your attempts of constitent prints?

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the_digital_dentist
All those things speak to reliability, not print quality, which is what the OP was asking about. I suppose actually finishing a print can be considered a quality issue, but for me print quality is about the surface finish, and accuracy of size and shape. None of those are affected much by the hot end. I think the drive mechanism that pushes the filament into the hot end is of much more importance to print quality, at least by my definition.

Have you compared the quality of using various hot ends?

I also thought that a hotend cannot affect print quality, until I got a reliable one (thanks to Reg Pye).

For me, a reliable hotend is one that does not clog even if you print 20°C higher than the recommended print temperature, nor if you print veeeery slowly or veeery fast, nor if you overextrude, nor if you print a first layer on a bed that is not flat at all, nor if you halve or double the hotend fan speed or some other fan around it, nor if you change filament color or brand.

In other words, it does its job (almost) independently of many other printing factors. This allows one to widen the range of parameters that can be reliably used to print, so that they can be optimized for other reasons (surface quality, mechanical robustness, ecc.).

For example, in some cases I had to reduce a lot printing speed to avoid some artifacts on object surfaces given by acceleration, and I couldn't do it with my previous (unreliable) hotend. Even worse, I read more than once on these forums that filaments of the same brand but different color caused several problems to some people: with my hotend I cannot care less about the filament color or brand. If it is PLA, it will flow out of my hotend at any temperature between 180°C and 230°C and no, it will not jam.
As another example, I print cheap ESUN PLA between 220°C and 230°C (quite high temperature for PLA I would say) to avoid delamination. With a less reliable hotend I may probably not print PLA at those temperatures, as it is maybe the case for those that abandoned ESUN PLA because of delamination.

If you have an extremely good printer, with most filaments you will probably not see the difference between a decent and a good hotend. But it is sure that if you have a good hotend, when something goes wrong you can already exclude one of the trickiest source of troubles.

Edited 1 time(s). Last edit at 07/27/2015 07:12PM by cristian.

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vegasloki
Have you compared the quality of using various hot ends?

I have not. I never considered it to be an issue. I'm still not convinced it is.

People seem to be conflating print quality with reliability. Yes, there are some bad designs out there and some poorly made knock-offs of good designs, but I doubt anyone could compare two prints made with same size nozzles and different hot-ends on the same extruder/printer and find any difference. As far as clogging and reliability go, I think the motor/gear drive that pushes the filament is more important than the hot end. A lot of shortcomings in the hot-end can be overcome by brute force from a good, strong extruder. The evidence of this is in these forums. When people are having extruder hot-end problems it is usually with 1.75mm filament. Why? I think it's because most 1.75mm extruders use the motor to turn the drive gear directly. The 3mm extruders all have gears that multiply the motor torque and can provide much more downward force on the filament. A few 1.75 mm extruders are available that use gear reduced/torque multiplied motors (such as the BullDog XL that I use).

Until someone actually runs a well-controlled test, all arguments on either side are just blowing smoke.

If someone is looking to make print quality improvements, the hot-end is the last place to look. Fix the floppy printer frame, the flexy guide rails, the sloppy bearings held on by nylon wire ties, the bad bed leveling design, etc., then look at the hot-end. Of course, if the thing can't print because the hot-end keeps clogging, you have to fix that first, but that's a printer quality issue, not a print quality issue.

Edited 1 time(s). Last edit at 07/27/2015 11:22PM by the_digital_dentist.

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

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the_digital_dentist


Until someone actually runs a well-controlled test, all arguments on either side are just blowing smoke.

It doesn't get any more controlled than running different hot ends on the same machine with the same material for a day or two each (if they can make it that long). This includes most all the US/Euro name brands and several of the import clones and knock offs. I've also got a couple of different direct drive extruder designs being tested in that same manner.

I'd also say your observations about 1.75 mm material and direct drive extruders aren't what I've experienced. For most 3 mm material has been supplanted by 1.75 mm as a factor of the market more than anything else which is a more likely reason there are more 1.75 support requests. Combine that with poor quality import machines in the hands of first time builders and it's the perfect storm. I still have one 3 mm machine in the farm but only because the extruder (which is a gear reduction stepper motor Maxstruder) performs poorly with 1.75 mm material. I haven't yet got around to replacing it with something else. On that design the heat creep combined with the torque of the motor makes feeding poor and kinks the smaller material once the heat builds up. A bigger issue for me with the 1.75 machines is the way in which 1.75 feeds off the spool and have seen more 1.75 spools that winding issues mid spool due to the smaller size, 3 mm wasn't pliable enough to loop like that.

Like the_digital_dentist's, most of the time my hotends either work or they don't. However, I have seen quite a bit of variability in quality of print. As I make all of my own hotends I have tried many things to optimize the print quality and have observed the following:-

That the nozzle hole should be a little over twice as deep as its diameter; for example, if it is a 0.35mm nozzle then the channel should be about 0.7mm to maybe 1mm long. Much more than twice as long will unacceptably increase the back pressure. If the channel is shorter than the nozzle hole diameter then extruded filament can be lumpy.

The edges of the hole in the nozzle should be sharp and without burrs, the flat around the hole should be smooth and either flat of slightly convex, the transition from this flat to cone around the nozzle should be very slightly rounded and without ridges and the finish of the nozzle should be without any oxidation or corrosion. Problems with any of the above will cause plastic from the print to be dragged along the trailing side of the nozzle.

The inside of the thermal break (assuming that it is not PTFE there) should be at least dead smooth and may benefit from being polished. Conversely, the inside of the melt chamber can benefit from being rough to transfer the heat to the melt. If the nozzle hole is small then the back pressure will be high so it becomes more important that cooling of the part above the thermal break is effective. Thermal break problems manifest themselves when filament is extended after a retraction resulting in patchy restarts.

Pockets in the melt chamber should be minimized as material can lodge there and re-appear after a new material is being printed. The entry to the nozzle hole from the melt should be conical and the transition into the nozzle channel should be slightly rounded.

If the "well-controlled test" that the_digital_dentist says is lacking were ever to be conducted then it should be on a wide range of materials, environments, printers and ways of using the printers. I am sure manufacturing variability is quite high and any comparative test would have to have multiple sample of each tested hotend, preferably taken from production runs at different times.

Mike

With a hot end you have two options when purchasing.

1 - Buy the best ones out currently and make it work with your printer.

2 - Buy the cheapest one and spend time and effort to make it work properly.

Since I am a cheapskate I chose the latter, but I can say this. How much is your time worth? I personally like to work with my hands so its more like therapy to me than work. I even created two videos on how to rework the cheapskate options and make them work. I have been very happy with the result.

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Modicum V1 sold on e-bay user jaguarking11

There's also a bit of a middle ground for buying a hotend that blends affordability and reliability. My first printer, the QU-BD Two Up, came with an awful Ubis clone hotend; it could print perimeters fine but could not do bridging at all, meaning that the top surfaces were spotty and weak. On top of that, heat would creep up the barrel even with a cooling fan installed, eventually causing underextrusion and jamming.

For my custom-built CoreXY printer, I initially used a direct-drive Aluhotend v6 and later switched over to a bowden E3D Lite6 for a lighter print head. Both of these hotends are affordable (~$50 for the Aluhotend with shipping and ~$40 for the Lite6) and they've been mostly trouble-free and have impressive print quality (the Aluhotend's smaller heatsink does require more aggressive cooling though). I'd definitely recommend getting one of these hotends if you're having trouble with a poorly made clone hotend.

I'm planning to get the E3D v6 tomorrow, any input about this hotend kit? or is there something else less expensive? I'm looking for a hotend that do for TPU and stainless steel etc... those type of filaments

thanks

I don't think a E3D will be able to print stainless steel....

I've had a J Head (probably Chinese) and a (definitely) Chinese e3d clone, the e3d clone works really well but I've gone from a 0.5 nozzle to a 0.33 (supposed to be 0.3 but it was a little larger when measured accurately using a set of watchmakers twist drills, verify the drill diameter first then measure with it) ,and I put the improved quality down to the sharper and smaller nozzle. Haven't had it long enough to test reliability.

My only gripe was the e3d clone fan had a dodgy bearing on arrival but for £11 ($17) delivered I am not moaning I just replaced it with a sunon fan instead (which cost half as much again worth noting these are 5v so a 100 OHM resistor is needed to run it direct off the 12v/13.2v rail).

I've ordered the original E3d v6, didn't find anything better to get other than multi nozzles, but they are too pricy, everything on this printer was clones when I first got it, I rather slowly replace them than buying another clone, I did get it running right for a week, then bit start to fail, begin with D9 fail on the ramp board to all sorts, the print head is the last piece to replace, might as well for the last time.