Hi mgg942
I doubt it, because at the moment Ultimaker is a very small part of Sanjay's business, that may of course change if this becomes a popular option with Ultimaker owners. You can however use the Ultimaker aluminium block if you want to use the Ultimaker thermocouple. The critical thread for the nozzle and tube is M6, the same in both.
Andrew
Hi mgg942
I doubt it, because at the moment Ultimaker is a very small part of Sanjay's business, that may of course change if this becomes a popular option with Ultimaker owners. You can however use the Ultimaker aluminium block if you want to use the Ultimaker thermocouple. The critical thread for the nozzle and tube is M6, the same in both.
Andrew
Thanks, Andrew. I'd seen that was what you have done and I plan to do the same.
Mike.
The assorted mounting options on here are looking really nice! Looks like you are all getting on nicely.
I'm fully in approval of re-using the ultimaker aluminium block/heater/thermocouple - as long as its got an M6 thread down the middle then you're golden really.
Nick Foley
The thermistor is the remaining pain point i'd like to get sorted, and I really have looked into those sorts of options. However I am unable to find a nicely packaged thermistor that is rated to any sort of decent temperature (150C+). I have even asked for them to be custom made from several factories in china, but to no avail. Something like this would be lovely: http://www.vishay.com/docs/29065/ntcascw.pdf
The final option we are considering is just to do our own production of a probe - by cementing the current standard thermistor into a very small socket head set screw or similar threaded object. It's just the labour of doing so is prohibitive right now.
Interesting to note. That matches up with the quotes I've been getting back from US Sensor.
Anyway...
...We seem to be having some clogging/plugging/underextrusion problems with this hot end. We haven't exactly figured out what's causing the failure, but we've had several prints over the past few days that slowly transition from solid part to underextruded fluff as the print progresses.
It seems to be related to small/thin-walled prints, and maybe somewhat related to retraction, but not entirely, because we're seeing it even with retraction turned down to 1mm. (Edit - it is not being caused by retraction, as I now have a print that, 15 minutes in, is starting to fail due to underextrusion, and it has retraction turned off.) The current print, which failed 3 times on the machine with this hot end, is now printing without error on our machine next to it which has a (more or less) stock hot end
Any ideas? Have you seen this before?
I have had this happen a few times...
Most times I have had this is when I have the heated chamber on my machine too hot, so the cold part of the hotend can't cool. This seems to happen if the chamber is close to the glass transition temperature, so around 45degC for PLA and 70degC for ABS. Obviously not an issue if you don't have a chamber.
One other thing to check is your filament diameter, I did have some filament that was large and quite elliptical, and wouldn't go through the aluminium part. I actually reamed the aluminium out by 0.2mm just to try it, and it seems to have worked OK.
Last thing would be a blocked nozzle. I do get this occasionally (the same as on the UM hotend) presumably from contamination in or on the filament.
What temperatures and materials are you running?
Hope this helps
Andrew
I'm trying to debug this right now, and I think it is exactly the second issue described - I think the tolerances on this hot end are so tight that any minor filament grinding/deformation from an area that has a lot of retraction cause a change in the size of the filament enough that when that section makes it up to the hot end, it causes a plug.
Printing Printbl PLA at temps between 205-220.
I think that I've had a similar problem with the standard V2 hotend with PLA filament with a mean diameter of 3.05 and fairly elliptical. To get this to feed consistently I had to change the Bowden tube to a nylon tube with a slightly larger bore and drill out the PTFE part with a 3.5mm drill.
Mike.
Yes, binding in the Bowden tube and at the interface to the hot end can definitely cause problems when filaments start to get above 3mm diameter. Poor quality filaments with high variability, or just filaments that have a modest variability on top of a true 3mm mean diameter (e.g., Taulman nylon) can definitely have problems. I just changed my Bowden to a 0.15" (3.8mm) internal diameter Nylon tube to see if it helps any. Drilling out the PTFE piece might also be a good idea, since by itself, the wider tube doesn't seem to be enough for me to get consistent results with the Taulman 318.
Cool. It doesn't seem to be happening now; whatever combo of voodoo and filament I'm currently using is working for the moment.
Someone needs to design a hotend which is just one clean aluminum piece, with no internal transitions. The nozzle, heatsink, and heater block should then mount on external threads just like the Makergear hotend does. Having internal connections is just too failure prone.
Someone needs to design a hotend which is just one clean aluminum piece, with no internal transitions. The nozzle, heatsink, and heater block should then mount on external threads just like the Makergear hotend does. Having internal connections is just too failure prone.
In spirit, thats is somewhat like what I have here:
http://www.thingiverse.com/thing:20572
Single internal transition from the PTFE to the nozzle tip. The second picture shows it best. Still never had a jam in over a year of service. Everyone likes to hate on the PEEK, but no troubles there either. None of any kind actually.
Honestly though, I have yet to try printing ABS. Maybe I'll do that in the next few weeks.
I am looking to add a second nozzle, but waiting to see what boils out of the current evolutions. I have been watching the E3D threads, and am interested in what transpires before I build a second home brew nozzle.
Matt
So, after another week or so of testing, I've got to say - This E3D hotend hates retraction. Even small retraction values (0.5-1.5mm) will cause underextrusion if it is a retraction-heavy part of a print.
The end doesn't seem to be clogging when small values are used, but it starts (and continues) to underextrude until it gets a few layers of retraction-light printing in.
It's a shame, because the lightweight printhead I've built this hotend into allows fantastic detail even at high speeds, but without the ability to use retraction, the fine details are frequently just lost in strings and blobs.
Any tips?
What's your retraction speed Nick. I recently noticed mine wasn't always pushing back as much as it retracted. The motor would squeal and it must have been missing steps at that point. So I backed the setting back from 45 to 30.
I've tried 40mm/s and 55mm/s. I'll try something slower and see if it can handle it any better.
Nick, if you are experimenting with retraction settings, you definitely need to build a recent Marlin from source, to make sure you have the retraction fix - otherwise, the actual retraction speed you get is a lottery.
The absolute fastest that the UM can retract with a standard extruder setup is 48mm/s. Anything faster than that will be capped at the firmware level, due to a limit of 40,000 steps per second. Additionally, you need to make sure that your firmware Vmax E setting is higher than whatever speed you set in your slicer, otherwise that will impose another limit.
If you have the recent firmware, you should find that a 'true' retraction speed of 35mm/s is plenty - you may even want to step down to 30 or less.
Hmm, good to know. I'll definitely play around with lower settings then. I did build this firmware 2 or 3 weeks ago, from ErikZalm. That is the source, correct?
That's the original master version yes. Personally, I tend to mirror the UM fork instead, since the defaults are guaranteed to be a bit more sane for UM users in that one. I talk about the options some here.
Received my eagerly awaited E3D hot end a couple of days ago.
Very nice looking unit, seems very well made.
I was disappointed to find that the bowden tube fitting was incompatible (too large) with both am001's design (http://www.thingiverse.com/thing:94678)
and Nick Foley's design (http://www.thingiverse.com/thing:121074)
BTW I know that Andrew noted this in an earlier post in this thread.
So, I've finished the installation all bar the Bowden tube as I'm awaiting delivery of a fitting, and I thought that I'd make a few comments about what I've observed so far.
The hole through the head, the heat break and in the nozzle appears to be pretty much 3.2 mm, similar to Ultimaker. However this diameter is over a much greater distance than in the Ultimaker so I'm worried that I might have difficulty with a couple of the larger PLAs I have. I got away with these in the Ultimaker by drilling out the PTFE to 3.5 mm (and using a larger tube, see below).
The Bowden tube supplied appears to be made from PTFE or a close relative. Very slippery. Same OD as the Ultimaker Bowden (1/4")
The bore size, however, is smaller.
The Ultimaker tube will comfortably accept a drill shaft measuring 3.27mm (but not one measuring 3.49mm)
The E3D tube will just accept a drill shaft measuing 2.97mm (but not one measuring 3.11mm)
I guess that I won't be using the supplied Bowden tube or fittings (could use one on the extruder end, though).
While I'm measuring tubing, I'll note that the tubing that I use for larger PLA will accept a drill shaft measuring 3.88mm (like the other 2, it's 1/4" OD).
Finally, there appears to be no way of securing the heat break in the body. The Ultimaker design squashes the heat break, PEEK and PTFE together.
Has anyone experienced any issue with the heat break getting loose in the body?
Here's and idea for you guys.
Take that coupler I sent you, and pull that little elliptical collet out. You'll see that it's an injection moulded part with tiny embedded steel teeth.
What happens here is that as you try and pull out the tubing, the little collet gets pulled back with it, when it's inside the body of the coupler there is a little angled ridge which compresses the little jaws of the collet to grip the tube. The whole coupler is designed around sealing and carrying gasses or liquids, but we don't care about any of that.
What you should be able to do is create a hole with an appropriate ridge in the printed part mount, just pop in the collet, and do away with the rest of the coupler.
I have tested this method with machined aluminium parts for a future product/update and it works well, saves a lot of space and is very neat.
I have had this happen a few times...
Most times I have had this is when I have the heated chamber on my machine too hot, so the cold part of the hotend can't cool. This seems to happen if the chamber is close to the glass transition temperature, so around 45degC for PLA and 70degC for ABS. Obviously not an issue if you don't have a chamber.
as a side note, Tg of PLA is about 65C and Tg of ABS is about 110C (chamber temp needs to be obviously way below those limits, as you said)
Has anyone experienced any issue with the heat break getting loose in the body?
Bummer that the coupler doesn't fit with your hotend. Is it the same black one they show in the photos?
I didn't use the E3D bowden because of the diameter reason you mention. You can re-use the Stock bowden just fine.
I followed the E3D instructions step by step during assembly of the hotend and haven't had to make any adjustments in the 100 hours of printing that I've done with this setup. The tighter bore of the hotend definitely makes it more failure prone due to ground filament, however, so make sure your retraction settings are turned down and your extruder spring is very tight so you don't ever get any filament slipping.
That being said, I still love this hotend, because the reduced weight allows it to be driven FAST while maintaining awesomely high quality prints.
Bummer that the coupler doesn't fit with your hotend. Is it the same black one they show in the photos?
Nick, hard to be sure (apart from the fact that mine are grey!).
The largest diameter is 19.5mm this is the diameter that bottoms onto the E3D and is the same dimension as across the edges of the hexagon section,
Thanks for the retraction and extruder spring tips.
Mike.
What you should be able to do is create a hole with an appropriate ridge in the printed part mount, just pop in the collet, and do away with the rest of the coupler.
What or which 'printed part mount' are you referring to? An existing one, or one that could be designed?
I like your point that the collet retaining features in this application are much less demanding than those provided for in commercial fittings.
He's talking about a redesign, essentially integrating the black (grey in your case) bowden fitting into the printhead itself. I like the idea a lot. Might try to rework my design to accommodate that, as it will be more universal and we won't have to worry about mismatched bowden clamp sizes like you are dealing with now.
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Re the thermistor.
I have an E3D on order. From what I've read it appears that Ultimaker customers would be best served if the E3D Ulimaker version had an Aluminium block with the correctly sized hole to accept the Ultimaker thermocouple. I wonder if Sanjay might consider this. I would make conversion easier and may generate a bit more business!
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