3poro
-
Posts
181 -
Joined
-
Last visited
-
Days Won
1
Content Type
Forums
Events
3D Prints
Posts posted by 3poro
-
-
For ABS, I really recommend closing the printing chamber. Here's my printer:
Actually, I have found it important to make the enclosure pretty tight. If there are holes/gaps in the enclosure, you'll feel the smell of ABS much more strongly.
The enclosure also helps in reducing noise from fans. In my case that's quite important, not least as I have added cooling for the print head.
-
Nice to see someone start hacking away on these all too shiny and new UM2 printers...
I only buy stuff I can afford to mess with
Here's how my UM2 now looks like:-
4
-
-
Holy mother board! I was dealing to make a proper fan for my board but after seeing this I wont delay it anymore! Btw nice hack
Thank you! Actually, I started to think about cooling for the motherboard as well. The circuit board around the stepper motor drivers for X and Y axes had yellow/light brown tint - so the temperatures must get pretty high.
-
1
-
-
Hello. Long time, no me. I've been fighting on other frontiers... Every now and then I've been printing bits an pieces, but nothing ambitious at all - partly because the performance of my UM2 was compromised. For Xmas gifts, I printed some Xmas trees and I used Formfutura's "glow in the dark" ABS - which turned out to be very abrasive:
The block I had on my printer didn't produce very good print quality anymore. I knew I should have simply changed the nozzle, but I pushed the thought back as I guessed I would have to re-make my self-made temperature sensor. When I inserted it to the nozzle block several months ago, I realized the fit was a bit too tight. Now, when removing it from the nozzle block, it didn't come out in one piece. I should have thought about it before. To the new nozzle block I drilled a hole for pushing the temperature sensor out.
Okay, so I took the time to change the nozzle and re-make the temperature sensor - and I managed to get a few nice prints out from my UM2. Then, I started having under-extrusion problems... nostalgic feeling, or something. After "some" troubleshooting, I realized the problem was in the stepper motor - or its driver. The torque just wasn't there anymore. Maybe it's me to blame - I have used the extruder stepper motor with 1.5A current. Maybe now this practice took its toll:
Great - so my UM2 motherboard needed changing. But wait - there was a reason why I felt I had to use the 1.5A stepper motor current - and even that didn't feel to be always enough. Before my UM-break, I had already ordered this kind of stepper motor:
http://www.robotdigg.com/product/29/Nema17-60mm-1.5A-high-torque-stepper-motor
But, if the standard stepper motor can be too much for the Pololu driver, probably the new stepper motor would kill it even faster? So, my UM2 motherboard needed changing but even that wouldn't have satisfied me. I decided to bypass the dead Pololu altogether and use an external stepper motor controller. I decided to try to make it in a way I wouldn't need to make a custom firmware - so, I had to remove the dead Pololu:
...and bypass it:
The contrast on the picture is a bit misleading - the board looks more clean to naked eye. Most importantly, the hack works. Now the critical digital outputs (pulse, direction, enable) are taken out from the UM2 motherboard to an external stepper motor controller. I happened to have an M542H stepper motor driver waiting to be used - so now I have a lot of headroom in case I need an even more powerful stepper motor for my extruder
I decided to use the existing extruder connector for the digital outputs - so I have to remember not to plug a stepper motor directly to the connector anymore.
I really need to catch up with Anders Olsson's work, the original UM2 heater/nozzle block has caused me too much headache...
-
3
-
-
Absolutely I can share the STL files:
https://www.dropbox.com/s/gi3qxp9en3va42q/front_door_fixtures.zip?dl=0
They assume 5mm wall thickness and some rubber/foam tightener between the door and the printer. My door is 30cm in height and 28cm in width; the top edge of it is right under the "Ultimaker" text. For the handles I used 4mm bolts and nuts.
Let me know if the files are of any help; I only designed the parts for myself, but I'm happy if they can serve somebody else as well
-
I keep you informed .... I have to sleep. :wink:
glloq - any updates?
So far, my experiences with Vespel washer have been very good. Having said that, I did have to drill it a bit to make its inner diameter match the diameter of my Teflon isolator. Ultimaker's translucent PLA (green) caused me headache. First, it's very tightly wound to its reel, so the feeder had trouble fetching it. I had to unwind the filament to another reel (and back) in order to lower the burder on the feeder.
Then, there were extrusion problems - I believe the threshold (3.3mm->3.1mm in my case) between PTFE isolator and Vespel washer was to blame.
I was thinking about making an isolator purely out of Vespel, but I'm concerned about friction. If Duratron doesn't have problems with friction, maybe Vespel would be OK as well...
-
Here you can find a conversion table for Pt100:
http://dev.emcelettronica.com/files/u4/Fig0058_0.png
To me 142 Ohms seems somewhat high. In my opinion you should get the bed changed. If that's not an option, you can also try to get a new Pt100 sensor for your build plate. The Pt100 sensors are widely available; you just need to make sure the new sensor is properly fixed to the build plate with some thermal adhesive.
(BTW - I now see your location fine on your profile.)
-
Seems very interesting! A few questions
- I have seen comments about all-metal extruders having trouble with PLA. Have you encountered any problems with PLA?
- Does your dual extruder reach the same speed and build volume as the UM2 stock extruder?
- What has been the primary use case(s) you have prioritized in your R&D? Soluble support material? Two colors? Different nozzle diameters? Something else?
Some photos of printed models would be great
- I have seen comments about all-metal extruders having trouble with PLA. Have you encountered any problems with PLA?
-
I have made a coupler in Duratron.
working temperature 310 ° C.
Cool! (Well, not literally)
I had thought 260C would already be on the limit for PLA - but you got good prints with 310C?
How easy/difficult is it to machine Duratron?
-
de vraag is, zijn ze nu echt versleten?
Ja. (No, I don't speak Dutch.)
More details in English... Your Teflon isolators seem pretty much the same as mine when they got worn out. You can see a photo and detailed discussion here:
http://umforum.ultimaker.com/index.php?/topic/7024-teflon-spacer-replacement/?p=67737
Basically, when there's such a distinct ridge, retraction doesn't work anymore normally - the prints will come out under-extruded.
-
Is it possible and how difficult would it be to print a box/enclosure which is about the maximum size of the UM2 build volume, i.e. 220 x 220 x 120mm?
My biggest ABS prints have been 205x205mm in size (X/Y) and I don't think it's possible to go much bigger than that due to need for raft.
Otherwise it's doable, it will take a lot of time though.
-
one could think that (maybe just for your needs) that the design needed improvement, but I actually think it is a
strength of Ultimaker that through its open source nature there is room for modification.
Did it benefit you specifically or do you feel you could have gotten this same result with any other machine?
If I would have needed to touch the SW side of things, I would certainly appreciate the open source approach a lot. I have some thoughts about what Cura should do better, but I can live with it as it is now - and I'm too busy to start coding the improvements myself. At some point I may want to go beyond 260C, then I'll have to start diving into the software - unless I make a HW shortcut
http://umforum.ultimaker.com/index.php?/topic/7710-print-more-than-260ºc-with-a-um2/?p=72634
What comes to hardware modifications, the community is actually more important than "open source" (OK, the latter might catalyze the community, but this gets a bit off-topic). If you see all the crazy mods people are making to their quadcopters, PCs, cars etc - source code is for sissies
...and Ultimaker certainly offers the community. Without it, there would be too much of unnecessary/redundant work.
I think it would also be interesting to have a follow up conversation with Poro and evaluate his mods.
What do you think Poro?
I'm trying to share my mods to get feedback and to help others... Sometimes I'm a bad boy and I'm making stuff the "old school" way. If I would have made my feeder stepper motor fixture 3D-printable, I would highly recommend it:
...but at the time of the mod, my UM2 was waiting for spare parts - so I had to use saw and drill instead
-
I can't understand why/how you can get a low success rate with PLA, it's very easy to print in my opinion.
I mostly agree. If I was printing exclusively PLA, I wouldn't have had many problems. No need for closed chamber, maybe not even need for new temperature sensor, additional insulation for the Teflon isolator etc. However, if you use ABS at least part of the time, even PLA becomes a headache - here's why:
- When you print ABS (or otherwise use high temperatures which are likely to cause the Teflon isolator to deform), PLA seems to get stuck to the ridges easier than ABS. This is probably due to its lower melting point and its hardness. My experience is - a half-used PTFE isolator might still serve you for ABS prints, but it will let you down when printing PLA.
- Printing ABS very easily leaves some ABS dust to the Bowden tube, feeder and extruder. As PLA is printed with lower temperatures, the ABS particles easily cause the nozzle to get clogged - or partly clogged. Changing from ABS to PLA needs to be done carefully and it makes sense to start printing PLA with as high temperature as possible.
Some of the problems with ABS can certainly be avoided by using PLA - and PLA only. However, when ABS printing works, the parts are really pleasant to work with.
- When you print ABS (or otherwise use high temperatures which are likely to cause the Teflon isolator to deform), PLA seems to get stuck to the ridges easier than ABS. This is probably due to its lower melting point and its hardness. My experience is - a half-used PTFE isolator might still serve you for ABS prints, but it will let you down when printing PLA.
-
why 3poro needed to make so many alterations to get a decent print? What are you doing different than the others who have 90%+ success rate ?
Good question. Either my prints are peculiar or I'm particularly demanding - or I was particularly unlucky with my UM2 (as it was out-of-box). Well - I am demanding and I am prone to having trouble with my hardware. What comes to my prints, here are some of the latest prints from my desk:
The filament reel is there for scale. Most of my prints are ABS with 100% infill, half of them have print times of over 12 hours - all the way up to 100+ hours. As I'm using them together with other components, their geometry needs to be consistent. To me it looks like others are mostly printing some sort of sculptures coming from fantasy/sci-fi scenes
As long as I didn't have my printing chamber closed, most of my prints came out warped. I did try different settings, different bed adhesion tricks etc - but I couldn't fight warping. For me, UM2 became really useful after mod #7. Maybe partly due to closed chamber (which increases the temperatures inside the printer), I really needed mods #5, #6 and #8. I have noticed I'm not alone - there are posts by other people addressing the same issues. IMHO, the original UM2 nozzle temperature sensor does not meet its specifications. Also, I certainly wasn't alone with my Teflon isolator problems.
What I'm actually most surprised about is the (relative) lack of discussion about the filament path. There are some mods around by different people, but it looks like it's not a huge problem for most. Maybe my lengthy prints set untypical requirements for it, I don't know. However, I couldn't really live with the original design. Significant part of my prints failed as the filament got tangled or didn't come out from the reel or got eaten by the knurled wheel.
The good news is - now I finally feel my UM2 serves pretty well as a tool. It feels reliable and it produces high-quality prints. A few months ago most of my activities with the printer were around fixing/improving the printer itself.
-
About the material getting to hot and plugging during lots of retractions. i have been actively cooling the hot-ends with a 35mm fan and fan duct on the front as well. The combination should reduce the overall heat in the hot-end and prevent that from happening.
The problem with two hot-ends and retractions has been discussed in some other threads as well, but I'm pretty confident that issue is not very difficult to solve. Cooling of the print head needs to be enhanced, but the original design leaves quite clear room for improvement - without redesigning the whole thing. While I have improved the cooling by ignoring noise levels, more subtle modifications should do it as well.
-
My success rate is over 90% nowadays - and most of the failures are somehow related to my own stupidity. For instance, leveling the bed frequently enough seems to be too much to ask from me. :oops:
However, getting above 50%-60% rate has required a few mods to my UM2:
- Printing IRobertI's feeder (twice, as the stock feeder didn't allow to print the feeder well enough)
- Replacing the knurled wheel of the feeder stepper motor with MK8 drive gear
- Improving the filament path (new reel location, reel holder with bearings, additional filament guides)
- New location and fixture for the feeder stepper motor
- Adding heat insulator between the heated nozzle block and the white Teflon isolator
- Improving cooling of the print head (new fans, new airflow direction, anodized aluminium parts)
- Building enclosure for the printer in order to close the printing chamber
- Improving nozzle temperature sensor
- Protective cover for the control wheel and the memory card on the front panel
- Using UPS for electricity intake
I have made some other mods as well, but those are not so relevant from reliability point of view. Mods #5..#8 wouldn't probably be needed for printing PLA. Mod #9 wouldn't be needed if I didn't have a 2-year-old son. The need for mod #10 (well, it's not actually a mod) depends on reliability of power as well as duration of a typical print.
Some people reach high reliability without mods - I can only envy them. Maybe my needs are peculiar as I'm mostly printing solid (100% fill) parts with ABS and I have quite strict requirements for their geometric consistency.
- Printing IRobertI's feeder (twice, as the stock feeder didn't allow to print the feeder well enough)
-
I'm very curious how the vespel has been holding up. I am actually thinking of ordering some here and running some tests with it for dual extrusion on the UM2, the problem with that is the deformation in the PTFE occurs faster as soon as you add the second Hot-end in the printhead. So actively cooling them with a 35mm fan on the front (and removing the small fan at the back for better airflow). I am however still a little afraid that is not enough to prevent the PTFE from deforming. So thats why i turn to the Vespel.
Vespel seems to hold up pretty well. I ended up making a pretty extreme test a few days ago - unintentionally. Here's how the story went... My UM2 has had some connector contact issue from its early days, causing the rear fan to stop breathing every now and then - but only for a second or two at a time. I noticed the issue maybe once a week or two, so I didn't pay too much attention on it. However, I have always wondered what would happen if the rear fan just stopped functioning. In my case this would mean stopping the two powerful Tornado fans I have installed to replace the original Sunon fan. As I typically print at 260C and I have a closed chamber, maybe heat would cause some damage?
A few days ago, due to human error (rather than poor connector contacts of my UM2), I was printing having the "rear fan" turned off completely. After several hours I noticed the print had failed and the filament was stuck somewhere in the print head. I had to open the print head to get my printer serviced. The last centimeters of the filament had grown in size - enough to cause the blockade. Obviously the filament had had problems with the increased temperature. However, both the PTFE and the Vespel parts were in perfect condition. No burnt surfaces, no ridges - nothing. I just had to reassemble the print head, cut the first few centimeters off the filament and continue printing.
My guess is - there is no need to modify the stainless steel insulator or to make some dramatic changes to cooling. The problems with PTFE are caused by the part being in direct contact with the hot nozzle. As soon as there's some "cushion" between the two, there's immediate improvement.
-
Great to see the washer has been taken into use by a real overclocker! Were you using "plain" PTFE isolator or the newer glass-impregnated one? I have only used the plain one as it feels softer and I thought it would act as a kind of a seal. Having an additional part/material on the filament path is of course not ideal...
What comes to the print after 6 hours, how was the print quality until that point? I would be very interested in printing PC as well, if your findings are encouraging.
-
I've been relatively satisfied with Cura's raft - I'm printing ABS. Here are my current settings:
Number of surface layers is an overkill - normally I have used 3 (which I think is the default). Now I was printing an object which was surprisingly stubbornly trying to lift its corners up...
For me it was important to increase the extra margin and to reduce line spacing - otherwise the raft didn't stick to the glass strongly enough in some occasions.
Depending on object, I may need to use knife to remove the raft. For me that's not a big issue, but naturally I would welcome an improvement
-
I think it will take quite some time before we'll see "conductive enough" filaments - unfortunately. Until then we'll have to stick to copper paint (http://umforum.ultimaker.com/index.php?/topic/3803-ultimaker-2-dual-extrusion/?p=73337). Especially under-extrusion problems and conductive filament don't really play well together.
How about using polycarbonate, PLA and a pressure cooker? http://en.wikipedia.org/wiki/Pressure_cooking
-
So comparing your speed (as a one person company) with a larger company is unfair.
I never said my business was a one person company. I did refer to "my account" as I was the business owner. A responsible company only sells what it can deliver - and delivery is more than just the box shipped to the customer. This is particularly true when you sell to consumers.
I forgot we are talking about refunding and not purchasing. Thus, it would also not be my first priority to optimize that process...
I very much disagree. There are lots of reasons why customers (or wannabe customers or lost customers) may need to be refunded. This is one of the critical points where you really need to show your commitment - in any case, it was the customer who first showed his/her commitment by sending you money. If the refunding process is smooth, you'll still get positive remarks and sympathy afterwards - and if you screw up, you'll get screwed.
-
It was explained in excruciating detail above.
Well - kind of. When I read Daid's message, I didn't understand what all the time is needed for. It probably takes a day or two to check how much was money was received and what needs to be refunded - OK. If the company is not in complete chaos, it shouldn't take more than an hour to check whether something was shipped already. Bank transfers very seldom take more than 3-4 days.
The only thing Daid detailed that takes considerable time is waiting for the next batch of external payments to be made. (I wonder what "external" means in this context - are there "internal" payments which are easier to make somehow?) This, however, is just showing the low priority of refunds. If you have outsourced your payments and you want to save from costs, chances are the payments are made infrequently. I would have bankrupted my business if I had decided to make payments every two weeks. I don't know if my payments were external, though - but money did leave my account when payments were made
-
Great stuff - as I wasn't analytic (or diligent) enough to use temperature probe, I'm very glad to get some numbers - thank you for sharing!
I would guess the temperature drops quite nicely by every millimeter of insulator - and the good news is, it doesn't actually have to drop a lot. In the original design the Teflon is in direct contact with 260C brass.
-
Teflon. I'm not sure if we switched those to glass filled teflon. If not, we're probably going to do that in the future.
Do you have enough statistics to make the switch? I have very limited stats in my use - I just know that of the 3 isolators I have lost on UM2 the original "pure Teflon" piece was the most durable one.
Here's how my UM2 now looks like:
3poro's comeback, featuring Pololu's death
in Third party products & modifications
Posted
Hello Sander!
The boxes above the power cord are (from the top) the M542H stepper motor driver and a no-frills 24VDC power supply. The latter is powering the new stepper motor as well as my print head fans (front + rear).
Here's my latest print, an enclosure for a quite simple electric device:
These specific parts don't have any tricky overhangs or otherwise challenging structures, but to get them printed some mods are vital. Warping has to be eliminated completely and layer-to-layer adhesion has to be really good. I'm very happy with the results: the feel is very solid.
The Olsson block I haven't tried yet. The UM2 original nozzle block serves me quite well - it's just quite a pain to replace. One more photo of my UM2: