|
Post by highcooley on Oct 4, 2012 18:08:50 GMT -5
Yessss, this is my first print after the upgrade to the fan less hot end (and my first longer / bigger print ever). It's the first part of Airtripper's fabulous Pocket Filament Reel Rollers, which look amazing and is amazingly simple to print and build. Done with Marlin on Repetier Host, sliced with slic3r at 35/45 mm/s at 195°C. Any suggestions, how to get rid of all these pimples sticking out of the print during the print or to improve the quality in general? Attachments:
|
|
|
Post by highcooley on Nov 5, 2012 5:32:21 GMT -5
Hey everybody What a pity, I did not get any reply on this question so far. Unfortunately, I am still fighting the same problems and really don't know what to try next. In the meantime, I upgraded my extruder to the design kindly provided by stohn (similar to the one airtripper shares on thingiverse) and changed to a MK7 drive gear. So there shouldn't be any issues with the extruders anymore. It is working perfectly. I further investigated the pimple problem and I do believe that it is related to other issues I am facing. Maybe this rings a bell what the reason for this mess could be. 1. How much I ever retract, I still get the same ooze. I set it to 3mm right now, but already tried 4mm which didn't change anything. As I don't like "scratch" marks of the nozzle over a nice finished surface, I set the Z-Axis to move away 0.1mm during travel over perimeters. This leads to ooze trails all over the place. picasaweb.google.com/lh/photo/RY_E45yqJMGdohV0fHQitkGVwBuUrXs5SDwV6OeE8vA?feat=directlink2. If I manually extract without retracting, the nozzle keeps oozing for about 10-20 seconds. 3. When printing parts with a lot of single small dots on a layer (a lot of retracting and moving), the filament thread gets smaller and smaller and finally the nozzle jams. However I can counteract this by pushing the filament manually with quite some force as long as the couple of layers with the single dots print. However this is extremely annoying, having to sit next to the printer and "helping" it to print. picasaweb.google.com/lh/photo/Cq45s0SqILXmB2K40Vulx0_evk_V6C-NpdtkxzRglKk?feat=directlinkCurrently I am printing Ultimachine's white. I have to print at 210°C to get a constant filament flow at 60mm/s XY speed. Maybe this is too hot and causes the oozing issues. On the other hand, I can print fabberdashery green at 195°C and still get the same results. Another thought is, if it could have something to do with Richard's new nozzle design. I still had to sand down the outer diameter of the bowden tube to stick it right to the bottom of the nozzle. Maybe there are irregularities with the inner diameter of the hot end which could cause a filament reservoir or bottlenecks respectively. Or is this too far-fetched? Richard mentioned something on his page: sumpod.com/forum/post/peek-and-nozzle-part-revisionMaybe I have to make this change...however this will be hard to reassemble the nozzle once more without breaking the bowden tube which is already almost too short. Thanks for your thoughts! Cheers, Andy
|
|
|
Post by airtripper on Nov 5, 2012 18:08:58 GMT -5
I don't use retract or extracting at the moment due to not having very good results. I do get a few strings on my prints but they clean off easily. I don't think the extras are needed for 1.75mm filament, and because of the oozing with PLA filament it's best in my opinion just to keep the flow rate going consistently, and with fast travel. Extract will not work if your hot end requires a lot of force to extrude because the pressure will be too high to stop oozing. This is because PLA filament swells a lot.
On close inspection of your prints, I would say your feed rate is too fast for PLA because your layers are not cooling fast enough to support the next layer. A feed rate of 16mm/s second and 60sec per layer cool feature will help you get the best out of PLA filament as a starting point. Faster printing with PLA requires a fan blowing across the build to cool the layers.
Setting the cool feature in Slic3r or Skeinforge will slow the feed rate as the layers get smaller during printing to allow the layers time to cool before they have to support the next layer. If the layers don't get time to cool, they can be pushed around by the nozzle printing over them causing uneven walls and cause messy peeks on top of your builds.
Mark
|
|
|
Post by hindessm on Nov 5, 2012 18:33:02 GMT -5
Personally, I've given up on my Sumpod (see www.temporalanomaly.com/blog/2012/10/07/sumpod-3d-printer-replacement/ ) but I had all of the same problems. Ooze could be solved (up to a point) by retraction but that led to more frequent filament jamming. Like you I could force it through and it would continue for a (frustratingly short) while. I also replaced the original (inaccessible) extruder with airtripper's extruder but saw no improvement - though I am certain this is a much better design. The bowden tube and direct drive extruder probably complicate things but the Rostock community seems to be quite successful in getting good prints with these designs so I am convinced the hotend is the main problem. I think filament is getting hot too far up the cold end causing it to expand and block the bowden tube. You might be able to rig up a fan mount or heatsink (see blog.atleberg.com/) but I suspect you'll be wasting your time and would be better looking at an alternative tried-and-tested mature hotend design. I really like the j-head hotends from hotends.com/. I own two one 0.5mm and 0.35mm and I'm waiting on another to use up my 1.75mm filament. I use a conventional aluminium plate to mount mine on my MendelMax but alternative mounting options (such as the one described in this blog richrap.blogspot.co.uk/2012/03/mendelmax-quick-fit-x-and-quick-fit.html ) might suit an original sumpod better. I'd recommend a 0.5mm nozzle to begin with as it is easier to print with. Hope this gives you a few ideas. I definitely relate to your frustrations and wish you luck resolving them. Regards, Mark
|
|
|
Post by airtripper on Nov 5, 2012 20:45:37 GMT -5
Unfortunately the extruder won't work if the hot end is not right. It has been a challenge to build a good hot end for 1.75mm PLA filament and some designers seem to think a modified 3mm hot end is good enough. Exruders are not designed to solve the jamming problems in bad hot ends. The bowden tube and direct drive extruder works perfectly as long has the hot end works great. I've done a blog post on my latest hot end configuration and the extruder system works great now. My extruder drive has had some good feedback and is used on the Rostock 3d printer prototype with excellent results. airtripper.com/801/hot-end-design-on-3d-printer-extruder/I've got a new hot end and some filament drive gears coming for testing which I'll be covering on the airtripper.com blog. The prices for these parts are very good and the shipping is sensible for a change, coming from the US. Check them out - store.qu-bd.com/Mark
|
|
|
Post by hindessm on Nov 6, 2012 5:28:23 GMT -5
I agree that having a good hotend is crucial. As you say good 1.75mm hotends are hard to come by. I'm very interested to see how you get on with your qu-bd design. I've only tested j-heads with 3mm filament but I'll report back on my 1.75mm j-head when it arrives (it's in the post and overdue ;-( ).
I disagree with your earlier comments about prints showing feed rate too high for PLA. I regularly print at 100mm/s with no fan on the print. I slow down for small layers and for layers with convex overhangs (which pull inwards so curl upwards). So I think the Sumpod is far from PLA limits and that limits are more to do with extruder/hotend limitations. Of course, you definitely need to slow down for small layers. I normally use slowdown_below_layer_time of 30s in Slic3r but if I wanted perfect prints I might change this up to 60s.
Regards, Mark.
|
|
|
Post by highcooley on Nov 6, 2012 13:46:56 GMT -5
Thanks guys for all the helpful tips, analyses and last but not least the mental support. Concerning the too fast print speed: I am aware of the fact, that I urgently need a fan to get better results. As soon as I am able to successfully print my fan nozzle, I can start working on that (it's actually quite complicated to design a suitable support for the sumpod). And I am looking forward to further improve the quality with that. However, the spikes in the picture with the aborted print was caused by the jamming. If the print runs through, I only have the ooze problems on the side and on top of the surfaces of the prints. I am currently already able to print very slow, but I felt it was time to improve to a more suitable speed, as I would like to be able to print more than only a single small part per evening. Hmm, maybe I really have to get over the $ 120.- I payed for the two hotend upgrades and start looking around for an alternative. I already checked out the j-heads. And the qu-bd ones really do have a very good price. Another one I am thinking about is this: grrf.de/de/catalog/hot-end. It's quite modular but not exactly cheap in price. But first I got one more thing I maybe want to try. If I can find somebody who can mill cnc, I'll produce a full block aluminium mounting part which tightly envelop the PEEK parts and should help keeping them and the pneufit parts cold. Oh well...or maybe it is time to move on and go for a completely new printer. The mechanical parts shouldn't be that expensive if I can reuse the electronics. Thanks again...I'll keep you guys updated. Andy
|
|
|
Post by airtripper on Nov 7, 2012 18:52:52 GMT -5
Of coarse hardware is important, but a batch of PLA can be very different from another batch, different extrudable temperatures, different cooling/setting times and different brittleness. The feed rate being too fast for PLA was related to the PLA's ability to cool down fast enough to accept the next layer. Your next batch of PLA may not work for your current set up, and at 100mm/s. The curl ups happen when the extruding filament is stretched and pulled from the nozzle as a result of printing very thin layers in relation to the nozzle size. You can reduce your overhang curl ups by increasing the nozzle temperature. This could mean more oozing and speed limitations due to cooling. I disagree with your earlier comments about prints showing feed rate too high for PLA. I regularly print at 100mm/s with no fan on the print. I slow down for small layers and for layers with convex overhangs (which pull inwards so curl upwards). So I think the Sumpod is far from PLA limits and that limits are more to do with extruder/hotend limitations. Of course, you definitely need to slow down for small layers. I normally use slowdown_below_layer_time of 30s in Slic3r but if I wanted perfect prints I might change this up to 60s. Regards, Mark.
|
|
|
Post by hindessm on Nov 8, 2012 7:55:02 GMT -5
I've got pla from 3 different suppliers (probably around 20 different types in all). I've only had significant problems with one type out of all of them even that I could resolve by calibration and a different temperaure to still print at 100mm/s. I am quite picky about who I buy filament from though - mostly faberdashery and grrf.de.
I'm curious to know what filament you have that might not work this fast.
I'm not sure the curling I see is caused by the same effect. If it was I think I'd see problems with holes being too small as well. I don't see problems with them - but it is possible that is due to slicer smarts rather than that the problem isn't there.
Also, I can resolve it by doing the opposite of what you suggest - using a lower temperature not a higher one. By printing at a lower temperature (and a little slower to allow for the filament bieng harder to extrude) the problem disappears. I'm experimenting to see if I can solve it without slowing down as I'd rather no slow down for "regular quality" prints.
Regards, Mark
|
|
|
Post by ramboni on Nov 10, 2012 12:04:01 GMT -5
Hi guys, just thought I would add my experience with my sumpod and hotend. With the original hotend I could not get it to work at all it just kept jamming so I did a search to find a replacement and I came across extrude3D.com extrude3d.com/store/Hot-End-Kits?product_id=65 I bought the x3d hotend kit and since fitting it I have had no jamming issues and I am happy with the print quality, there is a minimal amount of fine stringing but it is easy to clean up. Hope this helps www.flickr.com/photos/2print3d/
|
|
|
Post by airtripper on Nov 10, 2012 13:56:43 GMT -5
I've not been that picky about where I get the filament from, I just got the cheapest I could get. I've been trying to get hold of a good drive gear to replace the one that come with the Sumpod. To get the MK7 gear would have cost me around 50 dollars to get delivered from the US. However, I ordered, and still waiting to arrive, the Raptor Universal Filament Drive Gear, pictured below. It's possible that my old drive gear might not be up to higher speed printing where it might not have a good enough grip on the filament. Slippage is difficult to detect during printing but there may be enough slippage to cause symptoms with extruding. If the symptoms disappear at higher speed printing after installing the new drive gear, I'd be sorted. ramboni, Hot End looks good, and fits well on the Sumpod. I'm waiting for an all metal hot end to arrive.
|
|
|
Post by highcooley on Nov 14, 2012 5:31:03 GMT -5
I just had a complete jam again. The bowden tube burst inside the hot end due to a cavity between the PEEK and the nozzle. First, the bowden tube must have expanded which formed like a bubble in the tube diameter. Then the bubble filled with PLA causing the jam. After the burst, the PLA started flowing in between the tube and the nozzle, filling everything out. On closer inspection, I figured out that the PEEK part is flat as the nozzle has the usual bevel of the drill bit. I really start thinking about alternatives, as it is just not worth the effort.
I even started looking around for an alternative to the sumpod, as the MDF design definitely has its flaws. Can anybody recommend a complete Mendel Max hardware kit? So far, all the kits I found are quite pricey or are far from complete which would cause additional shipping costs as the shops don't offer the missing parts (Shipping costs and customs duties are cruel for Switzerland). Another interesting solution could be the Rostock Max. What do you think about the indiegogo campaign? Should I give it a try or do you think a lot of trouble could lay ahead with this new product? After all, the price is convincing and the delta arms design a real beauty.
|
|
|
Post by hindessm on Nov 14, 2012 12:39:17 GMT -5
I got a kit from Creative Machines in the UK: www.creativemachines.co.uk/shop/index.php?cPath=1_7Time was more important than money to me so I went with a full kit. It was quite a simple build; No real instructions but lots of info on the net about similar machines and the seller was on IRC. I had to buy a few extra parts to assemble the Y carriage - bolts, spacers and springs - but nothing complicated and the description has a vague warning about needing a few extra bits so I expected this. I am extremely pleased with my printer. My first print was better than any Sumpod print I'd made and I used the default Slic3r speeds - 60mm/s - so it was also much faster. I have a couple of videos on youtube of it printing, such as: www.youtube.com/watch?v=wqfF7iVs0_8You could do it cheaper using Sumpod for parts and the hardware only kit. You'd need another motor (don't use a new one for Z, use pair from the same source), cables, pulleys, belts, hotend, extruder, etc. (I didn't try this as I still had hoped to fix my Sumpod. However, I've now given up and plan to use my Sumpod parts to make a small CNC machine.) I looked at the Rostock as I also find it fascinating to watch. The design was fairly immature at the time and some people were having trouble with the bowden extruders so I avoided it. I think I'll probably make a Kossel/Cerberus delta bot at some point. It is like the Rostock but with extrusions and fishing line instead of belts. HTH, Mark
|
|
wills
New Member
Posts: 10
|
Post by wills on Dec 4, 2012 14:48:50 GMT -5
Hi Guys, I'm wondered where everyone had disappeared to from the sumpod forum. I've changed by hotend to a Polish one from ebay, where I got two for £50 and they work pretty well; it has got round the swelling/jamming problems.Although I do have a small fan cooling the top of the extruder, just above the melt chamber. I have also invested in a MendelMax from Creative, but I haven't put it together yet. Having just looked at Mark's vid I must get on and do it. Regards William
|
|
|
Post by highcooley on Dec 5, 2012 9:42:06 GMT -5
Hi William
Interesting hotend, you mentioned. Do you have any links to eBay where I can find the seller? THX
Andy
|
|