wills
New Member
Posts: 10
|
Post by wills on Dec 5, 2012 15:45:48 GMT -5
|
|
|
|
Post by brainbubble on Dec 19, 2012 11:46:41 GMT -5
Hi,
this is my first post on this forum as I recently got my SUMPOD Basic and it's running quite well (regarding I got since last week :-)).
But right away my first question... :-)
How did you manage to attach the push fitting to your new squeezewear hotend?
I just ordered one, could you provide information how you modded it?
Thanks,
Jens
|
|
|
|
Post by highcooley on Dec 20, 2012 5:31:13 GMT -5
Hmm, these Hot Ends are a real bargain. I would also be interested in the details about ordered PTFE length and diameter and how you mounted them to your sumpod.
Cheers
|
|
wills
New Member
Posts: 10
|
Post by wills on Dec 20, 2012 8:47:42 GMT -5
I bodged up something out of two pieces of old Aluminium rail and a small plate, then I printed a holder, but I've reverted to the bodge for the moment as I have been having problems with the PLA swelling and jamming ( hear of that before?) occasionally. I have now decided that the problem is the extruder gear. I have an early Airtripper on the Sumpod, and I used the Sumpod drive gear, which works 99% of the time, which is not quite good enough.
Today I have just received a MK7 gear from Denmark and I will try that ASAP and see if it sorts the problem. Trouble is it can run for hours (10) sometimes before it goes wrong, and then craps out in the last bit of a print ( there must be a corollary to Murphy's law to cover this).
I will take some piccies of the bodge and the printed holder tonight.
|
|
|
|
Post by highcooley on Dec 20, 2012 9:12:45 GMT -5
Hmm, the ole jamming & swelling again...
I changed to MK7 drive gear as well and it definitely makes a big difference in terms of abrasion and subsequent slipping or jamming of the filament. However, I don't see why this would cause jamming & swelling in the hot end? Is it because the plastic stays in the hot end for a long time without being extruded? Thank you for your clarification.
I am looking forward to the pictures of the mounting bracket.
|
|
wills
New Member
Posts: 10
|
Post by wills on Dec 23, 2012 18:03:12 GMT -5
|
|
wills
New Member
Posts: 10
|
Post by wills on Dec 24, 2012 12:16:35 GMT -5
To get the MK7 gear version of the extruder working, I had to continue with the old Sumpod gear to print a new Airtripper extruder. ( The MK7 gear is larger than the Sumpod one). This clagged up several times, with jamming etc. One interesting piece of information came out of this; to maintain good feed on the filament with the Sumpod gear, I have quite a lot of pressure on the passive ball race. When the filament retracts and runs forward again, the gear side of the filament gets quite cut-up. What I found was that if the design has a lot of retracts , the filament gets so rough, it is quite difficult to push through the PTFE tube, so then the Sumpod gear cuts extra notches into the filament, and the situation just gets worse and worse. Positive feedback I guess. Eventually, the filament gets stuck in the PTFE tube, and the Sumpod gear just spins on the filament, eventually cutting most of it away. But by this time your print is well screwed. I thought this was due to the PLA getting too hot in the hot-end and swelling up and jamming, but no, it's the distorted filament sticking in the PFTE tube.
Changing t the MK7 gear seems ( so far) to have fixed this problem. It doesn't chew up the filament anything like as bad.
|
|
|
|
Post by highcooley on Dec 27, 2012 3:09:44 GMT -5
Thanks for your detailed description of your extruder findings. I had about the same experience, when I changed to MK7 as well. However, since the hot-end situation is not fixed yet, I still get the jams. I'll keep you posted, when I start tinkering with the Sumpod the next time.
|
|
wills
New Member
Posts: 10
|
Post by wills on Dec 29, 2012 14:05:29 GMT -5
I think Mark(airtripper) has also trodden this same path but with a different hot-end. It was his notes about jamming/swelling that made me decide that the original Sumpod hot-end was letting the filament in the PEEK get too hot.
I did get some good prints from the original hotend, but not consistently. Then I wrecked the tip of the hotend ( don't try using frosted glass for the printing surface unless you can be sure that the tip never touches the glass; I ground the end off the tip in 2 minutes. I thought the PLA would act as a lubricant/barrier but it seems I was wrong). And as I couldn't get another hot tip I decided to try another hotend entirely.
|
|
|
|
Post by highcooley on Jan 4, 2013 9:18:29 GMT -5
...huh, I just got promoted to an admin without knowing anything about it in advance :-) well, ok then...
Back to the hot-end discussion. Same with me...results with the sumpod peek hotend sometimes turned out brilliant but the next print had to be aborted (actually the same with the "original original" hot-end with the heat sink). Good to know about the frosted glass. As I am using clear borosilicate, this won't happen, but after a few crashes, the tip would probably be smashed as well.
In the meantime, I invested into the Rostock Max campaign against all advises. It turns out, the kit is brilliant, well constructed with heaps of well-engineered details. So far, the single delta specific issue is some kind of stutter/jerk on carriage movement into the X direction, due to too tight sitting joints. The tricky thing is to figure out, which joints to sand without breaking or wearing off anything in the process, as everything fits together so nicely atm (and that's probably the main risk with delta printers) :-)
Besides that, I am currently facing the old hot-end configuration situation with hours of trial and error laying ahead. What I still don't get is why faberdashery PLA was so easy to get along with, as Ultimachine stuff almost freaks me out during configuration. Somehow, it seems much more forgiving, as the sumpod hot-end almost worked reliable with faberdashery village green.
|
|
|
|
Post by airtripper on Jan 4, 2013 20:54:15 GMT -5
Any hot end that pre-heats the filament before the melt chamber is always going to be a problem with some PLA filament batch types, the 1.75mm variety. The pre-heating causes PLA to swell before the melt chamber which usually causes filament to get stuck. No matter how much configuration you do to the hot end, you will never get rid of that swell. Configuring the hot end with hours of trial and error is about finding that right balance between temperature, feed rate and force that will allow you to keep pushing the filament swell down into the melt chamber until the end of printing. Even when you do get the filament extruding, there are no guarantee that it will not jam before the end of the printing. As soon as you unwrap a new batch of PLA, it's properties start to change and continually change until it's all used up. This reduces the chance of successful extruding repeatability. Hot ends that pre-heat the filament are more suited to ABS than PLA. There are good hot ends that work with 1.75 PLA and these are the ones that do not pre-heat the filament like the type I'm using: airtripper.com/801/hot-end-design-on-3d-printer-extruder/After a lot of effort I finally have a hot end that extrudes PLA on demand. However, the best feed rate I can get is slow, so I'm still looking out for a better hot end. I bought and tested the QU-BD.com MBE Single 1.75mm Extruder V9, it failed, did not get any printing out of it. It swells the PLA filament too much and the swell grips tightly inside the unpolished tube. I've ordered another hot end and this time it is a J-Head MK-IV Hot End 0.4mm Nozzle for 1.75 and 3mm filament www.ebay.co.uk/itm/J-Head-MK-IV-Hot-End-0-4mm-Nozzle-for-1-75-and-3mm-filament-Reprap-Mendel-Prusa-/281030253809?pt=LH_DefaultDomain_0&hash=item416eb55cf1If I can print at more than 50mm/s I'll be happy. If you are spending more time configuring than printing it is probably time to get a new hot end. Basically, you should expect to start printing within a few minutes of switching on the printer with the right hot end. I don't think this site needs to be Sumpod specific, so let's see some Rostock Max pictures Highcooley  |
|
|
|
Post by jamirie on Jan 5, 2013 19:53:11 GMT -5
airtripper: would be very interesting if you'd post how the J-Head MK-IV Hot End 0.4mm Nozzle workes for you. Highcooley: Yes, pics of Rostock Max would be awesomeeeee! I really like the design!
|
|
|
|
Post by airtripper on Jan 6, 2013 9:42:04 GMT -5
I'll be posting a review of this hot end on the blog which will include set up details.
|
|
|
|
Post by highcooley on Jan 7, 2013 5:38:34 GMT -5
Pics are coming soon :-) I was busy visiting my family and cutting a glass sheet for Rostock's heated bed at my dad's workshop over the weekend. The supplied PC plate may work with ABS but PLA sticks like hell and doesn't pop off as both materials have a similar temperature expansion.
|
|
