Guidance on installing heated bed

Hello, any advice/help would be appreciated as I am a relative novice to 3d printers.

I purchased a generic Kossel mini from Aliexpress after assembly and some problems solving I have it up and running and printing fairly well. However it came with a free heated bed to match the glass build area. One problem though, the bed came with nothing included to hook it up as well as the power supply for the unit not being able to handle it.

I know I can use a PC PSU and I have a spare one lying around with a few 6+2 PCI-e connectors on them. This as much knowledge as I have on the matter however. I believe I need a thermistor but not sure what type, also the heated bed will need to be wired up but I am not sure exactly how to proceed fro here. I do not know where to wire the thermistor or the heated bed to the ramps board, also where do I wire the PSU power to on the ramps board, if I use the PSU do I use it for everything on the tower or do I still use the power supply that came with the tower as well.

Also My kossel mini came with an extra endstop switch, Is it possible to set this up to use for autoleveling??

Thanks in advance for any advice given.

Edited 1 time(s). Last edit at 02/02/2016 11:03AM by SummersideGuy.

To begin, yes you can use a endstop for leveling but you will need a servo to deploy it.

For the heated bed you will need a compatible controller and power supply. After making sure your powersupply can supply 12v at 20a you will need to modify it to pow?er the controller. Connect the green wire to ground and expose a 12v and ground for the controller.

Connect the 12v to controller and plug the heated bed to the output on the controller. Next you will plug a 100k ohm thermistor to the heated bed thermistor input. Configure firmware accordingly. Use Thomas Sanladerer"s firmware basics for this.

Pictures help to make sure you get specific help.

Edited 1 time(s). Last edit at 02/02/2016 01:23PM by gmckee.

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

Thanks for the response I will take some photos and post them when i get home.

I have another question, I have had a couple of prints now where the filament is getting jammed inside the metal insert just before the bowden tube at the extruder end, preventing the extruder from pushing the pla through and cause my printer to continue printing withouth any plastic coming out. Any advice on this?

Maybe check you filament path is straight and there are no little plastic burs on the way into the bowden tube.

Hi its, not the tube the filament is getting stuck its the brass fittings the tube is connected to also if the roll is a little snug it happens, its as if the extruder motor doesnt have the torque to overcome it. My first half dozen prints were great never had this happen then it started happening after I got about 1/3 of the way through the roll of filament.
Is it possible my issue might be with Slic3r, I find it is doing a lot of retraction and this is causing wear on the filament at the mk8 drive gear.

Edited 1 time(s). Last edit at 02/03/2016 07:32AM by SummersideGuy.

When it sticks does your extruder chew into the filament or does the extruder click? If it chews the filament your idler is too tight.

Assuming that's okay, does your extruder motor have enough current, I turn my motors up to just below the level at which they hum and run it then, if they get hot, back it off a bit.

Can you measure your filament diameter? Is there a sudden jump. Presuming your using 1.75mm anything over 2mm will probably jam. Measure it at several degrees of rotation around the filament as it might be oval.

It is a combination of both, when it starts to stick it may chew it a bit or it will just click. It seems as it is getting stuck in the around the brass fitting area, possible buildup of chewed parts? Inside the tube I never have an issue just in the around the area where the brass fitting is, sometimes on the hotend side, sometime on the extruder side. I've gone through 1/3 of the roll without this issue now all of a sudden this issue the last 2 days. I am new to 3d printing and just completed the printer. If i sit there and watch the whole thing a loosen it off the roll every so often I can get it to work. For example this morning I am at work and set it up to print a small figure 5 inches tall, it got through 3 inches 1 1/2 hours in before the extruder jammed up and no more plastic came out.. I am thinking of printing a gear style extruder with the large fly wheel would this help with torque? Also I found an item of thiniverse for a part that you put a small piece of foam into and a drop of oil and install this at the extruder to ensure no contaminates go through the line. I might try this also. I have measured the filament at various intervals, small variances but nothing at 2mm, I think the most i got was 1.88. I did drill out the brass housing at the extruder end to 2mm to ensure no snags there. Had no effect though.

How do I turn the voltage up on the stepper motor, is it in the firmware somewhere? Also I read that I should switch to Cura as Slic3r makes too many unnecessary retractions which I find help chew up the filament a bit.

When it jams next unscrew the bowden coupling or decouple the tube then see if you can push the filament out of the heated extruder by hand. I say this as the most common filament jam with pla is in the heatsink area of the heatbreak, if this is getting just a little too hot the pla sticks. If you retract too far (more than 2mm direct drive or 4-5mm on a long 60-80cm bowden) with some hot ends like e3d it will jam.

If you can push the filament through the extruder then we can rule that out.

Be cautious of drilling anything metal in the filament path, if you do polish the inner surface (I use wire wool or some multi strand copper wire on the end of my drill and spin it in the fitting) any tiny burs or rough patches can cause filament jams.

Google or youtube adjusting stepper motor current it's not hard but you need to do this carefully. I'd avoid trying to measure voltages which the more technical guides suggest just set the current somewhere between too little (Motors don't move) and too much (motors make a humming menacing noise) but on the higher side to give you as much power as you need. The only downside to higher currents might be hot motors so back it off if they get too hot to put your hand on during printing. They can run pretty hot and work so don't sweat it too much.

Cura/slic3r it's horses for courses but simplify3d is meant to be very good if you want to spend money.

I haven't tried lubricating the filament I am dubious about that but it might help, it's whether it affects your interlayer adhesion that matters.

I am at work at the moment, but if it is a situation like you mention below, how would I remedy that?
"If you retract too far (more than 2mm direct drive or 4-5mm on a long 60-80cm bowden) with some hot ends"

The brass fitting i openned up a but is at the extruder side, ever since I did that it has gotten stuck there considerably less, I did have what you mention above with it getting plugged in the hot end at least once that I know of. Is it possible to reduce retraction on Bowden to less the 4mm. I have the Extruder mounted midway on the Z Tower in hopes to minimize the travel of the tube between the extruder and the Effector. But now that I think of it maybe I should mount the extruder on the top. I also find it very strange that I manage to a few days of prints, some spare parts, a bust of a family member, a small statue, without any of this happening then over the last 2 days it is happening non stop.

Edited 1 time(s). Last edit at 02/03/2016 10:00AM by SummersideGuy.

Change your retraction speed to 150mm/s, the extruder probably can't go this fast but it will pull back as fast as it can just not as far. Try 3mm length, increase it to 4 if you're still getting a lot of strings. Try to site your extruder so that your bowden tube is as short as possible. Opinions differ but I'm not a bowden fan, filament control worsens as the tube lengthens. However this is not related to jamming but precision in depositing plastic.

The other thing that can happen is the ptfe liner in some hotends breaks down if the temperature goes too high it's meant to withstand 265 deg C but I've had a few go having never been that hot.

Ok Ill look into those settings, I was home at lunch and did a test print, and it jammed up in the hotend. I had to pull it out and start all over. With a Kossell mini I have no choice but to go with a Bowden. Its beginning to get really frustrating, Also I find if I do prints that are small and circular it doest layer up right it is as if it is building up around the nozzle end. For example if I try to print a 2 inch tall minion it will not work out, but if I print a square it will work out. I have 4 spare .4mm nozzles, maybe ill swap one out, maybe my nozzle has build up in it?

Edited 1 time(s). Last edit at 02/03/2016 01:08PM by SummersideGuy.

Not sure what's happening there, you might consider the flying extruder search the forum. Reduces the bowden tube to 10cm on a Kossel Mini.

I am just about ready to give up, the filament keeps getting stuck and the extruder bearing either ends up chewing it or not spinning at all. I am not getting consistent even feed rates either I will have layers with too little as compared to other so there will be delamination of the plastic. I did not have these problems the first 3 days of printing and everything was going great. I have attached photos of prints from the first few days I had the printer up, running, and well leveled. Then about 3 days ago now it started feeding inconsistently and jamming and sticking. Now last night I took the whole hot end assembly apart and cleaned it all and put on a new nozzle and still the same thing keeps happening. I measured the filament in various sections and the diameter ranges from 1.5mm up to 196mm. It also is not perfect circumference for example if i measure a spot and get 1.54 then at the same spot measure the perpendicular i might get 1.74. I am not sure what it is. I don't know if it is my extruder, my hot end/assembly, the filament. I have been testing with various temps. All my successful prints have been with 205-220 for temps. In one of my attached photos I circle the most common area for the pla jamming up.

I dont know if I should by another hot end assembly or if the filament is shit, am I using too high a temp for the pla, if so why so many decent prints at that temp and now this

Its a pain in the arse when this happens - welcome to 3d printing - hours of pain and minutes of pleasure. The last time I had 3 filament jams in 24 hours it was the ambient temperature that was doing it. My printers were in the garage and it was cold. Now they are in the house and they have not jammed since.

One thing that might help you save time, but is not a fix, is that you can often clear a jam by heating the extruder, push the filament manually into the extruder a little then manually pull the filament out briskly. Often the filament swells in the heat zone in the nozzle, when you pull it back this soft wider area sometimes clears away anything jamming your filament as you pull it out. My last 3 "jams" I cleared this way which is much less of a ballache than a hotend strip/rebuild.

Assuming its an all metal hot end (i.e. no PTFE liner) have you polished the inside of the throat tube (the threaded heatbreak tube) in the area you highlight in your images? If not do so, it if is rough in any way jamming is much more likely. Some of the more expensive hotends (like the prometheus) undergo a very high spec. polishing (chemical/mechanical) during manufacture and are less prone to jamming. All metal hotends jam more than pfte lined hot ends, but you can print higher temp filaments (if you need to). Consider buying a pfte lined throat and rebuilding. If you can try to allow more of a gap between the heater block and the heatsink. Try to insulate your heater block with high temp fibreglass wool and kapton tape to keep heat in the heatblock, as little as possible should rise into the heatsink at all. Its a common misconception that the heatsink is to cool the hot end, its not, it is to keep the filament cold until it reaches the hotend and in the process ensure heat doesn't rise above the heatsink to melt the printed part holding the hot end in. Its the filament passing through the hotend and careful control of heater power which keeps the hotend temperature stable.

Get another roll of filament, compared to your time, the cost of this is negligible, and if thats all it was then you're now printing and happy, if its not the cause - you're going to use it at some point anyway.

Your temperatures are okay I print PLA from 185 to 210.

Are you getting enough air flow over the cooling fins on the heatsink? Consider a tight fitting fan shroud like this one (http://www.thingiverse.com/thing:1059245 - which I remixed, might need to change it to fit your heatsink its designed for an e3d v5). Are any of the heatsink fins hot when the extruder is heated to printing temperature and the fan running? Is the fan running constantly - it needs to be. You should be able to put your finger on the heatsink on the opposite side to the fan and it should be bearable to put your finger on it, i.e. below 50-55deg C (glass transition temp of PLA is 60 deg C).

Failing all of this, it might be worth trying to replace some items and see if it helps. Is it a kit - go back to the vendor and ask for their advice you won't be the only customer with this problem if something they're shipping is not quite right.

I am going to buy a couple of the E3D V6 knock offs from aliexpress $8usd with fan and shroud that completely wraps around the fins, they have the line which is fine as I dont plan on higher temps at least not anytime soon as I am just starting out, the one I am looking at has over 200 feedback and a rating of 4.9 on the item, at $8 bucks each it no big risk. Dirt cheap, gonna get an all metal extruder assembly too, found one there for another $8usd and some extra brass ends with rubber grip for bowden tubes only $0.40 each. For the moment I will set it aside until all these spare parts come in. The hot end currently on there looks like a knock off of the V5 and I disassembled it and found no liner inside. I did as you suggested already with the filament pushing and then pully really quick it is a temp solution that last maybe for 20-30 minutues worth of print time. The printer is in my study where the ambient room temp is around 18c. I cant really complete as I paid $212usd for the kit, I am just getting uber frustrated that it worked so well and then bam horrible. The parts I listed above are cheap enough that they may be worth a try without too much waste of cash.

Edited 1 time(s). Last edit at 02/04/2016 09:42AM by SummersideGuy.

Here are a couple measurements of my filament

Well its not very consistent, and I could see that maybe giving you printing artefacts, but its below the 2.00mm at which it will jam by just being too damn wide (especially once warmed up a bit).

I've had a E3D v6 clone for $11 on an i3 for 8-9 months no real problems, occasional jam but not that often, I've a genuine e3d v5 on a different printer which I've had about the same number of jams with.

$212 for a delta printer is good value and as you said you can't blame the printer as it worked initially.

Edited 1 time(s). Last edit at 02/04/2016 11:03AM by DjDemonD.

The roll of filament, the strand itself I find is very twisted, like if you took a straight piece one end in each hand and twisted in opposite directions. It is also springy, Could this be causing some of the issue with it.

Edited 1 time(s). Last edit at 02/04/2016 03:13PM by SummersideGuy.

Maybe but it should still feed. That being said it does look like bad filament.

Edited 1 time(s). Last edit at 02/04/2016 03:08PM by DjDemonD.

OK so I cut several meters off the roll and pulled as much of the twist out, I did this twice and with both pieces successful prints. So is I think the twist is causing my jams issues. After the second successful print I am thinking it must be the twisted nature of the filament as I got towards the midpoint of the spool.

Edited 1 time(s). Last edit at 02/04/2016 10:04PM by SummersideGuy.

Glad it's working better, there is a big difference between good and bad filament.

I think with 3d printers the cost of anything should be measured in time not money. There are some cheap products that work but not that many.