Ebay SINTRON Kossel Mini full kit

Quote
seanthemighty
I had done, however I realised I had an older version of slicer (1.17), so upgraded to 1.29, again made sure all settings were right(ish), and it printed (huzzah!). Strangely though, when I pulled to gcode into pronterface, it placed it outside the build area (but printed fine). Now it's on to calibration, have done 2 XYZ cubes now, first one better than the second (I updated the kinematics, made them more precise, made it worse oddly). Have just notice the effector is not perfectly level, seems one of the arms is loosey goosey, so in the morning will redo that. Think I need to slow down the homing speed too, is pretty quick so I think slight imbalance will come from that. Given (I assume) we have all the same printer (more or less), is there an accepted, community created set of marlin settings?

To configure those correctly I use DC42 calculator. He is a genius. The link is here:
[escher3d.com]

I understand your frustration when you first start out. And this is an old thread but I want others to learn from it. Also, if you go through this thread I have asked about the same issue you did about calibration cubes. I still use them to this day when upgrading to new motherboards. I have moved up from the RAMPS board to a DUET 0.6 to currently the DUET ETHERNET. The issue with calibration cubes relates to size. If you cube is off when you print it small it might be normal when you do a large cube or project. That is what I have noticed. So I just live with the slight size issues and make sure I print all the parts together at the same time (ie do not try and scale them to "fit" better).

Hi again..

I think that I need some professional help with my issues with kossel..

can someone of you pros give me a hint what could cause this "wavy under extrusion" and after that comes over extrusion..






layers before these top layers were printed fine..

Make sure the tension on your extruder motor is maintained

Do You mean that is the extruder properly mounted and does not move while extruding?
if so the answer is yes..

or do you mean that is there "constant" pressure on the filament..
then answer is yes and no (simply I am not sure)

I made some investigations to sort this problem out..
I have 5:1 geared extruder that is mounted to a "hercustruder", an airtripper variant.
It has MK7 gearwheel that feeds filament.. (all steppers have pololu drv8825 drivers adjusted to 1 amp [vref=500mV])

I tried to feed filament by hand trough the bowden and hotend it felt OK.. (newbie opinion)
then I feed filament by extruder only to bowden to check does the bowden cause extra resistance if I bend it (I made various tight corners)
extruder worked well.. then I attached bowden to the hotend and extruder started to "slip" and I think this causes the problem..

I am a bit confused because this extruder setup should work like a charm.. even with smaler nozzel sizes
I increased hotends temperature but it did not help much..(I did hotend pid and heatbed pid also)

by the way is the extruder max acceleration value 10000 too much in marlin config?

Edited 1 time(s). Last edit at 06/28/2017 03:47PM by OG.

Quote
OG
Do You mean that is the extruder properly mounted and does not move while extruding?
if so the answer is yes..

or do you mean that is there "constant" pressure on the filament..
then answer is yes and no (simply I am not sure)

I made some investigations to sort this problem out..
I have 5:1 geared extruder that is mounted to a "hercustruder", an airtripper variant.
It has MK7 gearwheel that feeds filament.. (all steppers have pololu drv8825 drivers adjusted to 1 amp [vref=500mV])

I tried to feed filament by hand trough the bowden and hotend it felt OK.. (newbie opinion)
then I feed filament by extruder only to bowden to check does the bowden cause extra resistance if I bend it (I made various tight corners)
extruder worked well.. then I attached bowden to the hotend and extruder started to "slip" and I think this causes the problem..

I am a bit confused because this extruder setup should work like a charm.. even with smaler nozzel sizes
I increased hotends temperature but it did not help much..(I did hotend pid and heatbed pid also)

by the way is the extruder max acceleration value 10000 too much in marlin config?

I am having the same issues with slippage but with Nylon. I cant figure it out yet.

But for your issues, You might want to tighten the pressure on the filament at the level of the extruder to prevent slippage. Sometimes however slippage is the result of the hotend not being hot enough to melt the filament.

I figured out this slipping problem and partly solved this under extrusion problem

I couldn't tight filament much enough to prevent slipping because idle bearing couldn't give much enouhg pressure against mk7 wheelgear
and that happened because airtrippers frame was too close to idle bearing and bearing abrade against frame.. could I explain this more complicatedly
some dremel and this is fixed in notime..

but I did not solve this under extruding problem

Then red from E3D V6 troubleshooting guide that bowden should be attached so that the "latches" (or what ever is the correct term for those) are pulled up and locked so they don't move while retraction and so on..
I did this and it improved quality a lot, but always last layer of top fails



as you can see there is some light markings of under extrusion and some bad under extrusion problems. I wonder why this bad under extrusion happens in the same spot every time..

Hi. I am not sure if this printer has a heated bed, but if it does its possible that your print temperature is slightly low. When the nozzle is close to the heated bed, it doesn't loose as much heat is the filament is extruded through it, but once it raises above the bed a little bit, the air is cooler up there and the extruded jams a little bit, causing this under extrusion. Try boosting your temp by 10c and see what happens.

Quote
Qdeathstar
Hi. I am not sure if this printer has a heated bed, but if it does its possible that your print temperature is slightly low. When the nozzle is close to the heated bed, it doesn't loose as much heat is the filament is extruded through it, but once it raises above the bed a little bit, the air is cooler up there and the extruded jams a little bit, causing this under extrusion. Try boosting your temp by 10c and see what happens.

I agree with QD. I have been testing my system with this file:
[www.thingiverse.com]

Its a temperature calibration file on thingiverse. Its really helpful. Place the file in vase mode and see how the print looks. It has helped me tremendously.

Yes I have heated bed, it is that aluminium heated bed that came with sintron's kit, but there is borosilicate glass on it (I tought that I have concave and convex surface on that aluminium one)

I have tried to print with temperature of 222C and I don't know dare I raise this temperature much..(I still quite noob in 3d printing)

I have heared rumors, that E3D v6 needs a bit higher temperature to work properly..but I am not sure..

Quote
OG
Yes I have heated bed, it is that aluminium heated bed that came with sintron's kit, but there is borosilicate glass on it (I tought that I have concave and convex surface on that aluminium one)

I have tried to print with temperature of 222C and I don't know dare I raise this temperature much..(I still quite noob in 3d printing)

I have heared rumors, that E3D v6 needs a bit higher temperature to work properly..but I am not sure..

I have the same aluminum heated bead. I added the glass plate as well. Unless you have the exact B and R values for your thermistor, the hotend temp may be off. That was the case for me. Even now I wonder if I have the correct temp. For example. I am printing Taulman Nylon230. Heat temp is supposed to be 230C. But my filament is burnt. So I print at 220C. Thats 10C off. Your thermistor may read 222 but in fact its only 180C possibly. The only way to know is to print with PLA first to experiment and use the calibration tower. I started at 180C with PLA and slowly moved up. After trying the different temps, 190C prints came out perfect with PLA.

Also, I had a similar issue with my prints. Your bed may not be level. Your Z height may be off. This would cause streaks in your prints.

What is B value R value is 100k and this exact thermistor, that e3d uses, was found in marlin config.. but I hope that this issue of mine is related to hotend heating..
because I am not that skilled in bed leveling so I am affraid that that causing the issues..

got to ask now, that when we are talking about bed leveling are we talking bed's mechanical leveling so that bed is attached to frame evenly so it is leveled that way or does this bed leveling procedure include endstop height calibration? I am so noob with 3d printing that I don't know even basic 3d printing terms/vocabulary or such.. but I learn (hardest way)

and what comes to attaching bed to frame what is the easiest way to do this so that bed is evenly "balanced". I have regular circuit board pillars, but I think this is not the best possible way to do it

also I have heard that e3d v6 with 0.4 nozzle is very very difficult to use.. is that correct information??

Edited 1 time(s). Last edit at 07/08/2017 02:03PM by OG.

I've printed pla at 250c by accident before, you won't hurt anything by bumping up your temps 10 degrees at a time you see if it makes a difference. I'd also recommend getting a digital multimeter with a thermocouple so you can verify the hot end temp. I had my thermistor set up correctly but the temps were still off by 10c...

You should get a 90 degrees square and check to make sure your bed is exactly at 90 degrees to each of the three extrusions, and it will also tell you of the bed is level. But that is not the issue here I don't think because that type of problem would show up in the first layer.

Edited 2 time(s). Last edit at 07/08/2017 02:54PM by Qdeathstar.

Quote
OG
What is B value R value is 100k and this exact thermistor, that e3d uses, was found in marlin config.. but I hope that this issue of mine is related to hotend heating..
because I am not that skilled in bed leveling so I am affraid that that causing the issues..

got to ask now, that when we are talking about bed leveling are we talking bed's mechanical leveling so that bed is attached to frame evenly so it is leveled that way or does this bed leveling procedure include endstop height calibration? I am so noob with 3d printing that I don't know even basic 3d printing terms/vocabulary or such.. but I learn (hardest way)

and what comes to attaching bed to frame what is the easiest way to do this so that bed is evenly "balanced". I have regular circuit board pillars, but I think this is not the best possible way to do it

also I have heard that e3d v6 with 0.4 nozzle is very very difficult to use.. is that correct information??

I do not own a e3D hotend. The one I got from Sintron was a clone. I have since remove that clone and replaced it with an all metal Hexagon Hotend. But I can only assume that the E3D is the standard nozzle to use.

I like to use a carpenters level on my heatbed. The one with the water bubble. I make sure that it is level in at least 2 directions ( x and y). I also do bed leveling calibration sequence with my IR height sensore. For the stock Kossel you can do the analog bed level calibration sequence that uses the hex wrench ? attachment.

So far as the temp calibration goes. QD is right. You can just keep upping your temperatures until you see that the streaks go away in your prints. Then you know that you are at the correct temperature

Hi again

Finally I had sometime to print this temperature tower and my opinion is that best reults are printed with temerature of 215 C
first readings of the temperature tower are not the correct ones
first 50 layers (markings in tower 220) are printed with temperature of 215 and next 50 layers are printed with temperature of 220 C
and so on..

I am sorry that photo isn't the best possible, but..



I think that best results are with temperature of 215 C and increasing it does not help me with my problem..
I am so out of ideas now..

this device totally takes time way more than it gives.. and I cannot say, that "time well spent"

I felt the same way. But you have to perfect the temp/ speed of the printer. I have no issues printing anything in PLA. My challenge is with PETG and nylon. I think I have PETG down to a science but still cannot print large objects with Nylon. Do not really know what the issue is? So its just experimenting.

But you have to keep trying. Stick with 215C and now change the speed. Make it slower and see what happens.

For me with the height restriction of Nylon (stops printing after 5cm high), I might compensate by making a 2 part piece and gluing them or snapping them together.

Edited 1 time(s). Last edit at 08/04/2017 04:20PM by DRTak.

hi again..

I have not tried to change speed settings because I have been printing with quite a slow settings and I don't think it helps me but guess I have to do it some day..

what I have tried to do fix this problem

belt tension -> no affect
disassembled and asembled the hotend -> no affect (on first try it made printings more worse )
bed leveling -> no affect (but the bed is now level (that was on todo list anyway))

maybe I am not that skilled in this hobby and I need to forget this..(maybe I try 0,5 nozzel before that) This device really eats up all my freetime and sleeptime..

I can honestly say that as far as printing with PLA is concerned, I have two printers and between them have used 4 different hotends over the past 3 years. The cheap Chinese ones were no different from an E3D, they all printed to the same quality.
The filament made no difference either, I just buy the cheapest and print at 202 degrees. No heated bed. The Smartrap now has a £1 Ikea mirror as a bed, and all I use to stick the parts down is cheap hairspray. I use a small hand held water spray to release the parts. I don't even need a brim.

You say that your prints are only going 5cm high and then stopping, are you using Cura? If you are and it is the old version (that's what I use) then there is a bug in it. It sometimes generates flawed Gcode, when the print reaches that line of code the printer hangs. I always wait 10 seconds after it tells me that the Gcode is saved before removing the SD card, this seems to fix it, especially on large or complicated objects.

Yes, printers will take up all of your time, everyone who buys one soon discovers this. The bonus is that everything that you do is something that you learn. It got me away from wasting my life away watching tv, I would much rather discover and learn than do that.

This is why there are two ways to buy a 3D printer. You either buy an inexpensive kit, assemble it and learn how to make it work properly, or pay 3x as much and buy a fully assembled one with factory support.

I use slic3r version 1.2.9 and repertier host for mac..

You are so right with this learning thing..

but if you look photos from my earlier posts you see what is the problem.. it is hard to explain with my reduced english dictionary

but it seems that everything is fine and it prints quite good quality but when it starts to print surface (some times bottom layers) it under extrudes and after a while it over extrudes and then continues printing with ok quality..

I would be very pleased if I could print something fancier and more practical than a calibration cube..I have been fighting with this printer about 8 months
I have changed tons of parts, every wire, crimped every connector (engineer pa21 pliers I recommend for every 3d printer owner) etc.. but outcome is stil zero..
but maybe some day..

I can understand the problem, but you are looking for a solution using knowledge that you currently have, which places a restriction on reaching the solution to the actual problem, if that makes sense. I have a friend who encountered problems with his printer, and no matter what I advised him to do, he simply pulled plugs out and put them back, or bought new components. He was just hoping that he could buy a solution, rather than sit down and solve the problem by learning something.

If I was having the same problem as you, I would do the following.

1. Check that the Z height is correct. Use the Escher tool to get the printer set up initially. (look it up on Google). The towers may not be 100% vertical, they may not be 100% at 90 degrees to the bed, the frame may not be a 100% triangle. The rods may not 100% the same length, or the effector may not be 100% horizontal.
2. Check the extrusion rate is correct.
3. Check that the filament is not slipping. Put a pen mark on the toothed gear and the bearing, and check they both rotate at the same rate.
4. If the extruder clicks then it is over extruding.
5. Check that the stepper drivers are all running the same voltage (videos on You Tube show how to do this).
6. Try a different slicer. Cura is simple to set up and use.

There is always a reason why prints fail, it is best to try one solution at a time, then try a reprint. This way you know what works, what it does, and what difference it made.

I have pretty much done all of that..

what I have not tried is cura.. I checked cura's website (ultimaker or what so ever) and there was information that newest versions of cura does not support deltas (and I never really tried to look older one)

I know that everything is possible but honestly must say that my skills are not on the needed level for example if I measure something and if I multiply that with inaccuracy of measurement tools then I cannot get everything in 0.05 mm accuracy or get everything in 0.2mm accuracy is very very hard to achive with the tools that I can get from the hardware store same rules apply to angle measurements because I do not have 0.00 deg reference point to calibrate my tools.. but mechanically this should be as accurately made that I possibly can.. but as you said that my skills are reduced and that is something I am aware of..

why I have changed parts honestly sintrons printed parts were junk and some of them broke during use.. without a printer it was quite demanding manufacture new ones so buying new ones were in place..

I changed 4988 allegros to pololu drv8825 because towers works bit better with those (no need for active cooling of stepper drivers with these) but anyway

but I need to double check double checked things .. maybe some day..

Hi,

I did not see the replies till now. Most 3D printers take more than they give, be prepared.

So, it is not a temperature issue,

Have you printed a test cube? eg, not that specific model, It is also possible that there is an issue with the model. Maybe try to print Melvin at 2x scale, you can find him on thingiverse.com


Maybe you are retracting too much, Set your retraction to 0. YES, you will give oozing and blobs, but if it prints the top layer fine you can then increase retraction to a point where you start having issues with the top layer again.

i highly doubt kinematics are to blame, so i couldn't worry about if the towers are perfectly parallel or changing stepper motors out. If you had an issue like that it would be magnified at the first layer, not the top layers.

Edited 2 time(s). Last edit at 08/12/2017 12:06AM by Qdeathstar.

@OG

I assume you are printing PLA because of the temperatures.

Might it be possible you are printing top layer with extremely fine extrusion width at average speed? ( = low ammount of PLA used)
Or do you even have a hotend-fan? - Is it at 100% all the time?

Both things might result in heat creeping up the hotend, PLA getting to soft and thus clogging. After some more preasure sometimes it comes loose again, and printing continues.

As you manged to print the temp-calib-tower without this problem, this would match, because there is no big, fine top layer.

Edited 1 time(s). Last edit at 08/16/2017 09:04AM by Dancer.

Does anyone know of a UK supplier of alloy top brackets for these? I have only discovered today that my degrading print quality is due to cracks in all three of mine. No idea why they have failed, the printer stays static in the same place on the workbench, I have asked Sintron UK if they will supply free replacements, but if those fail as well then alloy parts will be the only solution.

Quote
Dancer
@OG

I assume you are printing PLA because of the temperatures.

Might it be possible you are printing top layer with extremely fine extrusion width at average speed? ( = low ammount of PLA used)
Or do you even have a hotend-fan? - Is it at 100% all the time?

Both things might result in heat creeping up the hotend, PLA getting to soft and thus clogging. After some more preasure sometimes it comes loose again, and printing continues.

As you manged to print the temp-calib-tower without this problem, this would match, because there is no big, fine top layer.

Thanks man very very much!! This helped me a lot!! I don't know why but I had "default extrusion width setting" of 0.35 in slic3r and that overrides values that where set to auto including top filling..

I have hot end fan and I tried different kinds of speeds with that with no luck.. now I have removed hot end fan because I have took hot end that many times apart.. but I will put it back after I have managed to do some tests with my printer..

Again thank you very much!!

Hey guys!

I finished building a Sintron Kossel Mini kit I got for Christmas.

It is working OK. I haven't had too many problems, except that the instrution pdf was a bit lacking. I'm now trying to calibrate the printer and get auto bed leveling to work. I initially got the probe retraction to work, but that was with DEFAULT_AXIS_STEPS_PER_UNIT {100, 100, 100, 95}. After using the calculator, I've now set it to {80, 80, 80, 95}, and I've printed a 1cm cube which was about the right size. However, now I can't reach the probe retraction screw at the outside of the bed! I can't seem to reach any point outside of the bed when navigating with pronterface.

Has anyone else had this problem? What could be wrong? Maybe my rods are too long? I just used the metal rods that came with the kit, and tried to get them to be the same length.

EDIT: I just found the DELTA_PRINTABLE_RADIUS setting.. that solved it.

Edited 1 time(s). Last edit at 01/21/2019 02:56PM by burk.