Chinese eBay 3D printer - Story so far, and request for advice

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artur_k

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brs1701d
Hi artur k,

No expert myself, still learning, but I’ll try and give you some pointers.

The temperature issue is likely due to the wrong thermistors being fitted. They should have a resistance of 100kohms, the ones fitted to mine were 50kohms. Once replaced the readings were fine without any changes to firmware. I checked the Marlin config file for the resistors supported and fitted a 100k NTC 3950 sourced from ebay, and an NTC 100k from element14 (part number 135-104LAF-J01).

I had similar experiences with the motors. I was using pronterface to control the printer directly over usb whilst I got used to the functions and found it easier than using the LCD screen. It turned out I was forgetting to ‘home’ all the axis when first connecting, once this was done (one at a time to test the endstop switches), everything behaved itself.

I have found that the printer firmware to be setup adequately for my needs at the moment. I also initially beleived that I needed to update, and I probably will at some point, however I felt learning the basics before I jumped in too deep would be the correct path to take.

I hope these points help you make some progress, hang in there, I found it tough at the beginning also, it is worth persevering.

Thanks, I'll get those thermistors once I start the printer.
I tried homing, the problem is that the motors are not moving at all so cannot hit stops. One driver that is showing signs of life is acting weird as well. I only works in full step, 1/2 and 1/4 and only on low pot setting (full clockwise). In 1/16 it is still trying but unable to move. If I help it by hand then it moves but the distances are waaaaaay off.
I ordered a set of new motor drivers, to see if those were faulty. Contacted the seller as well, I'll see what he says.
In the meantime I tested heating elements and found that both are getting up to the temperature in less then a minute so all is well there.

I also have a question about the endstops. I received 3 endstops in NC configuration connected to XYZ MIN. The board has 6 ports for them. When I send M119 I receive back that XYZ MAX are tripped - is it the same on yours?

Yes, the XYZ MAX are reported as tripped. Hopefully the replacement drivers will work, have you made a close inspection over the rest of the board to ensure none of the components look fried?

I found the seller to be responsive, however, apart from a small refund, that was as far as it went. With the help of this forum, and additional research, I have had to solve the issues myself

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elwood127

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Mrp23
Hi brs1701d,

I ordered this: [www.ebay.co.uk] in LEFT hand and received the one on to the left of the picture so i would say it would be which side the motor is mounted (maybe?).
Please note that part did not fit correctly for me due to the orientation of the block in the the L shaped bracket so i used the springs and screws with this and printed myself out of trouble!


As you can see in my picture i have the motor mounted to the right side.
one thing i noticed after assembly was that when i homed the machine the etruder was off the table by 10mm+ has anyone else found this to be the case?
with this setup now it is perfectly aligned to the corner of the bed .

Having the hotend off of the plate makes for easy extrusion. Over the plate blocks this task.

A valid point, though generally i lift the z axis up before printing to inspect the nozzle with it pre heated, the geeetech firmware re-homes before it prints
anyway so i do not run into issues.

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brs1701d
Yes, the XYZ MAX are reported as tripped. Hopefully the replacement drivers will work, have you made a close inspection over the rest of the board to ensure none of the components look fried?

I found the seller to be responsive, however, apart from a small refund, that was as far as it went. With the help of this forum, and additional research, I have had to solve the issues myself

Ah, so the end stops are ok. I have inspected the board and it looks fine. All drivers are getting signal. When I put the only responsive driver in, I get motors buzzing and moving only with all jumpers removed.
I also checked voltages on the drivers with a multimeter and all is fine there - getting 5 and 12v. Checked the motors as well - all got 2 pairs.

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artur_k

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brs1701d
Yes, the XYZ MAX are reported as tripped. Hopefully the replacement drivers will work, have you made a close inspection over the rest of the board to ensure none of the components look fried?

I found the seller to be responsive, however, apart from a small refund, that was as far as it went. With the help of this forum, and additional research, I have had to solve the issues myself

Ah, so the end stops are ok. I have inspected the board and it looks fine. All drivers are getting signal. When I put the only responsive driver in, I get motors buzzing and moving only with all jumpers removed.
I also checked voltages on the drivers with a multimeter and all is fine there - getting 5 and 12v. Checked the motors as well - all got 2 pairs.

With my limited experience, I have no other suggestions for you at the moment.

Have you had any response from the seller?

Edited 1 time(s). Last edit at 03/25/2016 12:35PM by brs1701d.

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Mrp23
Hi ettie1972,

If you are wanting to clarify the positions of all connectors on the gt2560 board take a look here
under interface layout: [www.geeetech.com]

what exactly is the issue with loading the filament?

Hi Mrp23

Thanks for the guide really helped, the problem with the filiment not feeding is the feeder sounds like it is skipping, if i put pressure on the filliment then it feeds.... not sure whats causing it, i checked the extractor motor and turns the right way and is clean... any advise would be great

Have you ensured the extruder is at the correct temperature? At the moment my thermistor reads incorrectly, 15+ degrees higher then it should so i adjust for this before i print.
Might be worth testing by starting a print with 225 degrees if it goes o.k after 3 to 5 layers then drop the temperature 5 degrees and continue until the clunking starts again this allows you to see if its temperature related.
I also encountered issues with the feeding due to filament particles on the knurled collar for this i disassembled and cleaned it, upon reassembly i used a small length of filament and simulated loading the filament to very slightly alter the gapping between the knurled collar and vgroove when tightening the screws this also seemed to help.

Time for another update:

I have been printing smaller objects with relative consistency with no major problems now that I have a better understanding on how the various slic3r settings affect print quality and speed. I started experiencing filament feed clunking issues which were helped by reducing the print speed, however the problem deteriorated. Dismantling the extruder and cleaning the cog has seemed to cure that problem, at least for the time being.

I started to move onto larger prints with a larger base and started to suffer from lifting and warping, even to the point that it was pulling the blue tape off the glass. I am currently still printing with PLA and the blue tape is more than adequate for the smaller prints. I have made some attempts to print with a base or raft and there has been some improvement, but as lifting only manifests itself several hours into the print, this trial and error approach takes some time.

Yesterday I decided to try the hairspray method with a heated bed, this is when the fun started. I seem to have an issue whilst printing with the heatbed on in that the printing process, for want of a better explanation, becomes ‘possessed’. All manor of strange behaviour is demonstrated, from random filament feeds to Y and X axis moving around erratically. This had me pulling my hair out, not that there is any left to pull, and provided a frustrating couple of hours.

To get to the point, the heatbed will heat fine and reach the required temperature, but as soon as the actual printing process starts, all bets are off.

My first thought’s are power supply issues? I did try a bench power supply, however switching the printer on caused the power supply to reset (I’ll have to look up the specs), and an old PC power supply also did not seem to have the guts required. By this time it was getting late, so that was that.

So today I’ll switch back to the tape and no heat bed and test some prints whilst I research this issue. All good fun!

Has anyone else had this problem?

Update: Switched back to tape and no heated bed and printed several small parts this morning with no issues. So looks like I'll need to investigate power/heatbed to try and find the cause.

Edited 1 time(s). Last edit at 03/27/2016 07:01AM by brs1701d.

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brs1701d
With my limited experience, I have no other suggestions for you at the moment.

Have you had any response from the seller?

Yes I had response. He said that he sent a copy of the firmware to my paypal address but I haven't received anything and he also asked for pictures of the board.

I installed 4 new drivers - drv8825 and it is working fine now. I don't know what caused that all 4 drivers were faulty. I put new ones in and they worked straight away.

I also had some bed adhesion issues it was very frustrating. Finally I am just using plain glass without blue tape but I put some pva glue on just before printing. Now I have to work hard to pull the prints off the surface after printing. The print quality is very good for such a cheep printer.

My power supply which I received with the printer is marked as 180W. So 15A. I have no problems with it.

I have just one problem left. My prints are 0,3mm taller then they should be - exactly 1 layer?? It doesn't matter if it's 10 or 20mm.
Anyone knows where to change it in slic3r?

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artur_k

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brs1701d
With my limited experience, I have no other suggestions for you at the moment.

Have you had any response from the seller?

Yes I had response. He said that he sent a copy of the firmware to my paypal address but I haven't received anything and he also asked for pictures of the board.

I installed 4 new drivers - drv8825 and it is working fine now. I don't know what caused that all 4 drivers were faulty. I put new ones in and they worked straight away.

I also had some bed adhesion issues it was very frustrating. Finally I am just using plain glass without blue tape but I put some pva glue on just before printing. Now I have to work hard to pull the prints off the surface after printing. The print quality is very good for such a cheep printer.

My power supply which I received with the printer is marked as 180W. So 15A. I have no problems with it.

I have just one problem left. My prints are 0,3mm taller then they should be - exactly 1 layer?? It doesn't matter if it's 10 or 20mm.
Anyone knows where to change it in slic3r?

Glad that the replacement drivers solved your problem, guessing that was a relief.

I had a successful days printing yesterday, all small parts, cable chains etc, all printed fine so I am fairly happy that the basics are ok. I have an ATX power supply to try and see if that solves the bed heating issue.

I had a lot of weird problems with mine - but only when running from the SD card. At times it would seem like either the X or Y axis would home themselves before continuing with the print, and sometimes the extruder would reverse all the filament out of it. Since then I have added a raspberry pi as a USB controller running octoprint - and I've had no problems. I wonder if either the 5V regulator was flaky (and gets a fresh 5V supply through the USB port) or if there is a problem with the SD card.

Phil

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furbrain
I had a lot of weird problems with mine - but only when running from the SD card. At times it would seem like either the X or Y axis would home themselves before continuing with the print, and sometimes the extruder would reverse all the filament out of it. Since then I have added a raspberry pi as a USB controller running octoprint - and I've had no problems. I wonder if either the 5V regulator was flaky (and gets a fresh 5V supply through the USB port) or if there is a problem with the SD card.

Phil

Hi Phil,

I recall having the problems you describe when I was first testing the printer, seemed to be associated with having a PC plugged in whilst using the SD card as well. I have only been using the SD card recently, and all seems to have settled down.

The Pi with Octoprint is another option for me to try as well as another power supply.

Octoprint is new to me, so something new to learn.

Brian

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furbrain
I had a lot of weird problems with mine - but only when running from the SD card. At times it would seem like either the X or Y axis would home themselves before continuing with the print, and sometimes the extruder would reverse all the filament out of it. Since then I have added a raspberry pi as a USB controller running octoprint - and I've had no problems. I wonder if either the 5V regulator was flaky (and gets a fresh 5V supply through the USB port) or if there is a problem with the SD card.

Phil

Hi Phil

Thanks for mentioning Octoprint, seems to have resolved my issues with random movement, and with the heated bed. I have printed several parts using the heated bed over the last few days with no incidents, so fingers crossed that has solved the issue.

Octoprint was very easy to install, I did have a slight challenge configuring the wireless on the Pi, but all sorted now.

Brian

Hi, I've recently just bought one if these as well. I am having similar problems with the thermistors, and rasping on the extruder.

When the item arrived, the rods were bent, and the holes had been cut in the wrong places on the frame.

Does anyone know if it is possible to backup or download the running firmware on the gt2560 board?

Roger

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arleseydiver
Hi, I've recently just bought one if these as well. I am having similar problems with the thermistors, and rasping on the extruder.

When the item arrived, the rods were bent, and the holes had been cut in the wrong places on the frame.

Does anyone know if it is possible to backup or download the running firmware on the gt2560 board?

Roger

Hi Roger

The thermistors are relatively cheap and easy to replace, and I did not have to change any firmware settings to accomodate these and went for standard 100kohm.

As far as I am aware you cannot backup or download the current settings/firmware and a request for this information from the seller fell on deaf ears. The printer settings seem to be setup fairly accurately, and I have not yet had a need to address this. I have made a written note of all the current settings and am in the process of configuring Marlin ready to update when I feel the need, or desire another challenge.

I also had bent rods, and have replaced these.

I had some fun the weekend, I believe the nozzle came loose as molten plastic ran everywhere, created one hell of a mess.

Brian

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arleseydiver
Hi, I've recently just bought one if these as well. I am having similar problems with the thermistors, and rasping on the extruder.

When the item arrived, the rods were bent, and the holes had been cut in the wrong places on the frame.

Does anyone know if it is possible to backup or download the running firmware on the gt2560 board?

Roger

I tried several different ways to backup existing firmware. I finally just bit the bullet and installed Marlin1.1.0_rc3 and bit by bit got configuration.h set to what the printer liked.

As for the z-axis rods, mine were pretty bent too. I tried a few different things to get the alignment better, but eventually just bought some leadscrew and made some bushings and couplers and it works great. I didn't like the 4-start leadscrews as that seems to me to be way too much of a change (1.25mm to 8mm) in the pitch for my tastes (that's over 6x multiplier to any z-axis slop). I went with a single-start 2mm leadscrew, but could not find any bushings so I bought an ACME tap and made my own (I have a lathe) and I now have no z-axis banding at all.

I bought one of these and have built it up. It's my first foray into 3D printing and seemed a good deal to start with and improve as time goes by. My problem is the screen either comes on blank, is full of random glyphs or has random glyphs and seems to be scrolling but I can't make anything out so can't get it calibrated. All the motors and drivers are fine from what I can tell.
I was hoping someone has seen this issue before and can advise me on if it's a duff part or my error.
It's built exactly as it should be in the manual and this is the same as the geeetech specification for the wiring.
I don't think there's a lot wrong with it, maybe just my newness to 3D printers.
Has anyone come across problems like this?
I'll be able to post pics in a day or twos time to better explain my issue and show how I've wired it.

Edited 1 time(s). Last edit at 04/08/2016 09:20AM by ad456m.

Mine has two ribbon cables from the board to the display and I recall that there was no indication as to which was which. I plugged them in wrong at first and the display lit up, but nothing else. That might be something to check. Does the printer accept movement commands over USB? May just be a fried display. Are you using the supplied firmware, or have you uploaded something new?

I plugged them in as indicated in the manual. Ext1 to lcd and ext2 to sd. Might b worth a shot to swap em.
I'm still running stock firmware whatever it may be. I did think about flashing it with Marlin but don't know about configuration so guessed it was best left alone as to not create more problems.
I did hook it up to my Mac and cura but the printer need to onboard setting configured as the extruder comes over the edge of the bed as it is so left that alone too before I break something. It did give me the idea that everything else is fine apart from a clicking extuder. Lowering the feedrate might fix that.
Thanks for the ideas, I'll try them next time I'm home.

EDIT :- Swapped the cables but no joy, they must've been right to start with. here's some pics i took before the swap



I'm suspecting a shot lcd, I'll order another from somewhere to try out. Incase I've screwed up the config, does anyone have any settings for this thing? Or a firmware and settings to flash it with?(I'm competant with arduino but no master, lol)

Edited 1 time(s). Last edit at 04/08/2016 07:24PM by ad456m.

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ad456m
I plugged them in as indicated in the manual. Ext1 to lcd and ext2 to sd. Might b worth a shot to swap em.
I'm still running stock firmware whatever it may be. I did think about flashing it with Marlin but don't know about configuration so guessed it was best left alone as to not create more problems.
I did hook it up to my Mac and cura but the printer need to onboard setting configured as the extruder comes over the edge of the bed as it is so left that alone too before I break something. It did give me the idea that everything else is fine apart from a clicking extuder. Lowering the feedrate might fix that.
Thanks for the ideas, I'll try them next time I'm home.

EDIT :- Swapped the cables but no joy, they must've been right to start with. here's some pics i took before the swap

IMG_1293.JPG

IMG_1292.JPG

I'm suspecting a shot lcd, I'll order another from somewhere to try out. Incase I've screwed up the config, does anyone have any settings for this thing? Or a firmware and settings to flash it with?(I'm competant with arduino but no master, lol)

Hi, that is a funky screen. I have the occasional garbled characters, but majority of the time things are ok.

Have you tried Pronterface, very straightforward, will help you get the feel for the printer and help confirm everything is working ok. I used this myself for the initial checks (as I found the LCD quite irritating), and continue to use when levelling the bed.

You shouldn't need a firmware change if you just change the LCD (unless you go with a full graphics or something).

I pieced the firmware together myself as I had to erase the original. I've made a few mods though: new thermistors (both NTC3950s), new leadscrews (2.0 mm 1-start trapezoidal from 1.25 M8), and 1 DRV8825 board for the extruder stepper (double the microsteps).

Shouldn't be too hard to get you a working Marlin setup though.

WOOOOHOO! I have life, that Printrun is exactly what i was after

The calibration of the printer is a wee bit off but all the bits respond properly and I've got a clunking extruder but not worried about that, i'm sure I'll figure that out.

I was planning to replace/upgrade to drv8825 all round in (a short) time too, nice to know i can and i have those thermistors in the mail.

I'll have to read up on leadscrews as mine are slightly bent but don't care too much yet as theres plenty to learn.

Thanks ever so much folks, you've totally sorted my optimism out as i was starting to think i'd knackered the thing, lol.

I'll start looking through the fixes for the extruder now and find a nice wee cube to amaze myself with

Edit :- Any tips for calibration would be gratefully accepted, links or vids, i don't want to waste folks time writing a manual for me, its just that theres so much rubbish to trawl through on google!

Edited 2 time(s). Last edit at 04/09/2016 01:26PM by ad456m.

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ad456m
WOOOOHOO! I have life, that Printrun is exactly what i was after

The calibration of the printer is a wee bit off but all the bits respond properly and I've got a clunking extruder but not worried about that, i'm sure I'll figure that out.

I was planning to replace/upgrade to drv8825 all round in (a short) time too, nice to know i can and i have those thermistors in the mail.

I'll have to read up on leadscrews as mine are slightly bent but don't care too much yet as theres plenty to learn.

Thanks ever so much folks, you've totally sorted my optimism out as i was starting to think i'd knackered the thing, lol.

I'll start looking through the fixes for the extruder now and find a nice wee cube to amaze myself with

Glad you are making progress.

The extruder can be a bit temperamental. The plastic part which the filament runs through is held to the motor by 2 screws, and on my unit, these have a bit of play so I had to loosen them off and apply some inward pressure (with a piece off filament in place), and then retighten the screws.

Also I found slowing down the print speed helps as these printers seem to be configured to run faster than the kit can handle. However, I still have more filament feeding issues than I like so am currently looking at other Extruder / Hotend combinations.

I've been looking at replacing the extruder too as it seems to be the main weak point of the model.
I liked the look of a full metal one for obvious reasons but the different models are a mystery to me so i'll sift the wiki on here to fix that. Something with a tension lever seems the obvious route to me as I'll be able to adjust it without having to strip it down but this might be an uneducated guess.
Also turning up the heat to compensate for the poor/wrong thermistor may help me too, it'll be trial and error for now

Edited 1 time(s). Last edit at 04/09/2016 02:09PM by ad456m.

I've had no problems with the non-adjustable part. I did have to do some tuning to get the stepper to stop stalling, and I tried an adjustable version of the tensioner found on thingiverse ([www.thingiverse.com]), but the lever wouldn't clear the mounting bracket. I re-modeled the STL file to truncate the lever a bit, but it didn't do any better than the stock one so I have it in reserve for now.

I'll play around with what I have just now then, see if I can get a cube or at least something out of it for now and look at upgrades once I have a better idea of things.

Hy everybody... Soo i bought the exact same 3d printer and i can't calibrate the z axis ... i encounter 2 problems

1º doing the auto home the extruder get out of the bed
2º the extruder is crashing in the bed ...


Anyone facing the same problem ?

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Lucas Azevedo
Hy everybody... Soo i bought the exact same 3d printer and i can't calibrate the z axis ... i encounter 2 problems

1º doing the auto home the extruder get out of the bed
2º the extruder is crashing in the bed ...


Anyone facing the same problem ?

1 - adjust the end-stop position so it stops within the bed

2 - as per the other thread on this, what does a M119 show? i.e. does the Z stop switch get hit and the axis keep going?

Steve

---

My updated Instructable on our Prusa i3 Build
[www.instructables.com]

Make sure all the wires in the harness make contact. I had one yellow wire what was wonky, made the Y motor buzz like heck.
Pain in the butt to fix.
Later, the X motor wire harness, the res wire fell off, all by itself.

Hi all first post here, i have just got this printer but the instructions i was sent aren't great has anyone got an English copy.

Btw thanks for all the info on this thread can watch out for the issue that might come up.

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shifta
Hi all first post here, i have just got this printer but the instructions i was sent aren't great has anyone got an English copy.

Btw thanks for all the info on this thread can watch out for the issue that might come up.

When I received mine there was also a file on the SD card in English - Build Instructions.doc. If you do not have this, PM me and i'll get you a copy.

Brian