Which drivers? Have you checked motor polarities?

You need to answer all the questions I asked

 

Drivers are A4988. About the polarity, I presumed that it's correct as they work perfectly in isolation. Or there is more to it ? Anyway I plugged red on red, blue on blue, green on green and black on black, in that order, red at the opposite of the main 12V connector.

 

I'd say, if not a polarity issue, then jump to DRV8825's. I didn't even bother trying the cheap drivers that came with my cheap RAMPS board. I put the 8825's in from the start and with a front and rear Z-axis setup, run both off of 1 driver with little problem.

When you have them wired up, can you turn the shaft by hand with little resistance?

 

So each motor works when individually connected to the driver? But not when both are connected?

 

Correct.

 

I am prepared to upgrade to better drivers, at least for the Z axis. When only one is wired there is a great resistance, but not when both are there.

 

I'd swap the driver if i were you like @akneipp said. Off the top of my head, i can't see why putting them in parallel is a problem. FWIW, A4988's are Imax = 2.5* Vref. 0.6V might be a bit too much. 1.3V is certainly too much for any nema17 i've seen (assuming thats what you're using)

Wiring up is different to powering them up and holding position.

 

Hi guys I have a question. The part fan included in the rework file I am using on my Dbot sits lower than the nozzle on my e3dv6. I don't currently have a photo to show you because I am at work, but nothing I try seems to work lifting it up.

Is the bracket that mounts to the rear plate backwards? is there a top and bottom to it? I ordered blower style fans, but they are coming from China and won't be here probably till next week, so this is just a temporary solution till those get here. If there is an alternative solution please let me know. Thanks

 

I'd double and then triple check the wiring for the steppers. Dig up the schematic on them and check it a fourth time. Not just the wiring to the driver, I mean the wiring harness going into the stepper. Compare both of them. Something sounds off.

Also, 1.3 is way high for the driver. I've got mine set around 0.58-ish.

 

I had the same issue when I first built my D-Bot. Same fan duct and bracket. Couldn't figure it out for a couple of days, then I realized that the bracket was mounted to the rear of the carriage upside down. Flipping it 180° gave the extra mil needed and it has been fine since.

 

Ahh okie, I will have to reverse it when I get home tonight!! Go figure something so simple! Thanks for the reply!!

 

No problem!

It's the simple things that get you. I tend to focus like a laser on a problem, sometimes failing to look at the bigger picture. Happened to me last night. I have been having feed issues for the last two days with a roll of PETG that printed perfectly for the first half of the roll and I was frantic to finish a job with a deadline. Needed to be in the blue PETG, so I was desperate (only the one roll on-hand). Did pulls, cleaned the nozzle, checked diameters. Everything checked out, but the filament would stop extruding randomly during prints, like a partial clog of some sort. Even though I had been staring at the extruder for quite some time, it was not until I took a step back and looked at everything as a whole instead of just the immediate filament path. Then I saw it - a barely visible crack in the tensioning arm for the idler bearing that was flexing and reducing the pressure on the filament ever so slightly. A dab of epoxy and a little time, a new arm was printed and all is well.

 

I was also having an issue the other night that was causing me nothing but problems. I had rebuilt the Z carriage system with the rework files, so I had pretty much torn the printer all apart, all electronics etc. as I was putting it all back together I was having an issue homing the axis and it wasn't working.. Z was fine but X and Y weren't and I was like *** is wrong! I messed with firmware, changed min/max on the end stops , nothing would work. I knew something was wrong because the LED's on the Mechanical End Stops weren't lighting up when triggered but I just gave up that night and went back to it the next day. Then I rechecked the wiring and I had the power/ground pins backwards.. flipped it and it worked as it should.

Such a simple problem with such a simple resolution.. Sometimes its better to just stop and take a break and go back to it later with a clear head.

So now that everything is confirmed working I am going to do some cable management and trim up wires to the correct lengths so I don't have a bunch of excess in the ramps box.

 

Right, you should be able to turn them easily by hand, that'd be the first place to check: Zero binding in the system.

Also, if you try to drive it up too fast, you'll overwhelm it. I run mine at about 5mm\sec, you'll need to configure that in the firmware.

What drivers are you using? I switched to DRV8825's since the A4988's weren't powerful enough to lift it, even when both screws were in the back. Now I'm using SD6128's, which are way more powerful, but again, I still can't lift it too fast.

 

No error message. The heated bed and hot end work as expected and the Extruder stepper works fine. Just nothing on X , Y or Z.
Thx

 

Yes I am using Marlin/Ramps/Mega 2650
Marlin ver 1.0.2
I have set the voltage on the stepper drivers - I'm not sure how this is done but I will google it now
thx

 

I have this same pancake stepper for my Titan. How do you adjust the amperage to match the new pancake stepper specs??

 

Nice! CoreXZ?

 

I wish but no as it uses two motors like a normal I3 does.

I am seriously contemplating getting a Tarantula but they changed the leadscrew to the crappy 8*8 without telling anyone so my plan was to just buy one more for the left hand side and use a belt up top thereby using only one motor (alleviates the Z issue with a two motor system sharing the same driver) so I can use a direct drive as I do not like Bowdens. Don't get me wrong Bowden has a lot of fine qualities to it but for me I didn't like it. Not sure I like a Direct drive either but easy enough to switch that back to a geared system if I need to.

Sad that they went to the 8*8 leadscrew.

 

Does anyone here use PrintBite?

If so, has anyone had problems with it on borosilicate glass?

 

I have some on its way to me but why in the world would one stick that onto glass?

 

I just got my PrintBite in, and the directions recommend not sticking it to borosilicate, they recommend mirror glass, I would stick it to aluminum, but i don't have any i can use for it

 

Quote from http://mutley3d.com/gallery/printbite instructions.pdf

Application to normal 2mm window glass is not advised. Borosilicate glass is also not advised as it has significantly different expansion rates which can cause breakage of the glass when heated.

I've not glass break on me before. But my experience was micro fractures occuring in the glass and then PETG with glue stick would literally rip the glass apart as it cooled and shrunk. I switched to aluminum after my 2nd sheet of borosilicate did this.

 

Yeah, the bit in the documentation about the borosilicate glass is a somewhat new adition I think, it wasn't there the last time I had read the documentation for it, but it had been at least a few weeks before I had ordered it. I am printing on borosilicate right now, using the e3d heated bed stuff, but I haven't printed anything in pet-g because of the issues with it, I have been looking around for some aluminum I can find to use, but 215x315 is a somewhat difficult size to find and 6mm seems a bit thick.

 

Yeah they I've run into the docs changing midstream before myself.

As for aluminum beds, I run a 6mm bed, technically it's ¼ inch, but close enough. It works very well as it retains and spreads the heat out very well. I insulated the bottom with a silicone sheet and then cork. Even with a 12 volt heater, it heats up much quicker than I expected, faster than my 200mm uninsulated bed on my i3. I've been able to drop PWM for the bed because of the thermal mass in the aluminum.

As for sourcing the sheet, there are a number of places that will custom cut you a piece. Just need to ensure it's flat, MIC-6 is what I source when building beds. I'd guess a 215x315 bed custom cut would run in the $60-$80 range, based on the searches I've done.

 

Yeah, I found some that insta-quoted $29 for 8x12'', but when I entered 8.4x12.4'' it quoted $60

 

Makes sense because the Printbite is like a thin sheet of Fiberglass looking material so the glass (soda or boro) will want to expand differently than the Printbite and pow. This is why I would never mount anything sticky (Buildtak, Zebra Plate, etc...) to any glass because it will break when you least expect it. Only thing that saves you when it does is the sticky back holding it down or it would not be a nice outcome when it does what it wants to do.

 

I had my bed short out on me and it took my ramps with it and even when I replaced the mosfet it would not work. I had to buy a new Ramps (I replaced its fets with quality fets) before I could run it again so I am afraid of aluminum beds now.

Where did you get a quote for 29 dollars from?