Rattling platform / connectivity problem

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bjd9282
Posts: 4
Joined: Sat Nov 24, 2012 9:35 pm

Rattling platform / connectivity problem

Post by bjd9282 » Sat Nov 24, 2012 10:14 pm

Hi I am experiencing an issue with my UP Mini that is a bit bizzare, and that doesn't seem to be related to problems others have had on this forum.

When I got the machine I printed 2 small parts successfully (the stator file helix and a stl of a dog).
Since then the machine has acted strangely in a number of ways, and most prints have failed, ending with a blob of plastic in 1 small area on the board and a grinding/ rattling sound from the platform.
I have come to realize that the noise is not caused by the platform colliding with the printer head, but from the platform being lost as to it's position, and trying to move past its limitations in the x or y directions.

I have uninstalled the up software, reinstalled the proper drivers, and upgraded to the v1.18 software. I am still having this issue.

I even get this problem without printing. When I simply initialize, then begin to raise the platform up to the printer head to set the nozzle height, I will eventually hear a small clicking sound from inside the printer somewhere. This usually happens around 120.00mm, but not always at the exact same height. Then, when I click any of the FL, FR, NL or NR buttons, the platform will grind and fail to move correctly. I have deduced that the UP is then confused as to the position of the platform, until I initialize it again and it finds it's bearings. (none of this ever happens when the platform is lower than around 120.00mm, I can move through all of the positions with no problem). I have the same problems when I use the new platform calibrate menu and move through the positions with the platform close to the print head. Eventually, there is a click noise, and then the platform will grind and fail to move correctly.

Sometimes this is also accompanied by the software letting me know of a connectivity issue with the printer. In this case I have to unplug the usb and plug it back in, in order to re initialize. This happens only a percentage of the time, not every time.

Please Help! Any ideas as to what could be causing these symptoms is welcome! I would really like to get my UP Mini running correctly.
Thanks.

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: Rattling platform / connectivity problem

Post by roller » Mon Nov 26, 2012 8:03 am

I found two initial problems with my Mini which sound similarish to those you are reporting. I posted about them but they are long since lost in other Mini discussions I suspect.

First I found the umbilical from the mainboard at the back of the machine that goes to the bed (connects to rising platform) can grab on some of the connectors on the mainboard and stall the bed and stop it rising. The fix was simple - not all the umbilical was free and some was coiled up between the mainboard and the back of the machine. You simply have to reach through and pull a little more of the cable free - then the cables tend to sit against the back of the case rather than brush over the mainboard and catching. It wouldn't hapeen everytime and like you I got a few prints out before it became a repeating problem ... and sometimes it would be fine again.

Secondly, I found on my printer the lower half of the Z smoothrods were not lubed at all. This cause the bed to jam as it lowered during a print - the nozzle would keep depositing at the same height and eventually bang against the print, knock it free and end up as a blob stuck on the nozzle. To fix this I took off the back and using a clean finger took some of the excess lube from the top of the vertical smoothrods and while lifting the bed up smeared it around the lower half of the rods, just below the bottom bushings. You need very little grease for this type of design so as long as it feels just a little greasy that is plenty.

Hopefully all that will make sense when you look at your printer especially with the back cover off. Just beware that when you remove the cover and put it back on the umbilical cable that I talked about in the first part tends to go back to hiding behind the motherboard and needs to be pulled through again (at least in my case).

Hope that applies to your issues.

bjd9282
Posts: 4
Joined: Sat Nov 24, 2012 9:35 pm

Re: Rattling platform / connectivity problem

Post by bjd9282 » Mon Nov 26, 2012 9:06 pm

thanks Roller,

I did open the back of the machine up today and figure a few things out. The "umbilical" cable to the platform was fine in my case, and all the roller bars look fine. I wish one of these was my problem but it seems to be much more convoluted.

First thing I did this morning was check to see if all of the same symptoms were happening.
They were not, I could raise the platform up as high as I needed and move it through all positions. No connectivity problems.
This being the case, I went ahead and completed the "platform calibrate" software function, and proceeded to try a print.
I have yet to successfully print the calibration stl file correctly, so I went ahead with this as a test. The print failed in it's usual way: everything starts well and a few lines of the raft print, then there is some intermittent grinding/rattling from the platform, then the print head will print back and forth in a small line and form a glob.

The good news is that the calibration seemed to have worked well, the purge bead (which in this case is way out on the edge) printed well and seemed perfectly adhered to the board.

The bad news is that the machine is plagued with the same symptoms as before for the rest of the day.

A few things I figured out by removing the back and watching the malfunctions:
The grinding is a result of the platform trying to move front and back, not up and down. Nothing seems to be in the way or catching, the belt is not slipping, the gears in the platform controlling the belt just wiggle and the platform goes nowhere. I can move the platform in this front and back direction fine by hand when the machine is off and even when it is on and raised up. The print head moves to its correct position, but the platform grinds and stays put.
Like I said in my last post, after this happens and I initialize again, the platform responds fine when it is lowered (to the bottom or to anywhere under about 100, using the To: button) . Then at some point while I raise it up or while it is sitting raised somewhere above 100 or so, I will hear a little click sound from somewhere inside. I noticed today that when I hear the click, I also see the little yellow chips on the bottom of the print head light up. There are 3 of these on the bottom and back of the print head on little circuit boards, and they all light up, and then I know that the platform will no longer move correctly front to back if I tell it to.

Usually, this is when the software goes dead for a minute then lets me know the printer is disconnected (the USB is in place obviously, but the software can't communicate with the printer). Then I will unplug the USB from my machine and plug it back in, and the software will find the printer. Then if I try to move the platform front to back in Maintenance it will grind and I will then lower it and initialize again and then it's fine until I raise it up again.

That sums it up. Sorry this is long, but the problem I'm having is bizzare and I have to describe it in detail to make it clear.
At this point it doesn't seem like an easy fix, and I will be contacting x object to find out what my options are for repair or return.
Any advice or thoughts on this are welcome.

roller
Posts: 1622
Joined: Sat Oct 06, 2012 9:09 pm
Location: Brisbane, Australia

Re: Rattling platform / connectivity problem

Post by roller » Tue Nov 27, 2012 5:46 am

I may be thinking in the wrong direction but just just all your cables to the extruder/print head are properly seated. The grinding sound you describe could be the extruder missing steps usually because the head is too cold. Also make sure you have told your printer you are using ABS not PLA or the head temp will be too low.

Also just as a quick troubleshooting point of view because there have been weird issues reported by others - make sure you unplug your USB once the print job has loaded to the printer. I think some have issues with floating grounds and voltage potential across the two devices throws the mainboard into a spin.

mr6k
Posts: 327
Joined: Tue Feb 14, 2012 11:47 am

Re: Rattling platform / connectivity problem

Post by mr6k » Tue Nov 27, 2012 10:44 am

You mentioned the gears of the platform "just wiggle" If you mean the stepping motor that operated the back/forward belt & platform, I would suggest that a phase is missing on the motor feed. As roller suggests check all the cables. The fact that it initially works could be that the motor or its controller, or a connector go high impedance when they warm up. Depending on your technical skills you may wish to swop the back/forwards & side to side platform motors. If the fault follows the motor then a new motor is required. If it remains in the back/forward direction then its the connector or the motor drive electronics or something else.

cheers

Peter

bjd9282
Posts: 4
Joined: Sat Nov 24, 2012 9:35 pm

Re: Rattling platform / connectivity problem

Post by bjd9282 » Fri Jan 11, 2013 6:37 pm

Hi, I wanted to update this to let you know that this problem was resolved.
I contacted up3dusa who sold us the machine and they said there was definitely something wrong with the hardware in this case.
All I had to do was pack the machine back up in the box and put the shipping label on it that they emailed me.
They sent a new replacement machine, which worked very well.
This was all very easy, I wish I had contacted them first thing, but I didn't know quite what was going on until I had looked into it myself.
Anyway thanks to those at up3dusa

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