Replicator 2 Motor Broken?

[Matthew Meyer]

I was printing the other day and mid-print my Replicator 2 started making a horrible grinding noise and the extruder stopped moving. Now, when I try to start a new print, it is unable to send the extruder to the home position and makes the same grinding noise. I have attached a video to show you what I mean.

The printer has gotten a lot of use over the past 2 years, so I'm not surprised at the wear and tear... I am just hoping someone can look at this video and tell me what part needs replacing and where to find it for a decent price.

(I'm pressure sure it's not the endstops, as they light up red when I press the switches. I replaced the XYZ endstop cables about 2 months ago, and I replaced the XYZ motor cables about 6 months ago.)

The video: https://drive.google.com/file/d/0BzaMg2iYtQJrbGdyc2ZzeEw2WkU/view?usp=sharing

[DonaldJ]

With the machine unpowered, can you move the carriage freely along the X & Y axes?

Maybe something is getting snagged and preventing full movement.

Just a thought; I always check the easy stuff first.

[Kobus du Toit]

Have you been using hairspray inside your printer?

https://www.youtube.com/watch?v=4uodSLdgcIc

[Matthew Meyer]

I can manually move the carriage along X&Y with no problem at all. It doesn't appear to be a physical jam.

I have never used hairspray in my printer.

[Dan Newman]

The failure you have described sounds like the all too common breakage of the
wiring harness to one of the stepper motors. MBI did not use flex-rated wiring
and also did not route or secure the wiring well, especially the wiring to the
X axis stepper motor which is held in place on the Rep 2 by a roll pin. That
roll pin has a long, sharp edge running its length which can cut the wires.

But regardless of the cause, one of the wiring harnesses has a broken wire or two.
The breaks can be intermittent causing the problem to only happen at certain positions
(travel-wise). Or the break can be more serious and lead to near constant failure.

You can contact MBI and ask for a replacement harness or you can replace it yourself.
Difficulty with the Rep 2 and 2X is that MBI switched to custom wiring harnesses and
so the harness is not readily available.

Dan

[tramalot]

I assume that was a print start and it was homing, it seemed to go to the y endstop and then the x movement was blah, x cable might be bad, i would swap or replace that first

[Matthew Meyer]

That sounds familiar.

I've already had two wiring systems fail due to breaking wires for the exact same reason. I've already replaced the stepper motor cables and endstop cables... I don't think it can be either of those now, because I followed other people's advice and attached the new wires in a stress-free position so they would not break again.

In the past, I had intermittent failures, but with this latest problem it is 100% unusable. I'll try contacting MBI for a replacement harness and hopefully that will do the trick... I'm pretty tired of replacing their faulty wiring...

[Matthew Meyer]

Yes, you are correct. That was a print start and it was attempting to home the carriage.

I very recently replaced the endstop cables, so I don't think it is them. Pressing the endstop switches, they light up correctly without any problems at all.

[Dan Newman]

On 30/06/2015 4:43 PM, Matthew Meyer wrote:
> Yes, you are correct. That was a print start and it was attempting to home
> the carriage.
>
> I very recently replaced the endstop cables, so I don't think it is them.
> Pressing the endstop switches, they light up correctly without any problems
> at all.

Lighting up isn't very meaningful: the light turning on is generated locally
on the endstop and not by the motherboard. The endstop signal to the motherboard
travels on a different wire and that wire may be broken and the signal not
making it to the motherboard. However, you can easily test if it is the
endstops: disconnect them at the motherboard and try again. If the stuttering
still happens, then it isn't the endstops or the cables. Note that the carriage
will drive into the back and right and not stop since the endstops are disconnected:
just power the printer off.

Dan

[Dan Newman]

On 30/06/2015 4:42 PM, Matthew Meyer wrote:
> That sounds familiar.
>
> I've already had two wiring systems fail due to breaking wires for the
> exact same reason. I've already replaced the stepper motor cables and
> endstop cables... I don't think it can be either of those now, because I
> followed other people's advice and attached the new wires in a stress-free
> position so they would not break again.

And you used high flex rated cable such as cicoil? Because if you just
used ordinary cables, they ARE going to fail eventually. Doesn't matter
how carefully you routed them. So, just because you replaced them and
routed them carefully does not prove that they haven't failed yet again.
Indeed, your video looks incredibly like a failed stepper motor cable.

That said, check the endstop cables in the fashion I proposed in a separate
message. The stepper driver cards can also fail but I've never heard of
them partially fail this way: they invariably fail 100% and nothing then
works for that axis. That or they fail and get locked into a low microstepping
mode (e.g., 1/8th instead of 1/16th), but you're not seeing that.

Dan

[Matthew Meyer]

I got the replacement cables from robotshop, which was recommended to me back then.

I will try disconnecting the cables and seeing what happens as you suggested. I hope I can identify the problem before giving Makerbot a call... I have had nothing but horrible experiences with their customer service in the past so I don't expect very much from them now. If I can identify the problem and find a shop that sells the proper replacement cables I would much prefer that then trying to deal with Makerbot's phone system and outrageous support prices again...

[Matthew Meyer]

Update:

I disconnected the endstop cables at the motherboard as was suggested, and the problem still occurred.

After that, I disconnected the x-axis motor cable and tried it again. The Y-axis moved smoothly back when I ran the homing script. So I'm pretty sure it's the x-axis motor cable that is broken.

Can anyone recommend a good website to order a replacement? This will be the 2nd time I've had to replace this cable, so I'd like to make it the last time I have to replace it...

[Jetguy]

What part of a design flaw in the routing of the X cable is the problem is not obvious at this point?  How many cables do you have to have fail before you "get it"???

It doesn't matter who you buy the cable from, it's you installing the same cable into the same way that breaks it.

 

Stop causing the problem and follow suggested mods that resolve this.

http://www.extrud3d.com/x-harness

http://makerbot.wikia.com/wiki/Replicator_2_Modifications

 

It's not like this fix hasn't been known and posted about 100 times in every 3D printer group.

[Matthew Meyer]

That was unnecessarily nasty, Jetguy. I actually followed the mod on that second link the very first time I replaced the cable, thanks to advice from people like you, so me reinstalling it the same way isn't the problem. But thanks for treating me like an idiot for asking questions...

Anyway, thanks to everyone who replied. It was helpful, particularly the suggestions to unplug the cables one at a time to find out exactly which one was malfunctioning.

[tramalot]

buy 2 and some other consumables. and If the shipping is too high call them...... http://www.flashforge-usa.com/shop/parts-accessories/stepper-motor-cable.html 

On Tuesday, June 30, 2015 at 7:41:48 PM UTC-4, tramalot wrote:

[Matthew Meyer]

That's perfect! Exactly what I am looking for. Thank you!

[Joe Soap]

Is this a problem with the Wanhoa 4S, or have they fixed the issue?

On 01/07/2015 14:26, Jetguy wrote:

What part of a design flaw in the routing of the X cable is the problem is not obvious at this point?  How many cables do you have to have fail before you "get it"???

It doesn't matter who you buy the cable from, it's you installing the same cable into the same way that breaks it.

 

Stop causing the problem and follow suggested mods that resolve this.

http://www.extrud3d.com/x-harness

http://makerbot.wikia.com/wiki/Replicator_2_Modifications

 

It's not like this fix hasn't been know and posted about 100 times in every 3D printer group.

[Ryan Carlyle]

Rep2 uses ribbons, right? The FF/Wanhao type cables are only compatible with the Mightyboard RevE, not the RevG or RevH boards. 

[tramalot]

I always forget that part! sorry. I would convert it in that case, I think at the top of the forum main page is a source for connectors 

[tramalot]

https://groups.google.com/forum/#!topic/makerbot-users/EdTQZTNRfKw can these be used?

On Wednesday, July 1, 2015 at 1:15:41 PM UTC-4, Ryan Carlyle wrote:

[Dan Newman]

On 01/07/2015 9:32 AM, Joe Soap wrote:
> Is this a problem with the Wanhoa 4S, or have they fixed the issue?

The only long term fix is to use flex rated cable suitable to the application.
Doesn't matter if it is a Rep 1, Rep 2, Rep 2X or a clone of those: they are all
flexing the cables under normal operation. The problem can, of course, be
made worse by reducing the radius of the bends over which the flexing occurs.
But flexing is occuring, and quite a bit of it for most prints.

We pretty much see in all the forums cases of the cables giving out on these
Rep 1, 2, 2X style printers. In the Gen 5 printers, MBI actually did what
they should have done in the Rep 1: used actual flex-rated cables appropriate
to the application. I've not heard of the cables failing on Gen 5 printers.

Taking a defeatist point of view, I kind of like Wingcommander's solution which
is to just accept that the cables break eventually. With that view, switch over
to a readily available, inexpensive, quick-to-replace cable: a short cat5 patch
cable. Wire cat5 keystone jacks near the motherboard and stepper motors and then
just connect in the patch cable. When the patch cable fails, remove it and
put in another one. (And yes, there are even flex rated cat5e cables, but
they tend to be expensive and stiff. Probably some of the lightweight, $2.50
leviton "flex" cables work well -- "flex" as in flexible, not as in flex rated.)

Dan

[Joe Soap]

I solved this in my 2X by letting that cable dangle in mid-air. Unsightly maybe, however the cable isn't then being flexed around a tight bend as the Y Axis moves.

[tramalot]