Printing again. Again.

This will mark the 3rd time I've had to replace the ceramic tape on my extruder heads, and it was just as painful as the first two times. But hopefully this time it'll be the last. Because this time I've used high temp tape.

My theory is that the reason my tape keeps failing is because when a print fails the plastic touches the kapton tape and ABS plastic loves kapton tape which wrecks things. However now I'm concerned that the tape is going to transfer too much heat to the print. But initial prints are working, so we'll see how this metal tape works over time.

Had a bit of a scare while doing the repair. The washer that holds the thermocouple in place fell of. I always thought they were attached but checking the assembly PDF turns out they weren't. Good to know. So I've finally got my outstanding Etsy orders out the door before vacation. Huzzah!

Fixed again, mea maxima culpa

So it turns out my Makerbot is just fine. Remember that build platform upgrade I did a few weeks back? The removable glass platforms that BottleWorks made are longer on one side, I have no idea why, because the only thing that happens with that is if you put it on wrong it blocks the Y-gantry, which is what I did. Jog mode worked fine because the Z-platform and it's obstruction was out of the way between prints.

Of course I didn't discover this until after I had flipped it over an inspected the motherboard connections. They're fine by the way.

So my bad, my printer is just fine, I'm back in business and my biggest problem now is making sure prints stick to the build platform. Thank goodness for that.

And it's broke again.

When I can finally afford to replace this Makerbot, either because 3D printers have gotten cheap or I've become independently wealthy, I hope that the machines that replace them will be slightly more reliable. But that's not what I have. What I have is a few days of printing between problems. At least it feels that way right now. A week ago my offsets were off. Then I fixed than and suddenly everything stops sticking to the build platform. I think I've got that sorted and now this. I'm not sure what to make of it.

Basically, when printing, the Y-Axis refuses to move more than an inch back of the front lip of the build platform. But it's only when printing. Homing the axises or using jog mode it has no problem going past that point. I've asked for help in the usual place. I really hope I can get this sorted. I need to finish my Quarto set and my Doctor Who pawns need testing. Thank goodness there's nothing more urgent than that right now. Nevermind. The etsy store would blow up today.

Fixing the Ceramic Tape again

This is by far the most annoying bit of maintenance that the Makerbot needs. The ceramic tape is held on only by Kapton and frequently exposed to plastic from failed prints, which is what broke the right extruder's insulation this time. The left one also has problems in that the ceramic tape has broken down, turned brittle, and is flaking off into my prints. It wouldn't be so bad if it were easier to fix or if it was safe to continue printing without it, but this is a major thing that killed most of my Saturday morning.

Fixing it sucked a little less than last time now that I know what I'm doing, but it still required being very careful with the teeny-tiny little screws and needing to work with it hot to remove the nozzle. Lots of places this could go wrong, which fortunately didn't happen this time.

I noticed some discoloration of the heater elements. Hopefully that won't eventually become a problem.

I decided to employ a method of using 2 long strips of Kapton tape to tightly bind the cut ceramic tape onto the block. Seemed to work pretty good. I just hope that doesn't create more failure points later on. I keep thinking I'd like to find something to put over the heater blocks to prevent exposure to failed prints, like foil tape or something. I may still experiment with that. 3Dwannabe on the google groups suggests a cloth-like ceramic tape that doesn't degrade, I'd love to hear more about that, too.

For now, the job is done and I'm printing again.

Replacing the Ceramic Tape on the Heater Block

It's time to fix the ceramic tape. No patch job this time.

There is embarrassingly little written up on how to do this properly. The best I could find was a PDF on how to assemble the Mk7. In the end I managed but I made a lot of mistakes along the way. And sometimes the point of a tutorial is so that you don't have to repeat my mistakes. But I'm not about to let all my hard mistakes go to waste. So let's start with the don't list:

If you see this, you've gone too far

You don't need to disassemble the whole thing. I thought I needed to get at the bolt that holds the heater block from above. You don't. I thought I needed to get at the nut that's between the block and thermal barrier. There is absolutely no reason to do that. Besides which doing so demands heating up the extruder head periodically so the cold plastic inside them releases the parts. I burned my hands several times.

However, there is a problem. With a dual extruder there is no way to remove the heater block without disassembling it a little. I have no idea how it's done in assembly, but for dis assembly follow these steps:

1. Put this off for as long as possible. Seriously, this sucks. If you don't absolutely have to do this don't do it.
2. Heat up the extruder and remove the nozzle with a socket wrench.
3. Turn off the Makerbot.
4. Remove the Extruder assembly to improve access to the extruder heads.
5. On the bottom of the heater block beneath the heater element there is a teeny, tiny screw. (See picture above) This screw is not only small it's short.
6. Give this screw a 1/4 turn. Do not unscrew it all the way. If you unscrew it too far do not drop it. If you drop be pray someone around you has excellent eyes. (Thank you, Honey. Love you.)
7. With a pair of needle nosed pliers remove the heater elements. (See picture below)
8. Move the thermostat wire in front of the heater block. Unscrew the thermostat wire and remove it.
9. If you have two extruders and you're doing them both be sure to twist-tie the thermostat to the heater element and keep track of left and right.
10. With a box wrench around the heater block untwist and remove the heater block.
11. With the block removed replace the ceramic tape. (see PDF, page 23)
12. Reattach the nozzle.
13. Reassemble the block.
14. Reinsert the heater element.
15. Retighten the teeny, tiny screw.
16. Reattach the thermostat.

I am extremely glad to see that the latest makerbot extruder wraps the ceramic tape laterally. Hopefully 2X users will never have to go through this. I considered getting some heat resistant duct tape and using it instead of the Kapton, but decided against it because it would increase the thickness of the block. Since I had disassembled everything I accidentally put the heater elements in the wrong nozzle, but it was an easy fix. Then I had to re-level my print heads and build plat. So for now I should be back up and running for a while.

Panic attack turns I-D-Ten-T Error

Sometimes finding what's wrong with the makerbot is just a matter of knowing where to look. In this case the problem was between the keyboard and the chair.

This is not a good thing to see. Especially when it's just a little print. It was filling up the whole print bed, tearing the Kapton tape off, and clicking at the furthest extent of the Y axis. I had no idea what was wrong and was afraid my printer was totally busted.

Step 1, try a S3G file that I know worked in the past. Doing that I discovered that my print bed had gotten way out of level suddenly. Don't know how but the screw on the back right had almost fallen out. So I releveled the print bed and tried this S3G file again, this time watching the print carefully. And what to my eyes should appear, but the fact that I had built this file with the multiply plug-in on.

Unfortunately it ripped my patch off the right extruder, so I'm again down to one until I fix it again, properly this time. Hopefully I can take some time this weekend to do that.

They say that the hardest part about making something fool proof is dealing with the ingenuity of fools.