2.0 to 3.0 Upgrade First Impressions

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cbensch
Posts: 54
Joined: Fri Jan 24, 2014 9:52 pm
Location: Simsbury, Connecticut US

2.0 to 3.0 Upgrade First Impressions

Post by cbensch »

Received my 2.0 to 3.0 single extruder upgrade today. It took only two hours to disassemble the 2.0's plastic parts and put the 3.0 parts on. The parts themselves are very strong and very accurate. Most fits are tight, which is good. There were a few hiccups that I'd like to point out:

1) My primary concern is that the 3.0 design calls for the extruder wheel (brass colored wheel that pushes the filament through the printer) needs to be 2.5mm from the surface of the motor. However, this wheel has a small set screw that will no longer be set on the flush part of the motor axle but on the round part. Reliability at this location is questionable.

2) The spring leveling system is very nice. But the thin M4 nuts that go on the M4x30 set screws make adjustments daunting. I don't want to keep a wrench handy every time I need to make adjustments. So I tightened down each set screw just until it touched the bed. I then screwed the extra M4 nylon threaded nuts on instead. Now all I have to do is adjust the set screws with a 2mm allen wrench.

3) The "wood" screws that are supposed to hold on the z-opto sensor doesn't actually grab the plastic. I had to drill the opto sensor holder of the main z rail system an use my own "wood" screws.

4) I was REALLY hoping for a new x-axis pulley housing. I noticed that the belt tends to ride either up or down against the washers and never stays in the center of the pulley where the least resistance is. I had aligned both this housing and the housing holding the x-axis motor but never was able to make it stay over the pulley. At one print, I actually completed about 20 layers that were beautiful, then watched as the pulley snapped up to the top against the washer. Each subsequent layer was blatantly worse than the prior. I have a design in mind and I'll print it and give it a go and will share my results.

5) The single-bolt holding the fan and fan shroud, cooling fan for the extruder and the extruder itself seems a little light. I'm going to keep an eye on it.

6) There are three bolts (12mm) that secure the fan onto the airduct that are tightened with thin M4 nuts. I'd really like to see a 15mm bolt with M4 locking nuts. It's only a matter of time until this thin nuts vibrate loose.

7) Someone posted a new mod for the z-axis calibration unit. I saved the stl files and will print that and use it. The 3.0 z-axis fine adjuster is the same as the 2.0 and adjusting it with an allen wrench is a nightmare.

8) There are no holes in the z-axis housing to secure wire ties to hold the wires and it had to be drilled. The adhesive wire tie blocks don't stick to the new plastic either.

9) There is a LOT of hardware included with this kit that will not be used. I need to trace the 3.0 assembly manual to see where it all goes. I wish I was able to save the money by not having to pay for hardware I'll never use.

More later as I test this thing out.

cbensch
Posts: 54
Joined: Fri Jan 24, 2014 9:52 pm
Location: Simsbury, Connecticut US

Post by cbensch »

I designed and printed a new x-axis pulley housing. It now has three bearings allowing the belt three times more room to shift based on the alignment of the motor gear on the other end and position of the belt ends on the extruder truck. There is one small 4mm washer each at the lowest-most and highest-most points between the bearings and the housing. The housing itself is like the old housing where the x-axis track locks it in place at the top while a 4mm x 12mm bolt and 4mm washer holds it at the bottom. I used the old bearing and the two bearings that came as part as my upgrade kit.

There is a noticeable decrease in tension on the belt now that it doesn't ride against the bearing housing making the motor work less. My exterior perimeters are super clean now.

Here's a picture and the stl file:
Attachments
01_X_Pulley_Housing.stl
(33.29 KiB) Downloaded 47 times
IMG_8514.JPG

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