New Prusa snap fit x-ends not fit for PLA?

I just printed the new snap fit Prusa x ends, and ran into a few problems.

The red highlights are where the part cracked under stress. First from inserting the smooth rods, then along the holes for the zip tie, when I pushed in the top lm8uu bearing.

Print settings

This is printed in white PLA from Ultimachine @200 deg C. Nozzle is 0.5mm, layer height is 0.35mm, it has 2 extra shells (thus 3 in total) and infill of 30%. I believe the problem is the flexible part of the push fit design, which doesn't flex at all. I don't know whether it's because of the brittle PLA, or if it can be avoided by using either fewer or more outer shells. Heating the part before inserting the smooth rod will probably help, but

If this is a problem with PLA, I hope there will be an option to switch out the push fit with m3 nut and bolt. Looking forward to having a look at the OpenSCAD files!

Blame the user
The crack along the lm8uu holders is most probably my own fault, it was a tight fit, and I did manhandle the bearing quite a bit. There are some small lips to hold the bearing in place (in the z direction) and the bridge did sag a tad so the bearings didn't fit very well under the top ones. You can sort of see it in the second picture. Using 100% infill might solve this, as moving the holes up would just move the weak spot.

Edit 2011.07.11 :
I just printed the x-end idler, and the bearing holder snapped when I pushed in the bearing (had to use a wood clamp, it was that tight). This trouble might be my printer drawing outside of the lines, instead of on the inside. I'll be back with more info.

Difference in PLA?
This is the first object I have printed in this white PLA, and it might need a little skeinforge tweaking to get perfect. It seems to flow more, and thus pushes out more plastic than with the other Ultimachine PLA I have. (Silver, transulent blue, natural and black).

For this print I tried to drop the speed from 60 to 55mm/s, and on the x ends, it didn't loose enough y-steps to ruin the results. I have a theory it might be the weight of the plastic spool keeping the maching from rattling, anyone else experienced this? I still can't print gregs lm8uu x-carriage properly though.

New hot end review on the way


While I'm blogging, I might as well drop in a picture of a nice little puzzle I got in the mail:

It's an Arcol 0.35mm hot end, which I'm looking forward to try out. One thing I'm a sceptical about is the hot end relying on threaded PEEK to hold the pressure. People have a lot of good of things to say about this design, but to me a push-fit version just seems a the "safe" way to go. Also, it's a bit large to fit on gregs lm8uu x-carriage, so I have to figure out which printer to put it on, as it won't fit on Adesina now.

#RepRap Adventures #04

Click for full size.

My biggest print yet, and it's creepier than I thought it would be.

I've always wanted to print one of these, and when a simple straight-to-skeinforge-version with non-broken stl files was posted by RoTorIT - http://www.thingiverse.com/thing:9321 - I had no excuses any more. Thanks a lot. :)

The body piece is 22cm across, and printed diagonally it took every single mm of bed space I have available, which turns out to be 170x185mm. I even had to turn off skirt to make it fit, and it came dangerously close to the bolt heads on the bed. But it was totally worth it. the spider is HUGE.

Total print time was close to 24 hours @55mm/s. I had to print one piece at a time, because for some bizarre unknown reason I lose y steps if I print several objects at the same time. Some of the pieces are the same, and I'll post them here for your enjoyment:

• Part 6 & 7
• Part 8 & 9
• Part 20, 22, 24, 26 (small leg)
• Part 21, 23, 25, 27 (large leg)

The pieces doesn't fit together that well, and could have been 0.5mm fatter. Though both the mouth parts and tail parts sits tight amongst each piece and locks itself in place, the legs sit quite loose. I sort of solved it by squeezing / bending the print a bit while hot off the printer, which made most of it sit pretty nice.

In case you didn't notice already, it's printed in transculent blue PLA from Ultimachine, which is UV reactive. It looked far less scary when I took the pictures last night.

Imagine this scenario: You place the spider in a dark corner of the basement, with the room lit only by a single bulb. Then you hook up a motion detector which turns off the bulb and turns on several UV leds pointed at the spider. I'd do it, but it'll probably be smashed to pieces in blind arachnophobia fear, and I really don't feel like printing another one (before I have a giant bot farm).

#RepRap Adventures #03

Click for full size.

True story! Read it here.

#RepRap Adventures #02

Click for full size.

#RepRap Adventures #01

Click for full size.

True story!

Post your ideas/stories in the comments, and we'll see if something happens. :-)

PLA Review - supply3dpla.com

More filament suppliers is always a good thing, even more so when they are shipping from a location near you. After seeing a small advertisement on the RepRap forums, I chose to try out the PLA from supply3dpla.com who are located in Sweden.

First, the postal service managed to ship my package to Denmark, but Bo was very forthcoming, and shipped the package again. Total shipping time to Norway was 6 days, including a 4 days (unnecessary I might add) delay at customs. If you live in Norway (and outside the EU?), you can ask for the VAT to be removed, shaving a few € off the total price.


I ordered 400g of both the red and the blue, and got some samples of the transparent and black color as well. These are the only colors they supply at the moment, but Bo told me they plan to supply both green and yellow, and perhaps ABS.

How is the quality?

All the filament is "soft/smooth" to the touch, and feels quite bendable and "fresh". The diameter was a pretty consistent 2.88mm-3mm, and a bit oval. I forgot to compensate for this in Skeinforge 41 - dimensions, but the prints are looking very good, though it spit out a tad too much plastic now and then.

The PLA extrudes very easily at 185deg c, not needing a lot of tension on the extruder. All colors behave the same, as far as my small testing goes. It also stick very, very well to the heated build plate with glass @40 deg. So well in fact, that I pretty much have to clean with acetone after each build to get the stuff off.

What does it look like?

The colors are difficult to describe, as they are not a "pure" color, but rather a mix between several. I'll try my best with photos in different light conditions.

 The "red"           

In filament form it's very transparent, and looks delicious. When extruding it's almost completely transparent, and you need a couple of layers to really see the color. The final color is a kind of mix between red, orange and pink. I was hesitant at first, but the color is growing on me.

 The "blue"           

Just like the red, it's very transparent, and the same behaviour apply. The color is kind of "off" for me personally. It's like a strange mixture between light blue and cyan, and doesn't "pop" like the red one does. I might change my mind, but I doubt it. No UV-reactive goodness either.

The natural

In filament form it's almost 100% transparent, when extruded it's still pretty much transparent. In natural light it gets a bit of a yellow tint, but when you shine a led torch on it, it's quite nice and clear.

Most suppliers sell natural filament cheaper than coloured, but not here. It might be for you if you are incorporating lights in a model, but otherwise I'd go for something more funky.

 The Black           


This one is nice. It's a very deep, shiny completely opaque black filament. I thought the filament I have from ultimachine  was black, but there is a slight difference when comparing side to side. It's difficult to catch it on camera though. Note: The filament I have from ultimachine has been laying around for more than a year, so I don't know how it compares to what they supply now.

Bottom line

The filament they supply is excellent! I'm definitely getting more of both the red and the black filament from supply3dpla. I don't know how easy it is to handle the big 5kg rolls of filament they ship, which might be a downside.

A nice little bunch with 6.8kg of filament from ultimachine just went through customs, so expect a review and comparison of that later on.

-Nudel