Hand cranked geared heart troubles.

[Titus 170]

Dear community,

It's been a while I opened a new topic, I've slipped in questions in other topics etc, but with the troubles this print is giving me I thought it might be good for a topic/blog kinda thing. Questions or notes will be introduced by a '-'

Model: http://www.thingiverse.com/thing:253934

Based on: http://www.thingiverse.com/thing:243278

I'm printing it at .75 scale, because I was short on red, though I might have to buy new red anyway.

Basic settings I'm using:

0.1mm layer height for details

1.2mm top/bot thickness to make sure the top is nicely closed

0.8mm shell for 0.4mm nozzle

50mm/s Speed, slower than I usually print at 80

215C nozzle temperature for ColorFabb Red/blueish grey PLA

55C Heated bed temperature for bed adhesion

So far I've printed the white parts from this picture. Note, this is NOT my print but the picture from Thingiverse:

The base without trouble, the gears without trouble too.

-The axle however didn't fit in the holes. So I had to print it at .65 scale or something in order for it to actually fit. This is a reoccurring problem with prints that have to be assembled. I just can't print them so it fits. Many people suggested to create the parts with extra margin etc. But since I didn't create this model and many other people seem successfully printing it, I can't help but think the problem is at my end. I had the bottom layer set to 0.3mm still by accident. I made that 0.2mm, but yeah.

-When printing the heart base I used the pause on height trick to swap filament, which I learned during the Print Challenges. Super happy with that!!!! However during the red print I noticed a lot of blobbing as can be seen in this image(was also posted in latest print). It seems z hop on retraction was causing it. I've set that to 0 now.

- Now I've started the heart itself. I didn't dare to print all parts at once, mainly due to the lack of sufficient red pla. But that is also a reoccurring theme. I want to be able to fill up the bed and just print! But somehow I believe that messes up prints, and print 1 part at a time. Will investigate and try later. But do you guys print 1 part at a time, and start a new part manually each time, or just fill up the bed?

-I don't know why, but it seems like I'm getting high under extrusion on this part. I tried it separate, and now with another part at the same time. Or it might be something else, I just don't know. Temperature should be high enough, filament is not grinding. The print is retraction heavy as can be seen in cura/heard.

Retraction settings are 4.5mm at 45mm/s

I really don't know what is going on here, or why I just can't get it to work. The only thing I can think of is:

-The model(retractions)

-The material

I'll try to print one of these parts in white tonight, but I'm just clueless.

[cloakfiend 996]

retractions shouldnt be an issue, smaller stuff is harder due to heat being more of the problem, also id have either 100 % or zero infill as weird denominations on tiny stuff can damage the surface due to the walls still being affected by movement of the nozzle.

and yes don't print loads of different shaped stuff at once unless you dont mind seeing layer lines due to mismatched cooling times per layer.

Colourfabb red is fine, i swear by traffic red i highly recommend printing like 4 at a time, 2 may not give enough time to cool.

Not sure if my settings will work given that each machine may read temps differently but i use...

temp 185 layer height .06 speed 30. all walls 1.2. and fans on full from the very start. tats it everything else default on cura 15.04.2.

Edited February 9, 2016 by Guest

[Titus 170]

@cloakfiend, thanks for replying, I will try the 0 % infill, but with a higher top thickness, otherwise I'm afraid it won't close nicely.

I'll also try to print more than two at once. And even slower and lower temperature.

Here are the pictures from the finished print of today. I still notice blobbing, and also strange shapes in the wall:

[neotko 1,417]

Have you ever adjusted th aceleration of the machine? Because on my prints with low aceleration on small areas I got blobs and weird top layer quality.

I also avoid blops using coasting on s3d (cura beta has that) and wipe while retracting (s3d).

Edited February 9, 2016 by Guest

[cloakfiend 996]

im sorry i dont have a umo so my advice is somewhat limited.

[gr5 2,265]

I don't think you have underextrusion - at least not in the last 2 photos.  Instead you are having troubles with overhangs.  Colorfabb is less viscous - try much cooler - maybe 190C.  Is the fan at 100%?  You want it at 100% quite quickly as the overhang starts on the second layer.  Also print even slower - try 35mm/sec.

Edited February 9, 2016 by Guest

[Titus 170]

So I printed the same parts, now with 0% infill, 190C, and 35mm/s, fan at 100%

The top layers are a little bit nicer, less blobbing(probably due to lower temp), but I still get some strange wall structure, or overhang trouble.

[cloakfiend 996]

Overextrusion might help you, im having a lot of luck with that recently. Dial in a 0.6 nozzle for a 0.4 one and see how that goes?

[yellowshark 153]

Hi @Titus, I downloaded the file and had a go.

The LHS image was my first go. It is by no means perfect but I think it is better than yours. I used your settings except for

layer height - 150mm to speed up print

print speed - 20mm/s

extruder temp - 180c; although if I did it again I would use 185c

infill 26%

bed temp 65c

100% fan

ColorFab blue grey filament

For the RHS print, which is just about perfect, I changed my settings as follows

Walls - 1.6mm

Infill - 40%

Print speed 30 mm/s

Extruder temp 190c

Faberdashery Robot Silver

Also as the overhang changes from leaning to the left (on the lhs of the model!!), to leaning to the right, after say 10 layers I noticed a couple of artefacts and reduced the print speed to 20 mm/s which stopped that. I left the extruder temp at 190 after the speed change because I forgot to reduce it!

Edited February 14, 2016 by Guest

[neotko 1,417]

Maybe the problem could be related to cpu speed? This reminds me of something gr5 pointed out about the cpu limit

 

Don't set the value too high in you cad software - if the line segments are say 5 per mm it will drastically slow down your print because of how Marlin (the firmware) works.

Marlin can only read 12 moves ahead and doesn't know if a sharp turn (e.g. corner of square) is coming up on the 13th move so it has to be ready to stop 12 moves ahead and if all 12 moves are in the next 3mm it needs to print VERY slow.  It will cause bad quality.

 

[yellowshark 153]

Lol that is beyond my capability. I made two deliberate changes for the 2nd print. Firstly I increased the infill% to reduce retraction frequency. Secondly I thickened the wall in case the infill overlap was impacting on the surface. Unfortunately I also changed filament, making the understanding of what made the improvement less obvious.

[Titus 170]

 

@Yellowshark, Thanks for the detailed write up. Are you running on an UMO or UM2? Also I was wondering, could it be because I down scaled the model to 0.75?

[yellowshark 153]

Funny you should say that, it was a thought that went through my head when I first read the post. But it is a solid model so you can set your wall width as you desire, so I do not think it would affect it. But re-scaling is something I rarely do so I do not consider myself that knowledgeable on the subject.

I am running Cura but not on a UM printer but apart from extruder temp., which might need adjusting, there is no reason why you should not try my settings and see if you get close. I use all the standard retraction settings in Cura 15.04.2

[cloakfiend 996]

That looks like a really really nice print! I dont even think i could get my um2 to produce something that sharp and clean.

[yellowshark 153]

I have seen some great prints from the UM although I have not actually seen a UM2. I think one of the strengths the 3ntr has is that its drive system has no plastic parts (of course except for the Bowden tube), comprising CNC alloys through to the extruder/nozzle, which I am not sure whether they are machined in-house or brought in from a third party.

[cloakfiend 996]

Looks like a good printer, i dont care for aesthetics of machines as long as they do what they are told and can be maintained by me. Is is a quiet machine?

[yellowshark 153]

I would not say it is overly quite, there is no technical data on decibel measurement. I can work beside it quite easily without "hearing" it. Sometimes I sit in the room listening to my hi-fi whilst the printer is printing. If I have the amp turned up the printer does not intrude; if the amp is at more average values then I can hear the printer but I can mentally shut it out.

[Titus 170]

Ok, it's been a long time since I updated the thread. I postponed this print until I did a nozzle upgrade(@anders-olsson rocks!) and a dual fan upgrade(@neotko rocks too!). Remember what it used to be?

Check out the comparison, right is the post processed old piece, left is the unprocessed new piece

And the final product:

I designed a little knob to fit over the crank, as the downscaled heart didn't like the small crank as much.

Edited May 26, 2016 by Guest

[SandervG 1,521]

Wow that looks sharp! What do you think the difference is? The dual fan or nozzle?

Did you just install a new nozzle or something special?

[Titus 170]

I think it is both. For example on this comparison I believe the nozzle is responsible for better surface quality.

You can also see it in this example:

Left=original

Middle= just nozzle upgrade

Right=nozzle+dual fan upgrade

However if you look at the overhangs of the old pictures I believe the dual fan took care of that:

[SandervG 1,521]

Do you have any means to measure if your old nozzle was still 0.4 or could it be it got wider or the shoulders were almost completely shaved off?

Congrats on your new Ultimaker Original!

[Titus 170]

I believe the actual old nozzle was a bit worn, so I swapped for a new one at the time, without result, if I remember correctly.

Final settings:

0.1mm layer height for details

1.2mm top/bot thickness to make sure the top is nicely closed

0.8mm shell for 0.4mm nozzle

20% infill as usual

45mm/s Speed,

205C nozzle temperature

60C Heated bed temperature for bed adhesion

45mm/s retraction speed

5.5 mm retraction

initial layer 0.2mm

250mm/s travel speed

[Titus 170]

Just leaving this here as I hadn't done so:

https://vid.me/eDTF

https://vid.me/WdwR

[SandervG 1,521]

That is very cool! Did you use a lubricant to reduce any friction?

There is also a motorized version, I bet I could watch that all day while it slowly rotates. Such a cool design!

[Titus 170]

I added some sewing oil, but it didn;t seem to change a lot.

I know about the motorized version, but this one seemed more appropriate as a gift.

Edited June 14, 2016 by Guest