Tuning A Benchy

Discussion in 'Calibration, Help, and Troubleshooting' started by Spoon Unit, Mar 6, 2016.

  1. Spoon Unit

    Spoon Unit Well-Known Member

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    The benchy is a great test case and can pick up so many challenges for a printer that can aid learning to operate it to within an inch of its life. As many will go through this, it seems an ideal subject for this part of the forum.

    To kick things off, I present my first benchy and invite detailed criticism and offers for tuning.

    First, I should state that the settings are used were not what intended really. I allowed S3D to generate support for one, and went for 100% infill. As I was going to be out for the day though, I let it be to learn from it.

    Appearance no the bed appeared good when I returned home

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    At first, I think this looks pretty great as a first fully successful benchy. My first two had run into thermal runaways and bed detachments respectively. As a result, I did this with 50% max fan, and once I'd seen the temp fully settle at that, I manually tuned (well controled) the fan up to 63 and before it reached the beginning of the top half. After that it was up to chance as I had to go out.

    From a different angle, more issues become apparent:

    [​IMG]

    Little left over blobs on the top level could be just ooze (perhaps I could increase retraction distance, currently at only 1.5mm and 4500 speed), and it could maybe just be due to the lifting motion on retraction (currently at 0.5mm lift). The blobs (or barnacles) on the hull probably represent where that outline finished. I could perhaps try altering from in-to-out to out-to-in for shells, but when I tried that previously, the barnacles were much more significant.

    Next I removed it from the base (it was prett much loose anyway), and removed the support (piece of cake - not even sure why it bothered) to take a look at the base:

    [​IMG]

    Wow. Pretty happy with this. I'd been tweaking first layer a little to try to remove that lip created by compressed first layers and this was set at 95% height, 105% width. Clearly this led to very clear text and I think I'm ready to try 100%,100% next time.

    View from above

    [​IMG]

    Very clean. Not much to comment on here I think. Circles are great. the deck looks clean and well formed. I'm also wondering about flow as a reason for some of the blobs. I have this oddity where I've measure and tuned the filament e-steps, however had to adjust flow to 80 manually, and yet, even then, the FlowControl displayed on the front (is that what FC is?) seems to say 103%. I'd love for some to help me understand what's up with that.

    Try as I might, I could get the camera (Samsung S5) to properly focus on the text at the back. It's actually not bad I can say and given that I know what it says, I can actually read it. Not quite sure about the kink up the right hand side of the back corner as you look up the layers. Could be a trick of the light.

    Finally a view from the front focussed on the "cockpit"

    [​IMG]

    Clear stringing. Again I'm think about filament retraction distance here, 1.5 just seem way too low. And just maybe some of the strings are the result of lift+not enough retraction.

    OK. That's my first full benchy in gory details and I'm ready for your valuable input and, over time, hopefully your detailed benchies so that we can all eventually tune the perfect little tug and learn from the masters that are among us already. I'm fairly sure, a lot of the issues are to do with slicing more than machine build, but if you can see something indicative of a build issue I'd love to hear that for sure.
     
    Mike Kelly likes this.
  2. Pierce

    Pierce Well-Known Member

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    http://www.3dbenchy.com/dimensions/ you should measure it as well to see how accurate your prints are.
    I think the text on the back is only clear at .1 layer height so that's why it's not too clear as default is .2 or .25 or something.

    My benchy has the same zits on the outside so I am playing with retraction settings as well
     
  3. Pierce

    Pierce Well-Known Member

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    Ok think I have improved my zits on my prints.
    Under ooze control I changed the "extra restart distance" down from .25 to .1 and that seems to have improved the quality of my corners. Going to try zero here and see if thats better or worse.

    Also you might want to open this in a tab while troubleshooting prints https://www.simplify3d.com/support/print-quality-troubleshooting/ its useful for any slicer to give pointers about what could be wrong.

    E.g. drifting prints, I had a loose grub screw which reminds me to add some superglue or bluelock thingy to it.
     
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  4. PsyVision

    PsyVision Moderator
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    Both - I have 0mm extra restart distance. The retraction speed is good and 1.5mm distance is fine too. You should also take a look into coasting in Simplify 3d. I tried it in some of my dual colour cone prints and it worked well. Still not 100% happy with retraction for my dual profile though.
     
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  5. Spoon Unit

    Spoon Unit Well-Known Member

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    Well, I have two more prints with some really interesting results. I thought that base was good, I was wrong. Look at this:

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    This was using an initial layer height of 98% with 102% thickness and a 0.2mm layer height. Tuning the first layer height and thickness seems to be crucial, and I'm expecting that to be different for all materials. When you look at the printed parts for the big box themselves, where parts fit together, the fit together really well and the base layer doesn't have a lip. I think the ideal initial layer height has to be 100% with 100% thickness, maybe some materials are more accepting of that sort of setting.

    This last print was also clear of stringing:

    [​IMG]

    Well, OK, some fine hairs, but much improved. After this I noticed the setting to only retract over open spaces and I think that would help with the zits. Will let you know. This was the how it looked initially on the bed at print completion:

    [​IMG]
     
    Mike Kelly likes this.
  6. Spoon Unit

    Spoon Unit Well-Known Member

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    This is what I got the from supplied Benchy slice on the SD card. I had to manually manage the fan well into the print.

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  7. Spoon Unit

    Spoon Unit Well-Known Member

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    I've got a number of thoughts about the 3DBenchy supplied on the SD card build, but one thing leapt out at me again last night as I dived for the power switch. The supplied slice doesn't have a G28 homing step at the start. This means if you start the print from the dump bucket, your heart misses a beat and you dive for the kill switch. Maybe if Greg reads this, he can alter the supplied file for the SD card build.

    In the intervening time, if you want to simply add that yourself, open the gcode file supplied and add in the homing mechanism yourself.

    [​IMG]
     

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