Mini bearing pocket ID's

Hey guys,

Just got my MINI yesterday and I’m having a blast with it. I’d just like to confirm my results with what I should expect.

I’m going to be using the mini to create a lot of cases for arduino based stuff. Those boards use M3 screws to hold the board to the case. The engineers handbook recommends that for an M3 screw, the thru hole should be 2.5mm before tapping. To test accuracy, I had the mini make a boss with a 2.5mm ID. Once printed, I used gauge pins to measure the results. The ID/hole diameter of the part came in at 1.4mm.

Thinking it might just be small dimensions that are difficult, I printed another bearing I had which has an ID of 4.1mm. When I measured it with a gauge pin, the resulting part came in at 3.24mm. Working with SLA machines, I know that holes will come in a bit tight, but I wanted to see if I should expect more/less out of the machine for these types of details.

As for the run mode I’m using HIPS, Cura quickprint, FINE detail. See the results below:


Should my ID’s be closer to my solid dimensions or am I getting expected results for this machine? Should I be using the HIPS profiles you guys provide for expert mode? Should I be buying a smaller nozzle diameter?

Thanks guys!
-Jim

One other sample part:


Solid on the computer says the distance should be 7.88mm. Printed part came in at 7.43mm.

Same settings as I listed above.

Is my machine operating as expected? :slight_smile:

-Jim

Not sure if I missed it or not… But what modeling software are you using?
Not Sketchup 2015?

IF so… STOP!!! OR learn to measure twice after every step…<-- took allot of troubleshooting for me…

If not… I’ve noticed that within my small time with the Mini, it doesn’t do curved prints too well…
In that regard, circles are far from perfect and nothing I’ve done seems to fix it… Let it be said that I’m a bit of a newb…

With that… I would say that regardless of adjustment, that this guy in it’s stock form isn’t going to make precise models…

But my findings are that… While it does make some VERY awesome/fast prints; when we’re talking MM’s, it’ll be up to you to adjust after the print…

I think the next step is to find a different nozzle, slicer… Everything else is there though…especially out of the box :smiley:

Also, I’m not 100% sure, but I think the “expert” profiles are just the same as the quick settings…
I tried printing with both, and couldn’t see anything different while watching through the entire prints…

From my searches, allot have asked about that, and I’ve yet to see a solid answer from the “crew”…

Modeling Software: Siemens NX
Slicer: Cura

I saw lulzbot sells different nozzles. Are they easy to swap? Do I need more parts than just the nozzle? Is there a tutorial on how difficult it is to swap?

I’m assuming going to a smaller nozzle will increase the accuracy but decrease print speed?

Thanks
Jim

I’m not knowledgeable enough to give advice…

But a good test would be to render a small ring… and test it…
I’ve beat on this machine, and it’s “OK” from my experience… But it does drift a bit in my experiences… Like I said, making good circles seems to be hard to do…

I will find out how E-Sun filament works out, as it’s the only filament that they fully support, and I was lucky enough to find some in stock…

Otherwise, these are printed from the same STL on two different machines(Zortrax/LB Mini)… Default/similar profiles… Black is Zortrax and white is LB…
Funny, that the internal hex ID size was right on between both machines, but the OD and thickness was off…
20150319_222440.jpg
20150319_222453.jpg

You might look at this:

http://hydraraptor.blogspot.com/2011/02/polyholes.html

One of the first things you should check is your filament diameter. In the default Cura profile this is typically set at 2.85mm. On our mini we were having tolerance issues – but these were quickly resolved by adjusting the filament diameter (for us, we’re up around 3.07 mm with Lulzbot PLA eSun).

You’ll have trouble making this configuration via the quickprint settings. So, you’ll need to switch over to expert (please correct me someone if I am wrong) and load the desired PLA profile manually. Then - make the correction in the expert settings.

Ya, the quick settings and the expert settings are identical. If you switch to expert mode, you have to load an .ini, as it won’t transfer over the config automagickally (but will in future rev).

I hate to wreck jim2386’s post…
But thank’s a butt-ton for the info… I learn more and more each day…

I bought a couple of 3MM IC3D’s spools, only because it was associated well with LulzBot at Amazon…
Not only have I noticed allot of popping(air) in their filament, but it takes allot of cleaning to rid of the dye in their filament…<-- not to say that it’s cause bad prints… But it does have me wondering about filament…

Seems like every grandmother and their poodles are making filaments now-a-days…

I’ve just played with Gizmo Dorks’ stuff, and so far so good… Even their “glow-in-the-dark” HIPS stuff, and yet it prints pretty dang good…<-- and actually truly glows for the most part… But I don’t get the hissing/pissing/popping/and smudge like I’ve had from the IC3D stuff… They also advertise a 3MM filament, but the sticker says 2.85MM…
But like I said, so far Dorks’ HIPS and ABS prints very well for me…

I’ve tried to order stuff recommended from Lulz, But it’s hard to find in stock…
I got lucky and found a small roll of E-Sun, but have yet to print with it…

Thanks jebba…

That puts me at ease!!!
:laughing:

Hi Jim,

I’m having a lot of the same issues, questions and frustrations as you with the Lulzbot mini. I can only seem to make a print using the “Quick Print” profiles in Cura. I have learned on the first day that this model uses Self levelling (you see the machine probe each corner of the print bed before each print). This allows the software to bias and compensate for the current alignment error and height of the bed. This sounds like a good feature as it makes this machine reliable and easy to use, but this convenience comes at the cost of its flexibility.

After my first test print (I printed something useful and not an octopus: it was a gear, quite similar to your example). I found that the detail was less than I expected and that I could not tweak the settings using advanced mode in Cura or I would loose the self levelling routine and have a failed print.

When I discovered this Mini machine has a large 0.5mm nozzle, I looked into changing it out for a small one. But Support tells me that this is not possible because of the Nozzle cleaning and bed levelling routine. I was disappointed, but I do also appreciate that this printer is a commercial product, so I need to change my attitudes about viewing it as I would a CNC mill with the ability to change tooling to match my project requirements.

It would be great if a profile was released to allow for a 0.25 and 0.35 nozzles on this machine or instructions to print TAZ bed levelling parts to adapt to the printer.

What attracted me to this machine was it’s nice clean design, rigid frame and small footprint. The specifications also indicate that it is capable of very fine layers from 0.05mm (but I can’t seem to change any parameters in software). The large fixed nozzle size of 0.5mm does not seem to be mentioned in any advertised/Pre-sale specifications.

I will leave my machine as-is and not make any changes to it. I do like it as it is very close to being perfect and that’s what kills me the most. But I do have my fingers crossed that some new profiles or approved nozzle options will be available with time.

You can switch to expert settings and just copy over the g code for the nozzle cleaning and self leveling. I have only printed in the quick settings once. And that was for the test rock top us print. Just transfer over the basic profile from quick print to expert settings and then tweak it all you want to. I mostly print at .3mm layer height because this is really fast with the .5mm nozzle and still give a out decent quality but not perfect. If I want a more finished looking piece I print at .1. I haven’t tried to print at .05 because the print times are really long and I don’t think the increase in quality would be worth the extra wait.