Heated Print Bed "Welding Prints" and Tolerance Issues

[GIFT3D]

Hey Jackson,

I understand what the nasa wrench, ball bearings and gears are, but I don’t think I’ve heard of this situation before. All that I can think of is either the nozzle or print bed is too hot, whihpth the fan not cooling the filament down quick enough. This would cause the filament to drip into what should be gaps. To fix this check that the heat settings are correct for the filament including the fan. Good luck finding the problem. Hope this helps.

[keebie81]

You need to calibrate the printer still. Print a 20mm cube, then measure the sides. if its more than 20mm turn down your flow multiplier in cura. it defaults to 1 or 100%, i use 0.93(93%) on my Taz

[SSVT]

Fellow lulzbot mini owner here. When I first got my mini I had the very same problem, which sucked because I primarily got into 3D printing to make mechanical systems. A couple things that made a difference for me fast: Stopped using HIPS. I know, I know. Did you ever wonder why you can’t seem to find a really good selection of the stuff? Isn’t it weird that even the lulzbot store only stocks the stuff from esun, and it’s about the cheapest stuff around? Maybe I gave up on the stuff too soon, but there are just not good resources out there for dealing with it, and I was never able to get dimensionally accurate prints. I would often get beautiful prints, they were just slightly the wrong size. Another big leap was to stop using Cura. I wish I could tell you that by switching to Simplify 3D i didn’t see an immediate improvement with my ABS prints, but I did. The difference was night and day for me.

If you are dead set on trudging on with HIPS and Cura. Take a look at your Z-offset. It was set at the factory, and mine was slightly off. Because of this the first layer was always really squished, and that did make things slightly more difficult. Another setting to look at is the first layer width and height. With the Mini’s PEI sheet you should be able to print those at the same width and height as every other layer no problem.

I’m not sure what your aversion to PLA could be. For most mechanical parts in the things I make, gears and hinges and such, I use PLA unless it needs to be really strong. Mainly I do that because I know it will come off the print bed perfect on the first try.

Good luck!

[AardvarkMan]

Looking at the print you may actually be over extruding a tiny bit. Any over extrude on a heated bed with fit tolerances can be real trouble. Try the print with the extrusion reduced to 90% in the slicer.

The other options is to pick up a sheet of BulidTak or other bed adhesion material and print on a cold/not as hot print bed.

[huffworks3d]

I agree with the other users. Tune your Flow % in Cura down a bit and that should come out better. I run around 85% on nearly all my prints. May be a bit different for various filaments. But turning up the infill to 50% or so will help your top layers still come out nice.

[shall52]

Hi Jackson,

I have a few things for you to try.

Make sure the head to bed calibration is correct. It could be because the head is too close to the bed, causing the first layer to be flattened and fusing things together. I use Simplify3D which gives me much more control of the machine. You should check the first layer height, width and speed setting. Also, I’ve had to play with the Extrusion Multiplier setting and bring it down to as much as .8.

Try starting the print and stop it after the first layer to see if any of these things help.

Talk to you later,

Steve Hall

[Jackson_Moody]

Okay, thanks for the reply! I found in Cura that the nozzle WAS buried a little deep into the bed, and the starting layers were becoming squished. I can fix this problem in Cura. As for the first layer height width and speed, where do you find those settings in Cura? The extrusion multiplier also sounds like a great idea, and I will try that out.

Thanks for the quick response!

Jackson

[Jackson_Moody]

Thanks for the quick reply! Turning down the flow rate in Cura definitely sounds like a good idea. I will definitely try this!

Thanks for the suggestion!

Jackson

[Jackson_Moody]

Thanks for the reply!

I will definitely try to print with a lower extrusion multiplier, as a bunch of users seem to be suggesting this. As for the BuildTak, I haven’t heard of this idea before! However now that I think about it, having something on the bed itself would be a good idea! Do you think regular Painter’s tape would work? I know I have some in the garage…

Thanks for the great suggestions!

Jackson

[Jackson_Moody]

Thanks for the detailed reply! Man, everybody on 3D Hubs talk is so helpful!

As for Simplify 3D, I am definitely thinking about it. However, it still seems like a rather large investment for a software. I have also seen forums that say Simplify 3D has some trouble working with the Lulzbot Mini. For Simplify 3D, I would love to hear from a fellow Lulzbot Mini owner like you. If it isn’t asking too much, could you give me a rundown of how Simplify 3D works on a Lulzbot Mini?

As for the HIPS, I am open to other filaments, but I would prefer not to use eSun PLA. It is probably just because of eSun’s really cheap filament, but for some reason their PLA worked terribly for me! Maybe I will try Colorfabb or something.

In terms of the Z-Offset, are you reffering to the Initial layer width? If so, I will definitely try tweaking this, as it seems a little off. If not, which setting are you reffering too? As for the first layer width, what do you recommend changing it to? I have heard a wide variety of numbers, and I would love your opinion.

Thanks so much for the wonderful reply! You have really helped me a lot, and I can’t wait to try your suggestions!

Thanks Again,

Jackson

[Jackson_Moody]

Thanks for the reply!

I haven’t tried printing the 20mm cube, but that sounds like a good test print. I have heard about the Flow Multiplier, and turning it down sounds like a great idea!

Thanks for the suggestion,

Jackson

[Jackson_Moody]

Thanks for the reply!

I think my nozzle is at the right temperature, because HIPS has to be printed pretty hot. As for the fan, I will definitely look into turning up my cooling!

Thanks for the great suggestions!

Jackson

[Jackson_Moody]

Wow! I have received so many responses! This is my first time using 3D Hubs Talk as a support option, but it has worked really well! I am going to try every single response right now on my printer, until one works. I will let you know my results shortly.

I would also like to thank each and every one of you for at least taking the time to read this support post. I know all of you probably had better things to do, and I really appreciate your help! This issue has been bothering me for a little while, but I can’t wait to try your responses!

Thanks so much everybody, you can’t possibly imagine how much this helps me.

Thanks Again!!

Jackson

P.S Yeah, I know that sounded really sappy. But I would really like to thank everyone for all their amazing support.

[SSVT]

Let me prioritize my reply here:

Z-Offset:

Take a look at this thread here: https://forum.lulzbot.com/viewtopic.php?f=43&t=2494

The setting you are looking for is under Machine>Machine Settings>Z-Offset (mm) in Cura. I had to add just over a single layer height to fix the problem. You can also permanently adjust this in the firmware of your printer, but I was too scared to try it back then.

First Layer width and Height:

These are advanced settings under Cura. They are called Initial Layer Line Width (%) and Initial Layer Thickness (mm). Set the thickness to 0.0 or to the thickness of your normal layers(The tool tip will tell you those do the same thing). Set the Width to 100%. Beefier first layers help with adhesion in the same way printing with a brim does, more surface area to stick. But for mechanical parts, this ruins accuracy. Simplify 3D, for what it’s worth, seems to handle the calculations for the height a lot better than Cura, I’m not familiar with the Cura source code so don’t quote me, it could be they’re compensating for that thickness change too, but it caused me a lot more headaches with Cura.

That brings me nicely to Simplify 3D…

It works perfectly, right out of the box with the Lulzbot Mini. The one gotcha, is that for some reason they are using what I can only assume is an older out dated version of the auto-leveling sequence before the print starts. The major difference is that after the nozzle wipe, it pauses over the first contact point and waits for the extruder to reach a new temp, about a 20 second pause. Sometimes this little pause is enough to ruin the leveling sequence, driving the nozzle into the metal disk. It’s a pain when it happens, but it’s pretty rare. I’ve had it happen with Cura too, but it usually just means I need to replace the wiper pad. You can update this sequence pretty easily in the software, it’s just not done for you.

Other than that one thing, S3D works just fine on the Mini, and it works just like it does on any other printer. You can print directly from it while tethered, so it’s a drop in replacement for Cura.

S3D is worth the money, only if you frequently run into problems with Cura. Especially things like thin walls, or support sticking to the model. If you’re making stuff that works well with Cura, just stick to that. I’m perfectly happy with my purchase of the software, but I don’t think it’s so much better that I would say you definitely have to buy it.

Oh and as for filaments, that’s another lesson that took me way too long to learn. It turns out that you do tend to get what you pay for, the cheaper stuff is just that. I haven’t tried ColorFabb, though I’ve heard good things. I use Verbatim PLA, and I buy it on Amazon. The stuff is really really good. The difference between it and something like eSun is night and day. It’s also twice as much for a 1kg spool. I’ve found the same for ABS and HIPS. You still have to do your research, but in general I’ve found the ‘higher end’ filaments are worth their weight in plastic.

-James

[SSVT]

Every single one of us here has been exactly where you are now Jackson. Soon you’ll be an expert on all the things you’re struggling with today an then you will get a chance to pay the community back.

-James

[Jackson_Moody]

Wow! Thanks for the detailed reply James! I really appreciate the support

I will try and post my replies to your replies here. (I know that sounds weird)

As for the Z-Offset, mine was set to 0. Is this normal? If so, should I increase it to .2? I am not quite sure what you meant by “a single layer height” I will definitely try adjusting the Z-Offset and Flow Rate, as that seems to be what a lot of people are suggesting.

In terms of the First Layer Width and Thickness, I had already set the Thickness to 0, as I had heard this would help on other forums I had read. With the First Layer Width, mine was set to 150. You were suggesting I turn this down to 100?

Finally, with Simplify3D, I am leaning towards buying it, just because of the reviews I have read. I am definitely having trouble with support material in Cura, and I have heard that Simplify 3D is very good with support material. I haven’t had too many problems with thin walls, but I have had a few.

Wait, and for the Filaments, I have already ordered some Colorfabb XT for my printer, which has gotten some great reviews. I haven’t heard of Verbatim PLA, but I will check it out.

Thanks again for the SUPER detailed reply! All this support is awesome!

Jackson

[stopaginn]

Hey there,

If your model can support it, I put a .5mm or bigger parameter chamfer around the edges that contact the build plate. This lets the melted plastic spread, but under the outline of the model. It doesn’t have to be .5, just adjust what works then trim the excess spread.

Also, look at FLEX3D.com. I just received a build plate that will stick any plastics without heat and you lift it off with your print attached then twist or bow the build plate to remove the parts. They have all different sizes to choose from.

Jim

[shall52]

I just received 2 FLEX3D plates too. Firing it up with an ABS print right now.

I hope it works as good as they say.

Steve

[Jackson_Moody]

Thanks for the reply Jim! I will definitely try adjusting my parameter chamfer, and see what that does!

As for FLEX 3D, I have heard good things about it! I might consider ordering one just to see how it performs on my machine.

Thanks Again for the great reply!

Jackson

[SSVT]

Careful with this Jackson. Fleks3D is not compatible with the either the PEI print surface on your heated bed, or the automatic leveling features of the Lulzbot Mini. You would need to do some serious modifications to try that out.

-James