New MendelMax 1.0 Just starting to print

I built a MendelMax 1.0 and I finally got my belts (they were back ordered) and put them on today. I tried to print a simple part for a calibration check of the x and y axis but couldn't get it to stick. I am using PLA on a heated aluminum bed. 185 extruder, 60 bed. Is this a good place to start? I haven't picked up painters tape yet to try but I will. Any other suggestions?

If you have a fan on the extruder I'd run the first layer hotter say 205.
Slow the first layer print speed way down.
A lot of it is getting the layer height for the first layer right which is down to homing the ZAxis, the first layer should look a bit smeared, but only a bit.

IMO Kapton is better than blue painters tape for PLA, but either wi ll work.

I tried painters tape and that solved the sticking problem. Now if I can get the speeds and accelerations correct, the calibration right and
stop the filament from stripping I'll be just fine. :-)

I found that I was printing at too low of a temperature. I was trying to print orange PLA at 185 and I read that someone needed to print orange PLA at 220. I found that 210 worked fine for me. I printed up all the rest of the orange and had no problems. Then I switched to black PLA and have had nothing but problems. I have found that it will usually melt at 230, but not always. 230 is too high to get good prints but at any lower temperature it won't melt. Even at 230 it will get part way through a print an stop. I have to pull it out, cut off a chunk and start over. It may work the next time or it may stop again. Is this something I am doing wrong, a bad batch of plastic or just the black coloring?

I have some Blue PLA that behaves exactly like your Black, it'll print for a while then just stop, but in my canse it doesn't Jam, it just appears to require and inordinate amount of pressure to extrude, once it clears that little piece of PLA, it's fine again for a while.

My best guess is it's some sort of inconsistency in the plastic.
I've run through a lot of green since I got pissed off at the blue without issue, so I'm calling it a bad roll.

Is there any place that is known to sell better and more usable plastic (where I should buy from) or conversely, is known for selling lower quality (and I should stay away from) or do all suppliers seem to be hit or miss (depending on the batch, maybe) ?

I don't have enough of a sample size to say, the Blue PLA came from ultimachine which is what most would consider a reliable supplier, I've got white yellow and green rolls from them with no issues, so my guess is you can get a bad roll from pretty much anywhere, and I'd guess very few people have enough of a sample size to say definitively one place is better than another.

I got some blue and some red PLA from Faberdashery. The blue needed much higher temperature and had massive die swell. In fact it needed the same temperature as ABS (250C) and had more die swell. The red came out as a runny liquid at that temperature and had to be run at 220C.

I concluded that some pigments totally change the characteristic of plastic, not that it was a bad batch, as I assume Faberdashery use the same base PLA material in all their colours.

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[www.hydraraptor.blogspot.com]

Interesting I did try as high as 220, but never went any higher since I can extrude the green at 185, it's labeled as 4042D.
The odd thing for me was even at ~200 I printed about 25% of the 2lb roll without any issues, after that it extrudes fine for a while then just stops then extrudes then stops. But I guess it could be variation in the pigment mix, and it might just need higher temperature.
I'll give it another shot when I finish the green.

nophead Wrote:
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> I got some blue and some red PLA from
> Faberdashery. The blue needed much higher
> temperature and had massive die swell. In fact it
> needed the same temperature as ABS (250C) and had
> more die swell. The red came out as a runny liquid
> at that temperature and had to be run at 220C.
>
> I concluded that some pigments totally change the
> characteristic of plastic, not that it was a bad
> batch, as I assume Faberdashery use the same base
> PLA material in all their colours.


nophead, I'd be interested in knowing about the procedure you use to decide what temperature a filament need please.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

With PLA I normally increase it until it becomes like syrup and back off a little so it forms a solid filament rather than a liquid. The infill should pull into straight lines and not sag into the object, but that can be caused by trying to extrude bigger than the dies swell size as well.

With the blue it wouldn't extrude reliably at 220C so I kept increasing it until I got to 250C, which is the max I run extruders with PTFE at. It was still quite viscous and hard to push even at that temperature but I was able to build with it.

With ABS I run it has hot as I can (250C) unless is shows signs of burning or discolouring, normally around 260C for coloured ABS. The hotter it is the stronger the bonds are.

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[www.hydraraptor.blogspot.com]

One thing it address this is a little logbook I've made. It contains the name of the print, the unique print number (Basically a unique id number) and the main parameters of the machine. (Temps, material, etc.) I don't have my printer yet, but this will help me track and diagnose when I have problems, and establish best printing practices specifically for my machine.

I have tried the black at 250 now (it's most of the way through the Tornado Tube [www.thingiverse.com] and it looks like it is printing fine. I was surprised that it even did the horizontal bridges across the wide open center fairly well. All I had to do was blow on it while it was doing that portion and they didn't sag too much. I am putting a fan on it now and I'll see how that helps from now on. I had tried at 250 before and wouldn't do the top bridges correctly on the quick fit x-carriage [www.thingiverse.com], they all sagged down the side. I'll put the fan on and try it again.

jrsteensen Wrote:
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> One thing it address this is a little logbook I've
> made. It contains the name of the print, the
> unique print number (Basically a unique id number)
> and the main parameters of the machine. (Temps,
> material, etc.) I don't have my printer yet, but
> this will help me track and diagnose when I have
> problems, and establish best printing practices
> specifically for my machine.

That's a pretty good idea, would you mind sharing the (I assume Spreadsheet?) file with me/us?

Thanks,

Alex.