1 Topic by RGargus

  • RGargus
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Topic: Okay... Bummer!

So, I am working on a hydro pressure gold dredge, and after finishing the water nozzle section, I begin my 17+ hour print run.  I added a ten mm brim for added grip to my large  base, and started the run.  After a couple of hours the whole darned thing came lose.  CRAP!!!!  I am using a 1/8 inch glass surface with "white rain" hair spray, at 95 degrees C.  The ABS nozzle is at 195 C.  The whole darned thing, the largest I have ever tried printing, suddenly released and began to travel with the nozzle.  What the Heck.  I was on  like layer 15 or so.  Please check out the vid.. and if you have a helpful suggestion .. I am all ears.
hopefully this will take you to a video at one frame per second. 
https://dl.dropboxusercontent.com/u/186 … IP0006.MP4
Thanks for any help you can offer.

2 Reply by ronsii

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Re: Okay... Bummer!

I notice you don't have much if any 'smush' of the first layer to get it to stick... something this big and solid you will need all the adhesion help you can get. have you thought about a raft?

3 Reply by COASTER19

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Re: Okay... Bummer!

If you are printing that entirely solid, making it stick will be VERY hard.  ABS and acetone would be the only thing which could do it I think.  Also, increase your temp to about 200 and see if it helps those first layers stick better.

4 Reply by Merko

  • Merko
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Re: Okay... Bummer!

For what its worth. I like the camera angle for the time laps wink

5 Reply by RGargus

  • RGargus
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Re: Okay... Bummer!

ronsii wrote:

I notice you don't have much if any 'smush' of the first layer to get it to stick... something this big and solid you will need all the adhesion help you can get. have you thought about a raft?

I will re-level my bed and get it tighter at zero.  I had a 10 mm brim, is that different than a raft?  I will be trying the print again with the bed at 98 instead of 95 degrees too.

The print is not solid but I was just a few layers into the features other than the base plate.

After I get the project completed, I will post the stl's but for the time being, the whole project is theoretical and experimental, no sense in having others waste a bunch of plastic to reproduce non functional blobs. smile

The over all height is about 7 and a half inches, but that may be overkill on the upper pipe connection, so it could be shortened to be printed on an SD2.

At any rate, I will update this post as I move along and complete the design and testing.  This section is just the nozzles.

6 Reply by Briggs

  • Briggs
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Re: Okay... Bummer!

I have a lot of experience with big, solid, and thick parts that are tough to print. My approach is as follows:

-CAD your own brim. Why? Because the "grain" of the brim goes with the first layer of your part, because it is, in fact, the first layer of your part. The "brim" that Slic3r attaches to your gcode goes around your part in a circle, and easily breaks away. Your CAD brim will hold the part much better. Use the Slic3r brim if you still have room on your bed. I make my brim .3mm thick by about 12mm wide. Sometimes I make my own brim thicker and add shrink relief features.

-CAD more shrink relief features into your parts. Break them up with cut extruded features - slots, circles, squares, cute little hearts, anything. The more you have, the less material there is to shrink, right?

-Less infill. This is really an extension of the previous approach. Besides, 50% produces a ridiculously strong part in most cases, especially if you're using good filament, you're printing hot, and your printer is REALLY dialed in. So, why not try 25% infill? Ok, if you need 20 degree angle pressure gears for an industrial machine like I just printed a month ago, then fine, go 100%.

-I call this step "slurry in a hurry". Dissolve lots of ABS scrap in 100% pure acetone, shake, pour in cup, brush on surface. I even do this when it's hot, but I would NOT recommend this for anybody but me. (it just sizzles a bit, dries real fast) When I'm in a rush I will scrape my just printed part off my glass bed, slap on some new "slurry" with a paint brush, and hit run.

-Finally, do you have an enclosure???

Good luck!