Last layer issues !

Hi all,..

I use slic3r, and pronterface on a reprappro Huxley and everything is smashing, except...

yesterday I was printing out a nice foot with a 5mm peg on the top.

It spent nearly an hour printing out a beautiful foot, got to the top, printed the 5mm peg, each layer immediately after the preceding layer, and I ended up with what was clearly not a 5mm peg on the top.

What's the solution ?

I already have cooling fans, but it was too much for them to handle,

I *think* I could probably add some wait statements into the GCODE, between the specific layers, if I know this situation will arise again.
But editing GCODE sounds very manual and slow, and I'd have to wait an hour till the top of a print to see if I got it right ?

Are the any slic3r settings or anything I can do, any plugins I can install, or software i can use to adjust the gcode ?
to make sure my 5mm peg on the top is a 5mm peg ?

any help would be very gratefully received,

cheers,

Dave.

In skeinforge there is a 'Cool' module. This allows you to define the minimum time spent on each layer. If it estimates that a layer will complete quicker than the time you set it will slow down all operations so that the layer will take the predefined time to print.


I'm not familiar with Slic3r but I have had a look into the parameters and there is one which seems to do the same thing.

In the Filament Settings select the item 'Cooling'.

Tick the 'cooling' box. Then there is an entry saying 'slow down if layer print time is below 0 seconds'. Change the 0 to a more appropriate value, perhaps 20 seconds and I think that should do the trick. You may also want to adjust the minimum print speed.

Many (many) thanks for looking into that for me and finding that setting, I shall do some tests and post the results back for others,

cheers,

Dave.

What you could do, is have a "dummy" model printed at the same time - for example, a mini tower, say 10mm square and hollow (negligible filament waste), which is the same height or a mm higher than your model. The extruder then has to divide it's time between the 2 models allowing your main model time to cool between layers. Keep them close to avoid stringing or ooze. Other than that, I seem to remember a "Wipe" command somewhere (maybe Kisslicer?) that may do the same thing.

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_______________________________________
Waitaki 3D Printer

Your print speeds are too high. RichRap describes this in his slic3r is nicer post and gives a work around solution. See the bottom part of this post:[richrap.blogspot.com]

Dave, what kind of hot end are you using?

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Yvan

Singularity Machine

tanju Wrote:
-------------------------------------------------------
> Your print speeds are too high. RichRap describes
> this in his slic3r is nicer post and gives a work
> around solution. See the bottom part of this
> post:[richrap.blogspot.com]
> -nicer-part-2-filament-and.html

I think the filament settings I mentioned above do automatically what is described in the article, that is slowing down the print speed when there is not much to print on a layer. The article was written quite some time ago and I guess that functionality did not exist in Slic3r back then so you would have had to do it manually.

It's a RepRapPro Huxley, so it's a Bowden tube.
Does that make a difference then ?

Read all the RichRap blog about this. Lots to understand and test I think.

thanks for all the help, I can't test anything till about next Tuesday, will be off and running then ;-)

cheers,

Dave.

Does the hot end on your Huxley looks like this:

RepRapPro Huxley hot end

That style tends to radiate a lot of heat onto the plastic parts as they are printed, it becomes acute when building up one small part. Insulation under and around the heater block helps a lot.

Any trick to move the hot end away from the small part is going to help. Some software can do it, sometimes I printed a few small parts at the same time like Waitaki suggested. It gives each part a chance to cool off. I usually space the parts apart to help.

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Yvan

Singularity Machine

Hi,

Yep, that's exactly it.

I have all sorts in the toolbox I can insulate it with. I'll have a think.

Many thanks for the tip.

Here's a thing, its a 0.5mm nozzle and I'm thinking of rather than breaking it down to change to a 0.3mm nozzle, I might just build another hot end and swap them.
So my next Q...

(I'll post a separate thread tomorrow though if I need to, after researching, new topic new thread)

which is the best bowden hot end that will fit a Huxley ?!

cheers,

Dave.