Preparing STL files for slicer

Recently, I purchased an Airwolf AW3D V.5 printer from: AW3D V.5 Printer which is was derived from the Prusa air and Mendel 3d printers. So, far I have assembled the printer and only printed out the calibration circle now I would like to print out a cad file that I made for a custom LGA-2011 intel socket holder for a Vapo Chill phase change unit that came with an old LGA-775 adapter.

After saving the cad file as a stl file I have placed the file into meshlabs program to check for any manifold edges it does not show that there are any non water tight edges, however when using slicer to generate the g-code I have discovered along with the graphics display area in Repetier 98 that the image when the SCALE setting is at 1 x 1 x 1 that it is too small so when I put it at 100 x 100 x 100 the stl object is bigger than the bounding box?

Also, when set at 50 x 50 x50 which as the photograph shows that I uploaded to this site.

Accuracy in this print is important for the tolerances have to be +/- .003" in order for the holes to align correctly from the adapter to the motherboard that this will attach the phase changer's evaporator to the cpu.

Right now I need help in first knowing how to set the scale of any imported cad/stl file so that it will be in true realistic proportion to the actual cad file?

Plus, any other help on determining the other settings like extruders calibration to the g-code etc.

When I chose 50 for the locked scale it at least fits into the screens bounding box but when set to 100 it appears so large that it does not even show the whole image on my netbook?

Scale in your slicing software should be 100%, maybe a percent or 2 more if you are correcting for shrinkage. For ABS I print anything I need to mechanically fit to a pre-existing manufactured part at 101% XYZ.

As far as I have seen, all slicing software is in millimeters. Maybe you are going from inches to mm somewhere in your process?

Hello Dirty Steve,

I went back into Solidworks to go through all of the settings with a more detailed slower report to find that I did not necessarily have to change the actual design panel from inches to millimeters instead at the saving of the stl file there is an option at the top which must be selected.

Now the stl file when dropped into Repetier has the 1 x 1 x 1 scale setting which is the same as all of the other stl files that I have downloaded online, so the answer is to be absolutely certain that you select and save the file as millimeter from inch or any other design format in order to use the 1x1x1 scale in Repetier.

Hopefully it will not get hung up as it did better when generating the g-code it gave me the following message before:

"std-bad alloc" can not find g-code?

Time to give the slicer another try...

I use KISSlicer and Skeinforge, but I would slice with either Slic3r 7.2b (very stable) or the latest release of Slic3r outside of Repetier, and import that gcode to print.

Well, it has been a few days since I have been able to successfully save the stl file and generate the g-code for the custom adaptor that I have designed.

However, for the past 3-printing attempts I have on the first two tries seen the entire model lift off of the blue painters tape, so in response I went to home depot to buy some double sided industrial strength tape that worked extremely well at keeping the model tacked down on the tape but then something awful happened the filament spool holder's bearings locked up and the carriage lifted off during layer 80something out of 230 layers so almost halfway thru the print and subsequent layers afterwards were all out of whack so I stopped the print.

Then the extreme hold became an extreme pain in the you know what it took me much effort and some adhesive remover I finally got the double sided tape all clean off the borosilicate glass, I today have been trying to use spray on types of adhesive which I thought best both for laying down & later to remove compared to say double sided tape.

Unfortunately, the support material seems to be warping upwards and not staying down on the adhesive so I don't know if this model is going to start moving around at layer so and so?

I know that the black tape works too well at keeping models down but the removal is pure pain... but if I have another wasted print I will have to resort to finding a better method to remove the black double-sided tape since the black tape is so far the best at keeping a lock down on the print material...

This is going to lead me to finding the best "formula adhesive"?

Are you printing ABS or PLA?

PLA with plain glass or mirror and a 4:1 mix of PVA (Elmers Glue) and water. 60 degree heat. This has been working very well for me.
First layer printed at 35% speed.

ABS
Glass with Kapton Tape, scuffed up with sandpaper heated to 110 degrees.

So far I have had really good luck with the above. On some ABS I have added a single or double line brim if I think a corner may want to lift.


Good Luck.

You could also give the brim option a try with a material that down't stick so good.

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Spk64 Wrote:
-------------------------------------------------------
> Are you printing ABS or PLA?
>
> PLA with plain glass or mirror and a 4:1 mix of
> PVA (Elmers Glue) and water. 60 degree heat.
> This has been working very well for me.
> First layer printed at 35% speed.
>
> ABS
> Glass with Kapton Tape, scuffed up with sandpaper
> heated to 110 degrees.
>
> So far I have had really good luck with the above.
> On some ABS I have added a single or double line
> brim if I think a corner may want to lift.
>
>
> Good Luck.

Hello Spk64,

I'm using PLA, just got some ABS in and plan to use that as well, I will try the Kapton tape with the ABS as I too would like to have your success using that method.

I did have success... using scotch brite super77 the spray actually worked well... I sprayed two layers let the first one sit for 20 minutes then applied a 2nd and started the print in 5-minutes, with the bed heated to 65c the support material did at first seem to warp up on the back and front sides of the support material only the actual model material laid down and stay in place throughout the printing cycle.

Thing is it worked so I have my first print model, I noticed after the fact that while I got the placement of the interior perfect the screw locations for the LGA-2011 adaptor are too small I measured the screws but forgot that the screws actually fit inside of a hollow stand-off for the motherboard, see attached photo.

I will make a revised one later tonight with the corrections and show the adaptor in relation to the motherboard and the light that will fit inside thus the main reason for the custom design in addition to saving the $200 that it would have cost me with tax and shipping for one that does not have a light holder.

hairspray works well on glass, you certainly shouldn't need to use an actual spray adhesive, soulds like a mess to clean up.

for what it's worth, being captain obvious and all... couldn't you just put down a layer of blue, then the double-faced tape on top of the blue?

christiananthonykepler

I have been having a similar issue with Solidworks, but my files start in MM format from the get go.
I have had to use a 25x multiplier to get them to be the right size. I just dropped a downloaded 25mm cube on the graphic display in Repetier, then dropped my own "25mm" cube into the center and started scaling it till it matched. Worked. 25x seems t be perfect for me.

Also, I use ABS only, and have a glass bed. Here's how I get my prints to stick (works fantastic, easy removal, easy cleanup)

Generic decal vinyl sheet from a supply store or decal supply outlet.

I pre-cut an 8"x8" sheet of generic cheap white vinyl, peel the back, stick it on the clean glass while cool, smoothing bubbles as I go.
Get the nozzle hot (230C for me) get the bed hot (65C for me) then right before I print, I use a cheap spray bottle full of Isopropyl Alchohol, spritz the vinyl, and wipe it with a non-fibrous cloth. Makes the top just that much more tacky.

The prints stick like a champ, then, when the bed is about halfway cooled off, you can literally grab the object and tilt it. The vinyl "tents" off the bed, then peels off the bottom of the print. To clean up, either pull the whole sheet off the bed, or razor knife cut around the used area, and pull the trim off, then position other prints on good surface remaining.

If you have any glue from the vinyl on the bed, acetone takes it off instantly. The rolls are 24" wide x 150 feet, and are around $120 bucks, so roughly 3 cents a print +/-.

That's what works for me!!
Cheers