The best solvent based adhesive for PLA that I've found is
Dichloromethane (AKA methylene chloride). I dissolve PLA filament in it
until I have a thick liquid about the consistency of model cement or
slightly thicker. Apply quickly and don't waste any time assembling the
parts, as the solvent evaporates quickly. Thicker mixtures can be used
to fill in voids (color matched) or build up areas of a print for
finishing by other processes. Due to its super low viscosity, it can be
dribbled into a joint and it wicks in nicely, although not as strong as
the cement method (and it can be messy). Of the many adhesives I've
tried, it creates the very best bond in both adhesion and strength -
much like model cement on polystyrene. Small amounts are available from
a company called Flex-i-file.com. Product is called Plasti-i-Weld. It
costs around $20 on Amazon, however I was able to buy a 500ml bottle of
it for about the same price from a chemical supply place. Use
responsibly in a well ventilated area. FWIW, the MSDS says it's listed
on the iarc & ntp carcinogen list but not by OSHA - (but what isn't?).
On 6/4/2020 4:46 PM, Gregg Eshelman via Emc-users wrote:
For a toothed pulley with a flange on both sides I'd modify the 3D model to
make one flange a separate part, with features on it and the body of the pulley
to align it so that when glued on it will be concentric.
To glue PLA, cyanoacrylate (super glue) works well. So does tetrahydrofuran,
which is in some types of PVC pipe cleaner/primer. The PVC cleaners without THF
won't bond PLA.
The ridged surfaces of FDM prints can be used to make parts that fit together
like they're snap fit. Sizing part fits just right then adjusting extrusion can
make the same models easily drop together, a light press fit that holds but is
separable, or a press fit that's not tight enough to distort but is never
coming apart without something breaking.
On Thursday, June 4, 2020, 3:14:31 PM MDT, Chris Albertson
<[email protected]> wrote:
If you have not enabled supports and are printing an object like a pulley
you WILL have a total mess. 3D printer need a surface and an part of the
part that overhangs with just air onder it will not print well as the hot
plastic will just fall out the nozzle.
But that cross hatch pattern looks like support base so it must be enabled.
You can enable support either "from the baseplate up" or "everywhere"
and you need "everywhere" as at to support the top flange.
Yes, removing support is a PIA because on a pulley the teeth will be
completely 100% inside a ring of support material.
For a beginner you picked a hard project. Most people would start by
printing a one-inch cube or a 1/2 inch flat washer. Pulleys have need of
support and have printed threads for the set screw. Both as
"intermediate level" skills. Horizontal threads always have
support inside that needs pin punch (hex key) to remove
I had to modify the pulley design so it could print with minimal support.
Take all the ridges off the outside, make the flange thicker and radius the
inside of the flange
It is also possible to control the support density and pattern.
Getting all this right nly tak seconds if you know to do it. I start in
Fusion and vew thepart from al sides to see if it can be better designed to
reduce the need for support. Then in Cura I try a few suport techniques
and use preview to see where it is going to go. If it looks bad, then
back to Fusion to change an angle or whatever. This is why engineers
like really fast workstatins as design is iterative.
I'll look at a file if you can e-mail it.
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