<p>For a university project, my partner and I need to print the robot Poppy. This is an open source robotic project, <a href="https://www.poppy-project.org/fr/" rel="nofollow noreferrer">poppy-project.org</a>.</p>

<p>We are printing it with a double extruder SpiderBot with PLA and HIPS as support material. Our principal issue is the weakness of the pieces we print.</p>

<p>It prevents us from removing the support material without damaging the piece. We don't have the chemicals to dissolve HIPS.</p>

<p>Have you some advice to make the pieces stronger, or a more gentle method to remove the HIPS?</p>

<p>Thanks for the replies</p>

Why not try using PVA(Polyvinyl alcohol) for support material.
I use it for my support material with PLA, and it dissolves in water.
here is a link to some on Amazon.
https://smile.amazon.com/eSUN-1-75mm-filament-natural-0-5kg/dp/B00MVIQASU/ref=sr_1_3?s=industrial&ie=UTF8&qid=1508539512&sr=1-3&keywords=PVA