Bear with me on this one, I have a house full of fumes from a fibre glass resin kit so my head is feeling the effects.
Searching through all the posts on these forums there seems to be lack of tutorials for the actual building and modification of old robots so I wanted to ask how you guys do it?
My way may be wrong, it may not be the best way, I don't know, I just know it as my way, which is basically using the fibre glass resin kits (with and without the fibre glass matting) to initially fill in holes, join things where glue isn't good enough, etc.
I found that if you tape up the one side of a hole using ordinary clear tape you get a nice smooth finish when filled from the other side.
Also, using Pepakura (used for making 3d models out of paper but can be used for anything), printing out the plans for a bracket or whatever, sticking it together and painting it with resin you get a nice, quick, cheap (but smelly) way of building almost anything you need.
But what are your methods? What materials do you use?
Hey Rich,
I'm not comfortable with fibreglass yet. I've got some, but it kinda scares me because I don't know what I'm doing. Right now, I haven't really got any excess holes, so haven't got round to filling anything yet, but I also have some filler I need to practise with aswell.
For the most part, so far I have been using 3mm perspex and cutting it to the required shape and epoxy / hot gluing it in to place. For some parts I have made silicone moulds and others I have used Google Sketchup to design them and have had them 3d printed. I do like your idea of using Pepakura though. Really clever.
I know the way I'm working though isn't the best, I've just still got lots to learn.
"Experiment 333" is my first from scratch build so I am going to use what ever I can get my hands on.
I like steel mostly but that adds up to fast. So I'll start with wood base and aluminum structure. I am a nuts and bolts kind of guy so mount stuff will be on lexan and bolted down. Most of my electrical is from an industrial supplier, since I'm an electrician i am used to using that stuff. :D
Pepakura is awesome! I haven't seen that before. Thank you for sharing :)
I have worked with fiberglass in the past. It's actually a two stage process. You can attempt to skip the moulding stage by spending a million hours sanding and body-filling. But I suggest taking the extra time to make a mould.
I would use a peice of styrofoam block a craft store and carve it into the shape i wanted.
Spray 3M adhesive on the styrofoam and wrap it in saranwrap
cut fiberglass sheets into small squares
dip fiberglass into resin/harder mixture and lay on styrofoam block
once it hardens, you have a mould.
And to use your mould, you do the reverse process.. You will need to coat the mould with a release agent. I have used Vaseline in the past, but it is really difficult to get off - specifically if you are painting it may cause issues. Where you buy the fiberglass from, you can get Release Agents. I found this link that helps: http://www.fibreglast.com/category/Mold_Releases
hope that helps explain a bit :)
For some small peices in my Omnibot 2000, i used this: http://www.robotroom.com/Prototype-Plastic.html That stuff is pretty neat! You can see it in the video here: https://synthiam.com/Robots/Omnibot-2000
:)
Fibre glass is best used where it isn't on show, like for holding in hidden servos etc. mainly because of how hard it is to refine once it's cured (basically it is the toughest stuff I've ever had to sand down!). But it can also work great for filling big holes if you use it without the matting. And it's paintable, waterproof and can handle temperatures of up to 80 degrees C.
I haven't used Pepakura for the bot yet but have used in the past for other things. It has the potential to be an awesome tool. I've seen it used to build full size Ironman, master chief etc. costumes with amazing success (in fact, a project of mine in the planning is a full size ironman robot... way way down the line though!). But as @DJ said, take the time to mould, fibreglass is tough and takes a very very long time to sand.
@matt I think we all are still learning, aren't we? I know I am.
Just found this stuff on line. It looks like it could be very handy for making PVC parts. Check it out!
Closed Cell PVC Sintra
link
link
Don't forget to USE a Respirator when sanding fiberglass. The dust will get into your lungs and NEVER go away. This can kill you over time.
Dave Schulpius
most i like using light aluminium for inside my robots as i can and attach plastic to the sides,make it easy to mount boards ,sensors and more and if something breaks down easy to remove and repair i used fiberglass in the past,one time i made a small boat (canoe) and shell for a dune buggy about 8 to 9 years ago,very hard and painful work making the mold first and then using fiberglass plus cloth,and then sand and sand for weeks,and you need a good respirator and lots of sandpaper and do it outside,dust get everywhere,plus should have long clothes my favorate is always aluminum ,can cut to any shape needed,super strong and light weight and easy to use,and if need plastic on sides thin coat of liquid resin or plastics
other way to make plastic pieces or plastic molds is thermoforming,all you need is a oven and vacuum setup ,like a shop vac,i have done it before and fairly easy at my work i use a type of machine like that to make plastic cases and in house tester bodies