Tips and Tricks for making the Helmets

[sporgo]

Hey ThreeFN how smooth is the surface of those prints? From what I have seen of 3D prints the surface is kind of textured and it doesn't seem like that would be good for chroming. Do you have a plan for coating or sealing it with something? Just wondering.

[ThreeFN]

Hey ThreeFN how smooth is the surface of those prints? From what I have seen of 3D prints the surface is kind of textured and it doesn't seem like that would be good for chroming. Do you have a plan for coating or sealing it with something? Just wondering.

Not terribly good out of the machine.

As far as sealing goes, they're resin impregnated which adds mostly just strength to them. As my friend tells me, a lot of the times he sand blasts off that top layer to get back to the textured finish. I also think it removes some of the slight 'pooling' that happens as the resin cures, being that we live on a planet with gravity an all.

Each helmet will be requiring a good bit of priming and sanding to improve the finish up to chroming standards. It would be just sanded smooth except there isn't a lot of thickness to the part (about 1.5mm). It's going to require a number (as yet unknown) of layers of primer to help build up and smooth out the exterior.

I too am looking forward to leds, but this print is a lot about the 'fit and finish.' We needed to get the scal right first, then we have to look at where all the parts are going to go. Those will then get the mounts/holes they need, then the real things will be made. At least, that's the hopeful order of operations

[Daftchack]

Hey all...
My father had a great idea on how to best build a helmet.
with the program papakura TeamViewer 3 gets you a form, such as the helmet guy.
1. one tinkers from the paper form (paperkura viewer 3)
2. the completely bonded helmet, sealed it with silicon.
3. Stroking the inside of the helmet with gibs, gibs is waiting until the dried and then pours the helmet with gibs.
4. What to do now is called "vacuum forming".
Instructions can be found here (http://www.youtube.com/watch?v=BVVE5...eature=related)
5. if this is done you have the finished Form.
6. paint

[ThreeFN]

Hey all...
My father had a great idea on how to best build a helmet.
with the program papakura TeamViewer 3 gets you a form, such as the helmet guy.
1. one tinkers from the paper form (paperkura viewer 3)
2. the completely bonded helmet, sealed it with silicon.
3. Stroking the inside of the helmet with gibs, gibs is waiting until the dried and then pours the helmet with gibs.
4. What to do now is called "vacuum forming".
Instructions can be found here (http://www.youtube.com/watch?v=BVVE5...eature=related)
5. if this is done you have the finished Form.
6. paint

You really have no reason to be double posting everything. Stop.

It's not a terrible original idea. That was my plan in 2006 for my helmet, until realizing that it's incredibly hard to get a high definition pull with good surface detail with home hardware. To get that level of detail you need very thin (0.030" or less) plastic, which isn't a good structural support. I think a lot of us have settled on the silicone molding and slush casting technique because it's more forgiving, gives better detail, and doesn't require working at high temperatures. It's also stronger.

I have no idea what this 'gibs' is you speak of, let alone stroking it.

Plus we've all been talking about vac forming on this thread since the dawn of time for the visor of Guy-Man. It's pretty much the only method available to get the complex curvature.

[Teknologic]

hey ThreeFN! can you check my post in this thread and let me know of your opinion?

http://www.thedaftclub.com/showpost....&postcount=149

thanks!

[ThreeFN]

hey ThreeFN! can you check my post in this thread and let me know of your opinion?

http://www.thedaftclub.com/showpost....&postcount=149

thanks!

Um, then why not just post the question here?

Also, I'm failing to see what it is you want me to comment on.

[Teknologic]

Um, then why not just post the question here?

Also, I'm failing to see what it is you want me to comment on.

oh..what i meant is, i went to wal-mart and i saw there are some different type of fiberglass material.

are there any specific fiberglass that i should look out for? what's the cure time for fiberglass? can i just leave it over a day and then get to sanding it?

[ThreeFN]

oh..what i meant is, i went to wal-mart and i saw there are some different type of fiberglass material.

are there any specific fiberglass that i should look out for? what's the cure time for fiberglass? can i just leave it over a day and then get to sanding it?

Really? Walmart? is there anything that place doesn't have now?

What you want is glass fiber cloth, preferably in about 3 oz/sq.ft. or so. You don't want putty or anything like that which has crushed/broken glass fiber added as a filler.

There is also random fiber matting or fiberglass felt, which as the name suggests has randomly arranged fibers unlike a piece of cloth. But it still comes in a packed sheet and that's what you want.

From there, you have a choice of resins. The most common two are polyester and epoxy. Polyester is nasty stuff, reaks, eats at your skin, gives you headaches, or gets you some version of high or stoned, and not in a good way. Some say it makes you angry. Epoxy is much nicer stuff, but still not to be triffled with. Wear at least latex gloves and a paper painters mask, and work in a ventilated area. Make sure to read the directions on mixing as epoxy requires very precise amounts to set properly. Polyester isn't as exactly and just requires a small amount of catalyst to start the reaction. Epoxy on the other hand is a proper two part mixture, so like I said read up on it.

Most resins have a number of times associated with them: pot time, work time, cure time. Sometimes there's also gel time.

Pot time: how long the resin will last in a cup or container. Resins are somewhat exothermic (give off heat) and that heat speeds up the reaction. So, in a pot, more resin means more heat means less time in the pot. Mix in small batches and only make enough for what you need.

Work time: out of the pot, that extra heat can dissipate so you have a bit more time to work with it. Work time is typically a bit optimistic as far as how long before you can brush more on.

Gel time: gel time is when it's too thick to apply with a brush, but is still motile. This typically applies to things that are vacuum bagged, as the vacuum and outside pressure are enough force to move around the resin in the gel state.

Cure time: The total time before the reaction stops. This is typically from about 12 to 24 hours. While a part may be hard after only 2 hours, the epoxy is still curing and it hasn't reached it's structural stength and stiffness yet.

All of the above should be on your resin of choice somewhere on the box or label. Make sure as always to read directions and reread them so you know exactly what you're doing.

As far as application, you want to 'wet' the fiberglass slightly so that it will stick first. I do this on wax paper then very carefully pull the glass off the paper and onto the part. If you put too much resin on the fiber or work it in too much it will stick a lot to the wax paper and be a pain to pull off without coming apart. Now you want to slowly add more resin and work it into the glass as well as onto the part you are using. Less is more here. Apply thinly and spread evenly. You want everything to be 'wet' but not soaking. Rinse repeat.

[Teknologic]

that sounds complicated...... .....ill just find someone to help me do the fiberglassing.... le sigh...


oh what about a "gelcoat"?

[c_ride]

that sounds complicated...... .....ill just find someone to help me do the fiberglassing.... le sigh...


oh what about a "gelcoat"?

oh boy...

3FN - the LED demo is sick! You're definitely going to out-Herod Herod.