Albuquerque Storm Trooper Helmet Mold

[Elumusic[TK]]

Weather conditions were great yesterday after work so I did a pull with the HIPS.  And now I need some help troubleshooting the issues.  As you can see by the photos there are really thin spots in the HIPS.  Look at the last picture.  This is a picture of the inside of the face with light shining through the thin spots.  So my questions are was it too hot? not hot enough?  I'm guessing too hot.  And the last issue was the teeth detail.  It didn't pull into the teeth all the way.  That could be a vacuum issue and I need to make the holes a little bigger?  And I think the draw on the mold was too deep meaning maybe I should cut about two inches off the bottom of the mold so I can have more material available.  What do you guys think??

 

 

And here is the helmet portion.  The draw over the helmet was good, but thin in the front and so thin on the one side toward the picture that it blew out and lost the vacuum.  And the last question....is the Hips plastic really that lumpy?  My molds are smooth but the plastic looks a little bumpy after it comes off the mold.

 

[walt[501st]]

Pic of the mold for the face so i can point you in the right direction. .the helmet you need to change the position of how it sits

..it has to lay down more

[walt[501st]]

And depending on the thickness of the hips..you will have thin spots ...do you have run offs on the molds...not a bad start...and welcome to vacuum forming

[Elumusic[TK]]

And depending on the thickness of the hips..you will have thin spots ...do you have run offs on the molds...not a bad start...and welcome to vacuum forming

What is a run off?  The HIPS is .093.  Oh...and the face locked onto the mold.  I think I let it cool too long before pulling it off.  Here is the face mold.

 

 

[walt[501st]]

I would make a logner slop more

[Elumusic[TK]]

I would make a logner slop more

Well by slop I assume you mean slope and logner....I'm not sure.  lol.  I think you are saying that the chin/mic tip areas should point straight up giving a steeper slope to the mold.  I'm guessing about a 45 degree angle along the nose?  That will cause me to have to cut the bottom giving less surface/height to the mold.  Sounds like a plan to me.  And then the helmet I was going to make slope at about 45 degrees as well.

[usaeatt2]

Can I buy a vowel?  I'm guessing longer slope or slope more?

 

I think the idea is to angle the form so one side isn't pulling longer than the other.  I'm guessing you would want the angle so the front of the face is roughly parallel to the plastic - seems like that would pull more evenly.  For the back, I know you want the front angled down - I think this just decreases the depth of the overall pull, while causing the plastic to "drape" over the back while pulling more in the front.  Doesn't matter if the front gets thin because you're trimming most of it off anyway.

 

Seems like you're on the right path - just have to fine tune everything...form angles, temperature, how long to wait before pulling the plastic from the form, etc.  I've never done any thermoforming, but it sure is interesting and I've really enjoyed following this thread.  Good luck, Jeff!!!

[Elumusic[TK]]

Can I buy a vowel?  I'm guessing longer slope or slope more?

 

I think the idea is to angle the form so one side isn't pulling longer than the other.  I'm guessing you would want the angle so the front of the face is roughly parallel to the plastic - seems like that would pull more evenly.  For the back, I know you want the front angled down - I think this just decreases the depth of the overall pull, while causing the plastic to "drape" over the back while pulling more in the front.  Doesn't matter if the front gets thin because you're trimming most of it off anyway.

 

Seems like you're on the right path - just have to fine tune everything...form angles, temperature, how long to wait before pulling the plastic from the form, etc.  I've never done any thermoforming, but it sure is interesting and I've really enjoyed following this thread.  Good luck, Jeff!!!

I failed to recognize that the surface of the plastic needs to meet the object parallel to each other.  That will definitely change the angle of the mold.  

[usaeatt2]

I'm GUESSING - I've never done it.  I would definitely ask Walt to clarify before proceeding.

[walt[501st]]

Yes. .the higher the mold the longer you want a slop so the plastic won't pull to thin...As for the face braking you may need compressed air to remove...that and just trial and error. ..and this is why I said start with cheep hips. .it will take some time to get the technic down but I can help with the molds. .let me see if I have a pic with my kids lid helmet

[TD369]

Yea, I nice slope towards the bottom of the mold is always a good idea, plus make sure the bottom of your mold is as flat as possible. Both of these things makes de-molding after your pull much easier...

[Elumusic[TK]]

Here is my progress for the weekend.  I've cut down the face and helmet portions of the mold.  I took just over two inches off the bottom of the face mold and increased the angle just a little.  

 

Face before:

 

Face After: 

 

 

Helmet Before:

 

 

Helmet After:

 

 

I'm hoping to try my luck again in the next day or two depending on my schedule.

[TK bondservnt[501st]]

 

 

take note of the angle the slope on the front and the air holes  inside the detail parts

f you let the plastic cool completely you can cut the helmet off the mold.

then blow air backwards though the plastic.

 

if you don't allow it to cool completely it will warp

see how the front of the mold has a slope on the right?  this is to get the proper layoff to reduce webbing.

 

good work so far!

 

also take note the holes in the face, and the front layoff block

Edited June 16, 2014 by TK Bondservnt 2392

[walt[501st]]

Good pics vern....you want to avoid the long pulls down

[Elumusic[TK]]

Here is what I did last night.  The pulls came out pretty good.  I have decent detail, but the detail is still not getting pulled into the teeth and inside corners of the eyes.  I am pretty sure it's because the plastic is not getting soft enough to go into the smaller places.  And to add to this I added additional holes in between the teeth to try to get more suction, but it just won't do it.  I have a five holes in each tooth and still no detail.  This is why I am thinking the plastic is not getting soft enough.

 

My next problem to solve will be the depth of the oven.  the oven is only about 6" deep before the heating coils are on the plastic.  I'm certain the depth needs to be much greater to allow the plastic to sag further down.  So I will be re-doing the hardi-backer sides to get a deeper sag.  At that point I am fairly certain this will be the final tweak.  

 

 

Edited June 17, 2014 by Elumusic

[walt[501st]]

if it helps..i have 1 big hole in each tooth....looks good so far 

[Elumusic[TK]]

if it helps..i have 1 big hole in each tooth....looks good so far 

That totally helps.  

[usaeatt2]

SWEET!  I know there's frustration involved, but it is RAD watching the evolution of these pulls.  Keep up the good work, Jeff!

[Elumusic[TK]]

SWEET!  I know there's frustration involved, but it is RAD watching the evolution of these pulls.  Keep up the good work, Jeff!

You said it man...lol.  

[TK bondservnt[501st]]

some people run a bamboo stick ( think BBQ kabob stick) around the hole area to push the plastic down more into the frown.

[Elumusic[TK]]

I did a few more modifications to the face.  I drilled a crap ton of holes in the problem areas and i noticed after I cut the eyes on the test pull that they were not close enough together.  I also modified the eyes on the mold so someone can actually see out of the helmet.  ha!  I'm also making the oven a little deeper this weekend, probably about 4 inches.  Thanks for all the help guys. This has turned into a chore.  And I got some HIPS coming in today for a decent price.  Round 3 this weekend?

[walt[501st]]

also rember one thing....hips will sag a lot more the abs...try to lift away the hips befor you start revamping your oven

[haui[TK]]

Great work.

At the moment I'm collecting informations cause i'm thinking about building my own armor.

This is one if the best posts i found, thanx.

[Elumusic[TK]]

Update...This coming Friday I will be revamping the oven to allow a deeper sag in the plastic.  And then I will do a new pull.  I am expecting 100% success in the helmets....but then again crap happens.

[TK bondservnt[501st]]

how about putting the oven on top of the plastic and allow it to sag as much as you need? add a blower to your table to allow stretching the plastix

also you should ask troopermaster about pre-heating the abs at a lower temp prior to bringing it to a forming temp

 

last time I spoke with TM paul he mentioned a pre heat stage and then a forming stage for ABS