Frustrated - Need Advice

[scorch15]

This is my 2nd attempt at this Half Life HEV Chest Piece.

I have made two of these and am stuck at this exact spot...I have learned a painful lesson each time.

Where my finger is pointing on the first picture required me to use a lot of force to hold together while the glue hardened.

The part to the right of where my finger is pointing wants to flap outward. I wanted to cut near this seam so I can anchor a velcro strap inside, but my gut says it will flap out and contort again...am I right in thinking that would be a bad idea to put the seam near here? I am thinking of cutting much farther behind where it doesn't flap out...using a hot knife then putting velcro on the inside. This problem is on both sides, but worse on one side. Can't do relief cuts inside to prevent the contortion at this point.

Any thoughts would be appreciated.

Took about 3 months to make two of these and have already started prepping for my 3rd build of this = ( this next time I'm going to work with larger pieces by joining/disjoining in pep software.

Thank you.

 

[BuildsByBaz]

Use tin snips and cut a couple of pieces of sheet metal to fit behind the two edges. Glue them as a layer behind. They will hold the shape for you.

Baz.

 

[FalseShepherd]

I'm not a foamsmith, but I was gonna suggest something very similar to Sandbagger. Seeing that it's in an armpit (?) you could probably get away with the same idea on the outside if you think the recoil force would pull the foam away from the metal. You could also always Pep the chest piece. It seems the amount of time you have spent making two foams, you could have pepd it and it would be done. If you know that the foam ones fit then you already have the scaling done.

 

[scorch15]

Use tin snips and cut a couple of pieces of sheet metal to fit behind the two edges. Glue them as a layer behind. They will hold the shape for you.

Baz.

Thank you for this - this sounds like a good idea. Is there a particular kind to look for that would do the trick? I am searching sheet metal online. I think I did something like this one time but what I got was too thick once it arrived.

 

[scorch15]

I'm not a foamsmith, but I was gonna suggest something very similar to Sandbagger. Seeing that it's in an armpit (?) you could probably get away with the same idea on the outside if you think the recoil force would pull the foam away from the metal. You could also always Pep the chest piece. It seems the amount of time you have spent making two foams, you could have pepd it and it would be done. If you know that the foam ones fit then you already have the scaling done.

When you say pep the chest piece do you mean by making it with paper? Thank you for your help!

 

[FalseShepherd]

When you say pep the chest piece do you mean by making it with paper? Thank you for your help!

yeah. doing the cardstock model then layering on resin, fiberglass, Bondo to harden it. Its a lot of work, but working with paper, you generally avoid problems like foam that doesn't want to cooperate. The piece itself doesn't look too terribly complicated and it probably wouldn't be that hard to do in cardstock. You would have to buy all the resin and junk which can get pricey though. Certainly more expensive than just attaching a little sheet metal to the inside to shore up the connection.

The other thing I have been thinking about with chest pieces is seam placement. One logical place is under the arm like that but it does require you to split any pieces that span from the chest to the back. If you instead made those pieces whole and put the seam where they connected on either the front or the back, you might be able to avoid some of the "flapping" and the seam would be where a seam already should be- the connection between two pieces.