The tubes are the same in both shape and length.
They look thinner because the TIE earcap cutouts squish them.
The very back of the faceplate tubes fits into the earcap cutouts and easily pinches them to fit inside. The back of the faceplate tubes are VERY flexible.
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I don't think this is the case at all.
If you look at photos of the original "background" Tie helmet, you will see that the right tube (the tube that looks the longest and thinnest) doesnt seem to have any kind of pressure/stress on the bottom of it from the ear section at all.
The left tube is not even gripped by the ear section.
I want to see a Tie helmet replica with a face that matches the original and that includes the long slim tubes. I want to see THIS helmet match the original better, thats why i'm discussing it with you. I'm not nit-picking, i'm trying to help you make it even better.
I've used a photo from star wars helmets below (jez, if you want me to remove it just say), as i can't seem to find my CD at the moment.
This is a photo that shows what i mean about the tubes. If as you say is just an assembly thing, can you assemble yours so your tubes look the same.
The tubes on the ANH face that was molded were cut very short, so they would have to be made longer for a start. Maybe you have made them longer? if so, can you have more of them showing?
At the end of the day, the Tie helmets use a hero face and no hero face has been molded as far as i know. So a replica hero face will never be perfect IMO, but as you have a stunt mold there you can make duplicates of and you seem to have a lot of time to work on these things, i am hoping you can continue to improve the replica hero face.
Keith.
edited as i mixed up the left tube from the right tube.