need some info on trimming my ata lid

[Hannifan32]

So I am getting ready to start trimming my first trooper lid and ran into a speed bump. After going through all the tutorials that I could find I came to this. I copied a pictures from one of the tuturial threads on here for reference but am I supposed to free hand draw that line where the ears end up going? im just worried its not going to be even if i do it by hand. I just get the feeling I am supposed to trace it on the lid. The picture below shows the line I am talking about its the pencil drawn line for a guide to trim.

 

 

 

 

 

 

 

 

[Coastertk[TK]]

That's right. Freehand draw your line following the mold lines. Your ears will cover everything nicely.

[Koyaanisqatsi]

I find it helps to find a strong light source, get it in front of me, and hold the piece at an angle - move it around until you can really see the surface details the best. Then draw along the line between 'flat' and 'not flat' (you'll see what I mean if you haven't already). That's what I did with my ATA bucket.

 

Not sure if it's necessary, but I used a hole punch in the top corner to help avoid tearing...

 

 

You can follow my line if you like - it worked for me.

 

This is my first helmet/build so I'm no expert, but it seems like you want to leave more rather than less (don't trim too much). When attached to the face and with the ears are on, no one will see this part, and if you trim too much you can't connect the face to the cap & back as easily - you need to make sure you have room for all three ear screws to go through.

[justjoseph63[Staff]]

Great advice from Ken, Sam.  Drilling the hole at the seams will make it much less likely for the ABS to split or crack there.  And, like he also stated, leave more rather than less.  You can always remove more later!