Sunday April 3rd, 2005|
Fabricated/Drilled Firewall Parts; Started Dimpling Firewall
Today is Sunday, so after church I came home and started working on the firewall. There are several fabrication tasks that must be done here so I started with those. First I decided to fabricate these two inner brackets. I'm not quite sure what they're for, but I guess I'll figure it out.
This is the stock that you start with. The green sharpie is there for scale so you can see how big this stock is. This stuff it thick and heavy.
Then I measured and marked off the cuts to be made. My band saw actually struggled a bit with this task. I need to get a metal-cutting blade for it. I'm currently using the "general purpose" blade that came with the saw.
Some cutting, filing and polishing and a half-hour later I had these....I think they came out well.
This picture is for a new section of the site I've started, Blood, Sweat and Tears. Anyway, I cut my finger while clecoing parts to the firewall. The firewall will cut you very, very easily!
Next is some angle that goes on the bottom side of the firewall recess. This is the same stock as all the other angle on the firewall, but for some reason this piece must be fabricated (all the others are pre-punched and cut to length). I'm not complaining....I mean...this firewall would be COMPLICATED if it were built from scratch.
And here's the firewall with all the stiffeners clecoed on the the angles I fabricated clecoed on (the angles got match-drilled to the spacers that sits underneath it. I didn't get any pictures...but there are a lot of parts you don't see here. You can see where the stiffener angles go underneath some of the weldments and the fabricated angles. There are spacers under there that provide a solid surface for attachment of the rivets.
Next I needed to fabricate the aux fuel pump firewall doubler. It's very simple, but there are lots of measurements for the holes. This drawing is full scale (as you can see by reading), so why even bother with measuring???
Instead I raided the kitchen pantry for for a piece of wax paper and traced the drawing and holes in order to create a template. Then I taped the drawing onto the stock (after I had cut it to size) and drilled through it. Very easy and fast...
And yet again we're back to the angles I fabricated. Here you see where I backdrilled through the firewall and underlying spacers. This was done but turning the firewall over and drilling from the 'front' of the firewall.
And here's the firewall recess. This part really didn't fit very well at all and required a lot of bending, etc. It still didn't fit very well, but oh well. It fits good enough and I'm sure I can make it fit better whenever it gets installed...which is no time soon.
Then I took everything back apart (a frequent occurance in airplane construction, I've discovered) and deburred the holes. I tried deburring with my hex shaft deburring tool...but there was NO way it was going to cut the stainless. I ended up using a #10 bit and lightly touching the holes while slowly spinning the drill. Worked very well.
Then I stared dimpling the firewall. I decided to dimple all the holes I could with the pneumatic squeezer and I'll go back and get the rest with the c-frame tool. I got tired and decided to go in and watch a little television with Jaime.
Notice the oil spatters on the firewall. It gets spit out by the drill...you can't see it when it's coming out...but you can definately see the after effects!