Section 25-06: Reaming Question

This page tells you to ream a bunch of holes in the bulkhead with a 0.311 and a 0.375 reamer on the F-01403 and F-01404 bulkheads.

On 25-02 it says: "Always ream using a drill press set on a low speed"

well how is one supposed to use a drill press to ream the holes on 25-06 after the cover ribs (F-01438) and the side angles (F-01403D) in place on the F-01403 bulkhead.

The same thing applies to the F-01404 bulkhead.

Maybe I missed something or they notes are supposed to be reamed with a hand drill.

Any advice would be appreciated. I would prefer to not screw up the bulkheads since they are expensive.

thanks
ken

You can ream with a hand drill, just do it at low speed and keep the reamer as perpendicular to the hole as possible. Use or make a drill guide as to help. I use my Dewalt on low speed and use low pressure when I do this, and use a bit of boelube or equivalent for good measure.

I think that I might have figured out how to do it with a drill press. I will post pictures, if the plan works out.

I also used a hand held Dewalt at low speed with Beolube.

No problems keeping it straight at all. You come in through the large spar piece and you are really only reaming the thin material.

Start with the reamer inserted and lightly push through and keep going all the way through. When the reamer's flutes have exited the hole, unchuck it and pull it the rest of the way through. That way you aren't trying to push and then pull it back out. Very easy and very nice holes.

Same method on the 6 firewall reaming spots. I didn't even try to come up with a method to get that piece on a drill press.

Using a hand drill, I put the stem/shaft of the reamer through the hole from the back, then chuck it into the drill. Using slow speed and a lube oil, it's easy to center the shaft in the hole and draw the reamer bit out of the hole as it cuts.

Stockmanreef said:

This page tells you to ream a bunch of holes in the bulkhead with a 0.311 and a 0.375 reamer on the F-01403 and F-01404 bulkheads.

On 25-02 it says: "Always ream using a drill press set on a low speed"

well how is one supposed to use a drill press to ream the holes on 25-06 after the cover ribs (F-01438) and the side angles (F-01403D) in place on the F-01403 bulkhead.

The same thing applies to the F-01404 bulkhead.

Maybe I missed something or they notes are supposed to be reamed with a hand drill.

Any advice would be appreciated. I would prefer to not screw up the bulkheads since they are expensive.

thanks
ken

Click to expand...

The word "always" will be removed from that statement in a future revision. It does make it a bit confusing.... The intent was to emphasis using a drill press while reaming all of the holes in the next step, not the entire airplane.

On 25-06, the reaming is intended to be done carefully with a hand drill, which is the reason for the caution to "Avoid applying any side load".
The intent is for the reamer to be slipped into the holes in the bars as described in the manual text (and as described by others) so that the reaming process produces a hole in the rib, that is exactly aligned with the hole in the bar.