I have a AFS 3500 and recently I had to remove the EFIS. To be able to do that, I first had to remove the aft-mounted connectors.
As you all know, it's very tight beetween the panel and the sub-panel, so getting a flathead screwdriver in position on the small flathead screws on the connectors, is VERY hard. And it's even harder to actually start turning the screwdriver so the screw can be loosened. (or tightened for that matter)
After 30 mins, standing on my knees on the seat, partly bent over the panel, under the opened canopy, I finally where able to loosen the screws on all three connectors (that's six screws total) and could take out the EFIS.
Already I began to fear the job of installing it again....
I mentioned this problem to one of the guys on my building team the next day, and this guys is a real problem-solver:
On our next "RV-building day" (we build three days a week), he brought a tool with him and after alittle tinkering, he had made a GREAT tool for those ...#¤%£$@... small flathead tools on the EFIS-connectors.
He used it in the RF-5A's in Norwegian Airforce where he used to be a camera-technican: that tool where used to set the shutter on the camera's after the cameras had been to service. (The RF-5A's had four 90mm Hasselblad cameras mounted inside the nose)
It was very important that the shutters where set with the correct number of turns, so the norwegian technicans invented the tool theirselves:
they took a camera pics-counter from the previous recce-plane in the Norwegain AF; the RF-84F Thunderflash.
Then they made a special screwdriver for flathead-screws and mounted the counter on the screwdriver and then they could set the shutters on the RF-5A's 100% correct.
As you can see on the pic below, the screwdriver itselves, is slightly recessed: it's inside a small tube.
The ID of this tube is the same as the screws on the camerashutters, thus giving a trouble-free operation of the screwdriver.
What he did was this:
Shorten the camera-tool.
It had to be short enough so it could be placed on the connector-screws when the EFIS was installed in the panel.
The screwdriver-tip was just alittle to big for the connector-screws, so he had to make slightly smaller.
Then the tool could be placed on the connector screws:
If any of you would be interested of making a tool like this, I think you could make it with what you have in your shop: a small screwdriver and a piece of tubing. (for example a piece of leftover fuelvent-line)
To end with a little history here:
that tool used on the RV-5A's on the Norwegain AF is now back in use on another airplane, after spending some 25+ years in a toolbox in a basement...
Also; it's 100% sure that I've flown RF-5A's with cameras which have been adjusted with the VERY SAME tool.... because I was stationed at the same AF base (Rygge AFB) "way back when".....
It's fun to think about that I didn't have a clue back then, that I one day would fly another airplane which had used the same tool.... and this time the plane wasn't made by Northrop, but made by some friends and my self in a garage....
We didn't need the pic-counter from the RF-84F ofcourse, but I didn't want to throw that thing away, so the old counter now sits on my desk at home, reminding me not to throw away any old airplane-parts, because sooner or later, you'll get the use for them....