Enlarge holes in "One hole" eyeball bulkhead gromets?

[dwilson]

Bought the "One hole" firewall gromets from Van's.

Hole for the cable is .125. Cable is bigger than that.

How big do I drill the hole in the gromet?
1) So the cable moves easily through the hole,
OR
2) Undersized so it clamps the cable in place.

If 2 then how much undersized??

Thanks,
Duane

[sf3543]

I drilled mine so that there was a slight grab on the cable, but not too much.
Seems to be ok, but I haven't flown yet so I can't give long term results.

[Ironflight]

Just like above, I drilled mine with a slight compression to hold the cable, and it is working just fine at 90 hours. In my opinion, you want it to clamp the cable at the firewall.

Paul