Lightspeed install question

trib · #1 02-11-2008, 09:31 AM

For those of you who installed a lightspeed ignition, I'm curious how you routed the input cable from the sensing unit to the computer, in the cockpit. The input cable has a 15-pin connector, with the other end of the cable already soldered to the circuit board to attach to the engine. I'm reluctant to cut a hole in the firewall large enough to pass the connector through and I don't see that the connector pins can be removed as they are already soldered and heat shrinked for insulation. Anyone have a way to minimize the hole in the firewall for the ignition?

Jeff Vaughan · #2 02-11-2008, 09:41 AM

Tim,
I cut a notch down from the firewall scalloped edge to a hole. I inserted a grommet that had been split in half and placed around the wire. I then firesealed the notch really well.
I can send you photos if you are interested.

Mike S · #3 02-11-2008, 09:53 AM

Use these.

http://www.aircraftspruce.com/catalo...allshields.php

You want the split ones, scroll down to pick the correct size.

Guy Prevost · #4 02-11-2008, 10:22 AM

Just cut the connector off and re-solder it on the other side of the firewall. The schematic is in the manual. You've probably wired the rest of your plane by now, so this should be a no-brainer.

G

grover · #5 02-11-2008, 10:36 AM

I cut a big hole for the connector and fabricated a plate to seal things back up. would not do it again. I should have cut the thing off- - and run it through a normal firewall grommet of some sort.

Rick_A · #6 02-11-2008, 11:28 AM

If you take the shell off and work the connector in at an angle the hole is smaller then you might think. I made a mock-up on a piece of scrap to determine the minimum size. The mock-up then worked nicely as a template. Also used the split SS shields.

Mine ended up being about 1.25" x .5".

I believe Klaus specifically states not to un-solder the connector.

AlexPeterson · #7 02-11-2008, 12:09 PM

I'll post a picture of how I made the pass-through later tonight - don't have the picture with me.

f1rocket · #8 02-11-2008, 01:04 PM

If you use the stainless steel firewall wiring pass through tubes, the hole for the larger fitting was large enough to pass the connector through it.

Finley Atherton · #9 02-11-2008, 01:58 PM

Tim,
Have you riveted on the top fwd. skin? If not you can enlarge one of the notches on the edge of the firewall just big enough for the wire and associated bush/grommet, install the wire/bush in the notch then later rivet the the skin to the firewall to hold everything in place. I used a small snap bushing (split), sealed it with proseal and then a layer of firewall sealant over the dried proseal.

Fin
9A Flying

trib · #10 02-11-2008, 02:04 PM

I was thinking about Jeff's approach before I sent the post. A combination of Jeff's and Mike's suggestions might be best. Cut a notch down from the scalloped top of the firewall just large enough for the cable and cover the opening with the split shield. My concern with cutting the firewall from the top was that it might somehow lessen the strength, vs. cutting a hole in the firewall. The top skin would then be forced to carry the entire load. Anyone have any comment on whether this would affect the integrity of the firewall (by cutting a notch vs. a hole)? I'm looking forward to Alex's photos.

thanks all!