Installing magnetic pickup in Slick mag

maus92 · #1 01-22-2015, 05:53 PM

Anybody have any tips on installing the tach magnetic pickup on an already installed / flying RV-8? The pickup has the factory 6' cable permanently attached, and it's turning out to be a PITA to try to screw the thing into the housing (the cable really, really gets in the way.... is it possible just to cut the cable short and re-splice it, or does that cause RFI, reliability or other problems?

Larco · #2 01-22-2015, 06:33 PM

Not sure what tach sensor has a 6 foot cable but I would remove the mag, install the sensor and reinstall the mag. If I interpreted your question correctly. Larry

Canadian_JOY · #3 01-22-2015, 08:38 PM

If this is something like the AFS tach sensor, their recommendation is to install it on the right mag. That chunk of wire can be bundled up into a pretty small coil held together with zip ties temporarily. This will make it much easier to thread into the magneto housing.

If this doesn't work for you, the wire is Mil-C-27500 twisted, shielded wire. You can connectorize it close to the sensor if you wish, ensuring the shield passes through the connector to provide continuity of the shield all the way back to the brain box.

PCHunt · #4 01-23-2015, 04:30 AM

"Connectorize" ?? I know what you mean, but is that really a word??

RV6_flyer · #5 01-23-2015, 07:32 AM

Quote:

Originally Posted by PCHunt

"Connectorize" ?? I know what you mean, but is that really a word??

Yes there is such a word. See it here.

I used a UMA 1A9-1 RPM Sensor on a LASAR mag when I replaced my microMonitor with a Dynon EMS D10.

I "connectorized" it before installing it in the mag that was already installed on the airplane. I forget the length but guess it was between 6" and 12". I used a nylon Molex 3 contact connector that supplied 12V to the RED wire, Ground to the BLACK wire, and the WHITE wire went to contact 32 on the Dynon EMS D10. This setup has been flying for 2.5 years without issue.

maus92 · #6 01-23-2015, 08:02 AM

Quote:

Originally Posted by Canadian_JOY

If this is something like the AFS tach sensor, their recommendation is to install it on the right mag. That chunk of wire can be bundled up into a pretty small coil held together with zip ties temporarily. This will make it much easier to thread into the magneto housing.

If this doesn't work for you, the wire is Mil-C-27500 twisted, shielded wire. You can connectorize it close to the sensor if you wish, ensuring the shield passes through the connector to provide continuity of the shield all the way back to the brain box.

The docs Garmin doc for the UMA sensor recommends that the non-impulse mag should be used. Not sure which one is the non-impulse - how can you tell? The left sided has better clearance that the right side, that's why I chose that particular one.

As far as bundling up the wire, it is 6 feet long, and there really is very little clearance even when wadded up tightly.. As you can tell, I'm trying to avoid pulling a mag - mainly because I've never done it, and I'm not sure of the implications of doing so. I'm reading that there shouldn't be a problem shortening the cable as long as the shield connections is passed through the connector.

db1yg · #7 01-23-2015, 08:10 AM

I have an impulse mag (Slick 4371) on the left and a LS Hall effect sensor on the right. I cut the AFS rpm sensor (think I talked with Rob about it first--many yrs ago) within 6 inches of the sensor and "connectorized" it! Makes it much easier to remove the mag every time it fails---which has been twice in 500 hrs--not once for the LS!

Hope this helps.

Cheers,

db

aerhed · #8 01-23-2015, 08:39 AM

The left mag is "always" the impulse mag. It has a longer shaft and has a spacer between it and the accessory case. You MUST check the timing on a new engine so you may as well pull it off and learn what you're doing.

maus92 · #9 01-23-2015, 09:30 AM

Quote:

Originally Posted by aerhed

The left mag is "always" the impulse mag. It has a longer shaft and has a spacer between it and the accessory case. You MUST check the timing on a new engine so you may as well pull it off and learn what you're doing.

Yea, this isn't a new engine - it's a flying plane that is getting a new EFIS though... I guess I'll have to bite the bullet and pull the right mag. Or I could buy a compatible mechanical tach sensor (the old Westech RPM gauge used the tachometer port.)

Canadian_JOY · #10 01-23-2015, 10:18 AM

maus - you can get to the right hand mag with some patience. Having the proper tools helps (stubby tools so you can work with your hands close-in to the mag). Cut the wire on the sender and install a connector - it really isn't a big deal. If you feel you aren't up to the task of installing a multi-pin connector you can use "knife" style crimp-on terminals, then insulate with heat shrink over each connection. Tie the heat shrink in place with lacing cord or shrink it in place.

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