|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

11-29-2014, 07:37 AM
|
 |
been here awhile
|
|
Join Date: Dec 2004
Location: North Alabama
Posts: 4,301
|
|
But not on the control stick!
Even though I like the starter push button arrangement, I have seen a few cases where the starter button is located on the control stick. In my opinion, this is a very bad idea. I think it is much better for the button to be located out of the usual flow of motions so it takes a deliberate action to engage it. On my panel it is located at the upper left corner away from any other switches. I also have a 'starter light' to indicate a stuck starter contactor.
|

11-29-2014, 08:06 AM
|
 |
|
|
Join Date: Jul 2009
Location: Mojave
Posts: 4,652
|
|
A starter button is going on the stick on my Rocket so that I can keep the stick fully back while simultaneously manipulating the throttle/mixture/boost pump during a hot start. On an A model, this is not such a big deal, but a high powered, nose heavy tail dragger requires you to be on your toes, so to speak.
Agreed that the button should not be "casually" accessed, but I plan on installing an arming switch on the panel along with an associated warning light. This will require two separate acts to engage the starter (three, if the switch is guarded). It adds complication, but should ease the cockpit gymnastics.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.
Michael Robinson
______________
Harmon Rocket II -SDS EFI
RV-8 - SDS CPI
1940 Taylorcraft BL-65
1984 L39C
|

11-29-2014, 09:28 AM
|
|
|
|
Join Date: Nov 2013
Location: Annapolis MD
Posts: 457
|
|
Quote:
Originally Posted by Kahuna
Slicks use P-lead and switch to ground.
Starter relay uses +12 to switch relay contactor.
So on each of your toggles, one side of the switch to ground, the other side of the switch to the P-lead. Confirm with ohm meter that each switch is switching to ground with the p-lead OFF the mag. When grounded, the mag will not fire. You will get continuity through the mag on the P-lead which is why you test it with it off the mag.
On starter switch, one side of switch hot +12 to your bus fused. The other side of the switch to the starter relay +12 input to engage coil for starter relay.
|
The current setup has what appears to be a shielded wire, with the center conductor wired to the P-lead, and the shield conductor wired to the magneto GND screw. On the key switch side, both conductors are wired to tabs on the switch. I am still a bit unclear about the wiring, so bear with me...
To wire the mag switch, I need to connect one side of the switch to the P-lead post, and the other side to the airframe ground? To enable the mag, the circuit should be open, i.e. the switch is in the off position (not connecting to ground,) correct? To disable the mag, the switch is closed ("on" position,) connecting the P-lead to airframe ground, correct?
What is the function of the shield conductor in my current setup? Is it actually shielding potential RF noise? Could / should I use the shield conductor as the ground side of the switch, or should I extend the shield conductor to the FOT behind the panel?
As for the starter switch, I was going to use a button on the stick, but since I'm installing electric roll trim, I'll need that button for another function. The starter interlocking will be handled by VP-X.
Thanks for everyone's input, BTW!
__________________
CA
2000 RV-8A | O-360, SDS CPI, FP, G3X Touch, VP-X, EarthX | Eastern Shore | KESN
Last edited by maus92 : 11-29-2014 at 09:31 AM.
|

11-29-2014, 10:07 AM
|
 |
|
|
Join Date: May 2012
Location: Ga
Posts: 662
|
|
Start switch
I converted my -6 from a push button start switch to a traditional key start. I didn't want that prop spinning because a child or passenger or whomever decided to push the button or lean on it or whatever. My -3 had the push button also and I leaned on it accidentally once working in that cramped cockpit. Thankfully the visitors that day had already left.
Cj
Quote:
Originally Posted by vic syracuse
This is why I even hesitate to try to help any more on this site. There always seems to be a smart answer. All you see is annoyance to other pilots from being blinded by your strobes??? Give me a break. Most checklists actually recommend that the anti-collision lights be on for safety prior to starting. On busy General Aviation ramps with a mix of corporate and GA traffic where there are lots of loading/unloading of passengers and ramp crew around, I find it imperative to get the strobes on, look around and yell very loudly. Yes it is a safety factor. Strobes on do tend to get everyone' attention. If it's at night I pay attention and delay a start so as to not inconvenience someone, and I will in fact turn the strobes off after start and leave the Nav lights on if it is distracting.
As for security, many years ago I had a friend who lost his homebuilt on a ramp at a fly in due to a drunk bystander getting in and starting it up and almost killing people before the aircraft came to a stop. So it's always been on my mind and I try to add a second level of security to the START function.
As for the engines windmilling, it's true for our typical fixed pitch and even constant speed propellers without a feathering function. But not so with the Rotax. They WILL come to a complete stop in flight if there is fuel starvation, and do require starter engagement to get going again. I test this function on every Rotax-equipped airplane I test fly.
|
__________________
Craig
RV-3 Sold
RV-4 Sold
RV-6a Sold
RV-9 IO-360 CS, Built and Flying
Aerostar 600A, Family Hotrod
|

11-29-2014, 10:22 AM
|
 |
Senior Curmudgeon
|
|
Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 15,420
|
|
Quote:
Originally Posted by maus92
To wire the mag switch, I need to connect one side of the switch to the P-lead post, and the other side to the airframe ground? To enable the mag, the circuit should be open, i.e. the switch is in the off position (not connecting to ground,) correct? To disable the mag, the switch is closed ("on" position,) connecting the P-lead to airframe ground, correct?
|
Yes, the switch off/open is the mag enabled position.
While using a local airframe ground will work, but the usual way is to ground back to the mag with the shield, as you mention below.
Quote:
Originally Posted by maus92
What is the function of the shield conductor in my current setup? Is it actually shielding potential RF noise? Could / should I use the shield conductor as the ground side of the switch, or should I extend the shield conductor to the FOT behind the panel?
|
I would not attach the shield to the FOT (forest of tabs)
__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011 
Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
|

11-29-2014, 10:28 AM
|
|
|
|
Join Date: Nov 2013
Location: Annapolis MD
Posts: 457
|
|
Quote:
Originally Posted by Mike S
Yes, the switch off/open is the mag enabled position.
While using a local airframe ground will work, but the usual way is to ground back to the mag with the shield, as you mention below.
I would not attach the shield to the FOT (forest of tabs)
|
Thank you! I think I've got it!
C.
__________________
CA
2000 RV-8A | O-360, SDS CPI, FP, G3X Touch, VP-X, EarthX | Eastern Shore | KESN
|

11-29-2014, 11:29 AM
|
|
|
|
Join Date: Jan 2005
Location: Houston, TX
Posts: 868
|
|
Quote:
Originally Posted by vic syracuse
This is why I even hesitate to try to help any more on this site. There always seems to be a smart answer.
|
Seriously, I didn't mean to sound like a smart-a$$, but was just trying to wrap my head around how keyed start switches and starter thru the strobes add safety and security. Both of the posts I quoted mentioned those two items for safety and security, but then there was no explanation or rationale behind it to explain how, in your opinion, these things enhance safety and security.
Quote:
Originally Posted by vic syracuse
All you see is annoyance to other pilots from being blinded by your strobes???
|
Well... yes. In my opinion, another ships bright white wingtip strobes on a busy ramp are blinding, annoying, affects my vision, less safe. In your opinion, it's safer for people on the ramp. Everyone is allowed their opinion, so agree to disagree I guess.
I know when you build an airplane you can wire it however you like and that's part of the beauty of experimental aviation, but, I gotta say that I've never flown anything that had the starter wired through the strobes. If I bought a plane wired like that, it'd be the first thing on my list to undo. I'm thinking if you want strobes on for start, turn on the strobes separately. Again, just my opinion. As far as security for drunks and kids, I close the canopy to keep people out, or if I let kids in the seat, I watch them closely.
Fair enough?
__________________
John Bixby
RV-8 QB sn 82030 - 1750 hrs
O-360-A1D/CS/Pmags
Houston, TX
Last edited by jbDC9 : 11-29-2014 at 01:20 PM.
Reason: one little oops...
|

11-29-2014, 11:47 AM
|
 |
|
|
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
|
|
"...I converted my -6 from a push button start switch to a traditional key start. I didn't want that prop spinning because a child or passenger or whomever decided to push the button or lean on it or whatever..."
I thought of that, but it does take two bad actions to get the prop to spin, Master On and Press Starter button.
I think a modern kid would just as likely turn a key switch as press a button... 
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
|

11-29-2014, 01:43 PM
|
|
|
|
Join Date: Mar 2007
Location: Sonoma County
Posts: 3,821
|
|
Quote:
Originally Posted by az_gila
"...I converted my -6 from a push button start switch to a traditional key start. I didn't want that prop spinning because a child or passenger or whomever decided to push the button or lean on it or whatever..."
I thought of that, but it does take two bad actions to get the prop to spin, Master On and Press Starter button.
I think a modern kid would just as likely turn a key switch as press a button...
|
Being a smart a$$ here..... I just have to say that my last certified A/C, a Warrior did come with a removable key in the starter switch.
I hate key switches..... they are too complicated for what have to do. And as they wear out, they can become dangerous and fail in the HOT position.
If you are going to display your plane where the switches might get fiddled with, then make a lockable cover to protect important switches.
__________________
VAF #897 Warren Moretti
2019 =VAF= Dues PAID
|

11-29-2014, 02:04 PM
|
|
|
|
Join Date: Apr 2008
Location: Lake Havasu City AZ
Posts: 2,393
|
|
Switch
General opinion from other sources agrees with what I have always believed: rotating beacon, if installed, on for engine start. Strobe lights on when cleared for takeoff, off when clearing runway after landing.
If you operate stobe lights, especially at night, for start and taxi, be prepared for a LOT of flak from those who know better.
Regarding mag grounding, I have not seen mention that if you have one impulse and one non impulse mag, the non impulse MUST be off for start. This happens automatically with properly wired key switch. With toggles if you forget this you may very well trash your starter.
Mag wire shielding has been discussed many times on this forum. Only the mag end of shielding should be grounded, the switch end should be open.
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 08:11 AM.
|