Van's Air Force
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Toggle Switches for Mags
- Thread starter vonjet
- Start date
Look to GRANGER for switches. MAGS.... 4X849 NEED 2. STARTER BUTTON.... 2X894 NEED 1
the_other_dougreeves
Well Known Member
I've always thought if you went that route, you'd want either locking toggles (Stein has em, not cheap) or a flip-up toggle guard (cheaper, clunky, looks cool to some folks). Either way, make sure it's designed so that it's hard to turn off inadvertantly.
TODR
TODR
Rick_A
Well Known Member
Switch guards
Good point on the switch guards. I used the space shuttle guards from Perihelion Designs.
http://www.periheliondesign.com/
You can put these on every other switch, so 2 guards can protect 3 switches.
Good point on the switch guards. I used the space shuttle guards from Perihelion Designs.
http://www.periheliondesign.com/
You can put these on every other switch, so 2 guards can protect 3 switches.
Remember for a Mag, the switch will need to be mounted upside down....as "on" is actually closing the contacts of the switch, and therefore grounding the mag - so you need to mount them upside down. I've seen more than one guy who hooked them up only to get shocked or surprised with the mag (having left the switch in the down position thinking it was off, but instead was "hot"). We've used everything from standard toggles, locking toggles and also the switch guards from Eric Jones.
My 2 cents as usual.
Cheers,
Stein
My 2 cents as usual.
Cheers,
Stein
rvmills
Well Known Member
More switch guards...
I used the "NASA X-plane" switch guards, also from Perihelion:
Colored toggle covers are from Stein!
Probably would have used the shuttle-style guards like Rick, had I seen them before I drilled the holes...they're pretty cool! (Any pix Rick?)
Here's a generic one:
Cheers,
Bob
I used the "NASA X-plane" switch guards, also from Perihelion:
Colored toggle covers are from Stein!
Probably would have used the shuttle-style guards like Rick, had I seen them before I drilled the holes...they're pretty cool! (Any pix Rick?)
Here's a generic one:
Cheers,
Bob
Geico266
Well Known Member
Also, with the 2 mag switch set up don't forget you need to start on the impulse mag only. I placard the panel to remind me to; "Start on Left Mag Only". The right one will fire at 25 TDC and can cause a kickback damaging the starter or worse. As soon as she fires once I flip on the right mag and away she goes.
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AltonD
Well Known Member
I thought when the mag was grounded (switch closed), it ws OFF. and when the switch was open, it was hot.
You are correct. That's why when using a normal single pole/single throw switch it is common practice to mount them upside down. Then when the switch is closed, the mag is grounded and then actually off.
Vic
Vic
Canadian_JOY
Well Known Member
I fabricated my own toggle switch gaurds from 1/8" Lexan. Drilled the right size hole for the toggle switch (standard AN/MS switch from Spruce, AN3012-2, MS35058-22), cut the Lexan to the proper shape, then bent it on a break to provide a slightly less elegant solution than the Perihelion guard. Mine cost me nothing but an hour of labour, and after two years flying with them they still look fine and function perfectly.
Starting on impulse mag
My plan is to use a DPDT momentary switch for the stater and wire it so that when the starter is engaged the left mag is also grounded. This setup will allow me to flip both mag switches to hot and then just push the start switch..thus eliminating the possibility of me accidentally starting with both mags hot.
Does anyone see any problem with this setup? As far as I can tell this is essentially how the standard keyed switches work in certified planes.
My plan is to use a DPDT momentary switch for the stater and wire it so that when the starter is engaged the left mag is also grounded. This setup will allow me to flip both mag switches to hot and then just push the start switch..thus eliminating the possibility of me accidentally starting with both mags hot.
Does anyone see any problem with this setup? As far as I can tell this is essentially how the standard keyed switches work in certified planes.
Geico266
Well Known Member
In theory it is more complex, more can go wrong, but it is a good idea. Wire away!
R
Rutus
'Lectric Bob
If you use the Aeroelectric Connection approach (Bob Nuckolls) you wire the toggles so that the starter cannot engage if the advanced mag is hot - so there is no way to make a mistake and get a kickback. B&C Specialty has the switches, they are standard DPDT items as I recall. My setup, done per Bob's architecture, has been simple and trouble free for 4 years now.
If you use the Aeroelectric Connection approach (Bob Nuckolls) you wire the toggles so that the starter cannot engage if the advanced mag is hot - so there is no way to make a mistake and get a kickback. B&C Specialty has the switches, they are standard DPDT items as I recall. My setup, done per Bob's architecture, has been simple and trouble free for 4 years now.
LifeofReiley
Well Known Member
Mag/Start
I'm using a B&C DPDT with monentary for my left mag which will function as my start switch too.
Lightspeed on the right...
I'm using a B&C DPDT with monentary for my left mag which will function as my start switch too.
Lightspeed on the right...
AS WITH A BENDIX KEY SWITCH.....
YES, The problem is if you let off of the button and the motor has not fired, you also turn the advanced mag HOT, and it can backfire and break your starter.
YES, The problem is if you let off of the button and the motor has not fired, you also turn the advanced mag HOT, and it can backfire and break your starter.
On-On-On
Depending on all of your electrical setup you may have other items that would require a switch to be upside down. All of my switches are on-on-on but only have one side or the other connected to the load and the center to the feed. Keeps you from having to turn switches upside down (and keying them to lock in place) by just moving the wire to the opposite terminal. Also means I only keep one type of spare switch for 90% of my panel.
Andy
Depending on all of your electrical setup you may have other items that would require a switch to be upside down. All of my switches are on-on-on but only have one side or the other connected to the load and the center to the feed. Keeps you from having to turn switches upside down (and keying them to lock in place) by just moving the wire to the opposite terminal. Also means I only keep one type of spare switch for 90% of my panel.
Andy
Bill Wightman
Well Known Member
One more possibility: We put the starter button on the stick (Infinity grips). This was a lesson learned from my previous RV4, where I never liked trying to keep the stick trapped aft between my legs for engine start.
With the starter on the stick, and mags wired per Nuckolls (which requires left mag ON and right mag OFF for starter engagement), it's possible to hold the stick aft and hit the starter with the right hand and manipulate the throttle/mixture with the left.
.... just an ancillary thought rgds the mag switch wiring. And we did use locking toggles on the mags too.
With the starter on the stick, and mags wired per Nuckolls (which requires left mag ON and right mag OFF for starter engagement), it's possible to hold the stick aft and hit the starter with the right hand and manipulate the throttle/mixture with the left.
.... just an ancillary thought rgds the mag switch wiring. And we did use locking toggles on the mags too.
f1rocket
Well Known Member
I have a mag and a Plasma II in my Rocket and used to start with both on until it kicked back and broke my starter. I now start with the mag on and the Plasma OFF to eliminate the kick back. I also upgraded the starter to a more heavy duty one so the a kick back wouldn't break it.
f1rocket
Well Known Member
This will work fine but I worry about accidentally hitting the starter button while the engine is running. I installed a "starter" warning light on my panel when the starter is engaged, mostly to ensure that the starter solenoid disengages when the power is removed.
Do you have to use a relay or did you wire the push button switch in the stick directly to the solenoid?
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rvmills
Well Known Member
Randy,
Educating myself a little here, please bear with the query...
I'm guessing your mag has an impulse coupler, so kick back is therefore not an issue for that, and your LSI was assumed the culprit in the broken starter incident. I thought LSI's would not kick back. To explain...
When buying my airplane and getting checked out, I was taught that the LSI had an auto-retard feature that would prevent kick back, but my non-impulse coupled mag did not retard the spark, so I was taught to start with the mag off to prevent kick back. The original POH (and my transition training for this A/C) states to engage the starter with both LSI and Mag switches off, then after a blade or two, switch the LSI on. After engine start, then turn the Mag on. This procedure was explained to me as necessary to prevent the LSI from seeing a lower voltage during the initial electrical draw down of the first turn of the starter, thus extending the life of the LSI. It's an older LSI (black case) so that may be a factor in this too.
It's a bit OT for this thread (a bit of drift), but any feedback from the gang on this procedure. It's just opposite of what you said you do Randy, so just confirming that you have an impulse coupler on your Mag, and you felt the LSI caused the kickback. Tryin' to get smart on this!
Cheers,
Bob
Bill Wightman
Well Known Member
Randy, This was my first thought also. Taking Bob Nuckolls' lead, I used DPDT locking toggle switches for the mags. One pole of each switch is used for the mag p-lead itself and the other pole is used as a safety for the starter.
The second poles are wired in series so that you get continuity when the switches are positioned for engine start: L-ON and R-OFF. Any other switch combination will not allow the starter to engage.
Start the engine, switch the right mag ON and the starter is taken out of play. Pretty neat I think!
As long as you keep that in mind for a mid-air restart! Granted, that should be a very rare occasion, and only for a stopped prop....
Bill Wightman
Well Known Member
Greg, If the prop is stopped you have far bigger problems than looking for a bump from the starter... like no airspeed or an engine thats locked up internally.
f1rocket
Well Known Member
Bob,
Yes, I am pretty sure that the Plasma II caused the kickback and yes, my left mag has an impulse coupler. Now, maybe it was also a factor of too small a starter (small PM starter) on a larger engine (IO-540) so the engine turned over very slowly. When I stopped using the Plasma II on start, all my kickbacks stopped as well. Not proof, but good enough for me so I modified my POH and my process. I subsequently upgraded my starter to the larger geared model but I still keep the LSI off during start.
Yes, I am pretty sure that the Plasma II caused the kickback and yes, my left mag has an impulse coupler. Now, maybe it was also a factor of too small a starter (small PM starter) on a larger engine (IO-540) so the engine turned over very slowly. When I stopped using the Plasma II on start, all my kickbacks stopped as well. Not proof, but good enough for me so I modified my POH and my process. I subsequently upgraded my starter to the larger geared model but I still keep the LSI off during start.
f1rocket
Well Known Member
I agree, pretty slick. That's the best way I've seen of handling that situation yet! I may have to "borrow" that idea for my current build.
Bill Wightman
Well Known Member
Randy, I read right over your question from earlier today.
No need for any additional relays. The DPDT toggles handle the starter solenoid current draw without any problem. The solenoid we use, the usual one from AC Spruce, draws 3.6A at 12VDC.
We run power from the main bus through the mag switches, and then through the button on the stick and from there to the starter relay solenoid. The other side of the solenoid is grounded. Its connected so that continuity is only made when you have the mag switches properly positioned.
Click the link below for an image of how we wired everything up:
Electrical System Schematic
No need for any additional relays. The DPDT toggles handle the starter solenoid current draw without any problem. The solenoid we use, the usual one from AC Spruce, draws 3.6A at 12VDC.
We run power from the main bus through the mag switches, and then through the button on the stick and from there to the starter relay solenoid. The other side of the solenoid is grounded. Its connected so that continuity is only made when you have the mag switches properly positioned.
Click the link below for an image of how we wired everything up:
Electrical System Schematic
Finley Atherton
Well Known Member
This issue is explained in the Service Bulletin section on the Lightspeed web site. In my case, I had a pre 2004 Plasma III and sent it back to Lightspeed for the mod that prevents kick back even if the voltage drops excessively.
Fin
9A
rvmills
Well Known Member
Randy,
Thanks much, makes sense. My workaround procedure (start cranking, EI on, engine starts, Mag on) looks to have been born of the mag not having the impulse coupler and also not wanting the EI to see low volts and kick back early in the cranking cycle. I've thought about getting an impulse coupled mag to do as you do...glad to hear it works well. One last Q...what starter did you install? I also have an IO-540, and if you've found a good one, I'd like to put it on my XMAS list!
And Fin, thanks for the ref...good reading and clarified it. Will have to talk with Klaus about the mod. Thanks!
Cheers,
Bob
Thanks much, makes sense. My workaround procedure (start cranking, EI on, engine starts, Mag on) looks to have been born of the mag not having the impulse coupler and also not wanting the EI to see low volts and kick back early in the cranking cycle. I've thought about getting an impulse coupled mag to do as you do...glad to hear it works well. One last Q...what starter did you install? I also have an IO-540, and if you've found a good one, I'd like to put it on my XMAS list!
And Fin, thanks for the ref...good reading and clarified it. Will have to talk with Klaus about the mod. Thanks!
Cheers,
Bob
A few years back during development of the VP-200, we contacted Unison and they recommended a switch rated at 3A at 200VAC.
More here on the forums if you want to see details:
http://www.verticalpower.com/forums/showthread.php?t=37
More here on the forums if you want to see details:
http://www.verticalpower.com/forums/showthread.php?t=37
f1rocket
Well Known Member
Bob,
My engine started out with a Sky-Tec LS model light weight starter. It came that way from Aerosport Power. What a piece of junk. Wrong starter for this engine and Bart no longer uses them on the 540's. It's sitting on the shelf in my hangar and rattles like a can of rocks due to broken magnets.
I replaced it with a B&C starter and never had another problem.
The engine on my current build has a Sky-Tec NL Inline starter on it but I haven't started the engine yet. A friend of mine researched starters and found the the NL has a 6.5:1 gear reduction instead of a lesser reduction on the B&C. He found this to be better although I don't recall the reasons.
If I had my choice, I would go with a B&C simply because I've never had a B&C product fail on me yet. It costs more but to me, it's worth it to not get stranded somewhere (which the Sky-Tec did to me).
My engine started out with a Sky-Tec LS model light weight starter. It came that way from Aerosport Power. What a piece of junk. Wrong starter for this engine and Bart no longer uses them on the 540's. It's sitting on the shelf in my hangar and rattles like a can of rocks due to broken magnets.
I replaced it with a B&C starter and never had another problem.
The engine on my current build has a Sky-Tec NL Inline starter on it but I haven't started the engine yet. A friend of mine researched starters and found the the NL has a 6.5:1 gear reduction instead of a lesser reduction on the B&C. He found this to be better although I don't recall the reasons.
If I had my choice, I would go with a B&C simply because I've never had a B&C product fail on me yet. It costs more but to me, it's worth it to not get stranded somewhere (which the Sky-Tec did to me).
I used fairly cheap dpst switches without guards but they are in a location that makes bumping them unlikely. I wired the starter circuit using the extra poles so the starter can only be engaged when the impluse mag is on (ungrounded) and the other mag is off (grounded). Besides preventing kick-back when you forget and try to start with both mags on this gives a small bit of theft protection. Another trick along that line is to power the starter contactor with the nav or strope lights as it would seem unlikely that a thief would turn lights on prior to starting.
Chuck Ross
Chuck Ross
[email protected]
Well Known Member
Make sure you get locking switches for mags. That’s what I used on my RV10. You have to pull out on the toggle switch to change positions.
