Why?

[high time cub]

Most time I'm too stupid to understand the why's and what's that make it work. But I'm lazy enough to figure out what it likes to make it work, my bad

Glenn

Glenn,

I don’t want to nudge you too far out of your comfort zone, but all you have to do is look at the external workings of the stone-simple Apollo impulse to understand how it works.

The lower arrow in photo 1 shows a catch-weight (pawl) resting in its slot on the Apollo impulse coupling. There are two catch-weights 180° apart. As the name implies, they engage by weight alone. The upper arrow points to the non-impulse, direct drive coupling on the right mag.

The left arrow in photo 2 shows the direction of rotation. The right arrow points to the very shallow step or catch. As a catch-weight approaches the 12 o’clock position, it falls within its slot and is then caught by the step. Once caught, the internal impulse spring is wound for start-up. This engagement is rather tenuous and the shallow step is easily jumped by the catch weight if the rotation is too fast. Furthermore, since these parts are open to the environment, the step area and catch-weights need to be kept super clean and dry. A film of oil can keep a catch-weight from free-falling and even the slightest ramp of oily dirt at the step will make the catch-weight jump free like a California skateboarder.

The impulse stops functioning when the Kinner is turned faster than 80 r.p.m.

The next time you’re near Mark’s Fleet, open the left cowl door and check-out the Apollo.

Best,


HT & V

[cubdriver2]

Glenn,

I don’t want to nudge you too far out of your comfort zone, but all you have to do is look at the external workings of the stone-simple Apollo impulse to understand how it works.

The lower arrow in photo 1 shows a catch-weight (pawl) resting in its slot on the Apollo impulse coupling. There are two catch-weights 180° apart. As the name implies, they engage by weight alone. The upper arrow points to the non-impulse, direct drive coupling on the right mag.

The left arrow in photo 2 shows the direction of rotation. The right arrow points to the very shallow step or catch. As a catch-weight approaches the 12 o’clock position, it falls within its slot and is then caught by the step. Once caught, the internal impulse spring is wound for start-up. This engagement is rather tenuous and the shallow step is easily jumped by the catch weight if the rotation is too fast. Furthermore, since these parts are open to the environment, the step area and catch-weights need to be kept super clean and dry. A film of oil can keep a catch-weight from free-falling and even the slightest ramp of oily dirt at the step will make the catch-weight jump free like a California skateboarder.

The impulse stops functioning when the Kinner is turned faster than 80 r.p.m.

The next time you’re near Mark’s Fleet, open the left cowl door and check-out the Apollo.

Best,


HT & V

Thanks, I learned about this on Marks Fleet when we were together at the Marcellus Flyin. Mark has a starter on his Kinner but I have a small addiction for propping antique engines. So he was ready to go home and I wanted to prop him and he wanted to push the button and be done with me. But I won out and he agreed to allow me to fondle one of Sensenichs works of art. After about 10 minutes of enthusiastic flipping I was showing some wear. So Mark in his typical obnoxious plumbers customer reply voice says " pull it slowly " and laughs like a girlscout. That darn 5 cylinder Harley wannabe fired right up. I hate flying plumbers. You can't trust any biplane guys, Mr Ed was trying to get his Tiger Moth started just before dark to fly home and wore himself out trying to start a flooded engine. I told him to get in and I would get him going. That thing was so flooded that I flipped it for 15 minutes before he realized that the fuel had been turned off the whole time.

Glenn

[hotrod180]

..... Mark has a starter on his Kinner but I have a small addiction for propping antique engines....

Never heard of a starter on a Kinner before.
A friend of mine has a Kinner on her biplane--
it's actually kinda dangerous IF you don't know how easily they fire.
That prop should never even be touched with the mags on IMHO--
not hard for it to fire just moving the prop to a more advantageous position.

[skywagon8a]

That prop should never even be touched with the mags on IMHO--
not hard for it to fire just moving the prop to a more advantageous position.

I knew a fellow who lost two fingers doing just that on a PT-22.

[cubdriver2]

I knew a fellow who lost two fingers doing just that on a PT-22.

At the angle it sits your kneecaps are fair game anytime you move it

Glenn

[stewartb]

I'm a new Pmag guy and just reading about setting them up. Which leads to a question. Is your Emag set for RMSD? If your mechanical mag is grounded by the switch and your Emag is set for the start delay it might explain your issue.

[skywagon8a]

I'm a new Pmag guy and just reading about setting them up. Which leads to a question. Is your Emag set for RMSD? If your mechanical mag is grounded by the switch and your Emag is set for the start delay it might explain your issue.

stewartb, His issue started when he changed the prop and the engine turned faster while cranking. When hand propping it starts normally. This is screaming as an issue of the fly weights on the impulse turning too fast to engage.

[cgoldy]

stewartb, His issue started when he changed the prop and the engine turned faster while cranking. When hand propping it starts normally. This is screaming as an issue of the fly weights on the impulse turning too fast to engage.

I havent had had a chance to swap those p leads around yet Pete. I have been up to my armpits in carbon fibre making those windows and doors. It has turned into a mammoth job. Filling and fairing my first attempt. If I ever made them again it would probably take me a quarter of the time. But happy with the expected result. Very spiffy!

My LAME said to just remove the bridge on the back of the starter switch and then it will start on both impulse and Emag.

[skywagon8a]

My LAME said to just remove the bridge on the back of the starter switch and then it will start on both impulse and Emag.

That is the correct and simplest thing to do. Then when you use the electric starter it will start on the Pmag and when you prop it by hand the impulse coupling magneto will do the starting.

[AkPA/18]

CGoldy

Maybe you could just remove the P lead on the Impulse mag. This might better troubleshoot if it is the mag or the switch issue? If it starts it might be the switch and if not it might be the mag problem with too fast of rotation.

Mark

[PerryB]

I havent had had a chance to swap those p leads around yet Pete. I have been up to my armpits in carbon fibre making those windows and doors. It has turned into a mammoth job. Filling and fairing my first attempt. If I ever made them again it would probably take me a quarter of the time. But happy with the expected result. Very spiffy!

My LAME said to just remove the bridge on the back of the starter switch and then it will start on both impulse and Emag.

Just curious, what's the initial timing of the Emag?

[AkPA/18]

So if I was to do the same, replace with switches and a button, how could I disable the aircraft to satisfy CASA's. (FAA) security concerns?

Hello Cgoldy,

I keep rereading this thread hoping you have figured it out LOL. I came onto this question. Not sure what CASA requirements are but you could just use the keyswitch as the starter button in combo with standard mag switches. Would that work for you?

Mark

[kase]

Hello Cgoldy
Is your keyswitch an ACS. If so that is a common symptom of it going bad. I believe there might be a repair kit for that key switch. Also I believe there is a service bulletin or possibly an AD on that switch. This is just from several of my friends that have had that problem. You are not the only one. If not an ACS disregard

Mark

I just complied with that AD a few weeks ago. $17.00 for parts and 20 min of labor.


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