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echristley(at)att.net
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 Posted: Thu Apr 18, 2019 8:55 am Post subject: Choosing a solenoid |
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I replace an Aerovee carb with an Ellison TBI. The engine runs much smoother, and fired up with even EGTs once I got it primed. I didn't have a prime on the Aerovee, since the thing starts pouring fuel as soon as you open the shutoff valve, so priming was just a matter of waiting a couple seconds before cranking. Instead, I got her running by pouring the fuel from my sump drainer into the intake air box. Not the safest thing in the world to be doing, indicating a need for a real primer circuit. I have an electric primer pump on hand, and I could just run a small tube into the airbox to dump fuel right in front of the carbs intake. This will require a momentary switch and a wire run, as well as a bunch of fuel plumbing.
However, Rotec built a different type of primer into their version of the Ellison. It is a bulb that inflates a diaphragm, opening the fuel valve. For those not familiar with the Ellison, the diaphragm is inflated by incoming air pressure while the engine is running, and serves as a shutoff after engine shutdown. I was thinking of modifying my Ellison to play along the same line as Rotec.
The problem I have with airplane primers is that we dump some fuel in the intake. How much to dump is an obfuscated educated guess. We push a button or pump a handle a certain amount based on experience of how that amount of pushing or pumping has worked in the past, without really knowing how much is added. The downside of this approach is documented by POHs having a section dedicated to what to do when the over priming catches fire. Rotec's strategy has the same issue as all other primers.
So, if instead of a bulb, I mounted a plunger type servo on the diaphragm cover plate and tie that servo to the starter circuit. When I pushed the starter switch, the plunger would extend to push the diaphragm. The fuel valve would then only open when the starter was engaged. Fuel would never be dumped in the intake unless air was being moved through the engine. This seems to remove most of the chance of a fire caused by over priming.
I'm thinking a solenoid like this one would work. Small Push-Pull Solenoid - 12VDC but would like to see if there are any other suggestions.
<![endif]--><![endif]-->$14.87
<![endif]--> Small Push-Pull Solenoid - 12VDC
Solenoids are basically electromagnets: they are made of a big coil of copper wire with an armature (a slug of m...
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cluros(at)gmail.com
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| Posted: Thu Apr 18, 2019 10:52 am Post subject: Choosing a solenoid |
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That's brilliant. I assume you will run the power to this plunger through a switch so you can decide whether or not it actuates on any given start?
On Thu, Apr 18, 2019, 13:03 Ernest Christley <echristley(at)att.net (echristley(at)att.net)> wrote:
| Quote: | I replace an Aerovee carb with an Ellison TBI. The engine runs much smoother, and fired up with even EGTs once I got it primed. I didn't have a prime on the Aerovee, since the thing starts pouring fuel as soon as you open the shutoff valve, so priming was just a matter of waiting a couple seconds before cranking. Instead, I got her running by pouring the fuel from my sump drainer into the intake air box. Not the safest thing in the world to be doing, indicating a need for a real primer circuit. I have an electric primer pump on hand, and I could just run a small tube into the airbox to dump fuel right in front of the carbs intake. This will require a momentary switch and a wire run, as well as a bunch of fuel plumbing.Â
However, Rotec built a different type of primer into their version of the Ellison. It is a bulb that inflates a diaphragm, opening the fuel valve. For those not familiar with the Ellison, the diaphragm is inflated by incoming air pressure while the engine is running, and serves as a shutoff after engine shutdown. I was thinking of modifying my Ellison to play along the same line as Rotec.
The problem I have with airplane primers is that we dump some fuel in the intake. How much to dump is an obfuscated educated guess. We push a button or pump a handle a certain amount based on experience of how that amount of pushing or pumping has worked in the past, without really knowing how much is added. The downside of this approach is documented by POHs having a section dedicated to what to do when the over priming catches fire. Rotec's strategy has the same issue as all other primers.
So, if instead of a bulb, I mounted a plunger type servo on the diaphragm cover plate and tie that servo to the starter circuit. When I pushed the starter switch, the plunger would extend to push the diaphragm. The fuel valve would then only open when the starter was engaged. Fuel would never be dumped in the intake unless air was being moved through the engine. This seems to remove most of the chance of a fire caused by over priming.
I'm thinking a solenoid like this one would work. Small Push-Pull Solenoid - 12VDC but would like to see if there are any other suggestions.Â
$14.87
Small Push-Pull Solenoid - 12VDC
Solenoids are basically electromagnets: they are made of a big coil of copper wire with an armature (a slug of m...
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echristley(at)att.net
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| Posted: Thu Apr 18, 2019 11:42 am Post subject: Choosing a solenoid |
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With an Ellison, the engine won't start without some sort of fuel supply. It needs air flowing through it to create the pressure behind the diaphragm to open the fuel valve. It is something of a chicken-and-egg problem for the design. Whether opening the valve at starter engagement will be enough fuel to start is an open question. If it isn't, I'll be able to run a wire inside to a momentary switch for a more traditional primer setup.
At this point though, I'm sort of stuck on finding an adequate solenoid.
On Thursday, April 18, 2019, 2:53:10 PM EDT, Sebastien <cluros(at)gmail.com> wrote:
That's brilliant. I assume you will run the power to this plunger through a switch so you can decide whether or not it actuates on any given start?
On Thu, Apr 18, 2019, 13:03 Ernest Christley <echristley(at)att.net (echristley(at)att.net)> wrote:
| Quote: | I replace an Aerovee carb with an Ellison TBI. The engine runs much smoother, and fired up with even EGTs once I got it primed. I didn't have a prime on the Aerovee, since the thing starts pouring fuel as soon as you open the shutoff valve, so priming was just a matter of waiting a couple seconds before cranking. Instead, I got her running by pouring the fuel from my sump drainer into the intake air box. Not the safest thing in the world to be doing, indicating a need for a real primer circuit. I have an electric primer pump on hand, and I could just run a small tube into the airbox to dump fuel right in front of the carbs intake. This will require a momentary switch and a wire run, as well as a bunch of fuel plumbing.
However, Rotec built a different type of primer into their version of the Ellison. It is a bulb that inflates a diaphragm, opening the fuel valve. For those not familiar with the Ellison, the diaphragm is inflated by incoming air pressure while the engine is running, and serves as a shutoff after engine shutdown. I was thinking of modifying my Ellison to play along the same line as Rotec.
The problem I have with airplane primers is that we dump some fuel in the intake. How much to dump is an obfuscated educated guess. We push a button or pump a handle a certain amount based on experience of how that amount of pushing or pumping has worked in the past, without really knowing how much is added. The downside of this approach is documented by POHs having a section dedicated to what to do when the over priming catches fire. Rotec's strategy has the same issue as all other primers.
So, if instead of a bulb, I mounted a plunger type servo on the diaphragm cover plate and tie that servo to the starter circuit. When I pushed the starter switch, the plunger would extend to push the diaphragm. The fuel valve would then only open when the starter was engaged. Fuel would never be dumped in the intake unless air was being moved through the engine. This seems to remove most of the chance of a fire caused by over priming.
I'm thinking a solenoid like this one would work. Small Push-Pull Solenoid - 12VDC but would like to see if there are any other suggestions.
$14.87
Small Push-Pull Solenoid - 12VDC
Solenoids are basically electromagnets: they are made of a big coil of copper wire with an armature (a slug of m...
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
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echristley(at)att.net
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| Posted: Thu Apr 18, 2019 12:22 pm Post subject: Choosing a solenoid |
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This would be a better choice if it weren't so long. Mounting would be really simplified by just drilling and tapping a single hole.
https://www.amazon.com/uxcell-XRN-2-5-Linear-Solenoid-Electromagnet/dp/B07DM75BKK/ref=pd_sim_328_6/141-8437165-5384219?_encoding=UTF8&pd_rd_i=B07DM7M8M5&pd_rd_r=2bea8050-6213-11e9-b7b1-9768eea003d5&pd_rd_w=85TrC&pd_rd_wg=Vi86G&pf_rd_p=90485860-83e9-4fd9-b838-b28a9b7fda30&pf_rd_r=ZWMYPS2EGJX5RD254Y64&refRID=ZWMYPS2EGJX5RD254Y64&th=1
On Thursday, April 18, 2019, 3:43:30 PM EDT, Ernest Christley <echristley(at)att.net> wrote:
96<![endif]-->
With an Ellison, the engine won't start without some sort of fuel supply. It needs air flowing through it to create the pressure behind the diaphragm to open the fuel valve. It is something of a chicken-and-egg problem for the design. Whether opening the valve at starter engagement will be enough fuel to start is an open question. If it isn't, I'll be able to run a wire inside to a momentary switch for a more traditional primer setup.
At this point though, I'm sort of stuck on finding an adequate solenoid.
On Thursday, April 18, 2019, 2:53:10 PM EDT, Sebastien <cluros(at)gmail.com> wrote:
That's brilliant. I assume you will run the power to this plunger through a switch so you can decide whether or not it actuates on any given start?
On Thu, Apr 18, 2019, 13:03 Ernest Christley <echristley(at)att.net (echristley(at)att.net)> wrote:
| Quote: | I replace an Aerovee carb with an Ellison TBI. The engine runs much smoother, and fired up with even EGTs once I got it primed. I didn't have a prime on the Aerovee, since the thing starts pouring fuel as soon as you open the shutoff valve, so priming was just a matter of waiting a couple seconds before cranking. Instead, I got her running by pouring the fuel from my sump drainer into the intake air box. Not the safest thing in the world to be doing, indicating a need for a real primer circuit. I have an electric primer pump on hand, and I could just run a small tube into the airbox to dump fuel right in front of the carbs intake. This will require a momentary switch and a wire run, as well as a bunch of fuel plumbing.
However, Rotec built a different type of primer into their version of the Ellison. It is a bulb that inflates a diaphragm, opening the fuel valve. For those not familiar with the Ellison, the diaphragm is inflated by incoming air pressure while the engine is running, and serves as a shutoff after engine shutdown. I was thinking of modifying my Ellison to play along the same line as Rotec.
The problem I have with airplane primers is that we dump some fuel in the intake. How much to dump is an obfuscated educated guess. We push a button or pump a handle a certain amount based on experience of how that amount of pushing or pumping has worked in the past, without really knowing how much is added. The downside of this approach is documented by POHs having a section dedicated to what to do when the over priming catches fire. Rotec's strategy has the same issue as all other primers.
So, if instead of a bulb, I mounted a plunger type servo on the diaphragm cover plate and tie that servo to the starter circuit. When I pushed the starter switch, the plunger would extend to push the diaphragm. The fuel valve would then only open when the starter was engaged. Fuel would never be dumped in the intake unless air was being moved through the engine. This seems to remove most of the chance of a fire caused by over priming.
I'm thinking a solenoid like this one would work. Small Push-Pull Solenoid - 12VDC but would like to see if there are any other suggestions.
$14.87
Small Push-Pull Solenoid - 12VDC
Solenoids are basically electromagnets: they are made of a big coil of copper wire with an armature (a slug of m...
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
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ceengland7(at)gmail.com
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| Posted: Thu Apr 18, 2019 3:52 pm Post subject: Choosing a solenoid |
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What's wrong with a simple Bowden (choke) cable on a lever to actuate the bulb? Only problem is, with no electrons involved, we can't talk about it here.
Charlie
On 4/18/2019 3:00 PM, Ernest Christley wrote:
| Quote: | 96<![endif]--> This would be a better choice if it weren't so long. Mounting would be really simplified by just drilling and tapping a single hole.
https://www.amazon.com/uxcell-XRN-2-5-Linear-Solenoid-Electromagnet/dp/B07DM75BKK/ref=pd_sim_328_6/141-8437165-5384219?_encoding=UTF8&pd_rd_i=B07DM7M8M5&pd_rd_r=2bea8050-6213-11e9-b7b1-9768eea003d5&pd_rd_w=85TrC&pd_rd_wg=Vi86G&pf_rd_p=90485860-83e9-4fd9-b838-b28a9b7fda30&pf_rd_r=ZWMYPS2EGJX5RD254Y64&refRID=ZWMYPS2EGJX5RD254Y64&th=1
On Thursday, April 18, 2019, 3:43:30 PM EDT, Ernest Christley <echristley(at)att.net> (echristley(at)att.net) wrote:
96<![endif]--> With an Ellison, the engine won't start without some sort of fuel supply. It needs air flowing through it to create the pressure behind the diaphragm to open the fuel valve. It is something of a chicken-and-egg problem for the design. Whether opening the valve at starter engagement will be enough fuel to start is an open question. If it isn't, I'll be able to run a wire inside to a momentary switch for a more traditional primer setup.
At this point though, I'm sort of stuck on finding an adequate solenoid.
On Thursday, April 18, 2019, 2:53:10 PM EDT, Sebastien <cluros(at)gmail.com> (cluros(at)gmail.com) wrote:
That's brilliant. I assume you will run the power to this plunger through a switch so you can decide whether or not it actuates on any given start?
On Thu, Apr 18, 2019, 13:03 Ernest Christley <echristley(at)att.net (echristley(at)att.net)> wrote:
| Quote: | I replace an Aerovee carb with an Ellison TBI. The engine runs much smoother, and fired up with even EGTs once I got it primed. I didn't have a prime on the Aerovee, since the thing starts pouring fuel as soon as you open the shutoff valve, so priming was just a matter of waiting a couple seconds before cranking. Instead, I got her running by pouring the fuel from my sump drainer into the intake air box. Not the safest thing in the world to be doing, indicating a need for a real primer circuit. I have an electric primer pump on hand, and I could just run a small tube into the airbox to dump fuel right in front of the carbs intake. This will require a momentary switch and a wire run, as well as a bunch of fuel plumbing.Â
However, Rotec built a different type of primer into their version of the Ellison. It is a bulb that inflates a diaphragm, opening the fuel valve. For those not familiar with the Ellison, the diaphragm is inflated by incoming air pressure while the engine is running, and serves as a shutoff after engine shutdown. I was thinking of modifying my Ellison to play along the same line as Rotec.
The problem I have with airplane primers is that we dump some fuel in the intake. How much to dump is an obfuscated educated guess. We push a button or pump a handle a certain amount based on experience of how that amount of pushing or pumping has worked in the past, without really knowing how much is added. The downside of this approach is documented by POHs having a section dedicated to what to do when the over priming catches fire. Rotec's strategy has the same issue as all other primers.
So, if instead of a bulb, I mounted a plunger type servo on the diaphragm cover plate and tie that servo to the starter circuit. When I pushed the starter switch, the plunger would extend to push the diaphragm. The fuel valve would then only open when the starter was engaged. Fuel would never be dumped in the intake unless air was being moved through the engine. This seems to remove most of the chance of a fire caused by over priming.
I'm thinking a solenoid like this one would work. Small Push-Pull Solenoid - 12VDC but would like to see if there are any other suggestions.Â
$14.87
Small Push-Pull Solenoid - 12VDC
Solenoids are basically electromagnets: they are made of a big coil of copper wire with an armature (a slug of m...
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echristley(at)att.net
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| Posted: Thu Apr 18, 2019 4:19 pm Post subject: Choosing a solenoid |
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Activating the primer and starter at the same time is a juggling act. So you drop back to the "dump some fuel in the intake and hope it is the right amount" method that we're all used to.
On Thursday, April 18, 2019, 4:53:52 PM MST, Charlie England <ceengland7(at)gmail.com> wrote:
What's wrong with a simple Bowden (choke) cable on a lever to actuate the bulb? Only problem is, with no electrons involved, we can't talk about it here. Charlie On 4/18/2019 3:00 PM, Ernest Christley wrote:
| Quote: | This would be a better choice if it weren't so long. Mounting would be really simplified by just drilling and tapping a single hole.
https://www.amazon.com/uxcell-XRN-2-5-Linear-Solenoid-Electromagnet/dp/B07DM75BKK/ref=pd_sim_328_6/141-8437165-5384219?_encoding=UTF8&pd_rd_i=B07DM7M8M5&pd_rd_r=2bea8050-6213-11e9-b7b1-9768eea003d5&pd_rd_w=85TrC&pd_rd_wg=Vi86G&pf_rd_p=90485860-83e9-4fd9-b838-b28a9b7fda30&pf_rd_r=ZWMYPS2EGJX5RD254Y64&refRID=ZWMYPS2EGJX5RD254Y64&th=1
On Thursday, April 18, 2019, 3:43:30 PM EDT, Ernest Christley <echristley(at)att.net> (echristley(at)att.net) wrote:
With an Ellison, the engine won't start without some sort of fuel supply. It needs air flowing through it to create the pressure behind the diaphragm to open the fuel valve. It is something of a chicken-and-egg problem for the design. Whether opening the valve at starter engagement will be enough fuel to start is an open question. If it isn't, I'll be able to run a wire inside to a momentary switch for a more traditional primer setup.
At this point though, I'm sort of stuck on finding an adequate solenoid.
On Thursday, April 18, 2019, 2:53:10 PM EDT, Sebastien <cluros(at)gmail.com> (cluros(at)gmail.com) wrote:
That's brilliant. I assume you will run the power to this plunger through a switch so you can decide whether or not it actuates on any given start?
On Thu, Apr 18, 2019, 13:03 Ernest Christley <echristley(at)att.net (echristley(at)att.net)> wrote:
| Quote: | I replace an Aerovee carb with an Ellison TBI. The engine runs much smoother, and fired up with even EGTs once I got it primed. I didn't have a prime on the Aerovee, since the thing starts pouring fuel as soon as you open the shutoff valve, so priming was just a matter of waiting a couple seconds before cranking. Instead, I got her running by pouring the fuel from my sump drainer into the intake air box. Not the safest thing in the world to be doing, indicating a need for a real primer circuit. I have an electric primer pump on hand, and I could just run a small tube into the airbox to dump fuel right in front of the carbs intake. This will require a momentary switch and a wire run, as well as a bunch of fuel plumbing.
However, Rotec built a different type of primer into their version of the Ellison. It is a bulb that inflates a diaphragm, opening the fuel valve. For those not familiar with the Ellison, the diaphragm is inflated by incoming air pressure while the engine is running, and serves as a shutoff after engine shutdown. I was thinking of modifying my Ellison to play along the same line as Rotec.
The problem I have with airplane primers is that we dump some fuel in the intake. How much to dump is an obfuscated educated guess. We push a button or pump a handle a certain amount based on experience of how that amount of pushing or pumping has worked in the past, without really knowing how much is added. The downside of this approach is documented by POHs having a section dedicated to what to do when the over priming catches fire. Rotec's strategy has the same issue as all other primers.
So, if instead of a bulb, I mounted a plunger type servo on the diaphragm cover plate and tie that servo to the starter circuit. When I pushed the starter switch, the plunger would extend to push the diaphragm. The fuel valve would then only open when the starter was engaged. Fuel would never be dumped in the intake unless air was being moved through the engine. This seems to remove most of the chance of a fire caused by over priming.
I'm thinking a solenoid like this one would work. Small Push-Pull Solenoid - 12VDC but would like to see if there are any other suggestions.
$14.87 Small Push-Pull Solenoid - 12VDC
Solenoids are basically electromagnets: they are made of a big coil of copper wire with an armature (a slug of m...
|
|
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