Electronic solutions to modifying glow engines of all sizes to gasoline
07-01-2022, 01:00 PM
#76
As soon as power is supplied to the driver, the solenoid valve is always modulating, the duty cycle is varied to control fuel flow, so if the solenoid ever stops, then thats a crash in the sketch due to either a voltage fluctuation, or possibly something to due with Raleighi's BMP280 senor error checking system.
07-01-2022, 01:26 PM
#77
potentional conversion project
Bit of a background story
About 2 years ago i saw a ad in a national second hand site for a "shed clearout" pile of rc related parts.
Just pictures showing 2 crates with the parts.
I recognised some side frames and other parts for the raptor 30/50 helies i have.
The asking price for the whole batch was what i would pay for those parts alone
If there was any other things among it that where of us then that would be a bonus.
So agreed with the seller and one day he droped off the crates.
Lets say i was not disapointed...
The raptor parts where a almost complete kit still in there original bags.
Anyone old enough here might remeber a multiplex model called "smily"
The batch included a unbuild kit of that model.
It all had ben stored in a damp shed so all was verry dirty and most metal parts where corroded.
Judging at the average age of the items it could have been 15 years in storage
ANd then there was this;
The engine was totally stuck; no movement at all.
SO when i took it out and removd the backplate i found water inside....
WHat shoudl have been the bearrings was just a cruddy pile of rust.
Loads of wd40, later i was able to get most of the headscrews off and drilled of the heads of the others.
One snapped off flush so have to figure out later how to remove it.
Then i was able to push the liner up with a wooden stick from below.
With a lot of wigggeling the conrod came offf the crankpin so the piston was out too.
To my amazement there was no corrosion or any other damage to either the piston or the liner.
The piston pin (if that is how you call it) was stuck but was able to press it out and after a polish installed back in the piston and it feels smooth
The case with crankshaft was heated in the oven and placed on a wooden block.
A few hits with the heaviest hammer i own and the crankshaft came out with the rear bearing stuck to it and was also abl t push out the front bearring.
Could not get the rear bearring off any other way so cut in in half
So its needs new bearrings and once it runs (if?) this might be a posible conversion subject.
It has a small electric backup motor (originally with a switch controlled by servo...) so a stalled engine would not be a problem so a good testbed.
Thoughts?
Graupner Atlantic challanger
About 2 years ago i saw a ad in a national second hand site for a "shed clearout" pile of rc related parts.
Just pictures showing 2 crates with the parts.
I recognised some side frames and other parts for the raptor 30/50 helies i have.
The asking price for the whole batch was what i would pay for those parts alone
If there was any other things among it that where of us then that would be a bonus.
So agreed with the seller and one day he droped off the crates.
Lets say i was not disapointed...
The raptor parts where a almost complete kit still in there original bags.
Anyone old enough here might remeber a multiplex model called "smily"
The batch included a unbuild kit of that model.
It all had ben stored in a damp shed so all was verry dirty and most metal parts where corroded.
Judging at the average age of the items it could have been 15 years in storage
ANd then there was this;
The engine was totally stuck; no movement at all.
SO when i took it out and removd the backplate i found water inside....
WHat shoudl have been the bearrings was just a cruddy pile of rust.
Loads of wd40, later i was able to get most of the headscrews off and drilled of the heads of the others.
One snapped off flush so have to figure out later how to remove it.
Then i was able to push the liner up with a wooden stick from below.
With a lot of wigggeling the conrod came offf the crankpin so the piston was out too.
To my amazement there was no corrosion or any other damage to either the piston or the liner.
The piston pin (if that is how you call it) was stuck but was able to press it out and after a polish installed back in the piston and it feels smooth
The case with crankshaft was heated in the oven and placed on a wooden block.
A few hits with the heaviest hammer i own and the crankshaft came out with the rear bearing stuck to it and was also abl t push out the front bearring.
Could not get the rear bearring off any other way so cut in in half
So its needs new bearrings and once it runs (if?) this might be a posible conversion subject.
It has a small electric backup motor (originally with a switch controlled by servo...) so a stalled engine would not be a problem so a good testbed.
Thoughts?
Graupner Atlantic challanger
07-01-2022, 01:31 PM
#78
So where is Raleighi'? he hasn't posted in a couple weeks. Don't make me drive all the way out there. I'll come in the AC Cobra, and be there in less than 24 hours, with a string of state troops behind me ( way behind ) 
07-01-2022, 01:35 PM
#79
Senior Member
Thread Starter
It might prove difficult to establish a good fuel curve due to the fact that you have to do that under load, which means, a free running boat, which means it has to be out on the pond, but other than that it should absolutely be possible.
If that were mine, I would MOST definitely want to try it....
If that were mine, I would MOST definitely want to try it....
07-01-2022, 01:40 PM
#80
[QUOTE=1967brutus;12733531If that were mine, I would MOST definitely want to try it.... [/QUOTE]
Is that a offer? i could do a basic conversion , mount a ardupilot/ inav autopilot in it and aim it your way
[/QUOTE]Is that a offer? i could do a basic conversion , mount a ardupilot/ inav autopilot in it and aim it your way
07-01-2022, 02:04 PM
#81
Senior Member
Thread Starter
07-01-2022, 02:16 PM
#82
transport cost more then value?
Thing is 1.,3 meter long so posting it would be expensive.
Since its a scale model of a boat designed to break a record it might be fun to "re enact" it and see if it can make it over to the "mainland"
When was the last time you went to france?
Since its a scale model of a boat designed to break a record it might be fun to "re enact" it and see if it can make it over to the "mainland"
When was the last time you went to france?
07-01-2022, 02:38 PM
#83
I wonder if a Capacitor (like spectrum used for the brownout issue) would help the cause - I suspect its a very quick Low spike that triggers the issue.
Chris
07-01-2022, 02:50 PM
#84
if you can make the cap to power only the controller
If you can seprate the power for the solenoid (giv it its own voltage regulator) and then place the cap on the "v in" and ground pads (after the diode) then yes it should be able to power the controler for a while.
The diode should prevent it from powering the solenoid so you can use a lower value capicitor.
Or run a few of these caps parallel (that adds the amount of energy they can store) so they can store enough to power the solenoid too.
Keep in mind that when you switch the system on and the caps are empty there will be quite high charge current for a short while untill the caps are full. So any switch should be abl to pass that current.
The diode should prevent it from powering the solenoid so you can use a lower value capicitor.
Or run a few of these caps parallel (that adds the amount of energy they can store) so they can store enough to power the solenoid too.
Keep in mind that when you switch the system on and the caps are empty there will be quite high charge current for a short while untill the caps are full. So any switch should be abl to pass that current.
07-01-2022, 03:18 PM
#86
Senior Member
Thread Starter
Rob and all... I have noticed an occasional "voltage sensitivity" on my "Dave" controllers. I do run a 4 cell Nimh for the radio and controller and once when voltage was low (battery basically dead) I saw a lockup.. I have seen it also when running on a bench with a common power supply to the ignition from a regulator.
I wonder if a Capacitor (like spectrum used for the brownout issue) would help the cause - I suspect its a very quick Low spike that triggers the issue.
Chris
I wonder if a Capacitor (like spectrum used for the brownout issue) would help the cause - I suspect its a very quick Low spike that triggers the issue.
Chris
07-01-2022, 03:33 PM
#87
Senior Member
Thread Starter
If you can seprate the power for the solenoid (giv it its own voltage regulator) and then place the cap on the "v in" and ground pads (after the diode) then yes it should be able to power the controler for a while.
The diode should prevent it from powering the solenoid so you can use a lower value capicitor.
Or run a few of these caps parallel (that adds the amount of energy they can store) so they can store enough to power the solenoid too.
Keep in mind that when you switch the system on and the caps are empty there will be quite high charge current for a short while untill the caps are full. So any switch should be abl to pass that current.
The diode should prevent it from powering the solenoid so you can use a lower value capicitor.
Or run a few of these caps parallel (that adds the amount of energy they can store) so they can store enough to power the solenoid too.
Keep in mind that when you switch the system on and the caps are empty there will be quite high charge current for a short while untill the caps are full. So any switch should be abl to pass that current.
07-01-2022, 04:01 PM
#89
do you have a oscilloscope?
It is not in the current draw from the solenoid. In Hans' initial system with the separate pressure module, the solenoid did not make the difference (I could disconnect it without it solving the problem), and you absolutely do NOT want to parallel a capacitor over the solenoid as that will affect accuracy of the fuel metering.
And yes any caps should be in the power part of the system like in the power lead to it
Another strange thing is that part of the the program keeps running.
A full "freeze" of the "computer" would leave the solenoid either open or closed. Either of these states would stop the engine (by flooding or starving of fuel)
Unless i misunderstand the problem this appears not to happen .
07-01-2022, 06:15 PM
#90
I unplugged the controller while bench testing. The solenoid went full open, rich, but the engine didn't quit until I throttled down to idle. It's a good feeling to know that power loss to the controller or solenoid will allow for a shot at an approach.
07-02-2022, 02:45 AM
#91
Senior Member
Thread Starter
A scope could check any fast changes in the battery voltage only then you can be sure if that is a problem or not.
And yes any caps should be in the power part of the system like in the power lead to it
Another strange thing is that part of the the program keeps running.
A full "freeze" of the "computer" would leave the solenoid either open or closed. Either of these states would stop the engine (by flooding or starving of fuel)
Unless i misunderstand the problem this appears not to happen .
And yes any caps should be in the power part of the system like in the power lead to it
Another strange thing is that part of the the program keeps running.
A full "freeze" of the "computer" would leave the solenoid either open or closed. Either of these states would stop the engine (by flooding or starving of fuel)
Unless i misunderstand the problem this appears not to happen .
07-02-2022, 02:48 AM
#92
Senior Member
Thread Starter
Yes, an electrical faillure (powerloss to module or solenoid, or interruption in the solenoid windings) leaves the valve open and will cause the engine to go rich but with luck it will allow for limping home on a rich running engine, unless of course the faillure occurs right at a moment the throttle is closed for whatever reason, then the engine will most likely quit, but that is why I recommend to at least use the LS and HS needle to such an extent (IF possible) that the engine won't go blubbering rich in case of a solenoid faillure.
07-02-2022, 04:03 AM
#93
Yes Bert, but the "If possible" part is where it gets a little tricky.
My findings:
The solenoid has to be set up to lean the mixture throughout the entire rpm range in order to work properly. This became especially important with the introduction of the temp/pressure sensor. The controller needs to richen the mixture with colder temps and lower pressures, so richening "headroom" must be taken into account. This means the needles must be set slightly richer from the start.
On top of that, if the needles are set too lean it is near impossible to adjust the mixture using the fuel curve. Mixture adjustment range is severly limited. Adjusting the needles slightly richer fixes that problem as well, however by the time I've set set the needles rich enough to accomodate all these requirements unplugging the solenoid DOES produce a slobbering rich running engine, especially just above idle.
No matter, I'm not concerned about the robustness of the controller or solenoid, so far there have been no reports of failure. I have not experienced any weirdness either.
I hope to get back on this project some day. Life keeps getting in the way.
My findings:
The solenoid has to be set up to lean the mixture throughout the entire rpm range in order to work properly. This became especially important with the introduction of the temp/pressure sensor. The controller needs to richen the mixture with colder temps and lower pressures, so richening "headroom" must be taken into account. This means the needles must be set slightly richer from the start.
On top of that, if the needles are set too lean it is near impossible to adjust the mixture using the fuel curve. Mixture adjustment range is severly limited. Adjusting the needles slightly richer fixes that problem as well, however by the time I've set set the needles rich enough to accomodate all these requirements unplugging the solenoid DOES produce a slobbering rich running engine, especially just above idle.
No matter, I'm not concerned about the robustness of the controller or solenoid, so far there have been no reports of failure. I have not experienced any weirdness either.
I hope to get back on this project some day. Life keeps getting in the way.
07-03-2022, 05:35 AM
#94
cheap scope replacement
You can use a soundcard line in as a cheap oscilloscoop replacement
if you use a voltage devider resistor to reduce the max (in this case your battery pack) voltage under 1.414 then you can see the waveform on your pc/laptop screen.
While it will only only go up to 20 kHz that should be good enough for this aplication.
https://en.wikipedia.org/wiki/Line_level#Nominal_levels
https://www.nutsvolts.com/magazine/a...d-into-a-scope
if you use a voltage devider resistor to reduce the max (in this case your battery pack) voltage under 1.414 then you can see the waveform on your pc/laptop screen.
While it will only only go up to 20 kHz that should be good enough for this aplication.
https://en.wikipedia.org/wiki/Line_level#Nominal_levels
https://www.nutsvolts.com/magazine/a...d-into-a-scope
07-03-2022, 06:06 AM
#95
Yes, it seems the program keeps running in part, just the values at the moment of faillure seem to freeze. At least, that is what I have seen. Very possible that in my case the switch also was the issue (fairly simple on/off switch) but I never thought of that possibly being the cause so I never tested it bypassing the switch. Rob did, and he appears to have something there,,,
Chris
07-03-2022, 08:24 AM
#96
Senior Member
Thread Starter
Bert, Have there been issues with the Hans controller and the freezing issue noted. Now this is being discussed I have had a few weird moments during testing but I have never had it happen in the air. I also haven't had it happen on the controlers I have "resketched" with code eliminating the BMP. I wonder if its a "read" issue originating from the BMP. Im not good at "Code".
Chris
Chris
But I did fit all of them with a buck/boost regulator to combat the issue just in case.
EDIT: for all clarity: I fitted the OLD style of Hans' set-up (the ones with a separate pressure module and working via telemetry) with the buck/boost regulators, the latest rendering have a built in regulator and no issues to the best of my knowledge.
Last edited by 1967brutus; 07-03-2022 at 08:41 AM.
07-03-2022, 04:01 PM
#97
Bert, Have there been issues with the Hans controller and the freezing issue noted. Now this is being discussed I have had a few weird moments during testing but I have never had it happen in the air. I also haven't had it happen on the controlers I have "resketched" with code eliminating the BMP. I wonder if its a "read" issue originating from the BMP. Im not good at "Code".
Chris
Chris
Last edited by John_M_; 07-03-2022 at 04:07 PM.
