(Bio)Diesel Powered

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Noxz
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Re: (Bio)Diesel Powered

Post by Noxz » Sat Aug 11, 2018 8:03 pm

yeah, I guess kitchen was an okay idea afterall.. I am renovating the house and that will be converted into the master bedroom/bath, kitchen - which is currently a wet bar - will go to the first floor (why would you ever have a kitchen on the second floor? it is sort a duplex)
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Anywho, I rigged up everything last night and waited till today to do the high pressure testing because I didn't want to go to sleep in a bad mood in case things messed up.

I used a "blast shield" just in case..
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This actually worked well enough and I was getting results.. I could hand crank with a socket wrench up to about 8k psi.. tried to get readings best I could.. it would slowly leak down (even with the rail pressure regulator solenoid on full) so I could kind of time when, then hit STOP on the scope, saved the pic, released pressure.. rinse repeat.. I got a couple of numbers..

I tried the drill to crank it. This was able to get over 9k psi in a split second, and I was then using this to get up to pressure faster.

I then pushed it too far and I hear a *pop*
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.. That's the adapter that came with the LOW pressure fuel gauge (which is still between the filter and the HP pump, I regulate it manually to keep it around 60psi when cranking). I was actually curious if the brass fitting between that steel one and the new high pressure gauge was strong enough.. turned out the tube was the issue..

The mess this time was only a few paper towels.

Time to either figure out if I can use the existing injector feed line that is unused from the port I tapped into - or if I need to order something new.

I didnt get enough numbers to make it graphable yet.. need to go through a few times (in 1k increments) to get a good avg plot going.. it was actually seemingly working quite well before this failure.


Update1: Looks like the gauge has matching threads directly to the feed line! .. but even before, I should have drill out a round on the gauge first for better mating, but that isn't where the failure was before, anyways, that's the plan, just round out the hole for better mating of this line to the gauge, and I should be back in business - actually, second glance, the threads to the rail and the gauge are the same, but not the injector side, I may or may not have the right adapters on hand, and certainly no SS

Update2: I bacially yielded(broke) all the other adapters when torquing down.. will have to find an appropriate steel one.
Update3: Ordered two adapters. one will fit to the end of the stock feed line (where the injector would normally connect) and the other to go directly on the rail which I would rather try first but I still wanted both on hand.. Will be delivered on Tuesday

Noxz
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Re: (Bio)Diesel Powered

Post by Noxz » Tue Aug 14, 2018 10:26 pm

New adapter came in. (one was wrong, was was right)
First impression: Beefy
at least compared to the low pressure gauge kit contents - of which I yielded about half of the brass adapters. This is "aircraft grade" aluminum - I would have preferred steel (stainless) - but the 1/8"-1/4" wall thickness should make up for any concerns.

I am using the stock fuel feed line (that goes to the injector) and thus made for high pressure. I carved out a cone for better mating in the male end of the adapter which connects to said fuel line. Everything torqued as best as I can (with the wrench)..

I was able to test pressures by hand cranking it up past 6k psi no problem. I also might have primed the actual gauge a bit better this time around (used a meat injector to deliver fuel into the gauge tube and purge out most/all air)..

But I am going to a Goldsmithing presentation tonight and would rather not smell like fuel - so further number gathering shall wait for tomorrow.

(You can also see that I am using 10k pullup resistors as well, which was inplace last time)
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Noxz
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Re: (Bio)Diesel Powered

Post by Noxz » Wed Aug 15, 2018 9:52 pm

I believe I have the equations..

went from 0 to 10k psi.. finally figured out a "Decent" way to have my hands on all of the controls (75psi primer pump switch, rail regulator switch, hand drill->HP pump, STOP button on scope, eyes on the gauge as it falls... then flip off the primer pump to inhibit any leaks, then the rail regulator, then remember the numbers, run over to the computer and enter them in, come back, push RUN... repeat)

Stopped here, although can likely go a bit more, but appears I have a leak around the gauge.. I can still get pressures and whatnot, but would rtaher fix that first. I read to NOT put PTFE plumbers tape anywhere near a diesel high pressure setup since it doesnt come like that from the factory... but I just might try it (since I have some)

0.982 and 0.995 coefficient of determination is pretty decent if you ask me.. and this is based on my timing of pushing the stop button from the "natural"/"slow" leakage of the rail system (I have maybe one second from when I stop the drill to pushing stop on the scope).. so overall that seems pretty good to me!

Next up may be to "command" a certain pressure based on these formulas.. ie, regulate it.. (specify I want 3k psi, then 4k, and let the controller/injector driver figure it out) will also delve into the SCV (Suction Control Valve) on the HP pump.. I am not entire sure if I will need to hack the eval board so the two circuits (one feedback, which could be unused?) dont alter themselves from the back EMF..

(ignore the "0-4k psi" title of the graph.. that was obviously a stopping point when I was trying to figure out how to use openoffice)

Edit:
Something like..
voltage1 = -0.1*[kpsi]+4.594
voltage2 = 0.1*[kpsi]+0.555

or..
voltage1= -0.1*[kpsi]+[voltage1_zero_psi]
voltage2 = 0.1*[kpsi]+[voltage2_zero_psi]
since the starting voltage is obviously readable/usable..
super simple in the end.. just one tenth.. neat.. especially in relation to PSI specifically.. I wonder if the range is 45kpsi - I doubt it though


Edit2:
I had voltage and kpsi mixed up in the equation some.. fixed that, but also moving stuff around we should get..
kpsi = (voltage1-[voltage1_zero_psi]) * -10
kpsi = (voltage2-[voltage2_zero_psi]) * 10
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Re: (Bio)Diesel Powered

Post by kb1gtt » Thu Aug 16, 2018 3:56 am

An R2 of 0.98 to 0.99 is pretty good, I suspect most of your error is because of the gauge and its variations. I think your spreadsheet equation is reasonably accurate and it looks like you have a linear sensor. I'm not following sensor one be sensor two. Are they side by side?

I'm also not following your math. I under stand your spreadsheet is backwards. So you have to do some algebra to get it to play nice. You could swap the data in the spreadsheet then use that equation. I'm not following the 10 thing.
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Re: (Bio)Diesel Powered

Post by Noxz » Thu Aug 16, 2018 4:18 am

I think most of my error is the physical delay of expectation when the gauge hit's the desired number and me pushing the stop button on the scope.. there isn't much reaction time and no regulation based on the two solenoids (one 100% on, the other 0% on).. but yeah, to get R2 for linear up that high is pretty impressive imho..

It's a dual output sensor, 4 wires, one screw terminal into the rail - I believe for redundancy. I don't really have additional information (and thus the reverse engineering/black box) especially when the service manual stated it gave a PWM output (which would somewhat correspond to voltage, but meh). I think if the calculated PSI from voltage between the two strays more than, say more than "10%" (of total range?) then kill off the engine and flash the MIL for the sensor to be replaced.

Let's review my math (in case I goofed)..
Sensor 1:
per trend line: VOLTAGE1 = -0.1040*[K_PSI_1] + 4.5944
Sensor 2:
per trend line: VOLTAGE2 = 0.1001*[K_PSI_2] + 0.5548

y=mx+b
both of those "m"s look to be near enough 0.1 to me (negative 0.1 for sens1).. which is that 1/10th..
"b" should be the voltage at 0 PSI
so..
VOLT1 = -0.1*[K_PSI_1] + sens1_0_psi
VOLT2 = 0.1*[K_PSI_2] + sens2_0_psi

.. or move the 'b' to the other side(subtract the voltage by the starting voltage) and divide by 'm' (+/- 0.1)
(VOLT1 - sens1_0_psi) / -0.1 = K_PSI_1
(VOLT2 - sens2_0_psi) / 0.1 = K_PSI_2

dividing by 0.1 is the same thing as multiplying by 10..
-10*(V1 - S1_0) = K_PSI_1
10*(V2 - S2_0) = K_PSI_2


.. right?

Super happy that it appears this simple. Certainly worth the trouble I've gone through thus far (I would have loved the datasheet though :P)

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Re: (Bio)Diesel Powered

Post by kb1gtt » Thu Aug 16, 2018 10:08 am

Yup I'm seeing it now. I'm stuck on a cell phone right now and I didn't have time to do the math. I missed the /.1 =x10 thing. Looks like good progress.
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Re: (Bio)Diesel Powered

Post by Noxz » Thu Aug 16, 2018 3:56 pm

no worries, please excuse every step being dumbed down..

again, interesting it directly related to PSI instead of atm/bar or kPa.

good progress indeed.. next steps will be proper regulation.. and then the injectors!

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Re: (Bio)Diesel Powered

Post by Noxz » Thu Aug 16, 2018 6:09 pm

Double checked in the service manual. the HP pump is timed w/ the crank (1:1 ratio on the timing chain) likely to inject into the rail right before or during an injector delivering fuel to the cylinder.. 2 injections of fuel per rev of the pump/crank. I wont be able to simulate that, nor RPM guidance, on the bench since the hand drill isn't exactly accurate (even getting it "Straight" can be problematic)

The point that I am going toward was that the logic of expected pressure difference could be calculated and used for the advantage of predetermination and learning/estimating pressure curves + PWM anticipation.. not just adhoc: too much pressure? not enough? .. but v0.01a will be rough.

also (holds head in shame) I have yet to look through the rusefi code, if there is anything similar used for timing stability.

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Re: (Bio)Diesel Powered

Post by kb1gtt » Fri Aug 17, 2018 3:00 am

There was some talk / measurements about minium timing tick on the forums some time ago. From the bad memory Banks I think the minium was some thing like 0.01 mS or perhaps it's was 0.001mS. This should allow DI applications. I think you'll need a parameters changed to get this kind of minium tick. I believe the normal minium tick is something like 0.1 mS. See if you can find that threat. You should be able to find it by searching for direct injection.
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Re: (Bio)Diesel Powered

Post by Noxz » Sat Aug 18, 2018 11:37 pm

Got some misc electronics like hall effect sensors and whatnot to "know" when the pump as at a TDC or similar..

A bunch more math ahead and in the near future..

The initial goal is to determine the volume of the high pressure side. Common rail, lines, etc.. Because the high pressure injection into the rail can be calculated based on the initial volume, and knowing that 0.5ml is injected per stroke (two per rev..?) will allow to either limit the input(SCV), or the rail pressure regulator.

per https://www.engineeringtoolbox.com/bulk ... d_585.html the Bulk Modulus Elasticity can be expressed as
K = dp / (dρ / ρ0)
where
dp = differential change in pressure on the object (Pa, N/m2)
dρ = differential change in density of the object (kg/m3)
ρ0 = initial density of the object (kg/m3)

per DOI: 10.1007/s11746-000-0047-z
Methyl Soyate (the methyl trans-ester of soybean oil, which is likely the most common biodiesel available.. I do not know what I have)..
density at 0MPa: 0.88g/ml
density at 35MPa (roughly 5.2 K PSI): 0.90g/ml
K=35/((0.90-0.88)/0.88)
K=1620 MPa @ 35MPa
(strange that ref shows much different.. not sure how they calc'd it, as DOI: 10.1021/ef201608g nearly agrees with my calculation... so let's stick with it)

K = dp / (dV / V0)
K = (p1 - p0) / ((V1 - V0) / V0)

even w/o the hall effect sensor to know when an injection may happen it is very easy to set the scope to 1 second and crank it with the drill to hit high pressures, fast, and able to zoom in to look at the numbers..

ONE injection, ie, 0.5cc, raised the pressure from atm to 5.35 K PSi (36.8 MPa)

K (1620) = 36.8/(0.5/V0)
V0 = 22.01 ml

... I have no idea how accurate this is as I dont want to try to empty the rail nor all the lines and introduce air. There is also the chance regular diesel is still in a bit of the lines causing different pressures and whatnot. I tried to compute subsequent injections to try to verify - but initial graphs/refs dont really go above 35MPa(~5kPSI) of which is really only the one high pressure injection.


I can imagine a routine where this common rail volume is learned - by similar maths, but is entirely based on what fuel is in there. Knowing the stroke/diameter of the HP pump (so long as that is right....) and the density of fuels at various pressures is all that is needed to learn this new number.

this was WITH the manual pressure gauge on one of the lines instead of an inject, and with a small leak - I will need to recompute once the original injector is connected.. I really dont think I need the gauge on anymore since I got the voltage:pressure equations.

The idea here is if I only need to increase the pressure by [x] amount, then to use the SCV and limit how much fuel it intakes and subsequently outputs onto the rail instead of trying to maintain the pressure completely with the rail regulator - which is only the high-limit adjuster.. the SCV is the low limit - but it needs to be timed with the crank position (hence the hall effect which is less than optimal, especially when RPM is anything but constant when you are holding drill in your hand).


I've looked into about 4 or so papers on designing a common-rail regulator system/equations - some more reading needs to be implemented before I rig up more stuff, but having at least one number I didn't have before will help.

I may also try to learn GNU Octave (over matlab) to get some simulations going of the rail setup.

edit: also got a dedicated 5v PSU and some other electronics.. the 0 PSI voltage of the high sensor went from basically 4.6v down to 4.5v - but that shouldn't matter much, just a starting number, and is actually quite cleaner to work with in my head.. of course the STM and the KL are 3.3v logic so I'll divide that down with a 1k and 2k resistor for 2/3rds..
Last edited by Noxz on Thu Dec 20, 2018 8:43 am, edited 1 time in total.

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Re: (Bio)Diesel Powered

Post by kb1gtt » Sun Aug 19, 2018 3:21 am

Keep in mind most adc's and pressure sensor are ratiometeric. If both are ratiometeric then variations in rail voltage are of a lower importance. Aka the ratio is the same even if the rail changes.
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Re: (Bio)Diesel Powered

Post by Noxz » Sun Aug 19, 2018 7:28 pm

Another logic part of the puzzle..

Knowing that 0.5cc are injected at 100% (two plungers so twice per rev, but unknown when to TDC this happens just yet.. but it is timed).. What if I only wanted 75% of that 0.5cc?

the plungers of the HP pump are driven by a concentric (square or triangular based on # of plungers) cam that follows a completely sinusoidal path, just as any piston to the crankshaft. This means that at it's TDC and BDC it does not suction in as much fuel. This rate of change is actually the cosine curve ( yay! calc+trig... :/ ) and the area under this curve is the quantity injected.. This area is the integral, which just so happens to use sin, again..

(in degrees to keep my head sane for a moment, but will likely switch over to radians.. eventually.. 90 deg = pi/2..)

sin(90) - sin(-90) = 1 - -1 = 2
do to phase shifting and whichever we "start" at -90 for the sine curve.. logic maybe slightly screwy there, let's just use 0 to 180deg (pi) w/ cosine instead since it is the same.. why not, just ignore that last part, because of where the "starting" point of the suction/pump is why the offset exists..
cos(0) - cos(180) = 1 - -1 = 2

so,
2*(0.75 percent) = 1 - cos(x)
cos(x) = 1 - 1.5 = -0.5
x = cos^-1(-0.5) = 120 deg
75% requires the SCV to be turned ON (in my case) from 120 to 180deg

note: I'd like to look at 3 plunger systems at some point, my rough code for this stuffs so far does try to implement some logic into figuring out correct curves, but less effort has been made to make it work for everything in the world.

This was all very simple but I still wanted to map out some of the logic "on paper" - not to run anything by anyone, but more of explaining my step-by-step process of figuring this all out.

great.. my first issue: the hall effect sensor works for a little blip of timing, but it doesnt really give me position which would be much more useful. I do have encoders attached to some steppers for a CNC mill that never happened that I am going to take a look at if I can rip one off and hack it in. I almost considered using the stepper over the drill for power, but I don't think I have enough connectors on hand to hack it together.

Edit: My optical encoders dont have an index.. :/ possibly using that hall effect sensor as such, but it may require a bit of hacking, especially because of shaft size differences..

Edit2: I was actually able to key the stepper motor to a 1/2" socket with a nail I cut.. I may bust out my smoothieboard and rig it up.. certainly more stable than the drill method, even if I were to stablize the drill I think this will actually be better due to being able to affect the RPM in a much more precise manner.. it's a pretty beefy NEMA 34 stepper w/ 600+ oz-in torque, wired in parallel - so I would think it could turn the HP pump no problem but I honestly have never even used them because the adapters I kept ordering from overseas were always the wrong size, time and time again, which setback the CNC project a bit..
I'll need to rig up some more wood to hold it all in place, but using the encoder + hall effect sensor this way should work to detect and use the values for timing.. kinda rough but almost no different than a crank position sensor.. I just need to be able to drive all of this in a better fashion.. if I had a lowerpressure fuel sensor (up to ~100+ psi?) I would rig it up to the low pressure side and even control the starting pump, but that is currently on a switch and is easy enough, I could also stick a relay on it with a general timer..
I feel like using this stepper is going to be the way to go for further testing..

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Re: (Bio)Diesel Powered

Post by Noxz » Mon Aug 20, 2018 8:17 pm

Stepper mounted.. very stable and glad I wont have to deal with the hand drill anymore..

That hall effect sensor will be (no longer flapping in the wind) picking up a magnet on the socket, likely held in place w/ electrical tape.. the shaft of the stepper is not ferromagnetic otherwise I would have mounted it near the optical encoder. The whole purpose of it is to be able to index since the encoder doesnt have an index. I will then run it with the scope on the hall effect, and atleast one channel (A or B or both) of the optical encoder, and a pressure sensor output to know when the injection happens in relation. Based on that info, I will then drive, for the first time via the MC33816 eval board, the SVC at various percentages in relation to the timing and detect presure output, then rig up the rail solenoid to the driver board as well.. then once I have a stable pressure generator I can test the injectors!

I will be running the stepper in parallel winding @ 12v, since the 24v PSU that I got for the CNC originally isn't setup and would take a bit more time and wiring (hacking/soldering)

the tub "Blast Shield" no longer fits snugly over the setup thanks to the stepper mount.. but I havent had an issue since reinforcing (and using a proper high pressure steel line to the gauge, which will be going away once I make stable pressure.

I am awaiting a USB-A->B cable, arriving tomorrow, to interface with the SmoothieBoard (as MSD for changing the config/testing).. I couldn't find one as most of everything is using mini and micro nowadays.. The plan is to use the second serial interface on the KL25Z to talk to it (first one is programming the MC33816) since it has two..
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Re: (Bio)Diesel Powered

Post by kb1gtt » Tue Aug 21, 2018 1:40 am

Nice wood work.
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Re: (Bio)Diesel Powered

Post by Noxz » Tue Aug 21, 2018 2:37 am

kb1gtt wrote:
Tue Aug 21, 2018 1:40 am
Nice wood work.
hah! this was one of the biggest hack jobs I've done.. just glad to have everything on hand, including a hole saw big enough, to do it..

there is a gap at the top of the stepper mount to the other filler block because it was thinner than the 3/8" OSB and I didn't want to cut the 2x4 to actual width.. other parts were hacky as well

the SmoothieBoard (v1.0) is limited to 2Amps at the driver, hopefully that will be enough. Will initially be at 12v but if I need to bump it up to 24v, even though I have a 24v PSU for the CNC, I will likely use the variable PSU as it is good up to 5A and will require less hacks - that would be for attaining higher speeds, but I shouldn't have an issue going at 10 rev/s (600rpm) based on internet data which would be "idle" in my book..

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Re: (Bio)Diesel Powered

Post by Noxz » Wed Aug 22, 2018 6:26 am

I was able to program a UART serial port on the KL25Z to interface with the SmoothieBoard and send G Codes.. (took most of the night because I am fairly new to it all)

only a few configs needed to make a "standard" "mm"/rev and feed rate.. G1 X10 F6000 is one rev @ 600rpm.. so changing it up to X100 will give 10 revolutions in one second. I will have both of those rigged to buttons, and will be testing it out tomorrow, as I need to figure out how to compile and send the program (easy enough I think) vs being in debug mode, as I really dont want to try to bring my computer (no laptop) close to the flowbench, I almost wish I had another one, or the frankenso, to program back and forth easier..

from what I can tell, nothing is going to stop these steppers from moving, but that will be the main test, if it can generate pressure.

then onto timing w/ the hall effect and optical encoders to get SVC timing down.
then working with the MC33816 eval board and the SVC to do various percentages of pumping
then the rail regulator w/ pressure..
then the overall initial algo for that setup..

then the injectors.


I also got a new/better adapter for the analog gauge, still through the orig feed tube, though I will be removing it once I stabilize pressures as I will want access to all injectors.
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Re: (Bio)Diesel Powered

Post by Noxz » Fri Aug 24, 2018 4:08 am

So, I was able to rig up a stepper via SmoothieBoard getting G-Codes through the serial interface from the KL25Z.. and it was actually able to turn the HP pump once I fixed alignment issues with a u-joint socket..
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.. Somewhat ..
It was able to turn it while the rail wasn't "on".. otherwise it could really only do maybe 1k psi, if that.. just not enough umph.

So I yanked off the rotary encoder, and made a new setup with the drill.
Pump -> Sprocket Nut -> 13/16" 3/8" Socket -> 3/8" U-Joint Socket -> 3/8" drive to 1/4" Hex -> Drywall adapter with outercase removed (which is exactly 3/8" diameter, matches the diam of the rotary encoder) -> Drill (semi supported to the table)
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This is working a bit better than before, I think mainly because of the nice 3/8 "bearing" that I made in 2x4 that the drywall drive rests on (I added some silicone grease).
I also have the hall effect sensor somewhere in the middle there, and for one experiment I put on two magnets at 180deg to verify what I was finding vs what I initially thought. The ~5k PSI that I was registering "per injection" before was wrong, that was per rev, but was difficult to detect without a second blip from the hall effect sensor. One single injection is closer to 3k psi .. which may mean closer to 44cc of rail volume (this is also with the new, and noticebly better, and teflon tape'd, gauge adapter - but I am finding myself not looking much at it anymore and more on the scope)

Also moved the rail regulator from the light switch I was using before (hack job, but leftover from my fumehood where I used 3 and they were easy to gank and setup) to a button controlled relay.. the idea will be to hand this over to the uC and eventually to the injector driver board - why not jump right to that? maybe because I dont know how the feedback will work with both "fuel pump" drivers going on, and I want to focus on the SCV first.

I may use a relay (should?) for the drill, it can handle AC (mechanical not SSR which sometimes has diode effects)

I am currently figuring out the timing of this system. 500 steps of the encoder, two channels (picked [A] for best fit on these initial tests). counted the duration of hall effect on/off, as well as the time from that to when pressure started.. I had issues with this general problem because this scope doesnt have the option of specifying the current time window from specific numbers, only scaling via the knob, so sometimes I have to add or substract from a base number(# of Pulses) and is less than ideal. I need to work on the timing, I have a second stepper setup near the computer for simply using the rotary encoder still attached to make the dev board know/learn about basic timings and what "crankshaft angle" it is currently at.

the hall effect sensor/magnet is arbitrarily slapped on, so there isn't relation to when the suction starts (what "crank angles") but simply time of when the injection flows into, which occurs after the injection phase begins because it has to overcome some check spring tension... so stating it's not so straight forward.

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Re: (Bio)Diesel Powered

Post by Noxz » Mon Aug 27, 2018 5:52 pm

Didn't do anything over the weekend, because of life..

I noticed I didn't share this image, of a double SCV timing graphic. Comes from a denso service manual.

if I had an electronic low pressure fuel gauge I could read when the suction happens, with regard to a TDC, but I think I know it from test experience and resistance/whatnot of cranking in relation to the key of the HP pump shaft.

Also, only one week left of work, and a bunch of house work to do in the 4 weeks before school starts.. dunno how much of anything I will be able to get done, although the engine is more of a night time project currently, anyways.
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Re: (Bio)Diesel Powered

Post by russian » Mon Aug 27, 2018 11:26 pm

Noxz wrote:
Mon Aug 27, 2018 5:52 pm
Didn't do anything over the weekend, because of life..
Story of my 2018 so far.
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Re: (Bio)Diesel Powered

Post by Noxz » Tue Aug 28, 2018 2:45 am

russian wrote:
Mon Aug 27, 2018 11:26 pm
Noxz wrote:
Mon Aug 27, 2018 5:52 pm
Didn't do anything over the weekend, because of life..
Story of my 2018 so far.
I was wondering when you would stumble into my thread.. Was treating it as a dialog between only myself and kb1gtt for a while :)

The more the merrier.

Anywho..

The current effort is the timing of the SCV in relation to "the crank", gimick'd with a hall effect sensor - as some arbitrary known point such as TDC, and a rotary encoder - which will be replaced with a precise crankshaft position in the near enough future. Simply hand cranking the stepper (I could mount the encoder to a pen cap, 3/8" diameter, and drill a hole in a block of wood, almost no different than the flow bench, and spin the pen instead of some big clunky thing - as it may get too tiresome)..
The encoder has a CPR of 500 and if I go slow enough, on the stepper, I get a count of 490+ (timed to the ON of the hall effect) but if I go "fast" it can be as low as 400. I'm not using interrupts, just a while loop to see if certain pins are grounded (as buttons, using some simple transistors to use the greater than 3.3v results to drive it).. I really don't think it would be my logic, but at the same time, I'd think the 48mhz KL25Z would be able to keep up (that is in debug mode, though).. I guess I could also re-hookup the smoothieboard and power that stepper (not a bad idea, actually) instead of hand cranking and be able to map things out a bit smoother..

but the logic I am going for is simple: at X1,X2 degrees of the crank the suction starts, so if I want Y% then turn on the SCV (via the MC33816) at the the remainder needed.. rinse repeat

The problem I just saw was if this rotary encoder is going to be even near reliable (or the hall effect sensor at that) for basic tests.. it was certainly visibly working (fine?) from the scope when I was detecting the second injection and such, so maybe I just need to see where it might be goofing, and if fingers point to the KL25Z, then I should get the frankenso sooner than later (I am a professional procrastinator) for the extra compute power...

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Re: (Bio)Diesel Powered

Post by Noxz » Tue Aug 28, 2018 9:28 pm

Yup, it was the debug info.. specifically the printf I was using which uses a debug serial port.. obviously it is a blocking call
DS1Z_QuickPrint1.png
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I made an output of when the rotary encoder was detected(purple).. upon seeing the issue with the hall effect on/off, I commented out the prints and the missing pulses were then picked up.. of course without outputting the info.. but it should be 500 (and is within a few.. one is just 0.72 degrees off, which is going to be just fine for initial tests, especially since this is on the bench and not the engine - but upwards of 100 off was entirely too much and required the investigation.
once I removed the printfs:
DS1Z_QuickPrint2.png
DS1Z_QuickPrint2.png (63.58 KiB) Viewed 1672 times
I should now be able to do "correct" timing based on this info..

And I really should look at the rusEFI code (so sorry I haven't yet.. again) ... but is there any prediction model of what the timing/crank angle is expected at? the position sensor is likely a bit lower resolution
I could imagine it simply as velocity of the last pulse duration with time elapse, for simple method, could be more accurate taking a second order velocity into account as well..

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Re: (Bio)Diesel Powered

Post by kb1gtt » Tue Aug 28, 2018 11:08 pm

I see wave forms and comments about printf but I don't know what they mean. I'm not sure if my understanding of those comments is an issue or not. I suspect you're making good incremental progress, and you seem to have a plan that's allowing you to keep making the progress. I suspect that pretty much any comment I might make would only slow you down. So I guess I shouldn't comment to much. I'll say no need to reply to this. I'm just sitting here watching the show.

I think you are currently able to build pressure and regulate it. Or perhaps you're close to that step. It sounds like good progress.

On a side note, my dad has been trying to get me to do some crack pot experiments. He claims he mixed about 1 cup of vegetable oil with about 1 table spoon of tap water, in a blender. It takes a while to separate, but will remain mixed for a while. He then says if you put a drop (or a line) on some tin foil and spark it off with a propane torch, it's almost explosive. So if you happen to have a torch, and some time, perhaps you might want to try it and see if it does anything of interest. My dad's kind of crazy so it might not be of any interest. However he's also done a bunch of funky cool thing like this before, so it might be cool. I haven't verified it yet, so I don't know if it's a real or fiction. I suspect the water drops flash off and expose the oil to new O2. So a semi unique method of atomizing fuel. Either that or he was drunk off his ass and was seeing things. I'm not sure.
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Re: (Bio)Diesel Powered

Post by Noxz » Tue Aug 28, 2018 11:32 pm

kb1gtt wrote:
Tue Aug 28, 2018 11:08 pm
I see wave forms and comments about printf but I don't know what they mean. I'm not sure if my understanding of those comments is an issue or not. I suspect you're making good incremental progress, and you seem to have a plan that's allowing you to keep making the progress.
the debug printfs that I was making, for showing number of encoder detections per rotation(start detected w/ hall effect as a Top-Dead-Center reference), was blocking further encoder pulse counting which is why I was getting lower than 500 count
kb1gtt wrote:
Tue Aug 28, 2018 11:08 pm
I suspect that pretty much any comment I might make would only slow you down. So I guess I shouldn't comment to much. I'll say no need to reply to this. I'm just sitting here watching the show.
Although I am treating this thread as a "build thread" - specifically for the MC38116 and interfacing with the high pressure controls (I am thinking about making a second thread for the next stage of other sensors and whatnot, that is more engine specific), I welcome comments.. it lets me know I'm not just talking into the wind.. but I certainly dont need a reply for every picture I post, just providing the idea that I am working through my issues and how to do it is good..
kb1gtt wrote:
Tue Aug 28, 2018 11:08 pm
I think you are currently able to build pressure and regulate it. Or perhaps you're close to that step. It sounds like good progress.
working towards the pressure regulation system..
kb1gtt wrote:
Tue Aug 28, 2018 11:08 pm
On a side note, my dad has been trying to get me to do some crack pot experiments. He claims he mixed about 1 cup of vegetable oil with about 1 table spoon of tap water, in a blender. It takes a while to separate, but will remain mixed for a while. He then says if you put a drop (or a line) on some tin foil and spark it off with a propane torch, it's almost explosive. So if you happen to have a torch, and some time, perhaps you might want to try it and see if it does anything of interest. My dad's kind of crazy so it might not be of any interest. However he's also done a bunch of funky cool thing like this before, so it might be cool. I haven't verified it yet, so I don't know if it's a real or fiction. I suspect the water drops flash off and expose the oil to new O2. So a semi unique method of atomizing fuel. Either that or he was drunk off his ass and was seeing things. I'm not sure.
So he made an emulsion of veggie oil and a tad bit of water, put it on alum foil, and took a torch to it.. veggie oil is flammable in and of itself, and aluminum is very reactive - it makes the oxide layer almost immediately in air, and commonly for chemistry experiments you need to make an amalgam w/ Mercury to be able to use "elemental" aluminum (but I do have alternatives to this, when I made Aluminum TriIsopropoxide).. It reacts with water to make Al(OH)3 + H2(g) .. the heat of the combustion of the oil with the possible generation of hydrogen gas of the Al reacting with the water could cause more of an explosion than just a flame.. The flame may have pitted (or melted) the aluminum and the oil may have kept the water near enough for longer w/o evaporating... maybe.
This is basically what happens when you see the videos of someone dropping Sodium metal into a beaker (or lake) or water and it "explodes" .. what happens is that it'll generate hydrogen gas and LOTS of heat from breaking the bonds.. that heat then ignites the hydrogen gas.. the actual sodium isnt really what's catching fire (but does melt under the extreme temperature it experiences, and could vaporize)

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Re: (Bio)Diesel Powered

Post by kb1gtt » Wed Aug 29, 2018 10:20 am

I don't think the aluminium foil did anything. I think he just did that so it didn't absorb into what ever it was put on, and could handle some heat from a torch. As well clean foil is easy to obtain. I should try it some time and see if it does consume some of the foil. He didn't mention anything about the foil being consumed and I suspect the temperatures are to low for igniting the aluminium oxide layer. I would also doubt the temperatures were high enough for reaction to straight up aluminium.
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Re: (Bio)Diesel Powered

Post by Noxz » Tue Sep 04, 2018 4:27 pm

Today is my last day of work..
School starts in 3 weeks..

Still a ton of house work to do. I replaced the sheathing + windows of the oriel (sort of like a Bay window, but cantilevered up a story).. so I made good progress given the longer US weekend, but all that happened with the flow bench was that it got covered in drywall + OSB dust.. most of that is all cleaned up.. the yard is another story though, about to head out and clean that up.

Beyond that, the only thing on my agenda is to mail in my laptop to my manager..

I almost forget where I was on the project.. I think it was simply to figure out timing of the SCV and eventually develop/utilize an algorithm of deviation correction.. I read a few whitepapers on design of that control so it shouldn't be too bad.

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Re: (Bio)Diesel Powered

Post by kb1gtt » Tue Sep 04, 2018 6:18 pm

What your working on the house before winter set's in. What's wrong with you :)

Glad to hear it's still on the todo list, I'll stay tuned to see your next steps.
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Re: (Bio)Diesel Powered

Post by Noxz » Tue Sep 04, 2018 7:13 pm

I actually started back in december because it was relatively dry.. but I really wanted to dodge the hot sun - especially since that wall is west facing, although less daylight hours means less outside work.. I have the rest of that wall to resheath (+2 windows) and a longer wall with 4 windows to do..

oh, I also delayed because I never got building permits (working on that) and I was technically doing some structural changes - with new window sizes and such......

mailing the work laptop will clear off my desk, already looks much bigger/cleaner since I had to move it to access the windows. should have a nice spot for simple experiments.

edit: also, in the PNW, we dont really get snow or whichever (and I am adding insullation so it'll actually be warmer once done), but there is plenty of daily rain that will pickup soonish.. but I havent been here long enough to actually forecast

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Re: (Bio)Diesel Powered

Post by Noxz » Sun Sep 09, 2018 8:24 pm

ok.. I'm giving this more thought..
Now that I don't have a job anymore, in preparation for being a full-time student, I am wondering if going with the Smart fortwo as the shell would be a good decision considering I have a rolling chassis of my electric project car in the garage. Money isnt the biggest thing here, but space? I would really prefer not to park something small in the driveway just because the driveway is small.. oh, and convenience - I have a rolling chassis already.

it's an old kit car, so it's just riding on a vw beetle chassis (with vw 4 speed tranny) with a fiberglass top.. but it looks killer, and gullwing doors. It really cant get much simpler to interface with.

I would not just replace the electric project with this one, I simply need something more readily available/attainable for the near future (school+internship). The electric project is going at it from a diff angle, with the battery/energy storage problem first, then onto a new/different motor (orig 20HP GE Brushed DC motor).

Oh, there's only 1300mi on the car.

Pics from the "storage" area in the back yard in San Jose from a few years ago.
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Re: (Bio)Diesel Powered

Post by kb1gtt » Sun Sep 09, 2018 9:43 pm

Once you have a bench top engine, you can put it in any vehicle you want. :)
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Re: (Bio)Diesel Powered

Post by Noxz » Sun Sep 09, 2018 9:47 pm

Yup.. and cleaned up the kitchen today.. had replaced the window (that got drenched in bio) a few days ago.. flow bench kinda got a bit of sawdust + gypsum on it, but the real mess came from plant pots that fell over and spilled soil everywhere..

I may have a few days downtime of doing house work, so may be bale to return to the pressure regulation system soon enough.. it's all about the timing.

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