Axial/radial mounting of VR sensor at 36 bicyle wheel?

[ami8break]

Hello EDIS guys,
how should I fix a VR sensor when I'll use a 36-1 tooth wheel from a bicycle?
Axial or radial? Please see attached pictures.

Is it necessary to use the original Ford VR sensor to trigger EDIS modul or does any VR sensor work? I'd like to take a PSA(=Peugeot/Citroën) TDC sensor because I have some of them (as spare part for our dailydriver).

Thanks
»Horst

[78Spit1500Fed]

Hello EDIS guys,
how should I fix a VR sensor when I'll use a 36-1 tooth wheel from a bicycle?
Axial or radial? Please see attached pictures.

The axial mounting may work; you should use an o'scope to see the waveform. If it's zero crossing is smooth, then it shouldn't be a problem. (The wave should pass through zero without any "jagged" or rough fluctuations)

The raidal mounting would likely cause some problems; the window on most VR sensors is fairly wide... at least 4mm. There are smaller sensors which may fit the bill, those that have a more narrow window but I would be leary of a setup in this configuration. You not only have to worry about runout, but also the "flatness" of the sprocket.

Is it necessary to use the original Ford VR sensor to trigger EDIS modul or does any VR sensor work? I'd like to take a PSA(=Peugeot/Citroën) TDC sensor because I have some of them (as spare part for our dailydriver).

Thanks
»Horst

The Ford VR sensor is not special in any way... there are many installs using EDIS which do not use the stock VR.

-Brian

[ami8break]

Hello Brian,
thank you for your detailed reply!
I'm happy to hear that you recommend axial mounting because this is much easier to realize for me.

Do you think this is a good radial distance (picture) or should I move the sensor further more from (to?) center? Yes, I'll check with scope but which is best point to start? For stiff mounting I'll keep the hole as small as possible, space is rather narrow there and I can't test on bench.

Last problem are the screw hex heads used to fix the plastic ventilator. Unfortunality the screws have no metric thread so I can't replace them with others. Which distance could cause some wrong trigger signals? Is it possible to 'hide' magnetic flow of the screw heads? Maybe with a sheet of aluminium?

»Horst

[renns]

Horst,

The screws you refer to are for mounting the sensor? Since the screws won't be moving relative to the sensor, and they are around to the side of the sensor body, I'd expect no problems. The EDIS module has some built-in filtering which should help clean up any minor noise issues as well. From the MegaJolt site:

The thing to note here is that the EDIS module handles all VR signal processing. In fact, the EDIS module has a built-in VR signal hysteresis - when the VR signal is transitioning from negative-to-positive polarity (next tooth is approaching), the signal must reach 0.5 volts positive before the EDIS module will "arm". It then will "trigger" when the signal passes back thru zero from a positive-to-negative transistion, when the VR tip is aligned with the crank wheel tooth. We have measurerd and verified the hysteresis effect on the bench (in-circuit). This hysteresis helps prevent false triggering, and it is something to note when experimenting with the EDIS module.

I think you'll be just fine as you show in your picture. Test with the sensor about 1mm from the sprocket. If you don't get a good cranking signal, move it closer and try again. You'll want to ensure the sprocket is running true though, as any wobble is likely to cause you some issues.

Be sure to post the results of your tests!

Roger.

[78Spit1500Fed]

Hello Brian,
thank you for your detailed reply!
I'm happy to hear that you recommend axial mounting because this is much easier to realize for me.

No problem, I'm here to help!

Do you think this is a good radial distance (picture) or should I move the sensor further more from (to?) center? Yes, I'll check with scope but which is best point to start? For stiff mounting I'll keep the hole as small as possible, space is rather narrow there and I can't test on bench.

The distance is probably good. There is sufficient metal which will pass the sensor to cause a decent voltage swing... if you can slot the sensor mounting hole on one side, that will give you some "wiggle" room.

The EDIS trigger "wheels" (some aren't wheels at all, but castings in the flywheel, or even pegs drilled into a flywheel) are a varied bunch... the OEM flywheel variety usualy has a 50% duty cycle...that is the gap is the same size (or very near) as the tooth. Some teeth are pointed, and others yet are just pegs in a flywheel. What's important is that 0 volt crossing... however you get there is fine!

Last problem are the screw hex heads used to fix the plastic ventilator. Unfortunality the screws have no metric thread so I can't replace them with others. Which distance could cause some wrong trigger signals? Is it possible to 'hide' magnetic flow of the screw heads? Maybe with a sheet of aluminium?

You could replace the screws with stainless steel; they are non-ferrous and would not cause a trigger at the VR sensor. (I'm not sure what you mean by "no metric thread" are they ISO? Fasteners are easy to come by around here, what are you needing? I might be able to get some)

Other than that, there's really no way to hide that ferrous metal from the sensor. A sufficient distance is really the only way; that's something you'll have to experiment with. Keep in mind that the distance from tooth to sensor is about 1mm. At about 3mm you will probably loose all signal. If the screw heads are that far or farther, then you're probably fine.

-Brian

[ami8break]

Hello Roger and Brian,

I avoid a slot mounting of the sensor because it is fixed just with one screw. Maybe I'll add an aluminium sheet with its shape so I can fix the position (after testing) with 2 rivets.

I added 2 pictures to show the axial and radial distances, the screw head height is 4mm --> distance sensor - head is 4-5mm. (The inner extensions are just to touch the OEM flywheel for the 1st time assembling.)
It would be fine if I could move the bicycle wheel away from pulley/rim because I also want to add a camshaft sensor (a grinding machine modded dizzy - but this is another story) which is also *near* by.

In one picture you can see the thread of the ventilator screws --> I was afraid no stainless steel alternative is available, but this morning I tested with a M5 metric screw successfully (and THIS should be easy to purchase).

> , there's really no way to hide that ferrous metal from the sensor.
If I move away from pulley/rim what's about the Ø7mm holes in the disc?
The superfluous holes can be closed/welded but what's about the holes for the stainless screws? They keep active as noise trigger potential!
Axis distance between sensor and hole is not more than 6mm - could I move the trigger wheel til the height of the new stainless steel head (4mm) or even closer if I grind the srews head heigth down to 3mm?

Please forgive me but I have no easy acess to garage equipment so I have to consider all problems before to find a grind/drill/weld/plug&play solution.

Thanks, when this modification is finished I'll report here.

»Horst

[renns]

Horst,

If that complete flange with large hex bolts is spinning past the sensor, then you are right to be concerned! I was under the impression it was stationary, and the wheel was spinning separate. Stainless fasteners will help, but you still may get some noise. If there was more space you could put a shield in place between that mounting flange and sprocket, but it already looks pretty tight.

Roger.

[ami8break]

Hello,
Here is my 1st report.

I assembled 36-1 wheel and made scope views. It was not possible for me to see the missing tooth and no influence of the normal magnetic steel nuts.
--> EDIS-Trigger-steelhexnuts.gif
The trigger signal is a sensor 45°BTDC. I count more than 36-1 + 3 (holes for the fan screws) peaks at each rev.

Unfortunality my DIY cam shaft sensor had no space --> I had to hide the screws. --> IMAG0083-36-1-Kettenblatt-fertig.gif. It was not the cleverst solution but I bought stainless screws --> even surface but maybe magnetic fux from the holes. I'll buy common rusty screws the next days.

Yesterday I connected EDIS to circuit (but not to MS) and watched the PIP signal. --> IMAG0010.gif
I wonder that PIP signal is negative and at the same position than my engine trigger signal (45°BTDC). I thought it will come exactly at TDC. --> 45° difference
I also tested with the OEM 10°BTDC sensor as trigger signal - the same pic! I'm not an EE so maybe I made something wrong.
I turned crankshaft to 45°BTDC and added 4.5 teeth (36/8=4.5....45°) to get the EDIS-4 90°BTDC missing tooth postion. I tested with scope again (like IMAG0010.gif).

Then I tried the limb home mode and connected 'Coil1' wire to my OEM wasted spark coil. 'Coil2' was left because my engine is a flat twin (but no twin spark). Of course the MSnS plug from BOSCH ignition module was removed from my OEM coil before.
I expected that EDIS should fire at 10°BTDC but engine didn't start. I missed missfire so I think that there was no spark - I was afraid to check the 'Coil1' output wire with scope (1MOhm, 28pF, max 400VDC or pk AC + 10MOhm 'sensor').
I'm not sure that the EDIS module was working before I got it.

»Horst

PS: 'Edit' was just to upload EDIS-Trigger-steelhexnuts.gif

[ami8break]

Hello,
sumary: I welded a bicycle 36-1 tooth wheel at my pulley (fan) but couldn't get EDIS running or got any wave form at scope using a PSA inductive(?) sensor.
Plus (+), minus (-) and shielding - connected sensor (and some from the shelf) both possibbilities - no limb home spark. But when I triggered EDIS module with an audio file the sytem worked fine!

During winter break I could get an original Ford EDIS pick up sensor and tried it today again (=end of winter break). I wonders that the EDIS one is ferro magnetic - the PSA types are not!

To make the story short: Built in the the EDIS sensor (gap ~1mm) to bicycle 36-1 wheel and it worked at once (limb home mode)!

What the hell used PSA for their TDC test trigger socket? Hall sensor? I can't believe, because no +12V source is needed.

I'm happy to test MSnSExtra with 36-1 triggering the next days and later EDIS support and some more days later the second wheel decoder (a DIY cam sensor is also fitted).

It looks that a nice MS saison has been started today.

»Horst

[78Spit1500Fed]

Congrats!

Glad to see you got it sorted.

-Brian

[ami8break]

Thanks Brian,

JFYI: My free hand welding was not absolutely ok, surprising - isn't it. ;) Distance sensor - teeth changed (intervall <0.7mm):
http://megasquirt-de.serviceline.ch/suc ... BoxOFF.gif
Then I checked and corected on an spare engine block with an accurate distance device/clock(?) --> intervall <0.15mm:
http://megasquirt-de.serviceline.ch/suc ... BoxOFF.gif
Scope views were made with DIY-voltage dividers and soundcard as scope and nice software.

I didn't remember any problems during running EDIS, measurements wer made just for 'researching' and I'd silly if I hadn't improved/averaged distance gap playing with the wheel.

»Horst