Subject: O2 sensor mounting (oscilloscopes)
From: Rotary Engine
Date: 7/17/2007, 12:29 PM
To: AARotary Engine



> > Hi All-
> >
> > Now that I have my newly-updated EC2 and EM2 back in place, I wanted
to
> wire
> > in the O2 sensor to enable auto-tuning mode before I try for a > > startup
> > again.  The suggested O2 sensor, unfortunately, requires a
18mmx1.5thread.
> > A tough tap to find.  Worse, it requires a 16.5mm pre-drill -- even
> harder
> > to find.
> >
> > Anyone have any suggestions on how to get my hands on either/both of
> these
> > without spending an arm & a leg?
> >
> > Mark (Rocky mtn high)
> >
> > Magic words are Metric Hand Taps http://www.mcmaster.com/ Cost one
arm.
> >
> > Magic words are Metric Drills http://www.mcmaster.com/ Cost one leg.
> >
> > Or if worse comes to worse a 41/64th will work.
> >
> > Also try Enco or Airgas or Rutland Tool and Supply
> >
> > Don't forget to make a quart vac can to smooth out those
intake  pulses.
> >
> > I'll stop in on my way back or too OSH (Tuesday next week) and help
out.
> > It will help if you have or can rent a scope. We can take the lid off
> Tracy's computer
> > and put a scope on the output wire of the pressure sensor. Or we can
> > buy a pressure sensor and feed it some power and use it to monitor > > the
> pressure
> > pulses. Or I can bring my computer and power it up and connect to > > that
> pressure
> > sensor. We can tee off the pressure hose.
> >
> > Paul Lamar ...No rotor no motor.
> >
>
> For the O2 sensor, I got a "bung" that I welded into the exhaust > system.
> It's the same thread as an 18MM spark plug.  I think I got it at NAPA,
> but I'm not sure.
>
> Bob W.


Thanks, Bob -- the bung is clearly the way to go!

Paul - I have a choice of a steel bung for $5.95 & a stainless bung for
$6.95.  Any reason to pick one over the other?  (In terms of weld-ability
I
mean).

Mark (Rocky Mtn high)

Go with the SS. Do you have a scope? I might be able to bring mine
if not. We need to get a handle on this intake pulsation problem.
-- 
Paul Lamar ...No rotor no motor.



I do not have an oscilloscope.   Let me post a message to the local EAA'rs &
see if I can scare one up.


mrs

Great Mark. Maybe Doc has one. We can trigger off the crank angle sensor
signal.
-- 
Paul Lamar ...No rotor no motor.

I have been considering buying a scope. What bandwidth, channels, etc. is
needed?

I am extremely interested in this.

Doc Custer
Retired Software Engineer and sometime Audiologist

Well most scopes are 100 MHZ and two channels.
They still run about $1500 new.

You can some times find used bargains on e-bay.

This is a classic. Four channel and 350 MHZ
http://www.exphil.com/products/Tektronix/2465A

A bit over kill for single chip computer use.

http://www.google.com/products?q=Tektronix+2465A+&hl=en&um=1&sa=X&oi=froogle&ct=title

I have something like this one. Works great for single chip computer use.

http://www.google.com/products?q=Tektronix+465&btnG=Search&hl=en&show=dd
Make sure you get probes in the bargain as they can run into real
money.

Doc,
For working around airplanes, I can't emphasize enough the value of a
portable instrument.  I would suggest looking for a used Fluke 192B or
196B Scopemeter.
http://us.fluke.com/usen/products/Fluke+190.htm?catalog_name=FlukeUnitedStates&category=SCM(FlukeProducts)

Another good choice would be the Tektronix TDS1000B or TDS2000B.
http://www.tek.com/products/oscilloscopes/tds1000_tds2000/index.html

Another would be the Agilent (Hewlett Packard) DSO3102A.
http://www.home.agilent.com/agilent/product.jspx?cc=US&lc=eng&ckey=1000003120:epsg:pgr&nid=-536902749.0.00&id=1000003120:epsg:pgr

All of these scopes are inherently digital and can be interfaced with a
PC for data storage and analysis.

Aubrey Thompson


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