Tach source

[tundraotto]

Doug, I believe that they are truly inductive. I say this since the "sensoring end" is metal plated on the tech tach - ie. electromagnetic pickup. They work accurately on a multicylinder environment too, which I would imagine would preclude any type of audio pickup. Just point to the plug wire and you get the reading - if you offset too much from the pickup end you will lose your reading.

 

[dbabcock]

Based on that and the proximity deal, I would say inductive as well, Otto. As far as the multiple cylinders go, audio would work just as well as an inductive. The difference would be that an inductive would be placed in proximity to one spark plug and sense only that one. For a 2 stroke, the pulses are read directly and for a 4 stroke you get one pulse for every two revolutions, hence the divide by two function. For an audio tach, the processing comes down to how many cylinder firings the tach "hears" as well as whether the engine is a two of four stroke.

 

[tony marks]

my iny tach just starts over after 10.000
i checked it with the shops tachs and it seemed to be accurate.ie 12000 would read 2000. any comments or opinions welcome.

 

[bwalker]

The race pack gauge set on my snowmobile has a inductive tach I believe as it does not have any wires running to the ignition.

 

[tundraotto]

Originally posted by tony marks
my iny tach just starts over after 10.000
i checked it with the shops tachs and it seemed to be accurate.ie 12000 would read 2000. any comments or opinions welcome.

I had to send mine back (my original tinytach) to Steve because it stopped reading at 10k - it displayed numbers, but they were not correllating to the rpm. Steve also told me it only reads to 10k. The Techtach 20k that I use now reads perfect.

 

[dbabcock]

Tony,
Does this tach have a 4 or 5 digit display? Namely is the top reading 9999 RPM (4 digits), or does it have 5 digits and just blanks the first digit when it goes over 10,000? If it is only a 4 digit display, then I'll just roll over for RPM's over 10,000, namely: 12,000 RPM displays as 2,000, which is OK up to a point.. How much above 10,000 it will go accurately is anyone's guess.

 

[tundraotto]

Doug, the tiny tach that Tony is describing has a 4 digit display. It also incorporates an hour meter and can be had for about $37 from DTI. However, I am pretty darn sure that the tiny tach will not read over 10k rpm.

 

[dbabcock]

I guess what I'm saying is that while the display won't go over 9999 RPM, that this is just a limitation of the fact that the display only has 4 digits (cost consideration), not necessarily that the signal conditioning front end just stops working. If the display had 5 digits, the far left one would be a 1 and the 4 to the left of it would read the amount over 10,000 RPM; in this example 2,000. Of course, this may not be the case with the device in question. I've just seen it happen on other things.

 

[tundraotto]

yes, exactly Doug. The display was not the limiting factor in my tinytach. For example at about 11000rpm the display would show 590 or 460 or something of the sort - ie. no correllation to true rpm.

 

[z4lunch]

Echo PET 1100

Steve here...
Just picked up my new Echo tach from the dealer at lunch, WOW is that nice...WOW was that expensive 178 bucks!! Can you say put me on the ladder.
It is an awesome tach though. My tiny tach has been retired to my roto tiller,
the one I have is only good to about 5000 or 6000, and then it wigs out. I was told that is all it's for. The PET does 2 and 4 stroke 100 to 19000rpm on a 1cyl 2 stroke , display updates every .5sec and the accuracy is +or- 10rpm.
Steve

 

[tony marks]

it does register 9999.
thin starts back over .
it registers my 028 at 12600.actual reading 2600,after passing 9999.
my trimmer at 7900. which surprised me. thot it would be higher.hand held blower about 9000.
have no info as to its accuracy except it continues to register higher at the same rate the second time around as it does the first, in relation to how the engine is reved.
forgot to mention it registered my kohler at 3860. but ive backed it dn a touch since checking it. thot my mechanic was gonna thro fit. hes pretty good . he guessed within a hundred of what it was set at. i was duly impressed. he was not, an told me so.i like a feller thats willing to say whats on his mind.and he did in no uncertain terms

 

[dbabcock]

Tony,
Yeah that makes sense. If the tach is only rated for 10,000 then it's accuracy will be compromised at some point above that due to the electronics that drive the digital display, but who knows where it's not accurate any more.

Your Kohler should run probably run at the defacto govened small engine speed of 3600 RPM. This is only really critical for generators as it relates to a single magnet/stator coil to produce 60 cycle power line frequency.

 

[tony marks]

yea thats must be what he said.
really all i got out of it was that at 3600 it would create the most torque,as it would call for more power as the need for power increased .i also got the hint that that little fella thought i was less than brilliant. he sure dont like folks abusing their motors.but he is good at what he does, so i gotta respect that.

 

[don]

Wireless remote tachometer

Was reading this string and found the discussion wireless "inductive" tachometers.

What is the going price for one requiring no hookup?
A hundred dollars?

Is there any unique features a tach should have for saw tuning?

I see Stihl, Echo have there "brand" of tach, does it matter?
Are they all pretty much the same manufacturer similar model?

 

[z4lunch]

Don,
Steve here...
I bought the Echo version. Paid $180 for it.(WOW nobodys that stupid) The large Stihl logo'd model looks similar for less money. I don't think it will test all the diferent 2 and 4 strokes the one I bought does, but for saws I'm sure it's fine. I made some cuts with my 088kd and my 090. With the tach between my thumb and forefinger in my left hand, I was able to get readings in the wood. The unit just needs to be close to the plug or plug wire. It works awesome.
Steve

 

[don]

That's a pretty saw you got there

It needs to be within a foot or two to work, right?

Can you direct me to a site where they show the features and pictures of these wireless tachometers?

I did a search and come up with automotive tachometers.

 

[z4lunch]

steve here...
oops, here is the pic..

 

[z4lunch]

Steve here...
It needs to be pretty close. It depends on how powerful the ignition system is. I would say maybe an inch or so.(on a saw) If it needs to be farther away you can hook up the wire lead that comes with it, into the side of the unit, and clip the alligator lead end onto the plug wire

 

[z4lunch]

Echo tach info

Don,
Steve here... If you want, send me an email with a fax number and I will photo copy the owners manual and send it to you tomorrow from work.
Steve

 

[chainsawworld]

i just picked up a very nice one from Laser Sales. aim it at the plug wire or it has a clip that goes over the plug wire for hands free. marty