Rev counter sender?

[Anorak_ian]

Hi, I've been thinking of a rev counter for my bike, is there any way to use the alternator as a sender? More revs more current sort of thing? Just a thought.

Ian

[oilburner]

If you are using an automotive or industrial diesel with an external alternator, you can replace the alternator with one that has a tach output terminal.

FYI

Avery

[LocomotiveBreath]

Here
http://www.tinytach.com/tinytach/diesel.php

[Anorak_ian]

Thanks guys

[Diesel Dave]

How about using a cheap cycle computer - available for under a tenner.

Set it to read in KMH and the wheel circumference to 1667 mm and it should display engine speed x100 rpm - so 36 kph = 3600 rpm.

Use a small strong magnet close to the centre of the flywheel to keep the 'pass by speed' slow enough for the sensor to pick up. A blob of epoxy should hold it in place.

Regards
Dave
(Bodgit & Scarper Engineering inc)

[moose60]

Dave,
I'm probably just a little tired, but could you please explain the math behind the 1667 number?

I used MPH for grins. My math is as follows.
I calculate that a wheel circumference of 10.59 inches will be pretty accurate. I was mostly curious about the math used to get the desired wheel diameter.
I used (circumference in inches) X RPM (1000 cause it's easy)=distance traveled in one minute in inches. Divide by 12 to get feet, divide by 5280 to get distance traveled in miles. Because the thing will read in units per hour and we want units per minute (rpm) I multiplied by 60 at this point to get 10.026 MPH, which a driver could read as 10 X 100 RPM.

If I convert 10.59" to MM I only get 254mm though... which doesn't seem to match up with the 1667 mm figure even with some rudimentary conversion to KPH.

Lead me to the light.

[Diesel Dave]

Ok here's my attampt at maths....

I used Kmh 'cos its easier

Bicycle computers take their wheel size in MM (or CM if really old/cheap)

So if the circumference is 1667mm or 1.667 metres, at 3000 rpm you will travel 5001 metres in a minute.
Multiply this by 60 gives 300060 metres per hour
Divide by 1000 for 300.06kmh
(if your computer won't read this high then dumb down the wheelsize by a decimal point)

I'll say right now that I'm no mathematician and fully expect this to be flawed on any/many fronts.

Regards
Dave

[andrewaust]

Hi Guy's


Thanks Dave "LocomotiveBreath" for posting the tiny tach link up mate, I've just installed the Tacho on the Enfield today and took it for a run to see just how the RPM's compare to indicated speed.

Maximum engine speed at close to 100 k's/hr nudged 3950, but didn't go any higher, surprised that the engine is not revving as high as I thought and tends to be accurate with the performance graph that came with the engine "It dies at 3900rpm".

The Tacho has heaps of cool stuff for maintenance etc too. I was going to hook up a VDO Tacho, but the damn thing is just way to large for mounting on the bike, so the new Tacho is way better.

Oh yep! - Many are going to quiver with horror that I'm running the engine so high - The manufacturer stated 3800 rpm as max continuous speed, so as long as I stick to 90 K's that looks like it sits on 3650rpm, its sweet.

The one thing I did notice with the Tacho "and thought it would do it from other pulse sending units" - when you back of when coasting the tacho drops from no pulse/fuel being injected, but picks up the pulse well any other time.



Cheers


Andrew

[sbrumby]

Just a little note on a tacho. A few years ago I converted a P6 Rover to run with a diesel engine. As the dash had a big tacho in it that was originally run by signals from the points. I decided to use it with a PEC.
(photo electric cell).I could not get it to work at first then a boffin put me right with a simple resister. The PEC just looks at the flywheel that is painted black & white.I still have the car if anybody needs more details.

[andrewaust]

Tiny Tach Update



I'm a little disappointed with Tiny Tach's customer service - I've purchase a Tiny Tach 3 weeks ago, put it on the bike, wired it up and everything was great until Last week when the LCD wouldn't turn off and it showed only have the engines RPM "Unit Malfunction" . So I have checked everything coming to the conclusion that the seal Unit must be faulty, contacting both the supplier and Tiny Tach for help.

Over a week later = no word from either.

I'm going to contact the supplier again tomorrow to see if I can get a replacement or a refund - but not holding my breath.






Cheers


Andrew

[LocomotiveBreath]

Can I help in anyway as I'm in the States, I'll call them and give them heck if needed.

Let me know

Dave

[andrewaust]

Hi Dave



Thanks for the reply mate! I've contacted the supplier here in OZ, and he's really ticked off too, as he's contacted them many times, telling me the same thing has happened before, but told me he's given them a rather more firmer enquiry.

I'll let you know how I go in the next week, I cannot see me being able to do much with the unit I have - just really wish I could exchange the damn thing hay MMMMMMMM - so where is that cattle prod

I think the unit is a great little design with the other features, so hopefully this one can be sorted soon.




Cheers


Andrew

[LocomotiveBreath]

I called and spoke with Steve @ Tiny-Tach, I'm e-mailing this link for him but he seemed to know what the problem is, and can talk you through this problem. Mentioned to me that you might want to try and rotate the transducer 180 degrees, possible needing a more sensitive transducer. He asked what engine you were running. I mentioned the Yanmar L100, seemed he knew that these engines have very low line pressures. But all in all, I'm almost sure we can get you back up and running.

I'm hoping he will join the forum as he actually has been looking into Diesel-Electric hybrid.

Dave

[andrewaust]

Hi Dave


Thank you for doing that for me mate - really appreciate it.

I just tried to swing the transducer around 180 deg and give it a go on the SD33T Engine "Big Sucker", with the same results = Half indicated RPM and LCD wont turn off.

This SD33T truck engine has a very high line pressure, and one can actually feel the pulse in the line. It's indirect injection running @ 22.1 - Higher at boost, putting out around 130HP.

It was worth a go though! My suspicions are more with the unit itself, as the LCD display is always on, and wondering if a diode or IC etc may be the blame.

Running a multimeter over the leads proved they seemed OK. A bit of a puzzle really.

If you're talking to Steve again, just mention the unit not turning off the LCD display that might point him in the right direction. I know the LCD unit would turn off when the 12V power going to it was turned off - bit of a problem in there somewhere.

Being sealed its really impossible to put a good explaination to it = BUGGER .



Thanks again for your help on this one.



Cheers



Andrew

[andrewaust]

Hi Guy's


I'll post this one up just in case anyone else has a Tiny Tach and experience the same problem - just remember to consult your supplier first if it's still under warrantee, as it could void it if you tamper with the unit in such a way.

Good news is the Unit is working again - Thanks again Dave for your help - posted below is the reply I got from Tiny Tach.






Cheers

Andrew


-------------------------------------------------------------------------------------


Dear Steve,

The Tach that Andrew has can be reset, but he should turn the transducer
90% on the line to improve the signal to avoid locking it again.

This is done by removing the face label and taking the potting material out
down to the circuit board inside the rectangular hole in the case to the right
of the switch.

A hole in the board will appear that is 1/8 inch (3MM) Diameter, at the 1 O'clock
position the battery edge runs by the hole 3 MM down under it.

We will be shorting the battery to ground for an instant, this can be done with a
paper clip touching the inside edge of the hole (ground) and the outside edge of
the battery at the same time.

This will reset it.

Thank You

Steve Myers DTI

[Byrdman]

Jeeze, it sounds like you have to ruin your tach to "fix" it!

[andrewaust]

Yeah - thoughts were going through my head, Now if this really buggers the thing - will they take it back

Now fingers and just about everything else crossed, it won't do this very often - if ever again, as the face will only come off so many times.

I'll see how it goes.



Cheers


Andrew

[Anorak_ian]

Cycle computers at Lidl.

This one £12.99:

http://www.lidl.co.uk/uk/home.nsf/pages ... onitor.ar6

And this one £4.99:


http://www.lidl.co.uk/uk/home.nsf/pages ... mputer.ar6

Almost forgot, they also have motorbike clothing, helmets, map bags, tank bags, boots, intercoms, bat chargers, and a load of other stuff. Be quick though as this was last weeks offers.

[LocomotiveBreath]

Hello all, I just bought a Diesel Tachometer some of you might want to look at. http://tinyurl.com/38958y

I was cruzing ebay for Diesel stuff and I came accross this Diesel Tachometer/hour meter.

I got a great buy on it (Had to buy the speedometer also, but for $20 and I can still sell the speedometer, anyone have a boat?

I will need a proximity sensor, but I've priced surplus sensors for about $5

It's a Teleflex Model, also since it's for a boat, it is vibration and water proof.
See: http://www.teleflexmarine.com/

[dieselbikin]

I thought I’d share my tachometer from a bicycle computer experience. I wanted to measure the maximum and average RPM during test runs, so I attempted to build a tachometer from a $10 Schwinn 12 function bicycle computer.

The computer is only capable of handling 1920 pulses/inputs per minute as installed. The computer followed my Sendec rotating shaft tachometer perfectly until 1920 RPM then started showing a drop in RPM and shortly thereafter the display went blank. The problem is in the computer’s resolution rather then its sending unit, because I had the same result with the computer hooked up the Sendec’s sending unit. The computer can display up to 99.9mph and it was only displaying 19.2mph when it starts to have trouble. I should have tested the Sendec with the bicycle computer’s sending unit. O’well, I’m not taking the shrink wrap off of the wires again. LOL

Maybe I can try putting the the magnet closer to the shaft to slow it down and use a stronger magnet.

If anyone else has had success with this please let us know what computer you used. It would have to be able to handle 4000 inputs/pulses per minute. Thanks.

[Sibbo]

http://www.google.com/search?client=ubu ... 78&bih=844

[Sphere]

I need something for my Hatz so I can see the depressing RPM when riding against the wind (65-70kph at 5 Bft. ).

What you think about this?

tachometer