Adhesive Advice Needed

I would replace the magnetic pickup with a small electronic pulse generator and set the rate so the speedo always displays 100mph. This will really impress the girls.
 
Well, looks like you've got things in hand Downeaster. Sounds like for mph the calculation would be distance for tire circumference per full rotation. Time between beats is the parts of an hour. Probably need lots of spaces on one side of the decimal point for this one.
 
Finally went with 6 magnets spaced around the rim and Guesstimated the calibration setting. Seat of the Pants speedometer says we're close. Found a GPS Speedometer app for my phone that will let us check it and tweak as needed. Even got the Tachometer working after spending a couple of hours surfing Ewe Toob looking for clues. Turns out it works best if getting the signal from the ignition pulse generator. (Didn't know there WAS such a thing...)
 
I'm sitting here practically speechless with amazement over something my grandkids probably wouldn't even raise an eyebrow over.

I downloaded a GPS speedometer app for my phone. He drove it home and I followed him in my truck, watching the GPS readout while pacing him. (BTW, I guessed pretty damn close on the correction factor)

I was born in 1950. A telephone, good only for voice communication, was huge, black, made of bakelite and weighed several pounds. The handset alone was big and heavy enough to make a very effective bludgeon.

Today, I used a computer the size of a post card (and not much heavier) to connect with satellites in geosynchronous earth orbit to compute my speed over the ground.

Almost scary to think where we'll be in another 65 years.

--
 
Today, I used a computer the size of a post card (and not much heavier) to connect with satellites in.....
Wanna really blow your mind? Consider this; you hold in your hand more computing power than an Apollo space capsule used to go to the Moon and back. Is that incredible or what?
(BTW, I guessed pretty damn close on the correction factor)
Heh.... there's hope for us old geezers after all. Well done DE!!!:)
 
Yup - I graduated from engineering school in 1981 and we started with slide rules and finished with programmable calculators. Then I started my PhD in 1985 - and bought a Zenith PC for $3000 that had 640KB of memory - and now I have a cell phone that has 32GB of memory (I think that is 50,000 times more memory than the PC - plus it has a camera, it plays music and can send messages about 4 different ways AND it knows where I am) and the phone company GAVE it to me.

Holy cow.
 
Wanna really blow your mind? Consider this; you hold in your hand more computing power than an Apollo space capsule used to go to the Moon and back. Is that incredible or what?

Heh.... there's hope for us old geezers after all. Well done DE!!!:)

Heck, Jim, there are WATCHES out there with more computing power than Apollo had. Those guys had MASSIVE huevos!
 
Yup - I graduated from engineering school in 1981 and we started with slide rules and finished with programmable calculators. Then I started my PhD in 1985 - and bought a Zenith PC for $3000 that had 640KB of memory - and now I have a cell phone that has 32GB of memory (I think that is 50,000 times more memory than the PC - plus it has a camera, it plays music and can send messages about 4 different ways AND it knows where I am) and the phone company GAVE it to me.

Holy cow.

So, we should call you Doc? I'm impressed! :bow2:

And about that "knows where we are" thing...
paranoid.gif
 
Just want to say how much I love this forum. I have been searching for hours how to do this properly to put a Daytona speedo/tach on my build and this post has just given me all the info I need. I will be posting some updates on it shortly and no doubt be asking a bit of advice, this is the place thanks to all you guru's!!
 
Studied this for a cheap combo speedo/tach. On the rear disk brake models, placing the magnet in the disk carrier with the pickup mounted on the caliper mount seems to go.

On the gonzo pickup sim I drilled a hole in a circular saw blade and JB Welded it. Been spinning. it in a circular saw for over a year without issue. I must say when I first did it I was kinda of leery of the magnet flying out but it appears to be holding up fine. The circle saw spins much faster than a wheel going down the road .
One odd thing is JB Weld must have some steel in it because as it set it migrated over the top of the magnet on both sides making a dome shaped lump over the magnet. A little goes a long way.
 
Team Junk, interesting observation about the JB Weld migrating. Perhaps it contains a magnetic iron oxide to give the grey color. It is common to give undercoats a grey color by adding black iron oxide. This appears as grey in combination with the white coating fillers such as Talc, Calcium Carbonate and Titanium Dioxide.
 
I have fitted various electronic speedos to 3 different bikes, 2 that relied on magnets to trigger the sensor, and the third one (Koso) has an inductive pickup that senses regular steel objects (but not ss, aluminum, etc)
So I set up the inductive pickup to read off the brake disc floater button screws, which worked flawlessly.
For the speedos with magnets, they fit perfectly inside the 6 mm hex on M8 socket head cap screws (allen screws) holding the brake discs. As long as the screw is 8.8 or similar, the magnet will stay in place. But I also packed the internal hex with heavy grease before pushing the magnet in, as a precaution against corrosion and vibration. If using several magnets, like one in each of the 6 disc bolts, make sure that they are all oriented the same way (N vs S)
 
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