Author Topic: Anyone know how to design a program for a calculator to print a flywheel timing tape (Read 10519 times)

rsss396 · « **on:** July 21, 2013, 09:11:25 PM »

There is always so much confusion around timing with our motors that I would like to come up with a calculator to take can the diameter of the flywheel and produce a timing tape showing the degrees for that diameter flywheel.

here is some timing tapes from MSD but they do not have a calculator for other sizes

I can find diameter to circumference calculators and I can find rulers and scales along with degree wheels but can not find a Calculator where you can input a flywheel diameter and print out a timing tape.

With this timing tape you now can take a typical timing light and look at how many degrees of advance the CDI is producing.

I have heard of people doing on a cad program but was hoping we could do it like a typical on line calculator.

I think this Calculator would generate some hits on our site and possible help our sponsors from the increase in traffic.

Thanks
Dave

Polonda · « **Reply #1 on:** July 21, 2013, 10:04:09 PM »

Dave I will look into this! I also think its a great idea...especially for those without a fancy timing light.

rsss396 · « **Reply #2 on:** July 21, 2013, 10:25:30 PM »

Thanks, its really not hard to figuire out its really the circumference divided by 360 but I could not find a online ruler that I could scale and print

Tbone07 · « **Reply #3 on:** July 22, 2013, 12:35:21 PM »

You could get someone to write up a small and simple program in Visual Basic. I did something similar in college but it was to convert Celsius to Fahrenheit and vice-versa. I'll have to reach back in to that part of my brain

Langbolt · « **Reply #4 on:** July 23, 2013, 12:33:23 PM »

I could Draw one up in AUTOcad....maybe write a little AutoLISP routine to calculate the length of strip and spacing based on the Perimeter of the flywheel....Pi x Diameter = Perimeter.....or (Setq Perimeter (* pi Diameter))

Lol The spacing is just the Perimeter divided by 360 degrees ? Right ?

rsss396 · « **Reply #5 on:** July 23, 2013, 12:55:17 PM »

Yes, Perimeter divided by 360 to create the a mark for each degree.

A calculator would be awesome if it did different size flywheels but in reality if that is to much work then if we could come up with a printable timing tape for the stock trx250r,cr250 and cr500 flywheel that would be great also.

F-Red · « **Reply #6 on:** July 23, 2013, 12:58:26 PM »

Quote from: rsss396;5249

A calculator would be awesome if it did different size flywheels but in reality if that is to much work then if we could come up with a printable timing tape for the stock trx250r,cr250 and cr500 flywheel that would be great also.

This is a great idea!! I could use one of those.

rsss396 · « **Reply #7 on:** July 23, 2013, 01:04:28 PM »

Quote from: F-Red;5250

This is a great idea!! I could use one of those.

honestly your thread inspired this idea along with others in the past I have tried to help.

F-Red · « **Reply #8 on:** July 24, 2013, 06:38:41 AM »

And your efforts are appreciated. Thanks.

F-Red · « **Reply #9 on:** September 10, 2013, 06:43:15 AM »

Dave and others, any progress creating a printable timing tape? I would like to be able to use one soon. :joyous:

rsss396 · « **Reply #10 on:** September 10, 2013, 08:55:54 AM »

no but really it is something that can be done up with a digital caliper, pen and paper.
use this calculator to figure the circumference http://www.onlineconversion.com/circlesolve.htm
divide the circumference by 360 and lay out your lines on a narrow strip of paper.
after you are done you can tape it on to your flywheel with the 0 in line with a TDC mark.

To get the TDC mark on the flywheel it would be easiest to use a dial indicator since a degree wheel can get in the way.
There are machinist dial indicators and mounting bases that would require the head removed unless you have a long extension on it or there is dial indicators that can be threaded into the spark plug hole.
JJ&A sells a nice one

F-Red · « **Reply #11 on:** September 10, 2013, 10:15:48 AM »

Easy Peasy! I'll give that a try. Thanks Dave.

rsss396 · « **Reply #12 on:** September 10, 2013, 12:13:11 PM »

If you are running a CR250 ignition, we mounted a flat piece of alum off the 2 pickup coil screw holes used for the old 250r setup on the counterbalancer holder that extended out and was cut to a point right next to the flywheel.
We then rolled the crank around to TDC and marked the flywheel inline with this pointer this is now where you check timing from and its impossible for the crank and pointer to get out of phase with each other.
If you mount something off the stator plate it self or somehow mark the pickup coil you can throw off the phasing of your marks if you remove the stator and put it back on especially if you do not have the centering plates for the stator bolts

These marks are very important to have a accurate reading and there is not allot of difference from 1-2 degrees off

F-Red · « **Reply #13 on:** September 10, 2013, 01:13:44 PM »

That's a good idea about affixing a permanent indicator. First off, I really want to see where my timing was, when she ran last. Your so right about the importance of the readings.
For example, if the CR flywheel is 4" in diameter, that would translate to .035, for each degree. Not a lot to work with. I will have to make my index marks, much thinner. :pride:

udontknowme · « **Reply #14 on:** September 11, 2013, 01:23:11 AM »

motion pro is $15 and free shipping on ebay. since the numbers go backward just put white out on there and write in the new numbers other wise you get confused