Building your own generator

[jimmyhorns]

well.....

adding an inline diode seems to work....

the mosfet driving the opto-isolator driving the arduino doesnt though

[jimmyhorns]

Well, back to the hall sensor....

I had the flywheel off to set the points up correctly (the gap was a little too close, and I wondered if this was having an effect on running)...

Given the trouble I have been having with using the magneto windings, and the need to move things along with this project.... I found a nice mounting point for the hall effect sensor (spektrum crank sensor). I have cable tied it to the outer magneto iron.

I now, finally, have a reliable 1 pulse per revolution.... well reliable in so far as turning it over by hand and counting

Will see tomorrow if it works with it fired up (and if it still fires up after my dabbling with the points.... I dont think I have ever had points on a car, maybe on my very first before I converted it to a fuel injected engine....

[JoeBailey]

Building your own generator

I don't know if you've looked into this option yet
http://www.thestatorgator.com/

There used for ignition pickup to feed into Futaba governors. They work very well.
Don't know if it would help out.

[jimmyhorns]

I don't know if you've looked into this option yet
The Stator Gator

There used for ignition pickup to feed into Futaba governors. They work very well.
Don't know if it would help out.

Yes I did take a look at that, but I dont think it would work as it is designed for electronic ignition systems, as opposed to a magento and points setup...

[jimmyhorns]

Brilliant.... and now have no spark

This is going from bad to worse

[cjcj1949]

It's called engineering. You are gaining experience. Points can be very fussy things to set, especially with a worn cam. What opto isolator did you use? Fets can easily be blown up with static. The Hall Effect sensor should give better results. Just run it and display rpm.

[jimmyhorns]

Massively frustrating though....

I set the points to what they should be, and now it wont spark.... its a complete PITA to make adjustments as you have to remove the flywheel each and every time

[dillwhacker]

Assuming you have removed all the electronic codswallop...
Make sure the wire to the points isn't broken..
Is there a condenser in there across the points? Check that wire too.
If the cam is worn so that the correct gap gives poor timing, you could try adjusting them so that they open a little bit before Top Dead Centre by poking a stick into the plug hole...

[jimmyhorns]

Ive removed everything I added, and even removed the 'killswitch', so all should be well....

im back to an occasional spark on hand cranking now.... so getting somewhere....

[jimmyhorns]

well im back to a spark at 0.3mm rather than 0.5mm points gap..... now I know why they did away with points

[pgkevet]

Yes I did take a look at that, but I dont think it would work as it is designed for electronic ignition systems, as opposed to a magento and points setup...

There's 3 sorts of stator gator - for the rc format engine (magneto), the puh format engine (magneto) and one for electronic ignition
I'm guessing the puh format would be easiest to use if you wanted to

[cjcj1949]

The main difference between electronics and software is that in software there is usually just an error message, in electronics there is usually some pain when you make a mistake. That's why engineers tend to be conservative. The correct gap for points is the one that works. I had an old car that misfired on the correct point setting, but worked on the wrong setting.

[dillwhacker]

Well.....I think the way it is supposed to work is that the points gap sets the 'on' time when current builds up in the primary i.e. the on / off duty cycle. Then the exact timing is achieved by shuffling the backplate around, or turning the distributor in its mount, as we used to do on old cars.
But you might not have that option on this engine, so will have to set the timing by adjusting the gap.
Probably...

[jimmyhorns]

There is a little wiggle room on timing, but after taking the magneto off the chassis, I put it back on in the same location, as didnt want to mess with the timing...

I hadnt thought about the points gap effecting the timing too, but I guess it does...


Well its back to how it was, and im guessing that the gap was tightened up to make it run properly....

The rpm readout is good enough, and stable enough.... its reading under what my digital timing tach says it should be, by about 25%, but its a start, as all I need to do is know when its dropping too far or overspeeding, and we are talking about +/- 300 rpm here so its not going to need to be precision....

So, on with the program writing until tomorrow when I can make up some snakes to control the throttle and choke....

[cjcj1949]

Sounds promising. Once you've got it working you can replace the Arduino with a chip on some veroboard. 328 with UNO bootloader, crystal and caps less than £4 on ebay.