9YaTaH wrote:
A suggestion for that idler/tensioner...cut a shallow belt groove as a guide and a small bevel on the outside...
Thanks mate - I'll probably do without at the moment as it's all put together and normally an idler doesn't serv the purpose to keep belts in allignment (most that run on the outside of a belt are slick)
timmy201 wrote:
Great progress!
I’ve got nothing helpful to suggest for your technical issues
All good Timmy! I'm glad someone is watching with interest
I learnt something yesterday so I thought I'd share it with you in the hope of helping anybody out with similar issues or questions. If you're prone to nosebleeds, this is probably the point that you should find something else to read, or head to the shops to buy more toilet paper.
One of my Electrical engineer mates put me onto some electrical circuit simulation software and gave me a proof of concept based on the wiring diagram in the data sheet thing that I put a link to above. When you recreate the wiring diagram of the throttle position sensor in the software, you get this,
The potentiometers are obviously changing value as the throttle is opened, and using the slider bars on the right hand side, you can change the resistance of each potentiometer and see the effect on the output voltage on each pin (pin 1 and 3 - the two signal pins) in their respective plots against time down the bottom as represented by the green line. In the top picture - they're just at a static state. The resistance of the potentiometers and resistors are set at arbitrary values, but what is important to note is that
both potentiometers have the same range and from what I can gather in the data sheet, both potentiometers have a range of about 700-750 ohms. If they weren't the same then the mechanical movement rate of opening the throttle wouldn't be equivalent to the change in the voltage across the range of physical throttle movement and the ECU would have a hard time interpreting what is happening.
Now, as you increase throttle from 0 to 100%, each pin does it's own portion of making that happen, and they do that independently. So I slid the resistors bars from 0 - 100 on each and you can see the resultant change in output voltage on Pins 1 and 3 below that change independently from another. One goes to it's max value, and then the other.
Cool, so obviously once one pin has reached it's maximum value it doesn't do anything until the throttle is returned to within the range for that pin - this is obviously not useful in the situation where you only have one signal wire that is expecting to read a range from 0-100% throttle movement and not 0-20% for instance. I'm sure everyone could appreciate that it just wouldn't work and would be impossible to tune to (or at least very, very difficult).
Stuff it - let's just splice the signal wire to read both pins at once. Add a wire between pins 1 and 3 in the software and see what happens
Both pins now read the same voltage and changing the resistance of either potentiomenters changes the values across both pins - perfect. In the plots at the bottom you can see that both pins change voltage together at the same rate as the resistance of each potentiometer is changed. The little flat spot in the graph just represents me being slow in moving the mouse from one resistance slider bar to the other. Sweet! So the voltage ranges remain the same between 0 and 100 between the two scenarios but we can read the throttle position off a single wire now.
Yes I could've tested this with a multimeter but it's cold outside and my multimeter is a bit crap so I'm super thankful for Mark putting me onto this software and showing me how much smarter he is than me. Lol. not hard.
So I should probably buy a connector and get crimping and soldering.
If you're interested in having a play with the software - it's completely free and is a java based online thing. You can download it to work offline if you want
https://www.falstad.com/circuit/The wiring is coming along (slowly) and I realised this morning that I never removed a tooth from the trigger wheel... sigh..... I should probably do that.