Discussion in 'Engines From Castings' started by michael-au, May 11, 2015.
Mounting the Hall effect sensor
I decided to 3D print a bracket to hold the sensor, I super glued the sensor in the bracket and used a 1mm screw to fix it in to the distributor
They look a bit rough in the close up photos
But hopefully it will work out ok
Spinning the rotor by hand and it seems to fire the sensor every time
1 if it's close to high voltage it will blow the tx.
2 I always put a small cap and zener diodes in circuit.
I do speak from experience having blown many hall transistors, I now prefer to run the hall transistor from the crank with 2 trigger magnets to keep the transistor well away from HV.
Hope this helps
The crank trigger will not work as the firing is not symmetrical
I have 3 engines with the hall sensor super glued to the bottom of the distributor body. In 10 years I have never had a sensor blow up. It all comes down to grounding. I bring a #16 wire right off the coil to the engine block. Don't rely on the #24 or what ever it is to give a good ground. Current takes the path of least resistance. Negative ground lead of the coil bonded right to the block is about as "least" as you can get.
Great progress on your building.
I liked your aprouch to fix the Hall Sensor. I was thinking to do the similar thing machining a little pocket in a small piece of Acetall (i do not have 3D printing).
Great work on the radiator as well.
I'm curretly stucked with my PeeWee building because I'm strugling to make my small cnc lathe to work. I have decided to to change the control to Mach3.
Ok all I stand corrected, I didn't realise the engine had asymmetric firing. I still stand by the inclusion of cap and zeners though.
Got the fuel tank done, decided to make clear ends for a different look
And also the tank mounts
Really very nice looking!!
I did love the combination of the cooper color with the aluminum.
Michael, how did you fix the hall sensor on the distributor body undernith the Rotor?
Hi thank you for the comments
I used a 1mm self tapping screw to hold it in position
The sensor is super glued in to a 3 D bracket
Drilled and taped for 2mm Alan bolt
Then cut the slot
Wow that all looks good.
Made the water pipe that runs from one side of the block to the other side
Started on the exhaust flanges, they are made of stainless steal
First turned the blanks on the lathe
Then I made a fixture to hold them so the two holes can be drilled in one operation and then in the next operation the profile can be milled
One blank is a screwed to the fixture and the holes are drilled and then it is moved to the next position and the profile is machined, at the same time another blank is loaded in to the first position, so two can be machined and drilled at the same time
I know it’s not necessary to do it this way but I am teaching myself CNC and I think this is good practice, and satisfying when it goes right
Very good aproach. I'm also learning CNC programing.
I did the flanges on CNC at one operation. It did work well.
You are right, it is so satisfying when the pieces come out correct.
Good progress on your PeeWee. Mine is on standby since last Christmas.
I did some work this weekend. Will post some photos this week.
Thank you Edi
Was able to run the code once today and worked out good
Just needs a quick clean up with some wetrub
Would not the placement of magnets on the crankshaft to suit whatever firing arrangement be satisfactory?
After all, it has to fire somewhere in the crank rotation.
You'd have to have 4 magnets on the crank to suit the asymmetrical timing which would mean you would be throwing twice the number of sparks than is required, which can be a problem with some ignitions (limited number of sparks per minute available). Also, at a guess I'd say the extra sparks would potentially interfere with the correct ignition timing (considering you'd still need a distributor).
i agree with Cogsy, i had tested a homemade hall circuit, waste fire ignition the other day on a 4 cylinder dummy crank (turned by an electric motor for testing) and it started doing strange things past 40 000 rpm (forty thousand rpm) plus ... please dont try rev that high Michael... Nice Build By The Way!!!
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