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MR-ZAPPY

Tue Jun 18 2013, 07:03PM

Registered Member #16018 Joined: Fri May 03 2013, 07:19PM
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Posts: 53

Oops I kinda screwed up on the comment but what you do is use pots for a 555 timer in astable mode set to the fire rate then you take the output of you 555 timer oscillator and hook it up to a small transistor. The output of the transistor is hooked up to the coil of a realy which is wired in series with the live wire going to a MOT. Wire a Microwave capacitor in parallel with the output of the MOT

Ash Small

Tue Jun 18 2013, 11:09PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Mr.Plasma-CRAZY wrote ...

Oops I kinda screwed up on the comment but what you do is use pots for a 555 timer in astable mode set to the fire rate then you take the output of you 555 timer oscillator and hook it up to a small transistor. The output of the transistor is hooked up to the coil of a realy which is wired in series with the live wire going to a MOT. Wire a Microwave capacitor in parallel with the output of the MOT

An MOT will not run at ~1 MHz. It gets hot at 50Hz. I do think it's possible with flyback technology though.

MR-ZAPPY

Wed Jun 19 2013, 03:36AM

Registered Member #16018 Joined: Fri May 03 2013, 07:19PM
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Posts: 53

The 555 is just to turn on and off the MOT around 10 times a second so that is will spark fast the AC is still 50 hz is is just chopped up so that is will go bang bang bang 10 Times a second. That should ignite almost anything

Ash Small

Wed Jun 19 2013, 11:21AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Mr.Plasma-CRAZY wrote ...

The 555 is just to turn on and off the MOT around 10 times a second so that is will spark fast the AC is still 50 hz is is just chopped up so that is will go bang bang bang 10 Times a second. That should ignite almost anything

It's just occured to me that the flyback core from an inverter microwave oven might be worth considering here.

They seem to have two airgaps, one for the primary and secondary, and one for just the secondary. They also have a reasonable CSA.

I'll dig one out, and wire something up.

Ash Small

Sun Jun 23 2013, 10:14PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

paris wrote ...

Theres 3 indians running at Pendine , one is Grizz on 27 Chout (chief Mot / Scout frame) be great to be there. Im building a 26 scout at the mo.

Just for you Paris, Here's a photo of Chris Ireland taking his supercharged Indian up the Pendine sands earlier this afternoon.

It was an amazing weekend, I've hundreds of photo's. Thanks for the tip-off.

paris

Mon Jun 24 2013, 12:01AM

Registered Member #3042 Joined: Wed Jul 28 2010, 12:36AM
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Posts: 121

Ine been hangin out , wasnt gonna say any thing cause I would sound like an impatient brat but now Im like a giggly girl!!!
chris ireland is a custom guy and magazine editor, that bike "bella" has been reincarnated many times , its 1942 741 army indian 500cc , eventually rat bike chopper(80s) , then custom chopper(90s), then trike ,then salt bike in USA(2012) ,then that bike there,
its a well known bike, even in some books!! also on the net if google bella/chris ireland.

how about Grizz chout?

I am jealous as hell , the sound mustve been great, bet I know where youll be going next year
= hate you in advance :0) cheers

Ash Small

Mon Jun 24 2013, 09:00PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

I only saw the one Indian there, but you might appreciate this pic:

paris

Tue Jun 25 2013, 12:02AM

Registered Member #3042 Joined: Wed Jul 28 2010, 12:36AM
Location:
Posts: 121

those are the only JAP bikes I truely love!!

grizz has been preparing for 5 years or so.....:0(

feel terrible.....kinda off topic.....but HEY :0)

paris

Tue Jun 25 2013, 11:38PM

Registered Member #3042 Joined: Wed Jul 28 2010, 12:36AM
Location:
Posts: 121

have to do the responsible thing and contribute...
with cars vacuum advance , the plate moves , heres a HD advance = the cam moves and the plate is stationary
heres a crane cams ign module with a plastic rotor that goes on fly weight assembly and has mech advance so the firing as far as I know is just triggered by the placement of the 4 little magnets

pic = std parts on left, the fly weight has a pin sticking out at the centre about 11 oclock , cant see it, that is just a locator pin. the cam lobe has a flat on lower right side that corresponds to that pin just for orientation.
the plastic 1 has the same cut out "flat" so goes in the same and bobs ya uncle!

this is just 1 example of mech advance with out using a hand grip advance.

also... I dont know how the magnets are positioned , degrees etc , what I see is just whats there in the pics, rotor spins 1/2 crank speed so that stuffs my thinking process.

Ash Small

Wed Jun 26 2013, 10:21AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

I think cars also had the bob-weights, the moving plate was to do with 'vacuum retard' under acceleration, from what I remember.

As mentioned above, the bob-weight system is very 'hit and miss', especially when worn. It will get to max advance by ~3000 RPM, but will be all over the place at lower RPM.

The 'half crankshaft speed' thing, the camshaft turns once every cycle (two revolutions of the crank), so the crank turns 720 degrees for each revolution of the camshaft(s). You still place the timing disc on the crankshaft to measure the number of degrees BTDC or whatever for ignition.

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