Jo's Box

[Jo]

  That nice postman has just left me a little box.

Jo

[Ian S C]

Looks like you'v got a wee job with the soldering iron              Ian S C

[Jasonb]

Now lets see if you can resist playing with your box until you are supposed to.

And make sure Eric does not get his grubby little mitts on it either, you know what he does to things like this.

J

[Jo]

Now lets see if you can resist playing with your box until you are supposed to.

J

 

[ths]

Hmmm, a complex.

[b.lindsey]

That looks like a very nice kit there Jo. Minimag Co. seems to be growing and adding new products and doing so in a quality and well thought out manner. Will this be used on multiple engines or dedicate to just one?

Bill

[Jo]

Bill,

This box is designed to go between engines, save having one ignition for each. I am promised that it will work for both points and magnetic pickup  The quality is looking excellent, clear step by step instruction, even if I found the price but it is an early birthday present so I didn't pay for it

So far the nylon for the spacers has been horrible to turn  but the acetal for the HT outlet is ok 

Jo

[b.lindsey]

Jo, yes I noticed the price on their site, but if the quality is there it isn't so bad. I, like many here am just tired of the "take your chanced" quality often associated with far eastern goods. Hope you will keep posting your progress on the "build."

And yes.....acetal is a far better machining material than nylon!!

Bill

[Jo]

The HT terminal has to have a hole drilled across it and a nylon screw fitted in one side. A slot drill did a handsome job of squareing up the bottom of the slot. The instructions for setting the sparkplug gap confused me but follow it word for word and it all comes clear 

The battery tray drawing had me puzzled as it seemed to have a tapered top edge but the side of the battery is tapered that is the result of bending it up. I had thought of bending it with my benders that fit in the vice but because of that top angled edge I got my old trusty sheet metal bender out.

Next is the top panel. I really need a Q-max cutter for the meter 

Jo

[smfr]

You don't hang about, Jo! It only arrived this morning and you're already bending metal!

Simon

[b.lindsey]

I was just thinking the same thing Simon...I hope you didn't tackle the poor postman Jo and wrestle it from his hands 

Bill

[muddled engineer]

What size Q-max punch do you need Jo?

 :old:Eric

[Jo]

Thanks Eric but we are already past that bit 

That paper template looked too tempting not to use so a couple of bits of double sided sticky tape and the hole centres were punched.

Holes in 1mm aluminium, especially this stuff they do for panels is easy to cut. I measured up and found I could cut to nearly 60mm before the hole would show behind the meter so a 54mm hole saw came in handy. The 18mm for the HT output was customised up from 12.5mm with a cone cutter and one of my tapered reamers to finish.

The front panel has three of these self holding rivets. Easy to fit drill a 3mm hole, use a large diameter bit of bar with a 3mm hole in it give it a clout from the other side of the panel and they go straight in flush.

Then it is label time. Ignore their instructions only take an edge of the backing off and fold it along the length, then line that up before you rip the rest off, saves it getting dirty and lines up so much easier 

The holes in the label were cut out with a scalpel. They are a bit furry around the edges but they will individually be sorted when the components are fitted in the morning

And now I have this funny looking circuit diagram to think about, over a glass of that wine that a lovely gentleman gave me 

Jo

[Don1966]

Jo you will enjoy this little box and it does do what is says. How I know, I have one and it is simple to assemble and use. Just be sure to set the spark gap on the HV terminal. This is the keep the HV from distroying your coil should it fire without a spark plug installed. Good luck girl!

Don

[Jo]

Thanks Don,

Their lack of description as to why they did that on the HV terminal did have me a bit puzzled.

Do you have any experience on using these with normal points? 

Jo

[Don1966]

Jo, the way this unit is built it just a matter of using the signal terminal and ground terminal. The red power terminal is used with the Hall Sensor to power the semiconductor but the Hall sensor still uses ground to control the spark. One of the nice feature of this box is the dwell and speed can be read off the meter. The other great option is you can set your timing with the optional timing probe. The HV can be switched off while doing all the timing.

Don

[Jo]

Thanks 

I sweet talked the very nice man into throwing the timing strobe in with the bundle 

Jo

[PStechPaul]

I would be interested in seeing the schematics for the circuit boards. I came up with a design for an electronic ignition that would work on points or a Hall sensor, and would have voltage limiting for the spark by using a TVS on the primary. However, I have not built it yet because I've been working on other things and don't have an ICE to use it on. My intent was to bring it to CF and have someone try it on their model to see if it improved performance.
 
A capacitive discharge type ignition should have better control of the spark, in terms of voltage and duration. The spark voltage should be determined by just the ratio of the coil windings and the primary voltage, which can be adjusted using a boost converter. Unlike the inductive energy storage type, the duration of the spark can be set by turning off the primary voltage and shunting the stored energy back to the storage capacitor (or just dissipating it).
 
If I were to become really interested in a project like this, I would be tempted to build it with a PIC microcontroller and a serial (Bluetooth) or USB link to a computer, which could do all sorts of things for controlling the spark timing and performing diagnostics, perhaps even showing a storage scope display of the spark voltage and/or current. It would be a major project, and quite a challenge, but the concepts are fairly straightforward. I enjoy the initial design phase of things like this, but the actual implementation becomes tedious and I'll probably never get around to building anything more than the simplest version.
 
Good luck with the build! 

[Jo]

Sorry Paul the ignition is potted.

The front panel has been assembled as per the instructions and the earth grubscrew via that really fiddly little 2.25mm spring buzzed out 

My soldering iron is having a little heat up

Jo

[Stuart]

Jo

dont do what I did when I was still at school  ( it was a really good one because it was approved  )  at home tinkering as usual with electronics I left my soldering iron plunged it and forgot went to pick it up a while later guess which end I grabbed the hot end of course

made a nasty smell nice brand at the time but no lasting scars  :pink elephant:


Nice build and boy that looks a nice unit for you infernal combustion types 

Stuart

[Jo]

Wiring done, now to buzz it out 

Or it would have been but the family has just phoned up to say they are on their way.

Jo

[Jo]

  Its passed all its tests 

Ok I had to remove the washers behind the meter PCB as it was shorting the meter  And I still think it would be better with a separate earth stud rather than using the one the coil is mounted on.

But we have sparks and the emergency spark also works 

So now I have relatives and then this bit 

Jo

[Jo]

The body for the strobe was supposed to be drilled 10 mm then bored to 11mm. It wasn't happy, it was getting hot, wobbling, so I ended up reaming it the 11mm.

The end cap is a simple turning with a slot for the board. 

Then it is a case of soldering on the three wires to the board they provide and putting the case on. Pluging it into its socket on the ignition box and turning the switch on the strobe on so that it flashes when the plug sparks.

So a full set of the small engine ignition box all finished and working. 
-   -    -   
Now the challenge, I mentioned my visitors, that was my Mum and Dad. They brought this for me but they were disappointed when they couldn't see it run an engine. So I have been told... no problem we will be back on your birthday you can show us then 

Jo

[Jasonb]

Did they say which birthday

Does look a lot of plastic sticking out the chuck to be boring, could you not have used a 5c with just a little sticking out the end as this would support the plastic and dissipate the heat.

[Don1966]

You made short work of that project. Nice work Jo.


Don

[Jo]

Thanks Don, I am really pleased with it. 

Did they say which birthday

Yes the one about a month after yours 

Does look a lot of plastic sticking out the chuck to be boring, could you not have used a 5c with just a little sticking out the end as this would support the plastic and dissipate the heat.

  that was my idea but it is 13mm diameter and as yet I don't have a 5C that size and as you bore it the pressure of the chuck distorts the material so the final cut has to be done clear of the chuck.  I could have used a DA100 in a 5C, I keep forgetting those, but it is all done now.

Jo