The Breakroom > Resources

Minimag, another way to get your ignition sorted.

<< < (3/6) > >>

NickG:
John,

As I said, I think it's a brilliant idea, looks great and is definitely a better method than most being self contained and more representative of the real thing.

A slight concern I'd have for others building it is that I just think for a lot of people all the ignition system bumf is an add on, usually something bought off the shelf to get the engine they've made work. I saw your post to the guy something along the lines of guaranteeing that it will work, but if features really are required to be within certain limits for it to work, then the only way he could guarantee it working is if the tolerances were on the drawing or in the instructions. I know, it's really like any other model engineering, so you'd also be expected to know what limits & fits are required and the sequence in which to make things, and as you say, if they're making an engine they should be able to machine to pretty good tolerances anyway.  If they consider it as just part of the project it'd be fine and I think the majority of people considering it will be making a bigish engine with a pretty large outlay to start with so it will be fine. The only risk is to the newbee who is trying to make his first i.c. and thinks it'd be a good idea and ends up wasting 100 squid, where as really they maybe should have bought a box of tricks off the shelf with a glue on magnet to do the trick. To me, this would be like a whole new project on its own!!!

Nick

MrFluffy:

--- Quote from: NickG on January 11, 2011, 07:03:12 AM ---
I've never had one to bits but how do the ignition systems work on stuff like strimmer engines (about 20 odd cc) but they are self contained?


--- End quote ---
Absolutely, they trigger off a magnet on the flywheel somewhere, and everything including pickups etc is built right onto the coil itself which is tiny. The only wire off them normally leads to the run/kill switch which just grounds the pickup out to gnd to kill the sparks. The same with briggs vertical crankshaft engines. Just a trigger spot of a magnet on the flywheel passing the coil assembly triggers the spark event. The only tolerance there is the gap between magnet and coil/pickup assembly, which also sets the timing within a narrow range. They are tiny and easily hidden and easily adapted. Another source of these is mini moto engines, chainsaw motors etc.

Incidentally, smaller motorcycles and most older enduro/trials bikes are self contained flywheel magnetos too. The honda stepthru c90 wiring loom can be disconnected completely and the engine will start up. The key just providing pickup to gnd. On my sp400 enduro, it has a igniter coil and a rotating magnet on the flywheel too with cdi ignition, and that runs batteryless happily.

NickG:
Thanks Mr Fluffy useful info there, I have created a specific post about this and replied to avoid this going too far  :offtopic:

http://madmodder.net/index.php?topic=4175.0

Nick

Bogstandard:
Nick,

Thank you, I was just about to jump on that post as this is about the Minimag, not about other ignitions systems.

But to raise your points again, if you have the experience of building a decent engine, then these should hold no terrors at all.
Also even the very experienced people have taken the easy way out, electronical gubbins all over the place. Pretty soon they will have digitachos, and blowers, on a hit & miss engine. And they are the ones who scream out loud if it doesn't look right to scale.

They didn't have many batteries and chargers on farms many years ago.

This item is for people who want to get towards having an authentic running engine from a century ago, and not having a box of bits controlling everything. Fill it up, flick a switch, start and run it, just like the originals.


I hope to prove it when my engine runs on this one.

John S raised a point with me about it not looking authentic. If you look at the youtube vid where he has one of these running a full sized Lister engine, it shows what an original was like (on the floor, next to the engine), and with a little cover, one could be made to look very authentic indeed.





John

Rob.Wilson:
Interesting John

Just right for an R&B Engine  :med:


Rob

Navigation

[0] Message Index

[#] Next page

[*] Previous page