high tech battery hold down

comnoz · Jun 30, 2014

Here is a little project I did last weekend. If you don't like electrickery then now is the time to change the channel.

I took a piece of magnesium and made a new bar to go across the top of my battery. In the recess I put a little circuit board and a currant shunt.

I installed terminals and potted it with 2 part potting compound

I added some wires

Then I finished the potting with pourable silicone and heat shrink tubing and added connectors

The little microprocessor measures the voltage drop over the shunt and converts it to a voltage that runs the new amp gauge in my cluster

They are virtual analogue gauges. They don't photograph well but they are reflective LCD screens that look like a gauge with a needle that disappears when you turn them off . They are sealed units and are easy to see in direct sunlight. The left is an ampmeter, the center is cylinder head temperature and the right is a lambda gauge.

davamb · Jul 1, 2014

Most excellent - what's the micro? PIC or ATTiny? Trust there's no way the Magnesium can short the terminals?

SteveA · Jul 1, 2014

Jim,

Very neat. But I am interested in the cylinder head temperature part.

What sensor do you use? I have seen individual temerature guages used on air cooled strokers, one per cylinder, but the sensors go under the spark plugs and are secured by them. The connecting wire comes up alongside the plug, far enough out to use a plug spanner. As far as I can see you would need to machine away a small part of the head surrounding the spark plug hole to use these sensors on a Commando head?

Could take this to another thread I guess, but your inputs would be very welcome.

Steve

comnoz · Jul 1, 2014

davamb said:
Most excellent - what's the micro? PIC or ATTiny? Trust there's no way the Magnesium can short the terminals?

The chip is a dedicated unit as used in a tape storage motor drive from Oracle. [since my brother is a engineer for them] It's made by TI.
The board has a piece of Mylar under it so it cant short . Jim

Nater_Potater · Jul 1, 2014

SteveA said:
Jim,

Very neat. But I am interested in the cylinder head temperature part.

Could take this to another thread I guess, but your inputs would be very welcome.

Steve

Maybe we should start another thread. Here's a fleabay item that shouldn't require any machining, as it takes the place of the gasket. It's very similar to the unit I ran when racing karts back in the day. http://www.ebay.com/itm/like/151312858618?lpid=82

Nathan

comnoz · Jul 1, 2014

SteveA said:
Jim,

Very neat. But I am interested in the cylinder head temperature part.

What sensor do you use? I have seen individual temerature guages used on air cooled strokers, one per cylinder, but the sensors go under the spark plugs and are secured by them. The connecting wire comes up alongside the plug, far enough out to use a plug spanner. As far as I can see you would need to machine away a small part of the head surrounding the spark plug hole to use these sensors on a Commando head?

Could take this to another thread I guess, but your inputs would be very welcome.

Steve

I tried one of the spark plug sensors many years ago. It was very fragile and didn't last very long on a vibrating Norton motor.

I use a 3/16 diameter 2 inch long type K thermocouple in a hole drilled from the area above the carb flange. It goes down between the combustion chambers.
I use a PLX unit to convert the thermocouple output into an analogue voltage for the gauge.
http://www.plxdevices.com/product_info.php?id=SEMOSMAIT

I also use a plx wideband control to provide a signal for the lambda gauge and the CPU.
http://www.plxdevices.com/product_info. ... EMOSMAFRV2

SteveA · Jul 1, 2014

Nater_Potater said:
SteveA said:

Jim,

Very neat. But I am interested in the cylinder head temperature part.

Could take this to another thread I guess, but your inputs would be very welcome.

Steve

Click to expand...

Maybe we should start another thread. Here's a fleabay item that shouldn't require any machining, as it takes the place of the gasket. It's very similar to the unit I ran when racing karts back in the day. http://www.ebay.com/itm/like/151312858618?lpid=82

Nathan

Nathan, that is exactly the unit I was looking at, look how the cable attaches to the copper ring (thermocouple?).

I note Jim's point about vibes.....and my own nervousness drilling into my new Full Auto!

Hobot · Jul 1, 2014

Peel ran most her era with Westlake gauges using the spark plug washers sensors I didn't have to do anything but some care to nip up with the sendor leads in right position. Leads went to analog gauges on bar no interface needed. If when temp sender wore out not very expensive to replace for another few year informing. Getting temp needles into our small exhaust header is an adapting hassle though. Be careful placing the top bar am pmeter not to short on terminals. I want stereo controls in spare fairing space myself.

xbacksideslider · Jul 1, 2014

Can you feel my envy? Nice work.

MikeM · Jul 1, 2014

Very nice. I was looking at your photos in the link. Did you pretty much machine your own engine?

comnoz · Jul 1, 2014

MikeM said:
Very nice. I was looking at your photos in the link. Did you pretty much machine your own engine?

Well I have machined a few Norton [ish] engines now. The latest set of billet cases came from Australia however. Jim

swooshdave · Jul 1, 2014

Can we speculate on the amount of fireworks if the bar shorted? :mrgreen:

Maybe you have an extra piece and an old battery? YouTube it!

comnoz · Jul 2, 2014

swooshdave said:
Can we speculate on the amount of fireworks if the bar shorted? :mrgreen:

Maybe you have an extra piece and an old battery? YouTube it!

I think I will leave that one for Hobot. Jim

batrider · Jul 2, 2014

swooshdave said:
Can we speculate on the amount of fireworks if the bar shorted? :mrgreen:

Maybe you have an extra piece and an old battery? YouTube it!

Thought the same at first, remembering my chemistry set as a kid (and "flash powder") but evidently it is hard to ignite Mg in large pieces according to the Wiki experts

. However, the battery makes a great welder and has a lot of energy to set that off if it went across the terminals.

comnoz · Jul 2, 2014

batrider said:
swooshdave said:

Can we speculate on the amount of fireworks if the bar shorted? :mrgreen:

Maybe you have an extra piece and an old battery? YouTube it!

Click to expand...

Thought the same at first, remembering my chemistry set as a kid (and "flash powder") but evidently it is hard to ignite Mg in large pieces according to the Wiki experts . However, the battery makes a great welder and has a lot of energy to set that off if it went across the terminals.

Yeah, magnesium is very tough to light when it is larger than chips. I have welded it with a Tig welder. It doesn't work very well but it does not igntie. Jim

Hobot · Jul 2, 2014

Both comnoz and I had Cdos turned completely upside down so firm clamp down is vital. For the clumsy - just dip/paint on plastic/rubber insulation coat. Only sparks i want seen are Titanium off peg tips, handle bar bark busters and boot plates.

[video]https://www.youtube.com/watch?v=1ahgCh1azkk[/video]

high tech battery hold down

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