Zoom car seat buckle help

[cplus]

In case this is useful to anyone else, here's some information on fabricating a buckle that can be used with the airbag deactivation bar. Since Tool Pants said some people had luck with 944 buckles, I called Parts Heaven and bought one. I guess they just the buckle off an old lap belt, at least that what it looked like when I got it. The cost was under $25, including shipping.

Using the images as a guide, I made a small notch in the tongue. The notch is 5mm, flairing to abou 8mm at the tip. But the buckle was a few mm too wide, so I filed it down to 22mm. Now the buckle would slide in the latch, but wouldn't actually lock into place. I made up a duplicate out of aluminum stock and found that the tongue would need to be about 38-40 mm long in order to lock, but the 944 buckle was shorter (probably 38 mm). So I filed back some of the plastic-covered base to make the tongue the correct length.

Once it was the correct width and length, the buckle slotted in with a solid "click." I started the car and the airbag light flashed for 60 seconds, then went off. Just as it should.

Here's a pic and an outline with some measurements.

[ukchris]

You can also if you so chose replicate the whole mechanism with a switch and a couple of resistors. All that is inside the buckle is a switch that changed the resistance by cutting out a resistor once the buckle is inserted, the car detects this change and deactivates the passenger airbag. Too test this theory I made a little switch box with the approprioate resisors in it, it seems to work fine. The nice thing is that the car diagnoses if the system is working and tells you so by flashing the airbag light for 60 seconds to show it has been deactivated. I have the circuit I made somewhere if anyone is interested, $10 in bits from radioshack and it was complete.

The only tricky bit is getting the connector for under the seats, I managed to get one but it is an awkward part to get hold of. You could of course just cut the connector off and replace it with a more common one or splice in to the wires.

Chris.

[ukchris]

Grizzly,

I thought I'd try drawing this up, if we can get it right there are waterjet cutting places that could probably make them to order, I know a guy who could cut it out of acrylic fairly cheap which would probably work too. In theory if you print this PDF it should come out at actual size, could you line up your buckle and see how it compares? A picture of the printout with your buckle alongside would help too if that's viable.

Chris.

[cplus]

Printing at 8.5 x 11 isn't a full-size image so I can't compare them, but the shape is correct. I will say the "wings" are vestigal from my buckle being a lap belt in its earlier life, they can probably be eliminated resulting in a more streamlined design. BTW, the tongue is 3mm thick if you're going to have some made up.

Also, I'm not sure if the buckle can be acrylic; it may need to be metallic if the receptacle is anything more than a simple mechanical catch-activated switch. (I.e., if it's magnetic or passes any kind of current through the buckle.) My guess is that a non-metalic buckle will work but I really don't know.

[ukchris]

That's odd, it looked accurate on my screen. I wonder if it's because I left that bitmap in there, I'm trying again with it removed to see if this one will print more accurately. If you are willing please give it another shot.

I'm not really doing this to try and get in to making them to sell, just trying to get an accurate template that people can then download to make their own buckle or have one made, if we can get it accurate I'll post the files here so they are readily available.

Chris.

[Tool Pants]

This is the one that use to be sold on German ebay.

[Grizzly]

Originally Posted by cplus

Printing at 8.5 x 11 isn't a full-size image so I can't compare them, but the shape is correct.

"That's odd, it looked accurate on my screen. I wonder if it's because I left that bitmap in there, I'm trying again with it removed to see if this one will print more accurately. If you are willing please give it another shot."

Originally posted by ukchris


Your home computer won't scan or print at exactly 100%. Printers alter the print size, however slightly, so that we can't accurately copy things...like...say...money for instance.

...bastards.

[ukchris]

I think it must be the PDF file. I did the drawing in Adobe Illustrator and can assure you that when I print the results are very, very accurate. Maybe things get messed up when I save it as PDF or, probably more likely, maybe I made it the worng size in the first place! Hee!