Posted: Wed Apr 16, 2003 4:34 am
I'll follow up with more details later, but I just finished up building a two-lane timing system for our races.
Attributes:
Low-cost
Electronic circuit to ignore the back wheels and only trigger on the front wheels.
Disected stop watches are the source of the timing. These are matched in time and voltage source so they don't differ by more than .01 second over a 5-minute timeframe.
Home-made tape switches which are very low in profile and will trigger at approx 30 lbs of loading on a skateboard. These are constructed from two strips of .006" thick stainless steel separated by a .060" thick mat used for kitchen cupboard lining (with holes to let the strips come in contact under pressure). This is then sandwiched between .006" thick vinyl sheets and glued together.
The START of the timing system has a dual-mode switch, MODE A is to trigger both starts simultaneously with a tone. MODE B is to trigger each start independently with a tape switch.
It works on my kitchen floor -- we'll have to see how it works out on the hill. My daughter and I are timing each other on trips around the cooking island.
PS: No, I will not build you one. I will give you the plans for it though. The documentation should be done in about a week.
The full documentation for the timing system is at: http://www.pgrass.00sports.com under the "Links/Contacts" page -- at the bottom.
-- Pat
<font size=-1>[ This Message was edited by: Pat Chewning on 2003-05-13 01:35 ]</font>
<font size=-1>[ This Message was edited by: Pat Chewning on 2003-05-13 01:36 ]</font>
Attributes:
Low-cost
Electronic circuit to ignore the back wheels and only trigger on the front wheels.
Disected stop watches are the source of the timing. These are matched in time and voltage source so they don't differ by more than .01 second over a 5-minute timeframe.
Home-made tape switches which are very low in profile and will trigger at approx 30 lbs of loading on a skateboard. These are constructed from two strips of .006" thick stainless steel separated by a .060" thick mat used for kitchen cupboard lining (with holes to let the strips come in contact under pressure). This is then sandwiched between .006" thick vinyl sheets and glued together.
The START of the timing system has a dual-mode switch, MODE A is to trigger both starts simultaneously with a tone. MODE B is to trigger each start independently with a tape switch.
It works on my kitchen floor -- we'll have to see how it works out on the hill. My daughter and I are timing each other on trips around the cooking island.
PS: No, I will not build you one. I will give you the plans for it though. The documentation should be done in about a week.
The full documentation for the timing system is at: http://www.pgrass.00sports.com under the "Links/Contacts" page -- at the bottom.
-- Pat
<font size=-1>[ This Message was edited by: Pat Chewning on 2003-05-13 01:35 ]</font>
<font size=-1>[ This Message was edited by: Pat Chewning on 2003-05-13 01:36 ]</font>