Derby Talk

I'm not sure if this post needs to go under tracks or electronics?? But here goes....I have a homemade wooden single lane track used for testing with a Judge et timer. For some years, I have attached rubber band to starting peg and pull for starts. Recently, I though I would update and build a starting lever to provide more consistent starts. This is where my question lies.

I took one of my sons older cars and recorded three runs using the hand pulled starting method....then I recorded three runs wth the same car ( no mods) with the new lever pulled method. The hand pulled method was on average .03 faster. I repeated same procedure again with same results. My first thought was the lever method spring was too strong and causing flex or a vibration at starting line. I used a weaker spring and placed damper under track to absorb the starting peg swinging under track...same results.

I did notice on the hand pulled method if I pulled it slightly slower, the car would have a quicker et. I'm now wondering if one can pull starting peg by hand consistent enough for acurate testing?? It looks like the baseline I have used for years may not be valid. Will probably have to start over again.

Has anyone experieced this before? Thanks in advance for your comments and wisdom.

hotrod

If you load your gate with rubberband or spring so it "wants to open" and held by a latch, then the action will be so fast your starts will be consistent. A much larger contributor to variation in ET is how many times your car corrects direction on the lane guide. A car that corrects only 5 times is going to be a lot faster than the same car that corrects 20 times. This is largely beyond control, and is what makes derbies interesting.

The latch mentioned above is sometimes hard to find. A picture on one is at http://www.newdirections.ws/faq.htm#Q11 If you want one free, send a SASE (padded) to me.

John, thanks for the reply. I will take you up on your offer for latch.

Ed