Rocket car on J motor reaches 626 mph

[Mugs914]

Absolutely brilliant!! Santa Pod is probably the only track in the world that is still friendly to rocket power on any level.

When I was younger about half of the rockets I launched were fired horizontally and on wheels, but that is really taking it to a whole different level. (Well, level 2, I suppose...)

How was it timed? Did you use the track's timing lights?

 

[Mugs914]

By the way, if my guess at the wheel diameter is close (about 2.5"?) and I've done my sums correctly the wheels would be turning somewhere around 84,211 rpm...

:eyepop:

As I said before; Absolutely BRILLIANT!!!

 

[hartrockets]

The wheels are approx 70mm in diameter but some are made slightly bigger / smaller.

Sometimes we put slightly bigger wheels on the rear to create some down thrust.

Here is a photo of one of the older wheels. (All made professionally out of titanium!

 

[hartrockets]

The car went through a set of 12 timing gates. Where there was 2 thin wires set at 6 meters apart. The time taken between the 2 wires being broken gives the speed.

Here is one of the timing gates



Also had 2 racal timers on the track


Could not use Santa Pods own timing as the car is too small.

 

[rstaff3]

That's a very well executed project! Any yahoo could make a broke down J powered rocket car, but you did it right. The GSE is cool too!

 

[fyrfytr310]

This reminds me of some things I may or may not have done on my elementary schools parking lot with Estes motors and RC cars that I may or may not approve of now.

 

[Mugs914]

It is fantastic to see someone taking a project like this seriously. As Dick said, anyone can fire a J motor sideways, but I love how well you have done the job of thinking this through, designing the car and gathering the data. Please do keep us apprised of your progress!

Could I ask about details of the car's construction? What wheel bearings, for example?

 

[markkoelsch]

I think this beast of a car should be a little longer and then a Loki K1127 should be inserted. Just saying...more is more.

 

[GregGleason]

Wow!

It would be cool if you could get some velocity metrics about the time of motor burnout, near V max.

But for the run, Mach 0.84 is in the transonic realm and for something that small on the ground that's freaky fast!

Greg

 

[hartrockets]

Thanks for all the comments