Power Tool Drag Racing! September 25th Entries open.

[blazerbotics]

Re: Power Tool Drag Racing! September 25th Entries open.

BTW 50mph is nothing, Adam Harper (one of the original RW judges who worked for Sinclair) beat the electric land speed record...

Adam Harper, the driver who broke the world land speed record for an electric vehicle by whipping along at a staggering 150mph, was on hand to recount the tale of daring.

Adam, 39, from Kent, was one of the first C5 salesman and is now the only world authorised dealer.

'Up to 100mph it's like you're running on rails, it's really stable,' said the dare-devil driver, who also performed the first electric vehicle stunt in a C5 by driving through a 70ft tunnel of fire.

'Then at about 110 to 120mph it starts getting tricky. At that point if a tyre blew up or something happened you would be surely dead.'

[blazerbotics]

Re: Power Tool Drag Racing! September 25th Entries open.

Had to do abit of a rebuild today, the actuators turned out to be no good (burnt out 3 out of 4), so the throttles are now controlled by servos. A few little bits to do tommorrow and it should be done, couldn't run it today due to it raining.

[graeme]

Re: Power Tool Drag Racing! September 25th Entries open.

Looking good Alan, Just made a sproket on ours to run 10mph faster if we need to. Since the test last week i have improved it by more batterys and fixed the transmition so it changes up-got a spring in the wrong place. In theory should reach 60mph in about 80m now if it doesnt blow up. Just got to finish painting the front and move the lcd screen so mark can see it better. We havent got time to test it agian now until we are there.
You can run yours in the rain its not as bad as ours

[blazerbotics]

Re: Power Tool Drag Racing! September 25th Entries open.

rather drive yours in the rain than mine, the risk of electrocution is less than that of pointing the wrong way halfway down the track!

[terry]

Re: Power Tool Drag Racing! September 25th Entries open.

150 mph <blocked> that

[james...venom]

Re: Power Tool Drag Racing! September 25th Entries open.

All you have to do is paint it??? That cant be right lol. We are still working on ours lots of problems. This year the timing will be the same as drag racing with the top speed displayed

[big_nipper]

Re: Power Tool Drag Racing! September 25th Entries open.

Alan looks really good. We went with the beach buggy as should be stable (and it was cheap on ebay), allthough with the 5hp engine that came with it, it could lift the front wheels of the road, that why the grinders are as low as possible.

Want to see pictures of yours James.

It might be finished but that doesn't mean it will work on the day, you didn't build a 250V 35kW speed controller for under £150 . Just the isolator switch cost £60.

Graeme, got 2 110Ah lead acid batteries if we need them for the chargers on the day, should be able to do 2 full recharges before they go flat if they are ok. Wouldn't let me borrow the silverbird LiPo's

[blazerbotics]

Re: Power Tool Drag Racing! September 25th Entries open.

I'll bring my off roader Mark, thats got 3x 50Ah batts on it you can use to charge off.

That must be one hell on an isolater for £60, couldn't you have just an automotive keyswitch, theyre rated at a few hundred amps and only £15.

Fitted a speedo to mine today, only a bike one, but will give me an idea of speed. Fit wheelie bar tommorrow, then all done.

[big_nipper]

Re: Power Tool Drag Racing! September 25th Entries open.

Automotive isolators are only rated at low voltage, try to use them at high voltage and the contacts usually weld together. Couldn't find a resonalbly priced single one so got a 32A 8way isolator and split them between the grinders.

Thanks for the offer of the batteries. They will let us use the power inside if needed just need them incase we need to recharge quickly outside.

You can always download an android app to record your speed. I tried one at the weekend call car performance that records your max speed, time to 40mph,60mph, 330 foot (~100m) time and others using the GPS and accelorometer. Seemed to be quite accurate with my car, didn't try it with the dragster.

[graeme]

Re: Power Tool Drag Racing! September 25th Entries open.

Yes the batterys will help alan, thanks.
Just finished the bracket for the screen so its ready to go.

[geeza]

Re: Power Tool Drag Racing! September 25th Entries open.

Good luck to all of you competeing at the weekend, have fun.

[blazerbotics]

Re: Power Tool Drag Racing! September 25th Entries open.

bloody hell Graeme, there's more engineering your screen bracket then there is in the whole of mine! Had a quick test run on mine today, with just 2 engines (nobody else about, so didnt fancy risking it on 4) got to 31mph fairly quickly, and still had more to give, think it should easily hit 40mph within the 100m. One of the spark plugs is creating aload of EMF and causing the servos to not respond, so need to swap that out tommorrow. Don't want to test it too much as the belts are stretching and im running out of adjustment to take up the slack!

[mark_m]

Re: Power Tool Drag Racing! September 25th Entries open.

Still got loads to do on ours. With a bit of luck we'll be out testing tomorrow afternoon.

Damn 2 strokes.
We've also had issues with emf and servos. Now looking for somewhere we can pick up new spark plugs from

[blazerbotics]

Re: Power Tool Drag Racing! September 25th Entries open.

lookin' good, what are you using to control the servos?

[mark_m]

Re: Power Tool Drag Racing! September 25th Entries open.

Originally it was: potentiometer ->(analogue voltage) -> arduino ->(i2c) -> Servo control pic -> (pwm) -> servo. This works fine in the garage but when an engine is running it frequently cuts out. In some bench testing we found the pic was sensitive to noise (even the noise generated by servos was enough for it to lock up sometimes). Adding extra capacitance on the power lines appeared to cure that.
We're now going to try: potentiometer ->(analogue voltage) -> arduino -> (pwm) -> servo. to reduce the variables.

I think bolt lightning was using an Arduino to control there engines, so I think that should be tough enough to survive working near an engine. I'm not sure if they were using servos or something else though.