## Search found 9 matches

February 5th, 2019, 12:14 pm
Forum: Roller Coaster B
Topic: A very long Start Line
Replies: 5
Views: 810

### A very long Start Line

I ran across this situation as Event Supervisor at our Regionals... They had a very long start line that crossed the track multiple times. Where it crossed the track, it was perpendicular to the track. That way, they could choose their starting point after impound, after the target time was announce...
January 18th, 2019, 10:05 am
Forum: Roller Coaster B
Topic: Roller Coaster Scoring Discrepancy
Replies: 15
Views: 1940

### Re: Roller Coaster Scoring Discrepancy

That's it ! Thanks ! I am having trouble reconciling the 2019 Roller Coaster event scoresheet spreadsheet with my calculations based on the 2019 rules. Here's an example: Device height = 40 Gap 1 = 3 Gap 2 = 2 Gap 3 = 4 Run Time = 15 Target Time = 30 My calculation shows: Height Score = 3 x (60-40) ...
January 18th, 2019, 9:54 am
Forum: Roller Coaster B
Topic: Roller Coaster Scoring Discrepancy
Replies: 15
Views: 1940

### Roller Coaster Scoring Discrepancy

I am having trouble reconciling the 2019 Roller Coaster event scoresheet spreadsheet with my calculations based on the 2019 rules. Here's an example: Device height = 40 Gap 1 = 3 Gap 2 = 2 Gap 3 = 4 Run Time = 15 Target Time = 30 My calculation shows: Height Score = 3 x (60-40) = 60 Time Score = 5 x...
January 29th, 2016, 5:37 am
Forum: Wind Power B/C
Topic: Wind Power B/C
Replies: 351
Views: 56473

### Re: Wind Power B/C

My interpretation of the 3 cm in the drawing is that no part of the blade can be within 3 cm of the axis of the CD mount hub. I certainly hope this is correct - My scavenged CD motor uses a magnet to hold the CD in place - i.e. the student blade assembly sits between the motor and the magnet. The m...
January 29th, 2016, 5:35 am
Forum: Wind Power B/C
Topic: Wind Power B/C
Replies: 351
Views: 56473

### Re: Wind Power B/C

As far as I'm aware, the resistor is in series with the motor. Correct me if I'm wrong. That is not correct. Rule 2.d.iv. ..."wired in parallel with the motor/generator"... Interestingly, you are both actually correct. I've had this debate with many people, and it's both in series and parallel. Thi...
January 28th, 2016, 3:35 pm
Forum: Wind Power B/C
Topic: Wind Power B/C
Replies: 351
Views: 56473

### Re: Wind Power B/C

The rules state that a standard, 12cm diameter CD is used. On the diagram of the stand, however, it shows that the radius of the CD on the mount is 3cm. Is that a mistake, or am I just reading it wrong? :? Thanks! In the example diagram, the CD mount hub has a radius of 3 cm. The CD isn't shown in ...
January 28th, 2016, 3:24 pm
Forum: Wind Power B/C
Topic: Wind Power B/C
Replies: 351
Views: 56473

### Re: Wind Power B/C

...so I have a few questions, wondering if anyone could answer them? Sure! And does anyone know how to put a resistor onto the motor for testing? As far as I'm aware, the resistor is in series with the motor. Correct me if I'm wrong. That is not correct. Rule 2.d.iv. ..."wired in parallel with the ...
October 6th, 2015, 11:29 am
Forum: Wind Power B/C
Topic: Wind Power B/C
Replies: 351
Views: 56473

### Re: Wind Power B/C

A few things I have learned about salvaged CD motors.... - With an ohmmeter, look for two leads that have a resistance of 5 ohms or less between them. These are the leads that will have the generator voltage when the motor is spun. Since these are 3-phase motors, you'll actually find 3 leads that ha...
October 6th, 2015, 9:48 am
Forum: Wind Power B/C
Topic: Wind Power B/C
Replies: 351
Views: 56473

### Re: Wind Power B/C

I'm and event supervisor, and I'm in the same place. Tore apart two late-90's vintage CD-ROM drives. The motors have only ribbon cables going to them. This is getting to be pretty antique technology and even the 2nd hand stores won't take them.

Suggestions ?