Rally Cars Slotting Proxy 2023

Graham · 12th-Feb-23, 09:06 PM

(12th-Feb-23, 08:53 PM)Kevan Wrote: How are you measuring 'magnetic traction'?

Before we had a way of measuring magnetic effect we used a straight length of Scaley track inclined at 45°, if your car didn't roll down it failed scrutineering.

Now we have a mag effect checker which is a simple cheap digital weigh scale with a board over the top with a cutout for a block with thick shim glued on top which sits level with the top of the board. After hitting 'tare' on the weigh scale sit the car over the block and the scale measures a minus figure in grams, we allow -25g which is what a normal SCX motor reading would give at about 1 to 1.5mm ride height.

I bought the Scaleauto testing equipment, measures gms of displacement of a digital balance. It is very accurate and easy to use. You can measure with or without motors running

Kevan · 12th-Feb-23, 11:25 PM

That's good. So what measurement are you defining as excessive.

Kevan · 13th-Feb-23, 10:22 AM

Jag went in the post first thing this morning Thumbup

Graham · 13th-Feb-23, 10:28 AM

Good Morning

I totally forgot about the review on the new cars which had arrived for yesterdays Test Day run.

Rally cars slotting -2nd Test Day.pdf Size: 21.23 KB Downloads: 119

With the agreement of the Teams concerned, I will try to make some minor improvements on one or two cars, at least to improve their stability, and give the hosts an easier time.

Also the issue on the Parahna 25k rpm motors will need to be resolved, sadly there are two teams effected now.

I will expand upon the topic of "Excessive Motor Magnetic traction" on the Proxy Club Thread later.

But in future we will need to avoid this problem by specifying an eligible motor list, which I will start to look at today.

Savage GT · 13th-Feb-23, 05:58 PM

I believe the Piranha 25k use neo magnets, which are stronger and would cause the issue.

Kevan · 13th-Feb-23, 07:25 PM

Just an idea Graham but you probably already did this but take measurements from all the cars to create an eligibility list.

When my car arrives it has a Pioneer 18k motor.

Graham · 13th-Feb-23, 09:21 PM

(13th-Feb-23, 05:58 PM)Savage GT Wrote: I believe the Piranha 25k use neo magnets, which are stronger and would cause the issue.

That explains what they done to give the effect, but why ?
The 18 & 22.5K motors are OK

Graham · 13th-Feb-23, 09:27 PM

(13th-Feb-23, 07:25 PM)Kevan Wrote: Just an idea Graham but you probably already did this but take measurements from all the cars to create an eligibility list.

When my car arrives it has a Pioneer 18k motor.

Unfortunately the damage has been done for this proxy, with now the 3 of our entrants from the USA having fitted the same motors.

But yes for the next Proxy I have already said there will be a eligibility list- completed it today but there is a Maximum RPM limit 23K, so the offending Predator motor would not be eligible anyway.

Savage GT · 14th-Feb-23, 08:31 AM

(13th-Feb-23, 09:21 PM)Graham Wrote:
(13th-Feb-23, 05:58 PM)Savage GT Wrote: I believe the Piranha 25k use neo magnets, which are stronger and would cause the issue.

That explains what they done to give the effect, but why ?
The 18 & 22.5K motors are OK

The Piranha and Predator are different makes I think.

Graham · 14th-Feb-23, 09:48 AM

(14th-Feb-23, 08:31 AM)Savage GT Wrote:
(13th-Feb-23, 09:21 PM)Graham Wrote:
(13th-Feb-23, 05:58 PM)Savage GT Wrote: I believe the Piranha 25k use neo magnets, which are stronger and would cause the issue.

That explains what they done to give the effect, but why ?
The 18 & 22.5K motors are OK

The Piranha and Predator are different makes I think.

Yes of course, that would explain it, but I wonder if the Pirahna lower spec motors also use the "special" magnets ?