[Ade]

Test Rig currently being built to test up to 15m/s across all id, no it won't be a rug racing affair but purpose built

.

As we know Scorpius already tested at 10m/s and passed with flying colours

 

[rumrunner]

What does this mean to a lay person like me as I am eagerly awaiting this gem 2 system?

 

[Ade]

It's just for testing purposes , test past what the system will ever do in the real world to ensure 100% reliability..

Nothing to worry about though,firmware is rock solid and with the led beacons not buried in the slot it's already above and beyond other systems

and only needs one sensor to detect reliably as well

 

[Dr_C]

i am curious about the reference to 'burying' components at the bottom of slots... which I guess is a reference to SSD IR phototransistors being placed at the bottom of track slots... isn't that an advantage? for example increased vertical separation between LED and phototransistor leads to increased linear interaction length and hence faster vehicle operating speeds... also, it opens up opportunities for surechange guides improving ID readability during tail drift... all good right?

as I say just curious...

c

 

[injectorman]

Scorpius has track hardware at a recommended 3mm below track surface where SSD is 6 to 7mm below.
A difference of 3 to 4 mm.
We know doubling the distance with light quarters it's power.
Too close the window of opportunity is shortened. Too far the LED loses brightness.
Scorpius allows the the height of both emmiter and sensor to be played with to gain optimum performance.
Tests prove this theory with 10,000 out of 10,000 laps on Scorpius ID 24 at 10m/s speed.
So I can see Ade has a point in that the SSD transistor can never be less than 6mm from
the track surface. And of course a trap for dust. Does it still work? Yes. Is it as efficient as say Scorpius whos hardware and firmware was developed specifically for high competition use? We know it isn't.

So a few ideas as to why distance does matter

 

[injectorman]

Hi Guys
Currently making a custom made test rig for testing Scorpius, SSD and Carrera lapcounting and lane changing.
It needs to be deadly accurate so Ive had to pull on all my joinery skills and give the Makita tools a good workout.
The loop is constructed using the lamination technique building up layers 3mm at a time.

The car is a 1/24 Metal chassis Group 7 car. No lid.
Foam tyres, 55k rpm Parma Super 16D motor.
Just adding paint and copper tape to complete.
Testing transparency is of utmost importance here.

Should be a fun project to test all the new products in the pipeline for 2021.
Last pic shows first top coat on.
More soon on this.

Rick

 

[RikoRocket]

Wow!

I hope you have a long viewing distance, if that de-slots it will be more lethal than a bullet!

Projected speed? 20m/s?

 

[injectorman]

Hi Riko,
Centrifugal force holds it in the slot nicely. But yes a 200g steel projectile at 15-20m/s smack into the temple would certainly be a concern.
Top speed? I really have no clue. Let's say 15m/s ti be conservative and go from there.

Rick

 

[Ade]

We're looking at 35 - 45 mph actual speed @15-20ms...

...definately something you don't want to do in your living room with the Kids around

 

[injectorman]

Fact is digital is limited by nature of the lane changers.
Not sure if people actually think of those important issues

 

[Ade]

Yes, I know ssd can't achieve that speed range in stock form, you could of course move the sensor to flipper position but who wants to

With the configurable flipper what sort of speed do you think Scorpius could achieve

, I've seen NSR cars change lane flat out no problem on Scorpius competition flippers

 

[Ade]

Scorpius has track hardware at a recommended 3mm below track surface where SSD is 6 to 7mm below.
A difference of 3 to 4 mm.
We know doubling the distance with light quarters it's power.
Too close the window of opportunity is shortened. Too far the LED loses brightness.
Scorpius allows the the height of both emmiter and sensor to be played with to gain optimum performance.
Tests prove this theory with 10,000 out of 10,000 laps on Scorpius ID 24 at 10m/s speed.
So I can see Ade has a point in that the SSD transistor can never be less than 6mm from
the track surface. And of course a trap for dust. Does it still work? Yes. Is it as efficient as say Scorpius whos hardware and firmware was developed specifically for high competition use? We know it isn't.

So a few ideas as to why distance does matter

Also there are no need for led in guide flag for improved reliability , the offset beacon offers a very generous slip angle if you like show boating with loads of power oversteer, the results of angle to car being reliably detected are logged in this forum somewhere.

 

[injectorman]

Getting really close now. Copper tape in place.
Just need a few dabs of solder, a power supply, a 50A Scorpius WAM, dongle, software and Scorpius controller and off we go.
This project is turning out to be a lot of fun as I get to use other hobby skills like joinery etc.

 

[Dr_C]

For LED-to-Sensor distance the above recommendation for Scorpius appears to be 3mm... but I thought read earlier in the Scorpius installation manual that 4-5mm is recommended for fast tracks... so what is the advantage of going closer i.e. following the above recommendation of 3mm? I guess that is part of the objective of the new test rig... to explore how LED-to-sensor height affects max speed?

Just curious and really it was only Ades earlier comment about burying sensors (presumably SSD related) that got me wondering...

c

 

[injectorman]

There is no ultimate guide.
Ive found 6mm LED to Phototransistor works well.
Thats 3mm below track and 3mm above track
Or 4mm below and 2mm above
5 mm below and 1mm above. Etc
Then we have trucks where the chassis is 5mm or more above the track.
You get the idea.

Rick

 

[Dr_C]

Yepp - so the new test rig should help? I am thinking a simple graph for the Scorpius system of max speed for 100% reliable lap counting versus vertical separation between LED and sensor.

In general I think SSD keeps the vertical separation pretty much constant (perhaps slight variation of underpan-to-track clearance)... so one less variable to get right... I can see this is either an advantage or disadvantage depending on which lens you look through... mass market versus slotcar experimenter.

c

 

[injectorman]

Hi Guys,
So I managed to get the loop up and running with the Group 7 chassis and motor set up.
Previous best using a previous loop was 10m/s

Here the 6A power supply wasnt enough so out with the 30A lab supply.
Most I can get out of this supply is 16V so 16V it is.

Using a 30 second timer I count how many laps.
Knowing the diameter is 1810 we can deduce that 66 laps in 30 sec equates to 12.61 m/s
Or 45.396km/h
I realise now the faster you go the more centrifugal force, which in turn is essentially down force.
And the motor was starting to smell so yeah it was working hard.

I think though 12.5m/S is a good enough test speed seeing most digital cars never see half this speed.

Should I make a drag strip? Hmmmm

Rick

 

[Dr_C]

Remember...

kinetic energy =0.5 x mass x velocity**2

potential energy = mass x gavitational accel x height

so the car will be faster at the bottom of the loop... significantly so for the parameters of your system ... with the track sensor or LED (whichever) at the bottom of the loop it would make sense to measure instantaneous speed rather than loop average.

Serious hardware :thumbsup:

c

 

[Ade]

Fire it up Rick and lay it on its side, should change things a little

What Fun!! !

 

[Dr_C]

If you tilt it reasonable quickly... maybe the non-existence of centrifugal forces (room as frame of reference) will be observed... and the car will be seen launched in a random direction with linear velocity. Excitement for sure

c