[Dr_C]

This simple modification switches the lap counting sensor of the ARC PRO into an APB-compatible mode.

The modification relaxes the ID-LED-to-guide-blade constraints of the ARC PRO enabling cars with surechange guides and/or cars with ID LEDs placed a long way back from the guide blade, still, to function correctly. This is achieved by switching the lap counting dual sensor into an APB-compatibility mode.

In making this modification, the analog lap counting function is lost.

The modification is straight forward... and done carefully can be reversed if necessary.

The modification is for DIGITAL use only.

The following nine photos show the procedure (no text)...

C

 

[JayE]

Amazing! Bravo! Well done! Easy piecey!

Does it go for both versions? (0.3, 0.4)

 

[Mr Modifier]

Brilliant! Many thanks for sharing.

Time to go shopping for an ARC Pro...

 

[Dr_C]

Yes - this works for both version v0.3 and v0.4. It does not address the lap counting reliability issue with LC button pressed for v0.3 - that requires the resistor swap-out.

C

 

[JayE]

Excellent!

 

[Dr_C]

Just two points to ensure a successful result:

1/ Take care when removing the small white four pin plug... try not to tug on the wires... instead... carefully loosen from the sides of the socket.

2/ Take care not to damage the blade detect sensor parts which stand up-right from the pcb - these can be easily damaged. They are no longer used after the modification... but reversing the modification would fail if these parts become bent or damaged.

Enough from me

C

 

[Henk]

Can I also just cut the grey cable if I don't need backward compatibility? Seems to be easier, my Arc Pro is out of guaranty anyway

 

[Dr_C]

Can I also just cut the grey cable if I don't need backward compatibility? Seems to be easier, my Arc Pro is out of guaranty anyway

I would recommend waiting a couple of weeks before doing anything which is hard to reverse i.e. wait and see what others find regarding this mod. If you do decide to cut the grey wire... I would propose the cut is made 2-3cm back from the plug... so that a rejoining could be effected if ever desired.

Hope this helps.

C

 

[Klitgaard]

Maybe build in a switch so analog is still possible...?

 

[Dr_C]

Yes - I have a version which uses a pnp transistor with integral base biasing resistor... base drive supplied from the analog/digital slider switch. All running nicely. The transistor is on a small plug-in board for easy assembly. I have a batch made up for friends who asked earlier in the year. They are locked down in my lab at present so beyond reach.

C

 

[Dr_C]

If folk like the above mod, I will share the pnp design with Hornby for possible future integration into v0.5... lets see.

C

 

[Dr_C]

Any feedback on whether this mod is liked or not, and whether it does what it says on the can, would definitely help in due course please. Ive been using the mod for about six months with no issues whatsoever. Hopefully others will enjoy a similar experience

C

 

[Dr_C]

So there are three options...

1/ remove the grey wire as per above (DIGITAL MODE ONLY)

2/ butcher the sensor board and add a low profile switch (as per kind suggestion by Klitgaard and now as per photo below).

3/ wait for one of my DIY plug in boards with onboard pnp transistor which auto selects between modes. Apologies to everyone who is patiently waiting to give this option a try!

C

Switch position:

left= normal ARC PRO mode (digital/analog)
right= APB mode (digital only)

 

[Klitgaard]

Hi Dr_C
Two questions comes to mind...
Any downside to this mod?
Does this mod address the issue of not register non black guide blades?
Thanks

 

[Dr_C]

Hi Dr_C
Two questions comes to mind...
Any downside to this mod?
Does this mod address the issue of not register non black guide blades?
Thanks

Over the months...no issues with sunlight or LED ceiling lighting - I had wondered whether unmasking the blade sensor would risk 50/60Hz (x2) lighting flicker noise - but no issues. I cant see any downsides... others may of course prove me wrong... time will tell.

Yes, this also fully addresses the non-black guide blade issue - any type/colour of guide blade can be used. The modification switches off the side-facing IR LEDs effectively tricking the blade sensor into thinking a blade is permanently blocking the IR beam.

C

 

[cinnober]

Maybe build in a switch so analog is still possible...?

Excactly my thought

 

[cinnober]

Maybe build in a switch so analog is still possible...?

Excactly my thought

 

[Neillie]

Any feedback on whether this mod is liked or not, and whether it does what it says on the can, would definitely help in due course please. Ive been using the mod for about six months with no issues whatsoever. Hopefully others will enjoy a similar experience

C

I will be doing this mod Doc, but it will be once the airport opens up again...not willing to risk messing something up (even by accident) and then not be able to get a replacement PB until the end of June

 

[Dr_C]

Yes - using a functioning powerbase is far more fun than giving a hard stare towards a broken one

C

 

[Dr_C]

Anyone else given this a try? all feedback welcome! for example... was it easy or difficult? and... did it work...? ie were the results positive? or... was it truly awful?

C