New to chipping - some advice on scx

2426 Views 22 Replies 4 Participants Last post by MrFlippant, Feb 28, 2022

A_S

Discussion Starter · Jan 21, 2022

Firstly apologies as I am sure this is oft asked! Please direct me to where to find the info if that’s the case.

I’ve just ordered the arc pro after messing around on a friends set last weekend.

I have many cars bought in the 90s thst I would like to convert to run on digital.

the first tranch were going to be my SCX 4wd rally cars (celica, 96 Impreza, lancer evo 4, and Toyota Corolla. All so much fun without the magnets.

having opened up the Corolla I was surprised to find it has a long strip of copper wire connecting up the motor with the brades/guide.

I’m looking for some advise on converting this and the others.

I’ve had a quick scan of the database but either pictures no longer exist or the txt just says I’ve successfully converted x not how they did it!!!

So, is it just a case of breaking the connection between the guide blade end and the motor end of the brass strip and then soldering on the digital chip to each half? Or does it get more complex than that.

the second question would be how to deal with the lights? I presume if they are connected to the motor end then they will be determined by the trigger ifconnected at the guide blade end then perminantly on?

3rd and finally I had read somewhere that the scx motors draw more current and could damage the chip? Is this the case?

Thanks,
Andy

1 - 20 of 23 Posts

MrFlippant

· #2 · Jan 21, 2022

A simple and reversible way to disconnect the motor from the strips while maintaining their suspension properties is to put some heat shrink tubing over the little feet on the motor that contact the strips. This will isolate the motor from the power coming off the rails.

Then, as you surmised, tap the power to the chip off those rails. Be quick about it, as it's easy to melt the underlying plastic. Then connect the chip output to the motor as normal.

The lights on SCX cars are usually also connected to those rails, so make sure your chip does not interfere with that system. Fortunately, most of their cars have a shallow interior, so plenty of room for a chip to be installed. Some will even have stub axles, giving you even more room.

And finally, yes... those motors are a little much for the older scalextric solder in chips C7005 and C7006, especially if you want to keep the magnets in. Either pull the magnets, or use a heftier chip, such as the most recent DPR chip (which you can remove from the DPR plastic panel) or the slot.it SP15b (or SP15c) chip.

Make sure metal things that should not touch CAN NOT touch, either by shrink wrapping or electrical tape, or liquid tape, and you should be fine.

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A_S

Discussion Starter · #3 · Jan 22, 2022 (Edited)

Thanks - my chip is a new C7005 bought from Amazon this week, is that still sub par vs already mounted for chip (either saloon or F1?). If I bought the C8515 single seater dpr plug is it simple to take it out the plastic and use it in the same manor as the retro fit? I.e is the IR receiver connected direct to the PCB or by wires below the pcb and I presume I’d need a plug to access the pins on the main board? Not a problem just anticipating what I would need to do!

it seems that the motor is connected by those vertical rails - I was planning to just take them off - I can’t see how (in this case at least) i could shrink wrap anything round the lugs on the motor without unsoldering the vertical brass peice and the capacitor anyway (still yet to work out how the capacitor fits into all of this

In terms of the lights - will they be always on unless i connect them up at the motor end?

thanks again For the swift reply

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GRUNZ

· #4 · Jan 22, 2022

You main problem is going to install the IR LED: ideally I would put just behind the front axle.
However, given that the car is 4x4 you now have to negotiate the crown and the pinion.
You need to use an external IR LED on leads: either get some from ebay or desolder the one from the PCB.
Once you put it on leads, then make sure to drill a hole just behind the pinion and make sure that wires do not interfere with the pinion or motor shaft.
One place where I would install the chip is on the side of the motor: I think those F1 DPR chips will be ideal for this (you will need to modify of course by removing form the plastic case, putting the IR LED on leads and then connect the wires from the guide and to the motor to the chip.
It is doable but I think you got yourself one of the most complicated jobs as you first chipping.
Good luck and show us some progress pics.

A_S

Discussion Starter · #5 · Jan 22, 2022

Thanks. I still think it’s a fairly simple thing, it’s just a matter of thinking it through and planning. I’ll probably now use my C7005 to connect up one of my scalextric F1 cars and order the F1 DPR ready chip.

I have no problem with desoldering the LED - is it clear where I need to solder the wires on the PCB once the LED is removed?

what is the connector type that plugs into the 4 pin slot? As I presume I will also have to get hold of one of those and route the wires appropriately. I think soldering directly onto the pins would probably prove difficult and unreliable

Is there any videos or reading you can recommend where others have done similar. The only thing I could see on YouTube was a 956 conversion and that put the whole DPR plug into it, not just the chip

GRUNZ

· #6 · Jan 22, 2022

I am not aware of any specific how-to but have a look at the chipping database thread on this subforum.
Lots of good examples.
Some posts that might be of interest to you: SSD Chipping Database, SSD Chipping Database

The posts above show you some pics of the F1 DPR chip used in very tiny spaces.
To note: the IR led has been desoldered from the PCB and relocated (the wires have to be soldered back on the pads where the IR LED was soldered on the PCB); the connector has been removed and the wires soldered directly on the pads; the big cylinder capacitor has been removed and/or repositioned but I do not think that this is needed in your case.

hope it helps.

A_S

Discussion Starter · #7 · Jan 22, 2022

Thats great, this is what I may end up doing.

As a test run today I managed to fit the retro fit into my Jordan honda without trouble, all in all it took under an hour from concept to completion and that was a bloody tight space. so tight I didn't need to glue the PCB in, infact I didn't even glue the IR led in as the hole was drilled to a tight fit.

so at least I have a better idea of the mechanics now before attempting something more complex. 2 more chips ordered for tomorrow

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MrFlippant

· #8 · Jan 22, 2022

Some glue is still a good idea. the LED can work lose as the car trundles around the track, and tumbles in the turns. Same with the chip, which you want to ensure will never touch anything metal that may short any of the circuits on the board.

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GRUNZ

· #9 · Jan 23, 2022

Mr Flippant is right. I would glue the LED just to be sure.
Make sure that you use some glue that you can remove without damaging it in case you want to move the chip to another car.
I use G-S Hypo but anything similar will do.
As for the chip, I either use blu-tack or double side foam tape.
You need to install also ferrite men (FM) - one on the guide side and one on the motor side.
On the motor side make sure that the FM legs do not touch the motor can otherwise you might fry the chip.
With the slot.it SSD chip, you only need a FM on the motor side.

A_S

Discussion Starter · #10 · Jan 23, 2022

2

Thanks - no ferrite man on the motor side (yet anyways) as the chip does not come with one for that side - what is the benefit if the car runs ok? One thing I did notice in analogue mode was the sensitivity of the trigger - an on off switch between 0% and 100 over just 50% of the travel, if that!

I’ll probably get some and insulate with electrical tape as I can’t see how you would minimise the risk of it touching in such a tight space otherwise.

I’d also probably cut the wires next time and I’ve had to masking tape the excess to the motor to fit it all in.

Thanks for the tip on the securing the IR. I have a hot glue gun that should work or perhaps some poly cement.

I think the chip is ok as it’s wedged between the motor and suspension with the IR underneath.

I don’t think I took a picture of it with everything in place

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MrFlippant

· #11 · Jan 23, 2022

The benefit is the chip not wigging out on a digital track from the EMI the motor creates. This might not be prevalent when testing with analog, but when it happens on a digital track, you'll surely know it. You have half of one on that formula car, just need the ferrite bead added, and the wires connected to the capacitor above the ferrite bead.

Yes, Scalextric digital chip's analog mode is twitchy. The chip was designed to work at a consistently high voltage, so it does not come alive until it gets 10v or more, at which point, the car is already moving pretty quickly. Not very useful unless you leave the magnets in. If you want to run the car as an analog car, don't install a chip.

A_S

Discussion Starter · #12 · Jan 24, 2022

Thanks for all the help guys, I am getting there.

I've ordered 3x slot it SP15B chips (As the C wasnt available anywhere) to fit to my SCX rally cars, plus the seperate IR kit to connect an LED external to the board.... all seems to being well with the world, plus it comes with the Ferrite Man thingy, or ferret man as I have now officially called him!

The next thing is dealing with the lights. On the Toyota at least (not sure about the mitsubishi, but subaru is old school wires) the lights are connected by a brass strip from the car body contacting the rail on the chassis, so I have a few options here:

1.) leave it, and the lights will be on all the time as the power is isolated from the track at a later point in the circuit.

2.) snip off the connector and wire into the motor as per a classic layout then the lights will be determined by the power to the motor as in a classic scenario.

3.) I beleive I can wire the lighting directly onto the chip somehow?

I've been trying to do some reading on this but most of the info seems to suggest the connector on the board for lights requires another chip which then controls brake lights etc etc. Is this the case? Can I get any benefit by soldering my lights directly into the chip and if so how?

***Baring in mind that I do realise I would need the wires to connect to both the chassis and the body in this car!!! as the lighting circuit is held in the body not the chassis and connected by the rails thingy.

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GRUNZ

· #13 · Jan 25, 2022

Given that you are using SSD where basically there is no control on switching on/off lights, I would leave the lights as they are: taking power directly from the guide so that they are always on.

For wiring the lights on to the chip, there are two main approaches:

if you use the newest Rev H version of the DPR chip, then there are 4 pads on the chip: two are for front lights and two are for rear/brake lights. You will need to solder wires and connectors to make sure that you can remove the body from the chassis
if you use the slot.it chip SP15b then you have a 3 pin socket: if you put resistors you do not need to have the external light board (it is not a chip). Have a look at this: oXigen Chipping Database although that is for oXigen the principle is the same.
if you use the slot.it C chip, then you need the light board because they use a very small socket on that chip. However, have a read at this thread as there are some ideas on how to go around the need of having an external light board: Options to run lights from the C Chip.

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A_S

Discussion Starter · #14 · Jan 26, 2022

Thanks, I’ve ordered the B chip but haven’t got any plugs to utilise unless they are the same as pc morherboard connectors in which case I’ll be able to find some!

pits a bit late tonight but I’ll have a look at the oxygen thing tomorrow.

pis it better to wire upto tie chip or keep as is on the b chip? Will I giveme any benefit? As I say I’ll read tomorrow

A_S

Discussion Starter · #15 · Jan 26, 2022

4

First scx done - Corolla with the slot.it B chip. Took a bit more time than the scalextric cars due to the 4wd and having to solder the LED underneath then to the board but all worked first time.

One observation I will make, and it applies to all 4 cars I’ve converted - they don’t seem to have the same power in digital as they did before in analogue (or in anologue mode after conversion). I appreciate that the chip will draw some current to do it’s stuff but I didn’t realise the cars would be noticeably slower.

Its most noticeable on the mangnet removed scx conversion because I have a couple of hairpins (classic track inner curves) which I normally slide round on full power but in digital I am struggling to get the back round.

initial impression only and throttle map set To linear (mode C).

photos not quite the final setup as I still needed To put some heat shrink stuff on, tidy up the wiring and glue down the chip

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MrFlippant

· #16 · Jan 26, 2022

The chip will drop the voltage that reaches the motor by about 1.5v due to the full bridge rectifier on board to convert the AC on the rails to DC for the electronics and motor. That, plus the power loss through the base to convert the DC to AC, and it can be noticeable, especially with a motor designed to work at a higher voltage than a more typical Scalextric type motor. On top of all that, the SCX motor tends to be a little sluggish when it's cold, and speeds up a bit as it warms up. As a result, the performance of the same car between DC and SSD will be noticeably different. That said, I'm a little surprised that it won't kick the back out on a hairpin with no traction magnet.

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A_S

Discussion Starter · #17 · Jan 26, 2022

MrFlippant said:
The chip will drop the voltage that reaches the motor by about 1.5v due to the full bridge rectifier on board to convert the AC on the rails to DC for the electronics and motor. That, plus the power loss through the base to convert the DC to AC, and it can be noticeable, especially with a motor designed to work at a higher voltage than a more typical Scalextric type motor. On top of all that, the SCX motor tends to be a little sluggish when it's cold, and speeds up a bit as it warms up. As a result, the performance of the same car between DC and SSD will be noticeably different. That said, I'm a little surprised that it won't kick the back out on a hairpin with no traction magnet.

might have been a bad connection to be honest, as some of inner curve 90 degrees are old tri-ang stuff…! So the connections aren’t the best. All other cars were away in another room so this was the only one on track and nothing to benchmark against. They were kicking the back out on standard sport track curves - but the surface is smoother. As long as the loss of power is meant to be there that’s fine - it’s not me doing anything wrong!

A_S

Discussion Starter · #18 · Jan 26, 2022

Oh yes - am I right in saying the only sport option I have for tight inner curves - I think they call them radius one, are the 45 deg ones, the 90 ones are shallower angle? Presume they never released the old style tight 90 degree bends in sport as they were long discontinued in classic anyway!

GRUNZ

· #19 · Jan 27, 2022

you need this kind of connectors: 20 Pairs Micro JST 1.25 3-Pin Male & Female Battery Connector Plug Wires Cables | eBay

MrFlippant

· #20 · Jan 27, 2022

A_S said:
Oh yes - am I right in saying the only sport option I have for tight inner curves - I think they call them radius one, are the 45 deg ones, the 90 ones are shallower angle? Presume they never released the old style tight 90 degree bends in sport as they were long discontinued in classic anyway!

They did make 22.5 degree R1 turns, but you don't see them used much. C8278 according to my track planner. But yeah, if you want less joins, the hairpin is the only option in Sport. I prefer the standard R1 pieces because I don't like milk-toast squeezes like that one. A squeeze should be a proper squeeze like classic track had, or none at all.

For great power around the track, once you're happy with your layout, power taps are your friend. I even went though the work of jumping across every join with soldered wire as well.

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