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Club Controller

143321 Views 296 Replies 26 Participants Last post by  Gripping Pneus
Below is the updated diagrams for the controller used by 6 of the club members

Circuit Diagram

Construction Diagram

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Here are the Constructional pics showing main wiring of the control box and Parma controller wiring.

Internal veiw of main controller box

SCD Wiper Board setup

Parma Turbo Handle internal veiw
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As a user of this controller can I say how good it is

But just 1 thing John the photo's can't be of your one as I can't see where your power packs plug in

How hard a build is it John and how long does it take ?

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Controller build requires basic soldering skills & tools, plus suitable drills & files, it takes @5-6 hours to put together.
Two more club members are interested in building this design as a back up to their main controller, hence the posts.

Just for you here is the missing part of my controller not shown in the previous pics so far.

(Note photo taken with power switched off as the green halo fogs the picture)

NASA have expressed an interest.................

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where do you get the SCD wiper board from?
SCD wiper board can be obtained from here

And Bl**dy good it is too!

24 bands, pre-drilled for resistors or diodes (I have used it for simple Diode controllers as well) available as a PCB only or mounted on a Parma block ready to fit the controller via the existing bolt.

Chas Keeling also has the Parma Turbo kits less the resistor as well.
More Constructional pics

Front View Case

Rear View Case

Internal Controls wiring

Thanks to Simon for letting me dismantle his controller beofre the racing started to take these pics.
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Build details and Spec for Club Controller

Controller is an updated Analogue design based on the Chris Frost design from some years ago. Main improvements is the addition of diodes on a rotary switch giving a stepped brake response, a partial drift brake and diodes added before full power stop negating the transistor step to full power.

Specification for the controller as follows

Peak power @10 Amps during acceleration (Transistor Dependant)
Full power rating +20A (based on Parma contacts)
Continuous rating at ½ power through Transistor @5 Amps depending on heat sink for transistor & transistor used
Working Voltage 8-25 volts
Braking adjustable in 0.3V steps (1N5148 diode drop)
Drift brake @2 diodes (1n4006) 1.4V
24 steps + full power on sweep
Start speed sets the initial motor speed from off to manic effectively changing the voltage range the controller will sweep over.
Traction Control, restricts the initial power into the motor making the controller less sensitive

Design suits Parma Turbo/ RED Fox controllers with separate full power & brake pads.

Construction. (Refer to supplied pics for details & orientation of components)

1. PCBA (SCD Wiper Board)
a. Note Wiper PCB is supplied either with or without mounting block, if without, then a suitable block with 7mm hole sized to fit between the Parma chassis lugs needs to be super glued to the non track side of the controller otherwise jump to (f).

b. Best method to position the wiper PCB correctly, is to locate block in controller lugs with Parma bolt, then dry fit the PCB on top to establish fit under wiper.

c. Wiper must sweep across the brake pad to full power pad at the correct height

d. Parma trigger movement stops may need to be adjusted

i. Brake button support can be bent backwards
ii. Full power stop behind trigger can be filed
iii. Wiper will need to be bent slightly to run at the correct pressure & angle across the wiper PCB

e. When satisfied with the position, mark a line on the rear of the PCB, roughen rear of PCB with sandpaper then super glue in position marked

f. Clean track pads at top of PCB with ink rubber

g. Form 1st resistor to hairpin form i.e. bend one leg 180 degrees back pass body, pitch the leads to suit pads.

h. Locate resistor on non track side starting on R/H side one leg goes to pad 1, 2nd leg goes to pad 2, making a connection.

i. Repeat for 21 resistors

j. With Reference to front view of wiper board solder diode from full power pad to adjacent pad diode orientated at shown.

k. From the non track side connect a hairpin formed diode from last diode pad to adjacent pad (note orientation).

l. Should now have a chain of resistors from pad 1 to pad 22, then diode chain from pad 23 to 25.

m. Locate PCB in lugs secure with Parma bolt

n. Solder brake diodes as shown in pic from brake pad PCB in a chain to the brake button on the controller.

o. Solder wire from full power pad to full power button

2. Cable connections Controller
a. Solder 1 core to full power Parma controller pad

b. Solder 2nd core to Parma brake pad

c. Solder 3rd core to last pad of resistor chain

d. Solder 4th core to the wiper

e. Lay cable to chassis of controller as shown and secure with tie wraps or hot melt glue

f. Locate chassis in to controller sides and mark where the cable is to pass out.

g. File/dremel cable access recess in both halves of controller.

3. Controller box bottom fixings
a. Drill suitable cable sized hole in L/H or R/H side of case bottom

b. Take 2 A 3 pin plug & remove top

c. Locate top centrally on bottom of case

d. Drill 2 fixing holes to hold to case avoiding electrical contact between case and plug pins when re-assembled

e. Drill 1 or 3 plug wire holes below position of plug in case

f. Locate multi-block connector inside case drill fixing holes & secure with screws

g. Locate transistor either in bottom or side of case, drill & secure with screw. (Note transistor requires insulating mounting kit such that the metal tab of the transistor does not electrically connect to the case)

4. Controller box top fixings
a. Print off dial sheet on normal paper, tape to front side of case top

b. Drill 3 holes sized to take the 2 resistor pots & switch pot threaded shoulder where marked.

c. Remove paper locate pots in correct position finger tight

5. Controller Case wiring

a. Wire up plug with suitable cable (Flexible mains lead cores 1.5mm etc)

b. Locate plug to case bottom feed wires through to multi-block, trim, strip ends and locate in block (see diagram)

c. Solder diode orientated as shown to Transistor legs

d. Connects wires as per diagram sheet 2 from block to transistor and to front cover pots.

6. Front Cover finishing
a. Print off dial sheet onto photo grade paper, allow fully drying then adding a spray coat of clear lacquer to protect print and give a wipe clean surface.

b. Carefully cut clearance holes for pot shoulders where marked

c. Undo nuts of pots, remove, apply contact glue to top cover then lay sheet in position

d. Replace nuts & tighten

e. Add Knobs!

7. Testing
a. With a multi-meter check that
i. Wiper at the brake position there is less than 1 ohm between neutral pin and earth pin
ii. Live pin to earth pin is showing as no connection (high ohms)
iii. Wiper at full power Live pin to neutral pin is showing as less than 1 ohm
iv. Earth pin to Neutral pin is showing as no connection (high ohms)

b. Place car on track

c. Set Controller brake to 100%

d. Set traction to 0%

e. Set Start speed to 20%

f. Plug controller in to 3 pin socket, Lift back end of car pull trigger slowly
i. Motor should increase in speed
ii. Should reach full power at end of travel
iii. When trigger released motor should stop instantly

g. Common faults
i. Motor does not run until full power button reached
1. Check Transistor & wiper board wiring at end of resistor chain
ii. Controller case gets hot
1. Disconnect immediately!
2. Check for soldering shorts between brake pads & resistor chain
3. Check transistor leg wiring
4. Check for shorts by following wiring diagram ensuring the correct wires are connected to the correct point.
iii. Start Speed/Traction control works in reverse
1. Wiring to pots outer connection is on wrong side, swap over.
iv. No Brakes
1. Check orientation of all diodes on wiper PCB & brake pot, 1 wrongly connected diode will stop the brakes from working.

Apologies for the carp formatting, original notes written in word did not copy over that well.
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May i just add that this controller is becoming too bloody popular at the club which goes to show just how good it is. You can also hide a large amount of capacitors in the control box.
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There's just enough room to squeeze this in, now revealed in its powered up glory................although mine is the only one with it fitted!

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Hi chaps; I have built one of these controllers but I am struggling with it! It dont work! Should it work on my Scaley Sport home track or do transistorised controllers not function correctly at home.? It seems to have a mind of its own! (I want to test it beforeI go to the club this week)!.

The only thing I have doubts about is this test.... "Wiper at full power Live pin to earth pin is showing as less than 1 ohm". I get a high ohms reading on this test. Anyone know what this means or what to check?

John has been very kindly helping me via PMs but I understand he's on his way to a far off land.

When I have this thing working I will add a post to assist others in making one of these!

Hi Jim

Yes John is away at the moment

How is your home scalex track wired or are you using the standard powerbase ?

Have you kept the solder joints seperate on the wiper board ?

standard pb michael. I an pretty sure the solders are separate as i realised this was crucial and it was mighty fiddly!
2 things then

1 seems simple but I take it you wired it to a scaley jack plug then ? Is it the right way round ? as for the other tests do you get the right readings ?
2 take it to the club and try it

I only use mine at the club and so does all of our lot so not sure if it does work or not
Yeah i wired in a jack plud. I took a Scaley controller to bits to see which colour wire did what so I reckon I got them the right way round....!

All other tests come good; just the one mentioned. Will see on club night what happens!

Greetings from the land where slot cars are made (well most of them), currently typing this from my 21st floor room overlooking LinShui city (Near Shanghai) after yet another free dinner.

Jim, I suspect your problem is that the scalex plug only has 2 conenctions the controller needs 3 as per the club standard 2A roundpin plug to work. Without re-wiring the scalex track to suit braking it will not work at all or at best with no brakes.

Oh the instruction 7.iii is wrong should read live to neutral pin low ohms ie, the wiper (neutral) is on full power (live) otherwise you have it correct as live to earth pin will be high ohms.

PM me the track wiring details please if you still get stuck trying to power up the home track for testing

Did the controller work at the club ???
New modifications to the club controller

Introducing the anti lift wiper arrangement no more problems for all the right handed people using the Slot standard left handed controller.

Uses a brass slot bearing, a brass rod, spare suspension spring and the wiper arm made from a copper busbar. The contact pip is soldered to the brass rod, the bearing to the arm then the pip assembly is inserted with a spring as shown. (The copper busbar & pip taken from an old 100A Distribution board switch)

And here installed on a Red Fox controller. Note the long reach wiper arm for fast action and use of flexible Slot It motor wire.

Finally in the top left hand corner the ajustable spring tensioner for the trigger, where the screw can be adjusted via a hack saw slot in the bottom end of the threaded section.

And Mike get your money ready the PWM MKII has been debugged and works a treat

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Nice work John

Where are you at the moment are you back in England ?

If so will you be down on Monday Night

Bagsy 1st go

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interesting stuff there [email protected] Michael, mine didnt work as it should at the club. I had what turned out to be a break in the resistor chain. Thanks again to john for the tech help. Sorted yesterday and on rigging up a test bench all seems to be good! Will sort a build thread once i sort some pics out.
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