60 replies to this topic

[GotToRace]

For the infinity and beyond voters how would you implement it, mount a trigger on a pot or what?

Hall Effect Sensor with a little magnet on the trigger. Infinite bands, no drag to trigger movement equals smooth response.

[stoo23]

More important than the number of bands, to a degree, is the power curve and how it is set up

Yes,..I Totally agree.

[GTPJoe]

Guys,

I remember seeing an HO "wiperless" controller. The trigger was the post of a pot so that as you pulled it, it turned the pot up and a spring pulled it back down. That got rid of the arm and contact pads/contact. No arcing or cleaning.

How about that same idea with an electronic voltage follower circuit?? Not linear enuff??

Thanks!

[Jeff Goldberg]

While the simple answer is "infinite" and the easiest answer is "more is better", real answer can only be properly determined by measuring our customer's ability to precisely and repeatably position the controller trigger over the course of a race.

What I mean is this. Let's assume for argument's sake that the trigger sweeps though 40 degrees from brake to full throttle. If you can only control your finger movement in increments that produce 5 degrees of rotation, then only 8 bands are needed...anything more is overkill. If you can control your finger movement more precisely, say in increments of 1 degree, then a 40 band controller would be called for.

There's other factors at play as well. As controllers continue to evolve, some will use microcontrollers to convert trigger position to a PWM signal that drives the motor. The microcontroller digitizes the trigger position, giving it a numerical value between 0 to 255. That would mean that even though your pot is infinate, you are really only supplying one of 256 possible values to the MCU...so anything over 256 bands is wasted.

You can try a simple test. Look at how much finger movement is required to move the wiper from one band to the next on your controller. If your can easily tell the difference, then you will benefit from more bands then your controller has. If it's hard for you to tell the difference, then you probably have enough bands. If you can't tell the difference at all, you've more bands than you need.

Is the right number 18, 24, 100 or infinate? The marketing guy in me would of course say "24", but without observation, the engineer in me would still say the real number is TBD.

Jeff

[Rob Voska]

I think the number of bands is only part of the question. Depending on the type of racing you are doing I think the feel and power curve is more important. Also how that changes from one car / class to the next.

Most controllers have the same amount of movement / trigger travel so why not the "infinate" or even 30-40 bands that would be 1 band per degree and that's more then good enough that would take all the complaining about bands out of the way and we can concentrate on adjusting the feel / curve. That is what I would like to be able to adjust. Then the blame will be back where it belongs......on the driver!

Would also like someone that understands the new voltage regulating controllers to describe how they work and are better than what we have now or just different or worse.

[Dominator]

If you want some info on the voltage regulated controllers, call Lou Pirro. He has tried them and can provide some great info for you.

The number of bands on a controller are more of a selling point to a degree. As long as the power curve is consistent, the bands will more so determine how the power comes on.

[grego]

I think the number of bands is only part of the question. Depending on the type of racing you are doing I think the feel and power curve is more important. Also how that changes from one car / class to the next.

Most controllers have the same amount of movement / trigger travel so why not the "infinate" or even 30-40 bands that would be 1 band per degree and that's more then good enough that would take all the complaining about bands out of the way and we can concentrate on adjusting the feel / curve. That is what I would like to be able to adjust. Then the blame will be back where it belongs......on the driver!

Would also like someone that understands the new voltage regulating controllers to describe how they work and are better than what we have now or just different or worse.

I would not want to go as far as to claim that I understand PWM , or voltage regulating controllers. I do understand the principal of them, and I am driving with one. It uses "hall-effect", so there are infinite amounts of bands.

As it uses (electronically speaking) both sides of the PWM effect, it features braking the very moment one comes off full speed. No need to let the trigger go to the very end to get brakes. Less power = more braking. Unlike old fashioned controllers that seem to have a coasting effect, with this controller the motor is either "forced to go" or "forced to brake". As both sensitivity (power curve) and brakes are adjustable it is very easy to find a "sweetspot" which is more critical for twisty circuits than it is for big 8 laner with banked curves, but then we do not have a track here in NZ that has banked curves, the last one just having been taken appart and put into storage........

grego

[Slapshot]

I might add when I spoke of resistances above that refers to the resistance load used in series in each band of a multi band transistor controller. In essance a series of resistors in varied step rates at different bands actually finalise the transistor output. Power to the motors/track technically does not go fully through these small resistors on the wiper but does vari the power transistor. The wiper as it goes to each band adds a resistor in series up to the final total and spits to transistor base load resistor and emitter sensativity pot. More bands allows for less resistance between bands resulting in smoother or less jump. I will stop there on detail because thats why we have professionals like Ruddock, Difalco,Jeff,Howard, and may others who build controllers.

Jeff pretty well summed up the aspect of trigger response and it importance to efficiant trigger action.

My continued was to go into digital response multi band controllers which Jeff understands and explained quite well. That his expertise. His build uses programed signal to each wiper band which then varies the transistor output. I leave it simple since thats a whole different knowledge level.

Raymond

[CDavis7]

While the simple answer is "infinite" and the easiest answer is "more is better", real answer can only be properly determined by measuring our customer's ability to precisely and repeatably position the controller trigger over the course of a race.

What I mean is this. Let's assume for argument's sake that the trigger sweeps though 40 degrees from brake to full throttle. If you can only control your finger movement in increments that produce 5 degrees of rotation, then only 8 bands are needed...anything more is overkill. If you can control your finger movement more precisely, say in increments of 1 degree, then a 40 band controller would be called for.

There's other factors at play as well. As controllers continue to evolve, some will use microcontrollers to convert trigger position to a PWM signal that drives the motor. The microcontroller digitizes the trigger position, giving it a numerical value between 0 to 255. That would mean that even though your pot is infinate, you are really only supplying one of 256 possible values to the MCU...so anything over 256 bands is wasted.

You can try a simple test. Look at how much finger movement is required to move the wiper from one band to the next on your controller. If your can easily tell the difference, then you will benefit from more bands then your controller has. If it's hard for you to tell the difference, then you probably have enough bands. If you can't tell the difference at all, you've more bands than you need.

Is the right number 18, 24, 100 or infinate? The marketing guy in me would of course say "24", but without observation, the engineer in me would still say the real number is TBD.

Jeff

Jeff- I have a slightly different take on why infinite (or using a resistor instead of a wiper board) works best in most cases. 1) I agree with the person that can have precise control of 1 degreee benefits but so does the less accurate user because of: 2) My margin of error without catastrophic result is greater with more bands. In other words, if on one lap around the donut I squeeze the trigger slightly harder or softer, it has less of an affect on the car than if I were to be one band higher or lower on say a 7 band controller.

I hope I am explaining this well, but it simply comes down to analog versus digital control. The more closer to analog linear progression, the better for my driving style and experience.

CD

[Phil Irvin]

I would not want to go as far as to claim that I understand PWM , or voltage regulating controllers. I do understand the principal of them, and I am driving with one. It uses "hall-effect", so there are infinite amounts of bands.

As it uses (electronically speaking) both sides of the PWM effect, it features braking the very moment one comes off full speed. No need to let the trigger go to the very end to get brakes. Less power = more braking.

What is the name of the controler and do they have a web site. The hall -effect is used in many of our car distributers or ignition cylender fireiring.

PHIL I.

[Jim Difalco]

I would just like to remind racers that the so called wiperless controllers are not really wiperless. There is still a contact inside the pot wiping across either a carbon or wound resistor. You are just hiding the wiper from view. A friend of mine built one of these in the early 1980's. Not being able to control the power curve on these type controllers kind of turns me off to that type design. Not to mention the pot sticking out at the pivot.

[Dan Ruddock]

I would just like to remind racers that the so called wiperless controllers are not really wiperless. There is still a contact inside the pot wiping across either a carbon or wound resistor. You are just hiding the wiper from view. A friend of mine built one of these in the early 1980's. Not being able to control the power curve on these type controllers kind of turns me off to that type design. Not to mention the pot sticking out at the pivot.

Also these types of controllers must mount a micro switch so that when the trigger is released it will shut the controller off because most pots do not have a dead band in their innards.

To me the added complexity of this and like Jim pointed out lack of tune-ability for me rules out this design. When you design a circuit board you can tailor it for the application better than with a off the shelf part. Dan

[grego]

What is the name of the controler and do they have a web site. The hall -effect is used in many of our car distributers or ignition cylender fireiring.

PHIL I.

the brand is ACD pro and they come in several sizes. I have the pro 5 which lets me do up to C-cans of about 10Amp constant and 15 Amps peak.
http://www.yatronic.de

I am not saying that these controllers are the answers to everything but it sure works for me and when they say "maintenance free" they really mean it.
Another thing i really appreciate is that there is no heat, no fan and its very light. Furthermore, as the controll buttons are on the top it makes the controller ambidextrous which is important for a lefty like myself.
grego

[Rob Voska]

http://www.abslotsport.biz/page52.html This is a voltage reduction controller. I don't think I could ever figure out how to get it adjusted. I'm more of the KISS (Keep It Simple Stupid) type.

[Dan Ruddock]

One of the reasons I started this thread was to get people to think about this issue.

There is so much more to a controller than how many bands or what wiz bang features it has. If the focus by manufactures and consumers is only on number of bands and what new widget it has progress in other important areas will be neglected. I have seen this in other areas of endeavors where the numbers race madness blind people from what is a real improvement.

When shopping for a controller, consider all the major brands, Ask questions, Call the manufactures and listen to the reasons for the things they do. Don't just buy what some hot shoe recommends.

Here are some questions that need to be asked so you can clear threw the BS.

1. Is the controller overly complex and does it's complexity have a real advantages or just a
marketing one?

2. What effects does the complexity have on reliability?

3. Is the possible improvement that the complexity adds so slight that it is not worth doing? It is
important to understand that controllers operate under a very harsh environment electrically and must be very rugged electrically to survive.

4. Does the controller have any multi pin (more than three) I.C. chips?
Most of these devices have a low voltage ratings which can have problems with the harsh environment in the track, car and controller circuit. I have had first hand experience with this when I used a 30 volt rated schottky barrier diode and I started having a few not many failures of this part. I went to a 100 volt rated rectifier diode and the problem went away. So what's happening? the motors inductance in the circuit is generating high voltage spikes and oscillations. I question the wisdom of using these devices (chips) when a very good controller can be built with out them.

5. Is the mechanical trigger mount to wiper contact design flimsy, inaccurate and difficult to repeat?

6. Does the controller have one or two power transistors to ensure enough amperage head room and to reduce voltage drop at full transistor power?

7. Does the controller have individual bands and resistors to allow it to be re-curved?

8. Does the controller have a fuse on it's transistor output saving an unnecessary repair?

9. Does the controller have the ability to load regulate (the sensitivity feels about the same when you change to a different wattage motor). Controllers with out this can sometimes be a pain to get it to feel right and require more adjusting to get things right.

10. Does the controller have no dead band? This can really create problems. With no dead band if the trigger stop contacts are fouled with dirt not only will you lose brakes it will also not turn off the transistors making for an even harder wall blast.

Back to the band # controversy. Yes I could of put more bands on my new 18 band board but I was concerned that if the bands became too narrow that the glue that bonds the copper to the board might fail over the long term. Also the gaps between the bands need to be big enough to reduce problems with conductive dirt bridging the gaps.

It's important to understand that as you increase the number of bands the voltage increase from band to band gets very small reducing the chance of upsetting the car and also your finger only has so much precision to it.

This is where a smooth trigger is very important which makes it easier to control your finger. I have had racers ask me if ball bearings really help and my answer is a definite yes. After building thousands of controllers with and without BB the controllers with the BB just feel better. The trigger returns easier, has less play in it and it is just easier for your finger to control the trigger.

Did my best to not name any brands but these are questions that anybody should be asking when considering a controller purchase. Dan

[Rob Voska]

The wiper button is round / convex in design so I'm sure it's touching more than 1 band at a time no matter how many bands the controller has. How does that affect the controller?

Seems with more bands that problem gets worse so 1/2 to 1 band per degree (20-40 bands total) of movement should be more than enough.

6. Does the controller have individual bands and resistors to allow it to be re-curved?

Is this do-able with a adjustment pot or DIP switches like the Carsteen? Or does it take a chip set?

An HO or stock 2 OHM resistor is "linear" in feel but is it in power output?

[okibono]

One of the reasons I started this thread was to get people to think about this issue. There is so much more to a controller than how many bands it has.

If the focus by manufactures and consumers is only on number of bands progress in other important areas will be neglected. I have seen this in other areas of endeavors where the numbers race madness blind people from what is a real improvement. Here are some questions that need to be asked.

• Is the controller overly complex and does it's complexity have real advantages or just a marketing one?
• What effects does the complexity have on reliability?
• Is the possible improvement that the complexity adds so slight that it is not worth doing? It is important to understand that controllers operate under a very harsh environment electrically and must be very rugged electrically to survive.
• Is the mechanical trigger mount to wiper contact design flimsy, inaccurate and difficult to repeat?
• Does the controller have one or two power transistors to ensure enough amperage head room and to reduce voltage drop at full transistor power?
• Does the controller have individual bands and resistors to allow it to be re-curved?
• Does the controller have a fuse on it's transistor output saving an unnecessary repair?
• Does the controller have the ability to load regulate (the sensitivity feels about the same when you change to a different wattage motor)? Controllers with out this can sometimes be a pain to get it to feel right and require more adjusting to get things right.

Back to the band # controversy. Yes I could of put more bands on my new board but I was concerned that if the bands became too narrow that the glue that bonds the copper to the board might fail over the long term. Also the gaps between the bands need to be big enough to reduce problems with conductive dirt bridging the gaps.

It's important to understand that as you increase the number of bands the voltage increase from band to band gets very small reducing the chance of upsetting the car and also your finger only has so much precision to it.

This is where a smooth trigger is very important which makes it easier to control your finger. I have had racers ask me if ball bearings really help and my answer is a definite yes. After building thousands of controllers with and without BB the controllers with the BB just feel better. The trigger returns easier, has less play in it and it is just easier for your finger to control the trigger. Dan

Dan, how does all of this effect drag controller? I have one of yours from about 2002, and its been working great ever since.

[grego]

quote:
"""""Does the controller have the ability to load regulate (the sensitivity feels about the same when you change to a different wattage motor)? Controllers with out this can sometimes be a pain to get it to feel right and require more adjusting to get things right.""""

This point in my oppinion is the most important aspect of a non resistor controller. It gives one a possibility to always have the same "feel" regardless
of whether we are driving a Scalextric f1 or an open class wing racer.

grego

[Slapshot]

]IIIIIIIIIIIIIIIIII[

It is as you say not the number of bands it is the feel and response of the controller. Ball bearnig I agree are a boon to smoother trigger response. I have used a pair in my controllers for over 30 years and they still are a benifit. Most pros first thing they look for or ask if it has ball bearings in the trigger

I will answer this with general answers for all controller manufacturers

Questions 1-3 Pro Eurosport /GT12 and some GP10 steel chassis racers prefer all the fiddles. Those classes are so darned competative for pros. During a euro race if your car and controller is working properly you don't have to adjust. In Open Eurosports if your in a tight race with someone that allways is the advatage to the racer that can step up or down the sensiativtyy via a switch as opposed the senativity pot. That way they can revert back when conditions change without having to readjust at the pot. Motor conditions change so does the controller and situation. If you were racing mild Falcons the fiddle issue would be moot.

On Q4 the trigger does need to be accurate and not heavy.

Q5 If one transitor is loaded up and it heats excessivly or becomes inconsist then two might help but the heatsink/cooling normally is the first answer. High amp (non Darlington) transistors are continually becoming scarce in the 50-80 amp range. As long as you can keep the trasnistor constant after a long fourty minutes then we are good.

Q6 I think we are at the limits of number of bands 15-18-20 is pushing it. The first thing I haven't seen too many boards fail but again too thin a band is not desired after having a wiper button knawing at it all the time. Narrowing the brake and power band might be the option but that also involve narrowing the wiper button. The only other option is using a thinner resistance wire but if the wires larger or the triggers wiper is not set up correctly then we are back to a gratey feeling trigger. You loose later adjustability but it can be done. The last option is wire breadboard bands attached to individual resistors/trimpots again the gratey feeling if not set up correctly or too large a wire. Non wiper way is just too difficult.

Q7-8 Its a common gimme allways fuse we are all human.
Load regulation might be a hiderance and a boon. We don't change motors if at all during a Euros race in but the motors do change as different arms are used. A switchable load or variable electronic choke pot of sorts is always handy or possible along with the standard wire choke cuircut but then the range and linear action change so you back to square one.

The controller purchased is usually revilent to the type of class you intend to run. Running a Scalextrics home track car,or a flexi Falcon as opposed to a open eurosports has each has different requirments. Most pros have upwards of two to three controllers for individual classes. Having one would be great but most times theres a favorite or special for individual classes.

One of the best options of a controller is the have the heatsink at panel side. The weight of the controller is important and keeping the heatsink away from the elbow is also important. That lightweight controller still becomes awfully heavy after fourty minutes of finger exercising.

I think that the controllers on the market today are all excellent workmanship. To a point I agree it is not how many bands but the quaility that is instilled in ones product that make the brand. The difficult part is to keep the quality value level at the price being sold at.

Raymond

[Jim Difalco]

I agree with a number of things Dan says. I think we are both the type of controller makers who operate on the K.I.S.S. principal. I want racers to be able to easily repair and maintain their own controllers. I purposely have the last band slightly further to the power side just to get a few more thousands of width per band.

I have zero worry about bands lifting because our board is CAD designed, not hand drawn, and the gap is incredibly consistent. While the bands look thin, mine are .026" wide, modern manufacturing can make traces much thinner, without a problem of them lifting. Now if someone thinks I should push this design to 40 bands, I would say that would be going too thin, not to mention the diminishing performance return of 1/3 more bands.

[Dan Ruddock]

Dan, how does all of this effect drag controller? I have one of yours from about 2002, and its been working great ever since.

Very little of what I said has much to do with drag controllers. I hope if you are using my controller on a drag track that it has a red brake post as I don't recommend using my controller without a brake connection. Dan

[okibono]

Very little of what I said has much to do with drag controllers. I hope if you are using my controller on a drag track that it has a red brake post as I don't recommend using my controller without a brake connection. Dan

My bad baby... I made a dumb post...

Duh...

[Mark Johnson]

I use a Bruce Thiesen controller with infinite bands and am now forever spoiled.

[mazur50]

Also these types of controllers must mount a micro switch so that when the trigger is released it will shut the controller off because most pots do not have a dead band in their innards.

To me the added complexity of this and like Jim pointed out lack of tune-ability for me rules out this design. When you design a circuit board you can tailor it for the application better than with a off the shelf part.

If you have a microcontroller controlling your brake, you don't need to use a micro switch to control your brake.

[Dan Ruddock]

Yes, that would work but do you think it is a good idea?

Dan