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Rolla Controllers


roythebus
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Does anyone remember the RollaController? I seem to remember seeing adverts for them and seeing them at Central Hall many years ago; quite novel controllers, a box with long rods sticking out of the end. The advert said they worked on the split potential system.

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Does anyone remember the RollaController? I seem to remember seeing adverts for them and seeing them at Central Hall many years ago; quite novel controllers, a box with long rods sticking out of the end. The advert said they worked on the split potential system.

Made by a firm called Rollason, ISTR.

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I would think that the continual mechanical breaking of current in a reactive circuit would give rise to arcing and burning of the contacts. The use of transistors or thyristors would be rather more economical and reliabie (and allow the use of feedback to maintain speed). I have built an electronic pulse width modulated feedback controller of this type which gives excellent control. However, it does cause overheating of some motors. My Rivarossi N gauge B&O 0-4-0 was very unhappy when I tried her with it. I believe coreless motors are particularly allergic and require smooth DC.

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Thanks 5050.

 

It is fascinating and I want one!

(Although I would never use it except to see if/how it works.)

 

I wonder if it was noisy?

 

 

Kev.

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I don't think such electronic devices were cheaply or readily available in 1961!

 

The mechanical solution was probably the easiest at the time. As for transistors, I think you were more or less limited to the OC35 and similar as a power device, but there were others not long afterwards. Progress was quite rapid in the sixties.

 

EDIT

 

I found these, but I have no idea as to cost...

 

http://www.semiconductormuseum.com/Transistors/LectureHall/JoeKnight/JoeKnight_EarlyPowerTransistorHistory_Bendix_Index.htm

 

and Wiki has this to say

 

http://en.wikipedia.org/wiki/Power_semiconductor_device

Edited by Il Grifone
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The Jan 1939 MRN 'Trade Topics' refers to a 'novelty' controller ("an electrically controlled controller") introduced by Walkers and Holtzpaffel that allowed an "electrically driven locomotive to run at any speed from a mere crawl to its maximum".  A small 0-6-0T was demonstrated backing slowly onto a train and then reversing without any reduction in power.  The engine also moved slowly at a rate of 1 wheel revolution in 120 seconds with maximum tractive effort being developed.  The unit was enclosed in a "neat box from which protrudes only one knob by which means starting, stopping and speed control are effected".

 

Now whether this is the same design as the 'Rolla-Controlla' can't really be ascertained.  In a later issue of the MRN there is a W&H advert for the controller which I will try and post tomorrow.

 

BTW, is 'rjh' still a member on RMWeb?

 

EDIT - I've noticed that I've been spelling the 'H' of W&H wrong for nearly 60 years!  It's 'Holtzapffel' not 'Holtzpaffel'!  DOH!

Edited by 5050
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W & H adverts for their controllers in 1939.

 

First the OO version -

post-807-0-81146900-1392721209_thumb.jpg

 

Then an 'O' gauge model -

post-807-0-14014700-1392721252_thumb.jpg

 

Note that the original model is advertised as being suitable for SP (split potential) useage.  And 'no resistance wires' does suggest something similar to the Rolla-Controlla.  I wonder what happened to the W&H version, possibly the war literally killed it off.

Edited by 5050
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..It is fascinating and I want one!

(Although I would never use it except to see if/how it works.)

 

I wonder if it was noisy?...

 It's an unecessarily complex construction. Much easier to have a slightly ovoid commutator, rotating at a fair rate, with its axis on a cam. The contact sprung but well damped, standing out of contact with the commutator when the cam is at bottom position. As the cam lifts the axis, the contact gets brief power pulses on the high points of the commutator; move the cam all the way to the full speed position, and the contact tracks the commutator continuously for full output. At which point a bypass switch can make full contact, and shut off commutator rotation.

 

I shall call the standard model the OVOtroller. Sound output of chuffing shall be produced by using the modulation generated. (An alternative slightly off-symmetric three lobe commutator model will be available for afficianados of the quality, and it shall be called the BEATroller.)

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Split potential used two windings to give plus and minus supplies. The traction voltage could then be tapped off between them, avoiding the need for a reversing switch. The reversing switch is usually incorporated into the speed control these days, so the system is more or less obsolete.

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  • 1 month later...

The Jan 1939 MRN 'Trade Topics' refers to a 'novelty' controller ("an electrically controlled controller") introduced by Walkers and Holtzpaffel that allowed an "electrically driven locomotive t:o run at any speed from a mere crawl to its maximum". A small 0-6-0T was demonstrated backing slowly onto a train and then reversing without any reduction in power. The engine also moved slowly at a rate of 1 wheel revolution in 120 seconds with maximum tractive effort being developed. The unit was enclosed in a "neat box from which protrudes only one knob by which means starting, stopping and speed control are effected".

 

Now whether this is the same design as the 'Rolla-Controlla' can't really be ascertained. In a later issue of the MRN there is a W&H advert for the controller which I will try and post tomorrow.

 

BTW, is 'rjh' still a member on RMWeb?

 

EDIT - I've noticed that I've been spelling the 'H' of W&H wrong for nearly 60 years! It's 'Holtzapffel' not 'Holtzpaffel'! DOH!

 

hello - rjh here - and I now am the proud possesser of an actual working Rolla Controla, thanks to Andrew Emmerson, who spotted it at a swapmeet/toyfair

 

 

more soon; .......

 

 

regards, Rodney Hills

Edited by rjh
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hello - rjh here - and I now am the proud possesser of an actual working Rolla Controla, thanks to Andrew Emmerson, who spotted it at a swapmeet/toyfair

 

 

more soon; .......

 

 

regards, Rodney Hills

Oooh, looking forward to that!

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hello again

here'ssome stuff that a few of us in MERG [ www.merg.org.uk ] collected/authored back in 2010, long before we captured a real live R-C......

 

Enjoy.

 

rgds, Rodney

 

ps - more to come...

 

 

pps- l'll try and arrange to bring the R-C to the Epsom & Ewell show [ on Sunday week ] if any of you will be therespring_2010_split_39_to_39-1.pdfspring_2010_split_40_to_40.pdfspring_2010_split_42_to_42.pdfspring_2010_split_43_to_47.pdf

spring_2010_split_38_to_38.pdf

spring_2010_split_41_to_41.pdf

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It worked incredibly well when I watched the original demo at the Model Railway Exhibition.

 

Since I was just a schoolboy at the time, I couldn't afford much of anything then.  But I think it suffered from having 4 controls at a good average price, but that couldn't be located away from each other. Also they all had a common connection IIRC.

 

Andy

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hello again

here'ssome stuff that a few of us in MERG [ www.merg.org.uk ] collected/authored back in 2010, long before we captured a real live R-C......

 

Enjoy.

 

rgds, Rodney

 

ps - more to come...

 

 

pps- l'll try and arrange to bring the R-C to the Epsom & Ewell show [ on Sunday week ] if any of you will be thereattachicon.gifspring_2010_split_39_to_39-1.pdfattachicon.gifspring_2010_split_40_to_40.pdfattachicon.gifspring_2010_split_42_to_42.pdfattachicon.gifspring_2010_split_43_to_47.pdf

That's brilliant!  After 50+ years I now understand what it was all about.  Thank you!

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