Rolla Controllers

[rjh]

Good morning,

 

A Rolla Controla will be operating TODAY Sunday 15 May 2016 St expoEM,, Bracknelll Leisure Centre, Berks, RG12 9SE, open 1000-1630.

 

on arrival contact me either at the rear of Stand 25 Metropolitan Junction layout, or by the Test Track. Bring an EM or P4 loco !

(not siutable for coreless motors)

 

regards, Rodney Hills

[bertiedog]

The mystery pre war W&H controllers without resistance wire.....you have nearly all used them if your older, they became the H&M controller, with the tapped transformer. It used a special centre tapped transformer to give two outputs of AC voltage relative to the centre tap, the voltage being obtained from the exposed wires every few turns through the entire winding.

 

Other makers used this tapped transformer quite widly, inc Fleischmann and especially East German makers.

 

The problems came with simplification to allowing the wiper to run on the actual wires in the transformer, they wore away. But it did give a stepless range compared to the W&H version.

 

The whole design was derived from the Variac transformer, still made today in various forms,

.

The problem with the Rolla was wear and tear from arching, it used a rotating motor driven core that gave a variable pulsed output as the arm was moved.

 

Stephen

[Gordon H]

Any pictures?   

 

Here are a couple, taken on Saturday while the unit was disassembled for inspection.

[Edthefolkie]

I remember the ads for the Rolla Controlla, and I think I saw one demonstrated at one of the Central Hall exhibitions. Never seen one with the top off, so thanks for that Gordon H! The motor looks like a standard bought in item, the sort of thing found on good turntables and maybe tape recorders of the Fifties and Sixties. They were engineered to run quietly for obvious reasons.

 

I did a quick Google and a W A Rollason came up in connection with light aircraft servicing in the mid Fifties. I wonder? I am unsurprised at anything of this type these days, after finding out that Alan Sugar used to hawk reel to reel recorders round North London! All sorts of little engineering/electronics works around then.

[SHMD]

That motor is a "shaded pole motor".

 

It's AC, robust, cheap, reliable and quiet but they are heavy and they do run hot as normal.

 

The heat does not bother the motor as long as the correct insulation has been used on the windings.

The thick shaded pole winding (normally just 1 turn and is just visible on top of the motor's steel laminations) is normally un-insulated.

 

 

Kev.

[bertiedog]

I am sure that you have had a qualified electrician check it over, for testing to standard, but I would advise changing the capacitors used for suppression with modern replacements, the older ones may be all right, but capacitors do not last well. They were there to help stop arcing on the contactor strips, and stop wear from the sparks, as well as suppression, which was aided by the metal earthed case. Electrolube cleaners can help clean the commutator unit.

 

A lot of early control equipment was very well made indeed, there were lots of radio engineering companies who made the items, and Graham Farish became involved in models, his company having previously made radio parts.

 

Stephen

[Il Grifone]

The electrolytic capacitors look OK (no sign of leaking electrolyte), but their replacement wouldn't hurt. They tend to dry up with age and lose capacity.

 

Take care to respect the polarity with replacements. Reversed electrolytics can explode (guess how I know! ). It is not impossible they are the non-polarised type, for which it is essential that the same type is used as a replacement.

Edited May 15, 2016 by Il Grifone

[bertiedog]

In the 60's the values are clearly printed on the can....usually! These days you need a Microscope, Chinese dictionary, and code book to interpret them, especially micro SM types. If, by the way, you have elderly audio equipment, then it is vital to replace the lot! power supply and output caps dependent on the design.

 

In passing is there a way of the owner of the Rolla getting the RPM of the mains motor measured, a lot of electrical engineers have optical tachometers these days and could check. I would then be able to duplicate the mechanism, as I know the construction of the contactor on the shaft already. I would guess from the appearance of the motor that runs in the region of 400 rpm, which after the 4 way contactor would give a base frequency of 1600 hz for the pulse train. some rolla's had two way commutators, some 4way,

 

Stephen.

[Nearholmer]

Can we please have an itinerary, giving details of when this beast will be displayed?

 

Is it coming to the TCS Summer event, for instance?

 

Kevin

[bertiedog]

in case your wondering where the 12 volts power came from, the shaded pole motor had extra windings added to the coil to act as the transformer, in the original design. They may have changed to a separate transformer later on. Normal rectification was applied to the AC, before applying it to the commutator unit to turn it into pulses of various widths.

 

The whole idea came from military equipment made in the war to act as high voltage convertors to make HV for valve sets from 12 volt car batteries etc. Although the Rolla does not step up, it was based on a variable power supply unit meant for the RAF. The output of the RAF unit was smoothed by a couple of large value capacitors and a choke, to give pulseless DC

 

If the output of the Rolla causes noisy running of a loco, then capacitors can be added to partially smooth the output, even a switched bank of various values could be added to suit different motors, even coreless types.

 

The automatic control they talk about was possible as eack control has a common earth, so each output could be sent to a section of say a loop, with each section set to the correct speed.

 

Fascinatingly over engineered controller.

 

Stephen.

[Gordon H]

Is it coming to the TCS Summer event, for instance?

 

 

Not familiar with this particular event - where/what is it?

[Nearholmer]

Train Collectors Society summer meeting, usually at Biggleswade in early July these days.

 

There is quite a bit of interest in old control gear in the TCS. At a meeting at Leicester a year or two ago, one gentleman had a massive display of such kit, mostly from Shenphone IIRC, and plenty of members spent lots of time investigating it all.

 

Kevin

[Il Grifone]

 

I would agree with replacing all the electrolytic capacitors in audio equipment. I bought a NAD 3020B amplifier from my local Cash Convertors a year or so ago (at a very Grifone friendly price!). This produced an immediate improvement on the Pioneer* surround system, but quickly developed a loud hum on one channel. Silenced by replacing one of the supply capacitors. Foolishly I left it at that and now it hums briefly on switch on....

 

Many years ago, I had a 12" portable B/W TV (then quite new) on my bench with a myriad of weird faults. These disappeared one by one, as I replaced every last one of the electrolytics. Those in the know will not be surprised that they were all marked 'Rubycon'.

 

Edited May 18, 2016 by Il Grifone

[Nearholmer]

Remaining off topic: NAD???.... Well, that brings back memories of spending a lot of money for the time on my first "proper" Hi-Fi set-up, in about 1981. I even remember the special shelf I made for it!

 

K

[giz]

I bought a 3020B amp, 4020A tuner and a 6050C cassette deck back in '83. I still have the tuner in use in our holiday house in Slovakia, my mother uses the amp and the tape deck needs new drive belts but is otherwise OK. Not bad for 33 year old hifi equipment.

[Il Grifone]

  This concerns vintage Hi-Fi - ignore if not interested and apologies for hi-jacking the topic.

 

My first proper Hi-Fi amp was a Rogers Cadet II bought in the mid sixties (reduced to £20 - IIRC list price was around £30). It was only rated 6W + 6W, but produced a lot of sound through a pair of Wharfedale 8" Bronze/RS/DD speakers in infinite baffle cabinets*. I later added a sub-woofer a Wharfdale W15/RS powered by my version of a Mullard 10 watt amplifier which used surplus 6V6GTs as output valves (these only cost 1/- each, whereas the specified EL84s were at least 5/- !). Records were played on a Garrard 'Deccadec'. The later upgrade to a 301 and Decca magnetic cartridge was a great improvement.

 

http://www.troelsgravesen.dk/Wharfedale.htm (This refers to the Super 8/RS/DD which was the up-market version of the Bronze at nearly twice the price - the Bronze was £3/12/6d IIRC)

 

* I bought a pair of these in proper Wharfedale cabinets at a boot sale about ten years ago. They still produce excellent sound. The cabinets for my original pair were acquired surplus and originally intended for the old EMI elliptical speakers. (Grifone bargain scavenging is not a new thing.... )

 

I found this while researching   http://www.vintage-radio.net/forum/showthread.php?t=119339

I can supply specs. for the BSR cartridges - M(ono) and S(tereo) cr@p H(igh output) very cr@p - very popular and nasty rockbender cartridges guaranteed to destroy vinyl in one play. My very first upgrade to my first stereo player was to replace the TC8S with a Ronette BF40. This gave a loss in volume, but a great improvement in sound at a lower tracking weight. The next was replacement of the rubbish BSR changer with the Deccadec (A Garrard SP25 with a Decca Deram cartridge in a special anti-rumble mounting).

 

We/I appear to have strayed away from Rolla-Controllas again!

 

EDIT

It would appear that memory fails me yet again and the 8" speakers were 'Bronze' and 'Golden' refers to the 10" (not that it matters much).  http://www.ajaudio.co.uk/Whafedale%20speakers.pdf 

Later I added a pair of economic (about £1 each) tweeters that hailed from the Far East fed through a simple capacitive crossover to plug the 10dB dip above 8 kHz.

 

EDIT for punctuation and the missing 'r' in 'Garrard'.

Edited May 19, 2016 by Il Grifone

[Nearholmer]

Well, I paired that NAD amp that I mentioned earlier with Wharfedale Linton speakers. I can't recall what else went into the assembly.

 

On a "rather too late to act on" basis, is Grifone's opinion that I chose well, or badly?

 

K

[Il Grifone]

Having one myself I can't criticise your choice of amplifier in any way!    It was always considered excellent value. As I said before, it was immediately superior in sound to the Pioneer (which certainly isn't bad). The bass is noticeably 'tighter' for one thing. This is related to low amplifier source impedance giving better damping. (My B & O speakers are relativly low in nominal impedance.)

 

As always, speakers are a personal choice, but I have never heard a Wharfedale I didn't like. There are several variations of the Linton

 

It would appear that I'm not alone.  http://audiokarma.org/forums/index.php?threads/wharfedale-linton-xp2s-no-respect.497965/

 

The thing that makes no difference whatsoever are all the 'snake oil' cables and similar available at silly prices. (Most engineers will agree on this and that 'Apple' is just another way of parting people from their money.) (IMHO)

 

About twenty years ago I read in Hi-Fi magazines :- a test of speaker cables - the best was twisted 2.5mm² multi-strand* mains cable (2 pairs per pole i.e. 4 cores) and a blind amplifier test between a 200$ Pioneer amplifier and various 'high end' competitors. None of the 'golden-eared' experts could identify it.

 

* It was an Italian magazine. Italian mains wiring practice favours multi-strand individual cables rather than the UK solid 'twin core and earth'.

Edited May 18, 2016 by Il Grifone

[Nearholmer]

Er, I reckon the chap who wrote the article in that link must have been the chap I sold mine to!

 

Joking aside, they are exactly the ones I had.

 

K

 

(Apologies for rattling on about all this. It's a bit of a trip down memory lane, because I've had pretty hefty fixed-frequency, about 1200Hz, I think, tinnitus for the past 20+ years, following damage caused by a benign growth inside one eardrum, and the operation to remove it, and I rather miss sitting quietly, enjoying the subtleties in music.)

[rjh]

Train Collectors Society summer meeting, usually at Biggleswade in early July these days.

There is quite a bit of interest in old control gear in the TCS. At a meeting at Leicester a year or two ago, one gentleman had a massive display of such kit, mostly from Shenphone IIRC, and plenty of members spent lots of time investigating it all.

Kevin

hello

 

thank you all for your comments and suggestions.

 

regarding showing the Rolla Controla, I am not a member of the TCS (*) but would quite willing to bring it along to a TCS event.

 

unfortunately your July Biggleswade date clashes with a prior committment, but I see you have something on at Alresford the weekend 18-19 June. That might be possible....

 

* - My good friend Andy Emmerson, a TCS member, spotted this R-C at a toyfair and put me in touch with the seller.

 

regards, Rodney Hills

[rjh]

hello again

 

Stephen/Bertidog asked about R-C rotational speed....

 

(I shall try and scan all the paperwork and upload it somewhere)

 

quote..

The current fed to your loco is 12 V.D.C. full wave rectified current, in the form of impulses having a variable dwell to control speed. These impulses have a frequency of approx 180 per second.

 

The commutator has four tapered pickups for each direction.

Yes, shaded pole motor 3000 rpm = 50 rps

about 45 rps in practice which matches Rollason's 180 pulses per sec with four pulses per rotation.

 

My standard model has NO 12v supply, there are two power pack (pp) models that do

 

prices inc purchase tax

R.C.1 standard £4-19-6

R.C.2 2amp pp £6-19-6

R.C.4 4amp pp £7-15-0

 

regards, Rodney Hills

[rjh]

hello

thank you all for your comments and suggestions.

regarding showing the Rolla Controla, I am not a member of the TCS (*) but would quite willing to bring it along to a TCS event.

unfortunately your July Biggleswade date clashes with a prior committment, but I see you have something on at Alresford the weekend 18-19 June. That might be possible....

* - My good friend Andy Emmerson, a TCS member, spotted this R-C at a toyfair and put me in touch with the seller.

regards, Rodney Hills

 

Good afternoon

 

I plan to take my Rolla Controla to the Alresford show on SATURDAY 18 JUNE 2016. and hope it may be possible to have it operating

(not suitable for coreless motors)

 

Thi,s is not a TCS show but is organised by Bob Leggett. There will be a TCS stand, manned by Rod Hannah, that would be the best place to inquire if you wish to contact me on the day.

 

I shall also try and post this notice to the TCS Yahoo Group.

 

regards, Rodney Hills

[rjh]

Good afternoon

I plan to take my Rolla Controla to the Alresford show on SATURDAY 18 JUNE 2016. and hope it may be possible to have it operating

(not suitable for coreless motors)

Thi,s is not a TCS show but is organised by Bob Leggett. There will be a TCS stand, manned by Rod Hannah, that would be the best place to inquire if you wish to contact me on the day.

I shall also try and post this notice to the TCS Yahoo Group.

regards, Rodney Hills

Hello again,

 

DUE TO HEALTH PROBLEMS LAST NIGHT, I DID NOT MANAGE TO GET TO THE ALRESFORD SHOW, today Saturday.

 

SO no Rolla Controla on display this year, sorry.

Perhaps next year...

 

regards

Rodney Hills

[roythebus]

Going back off-topic for a minute, my first decent hifi was a Leak stereo 70 amp and Wharfedale Unit 3 speakers, and excellent set-up. I used these for mobile disco work in the early 1970's until I found they kept blowing for some reason!

 

I recently bought a leak stereo 70 off ebay for a sensible price. It worked but hd a nasty fluffy hum which I found was a broken circuit board, probably damaged in transit as the box was broken too. a bit of solder across the broken track soon cured it, and paired with a pair of Wharfedale  XP2 speakers bought from a boot fair a few years back and I have a good representation of a decent 1970's hifi! Another addition was a Sony TC630 tape recorder to replace my original one which was by then only fit as a donor machine! I have a Goldring GL70 record deck to go with that lot, but only use that for 78's, preferring a Technics 1200 for 33s and 45s!

 

Maybe we should start a vintage hifi section one here??

[Il Grifone]

 

How about this one from the late 70s?

 

https://zstereo.co.uk/2013/03/29/bang-olufsen-beomaster-2400-2/

 

Mine was bought second hand with its matching turntable and at present drives the above Wharfedales, though I have acquired a pair of B & O speakers to go with it.

 

Should we start a topic here under Collectable/Vintage or in Wheeltappers?