Author Topic: Lack of charge - REASON FOUND!  (Read 1606 times)

Offline alanp

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Lack of charge - REASON FOUND!
« on: 31.03. 2011 16:54 »
I have been struggling with a lack of charge for a few weeks and carried out wiring connection checks, swopped voltage regulators and did the usual voltage check of the 6V dynamo running a 12V regulator. I could get maybe 9 or 10 volts if I ran the engine at 4000 or so which was weird since the dynamo had been completely refurbed last year and the brushes and comm looked fine. Eventually I decided to bite the bullet and take the timing cover off to remove the dynamo and get it looked at by a specialist. When the cover came off the reason was obvious from the bits and pieces of the teeth from the timing belt drive to the dynamo. The dynamo turns freely by hand so I'm not looking at seizure. See photo attached of the belt. I recall tensioning the belt nicely on installation so I'm convinced I didn't install it loose and the dynamo was securely clamped.
A new belt is on order with the advice from the supplier to consider lowering my bulb wattage since it sounds like I'm overloading the dynamo. I'm running 45W halogen headlight plus the usual stop/tail and instrument bulbs and also 2 x 21W indicators. Now I thought that putting too high wattage bulbs on your bike just meant that the battery would eventually go flat but apparently there's more to it than that.
Anyone got any ideas re this bulb wattage versus dynamo output situation?
Cheers
Alan
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Online RichardL

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Re: Lack of charge - REASON FOUND!
« Reply #1 on: 31.03. 2011 17:24 »
This would be a good place for Mike from Manortec to chime in, but my thinking is that, no way does the additional load of higher power bulb require so much additional torque at the dynamo as to rip teeth off the belt. Really, most of the required lamp current is coming from storage in the battery while the dynamo replenishs charge when low. Yes, if the baterry is dead, the dynamo is doing it all, but it still ain't going to rip off teeth (of any quality). If I'm being wrongly cocksure, I expect to be slapped in about 9 minutes.

Richard L.
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Re: Lack of charge - REASON FOUND!
« Reply #2 on: 31.03. 2011 19:34 »
G'day Alan,
               one of my belts did the same. Not sure whether it stretched from the heat or was not meshed properly when tensioned. It was hitting the screw boss between the two pulley's. I cut off the boss and use a countersunk screw in there now, just in case.
Not sure about the extra load on the dynamo, but I can hear it working when I switch my 90watt high beam on.
Cheers
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Offline Rich

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Re: Lack of charge - REASON FOUND!
« Reply #3 on: 31.03. 2011 19:43 »
you are not the only one this has happened to, Shaun Hawker now does a double belt kit, as his original belt kit has this problem, which means getting new pulleys to take two belts, my opinion is that these belts are not up to the job as no matter how good the seals there is always oil mist about and the belts seem to suffer when oil gets on them and they break up. , when this happened to my bike, I purchased an SRM kit which is a wider belt and of some sort of plastic which is impervious to oil and wider so able to take tha bashing a belt driving the dynamo faster than the original chain.
I also hear that Steve Macfarlane has come up with a kit which has an even wider belt than the SRM one, now if Steve has put his mark on a kit then you can be pretty confident it will be up to the job, then I would say that as I am biased as I know and talk to Steve often
Richard

irvinjps

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Re: Lack of charge - REASON FOUND!
« Reply #4 on: 31.03. 2011 20:06 »
Hi there

I'm new to this forum and noticed your thread.  I noted you said you're running a 12v system on a 6v Dynamo.  I've done this in the past and it did the following.  The wires to the brushes on the commutator burnt out/melted and i got no power at all.  A guru in all things Mag & Dyno, Charlie Hamilton in Sunderland, used the analogy 'You're asking a donkey to do the job of a race horse'. The 6v dyno will put out 12 - 13v but whilst running a 6v system the regulator cuts the load from the Dyno to the Battery, as that's its job.  Use a 12v system and the regulator will be asking for power all the time to keep the battery topped up (especially if you have your lights on).  Hence the reason it burnt out.  It may not happen to you but be aware should you get issues in the future.  He recommended upgrading the Dyno to 12v as well.  He didn't sell or supply them so it wasn't a sales pitch.  I've no wish to alarm you but it may be something to consider.
Kind regards
John

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Re: Lack of charge - REASON FOUND!
« Reply #5 on: 31.03. 2011 21:21 »
Warm welcome to you John. I'm not alarmed!
But sorry to say I'm not quite with your mate on that 'donkey / race-horse' analogy though.
A standard so-called 6v-wound dynamo (and field coil) is made of sterner stuff than a finer-wound so-called 12v armature (or field coil ). The sole disadvantage is that the coarser-wound '6v' object needs more revs to get to the point where it can cut in to support a 12v system. Which makes it less good in town riding. But a belt drive with gearing step-up helps here.
A dynamo is delivering all the time loads are applied, whatever the system voltage, so there is no holiday for a dynamo at 6v as opposed to 12.
The '6v' dynamo itself is easily capable of producing the volts (just as '6v' Lucas alternators are too for that matter), so talk of the voltage isn't really much use on its own. A standard E3L is rated at 10A continuous and will deliver its 60 watts till doomsday in a 6v system. At 12v it will safely deliver 80-odd watts continuous, which is under 7A and to that one extent less onerous. A fine-wound so-called '12v' armature running at 12v with a suitably-matched field coil can only safely deliver 60W, ie has a 5A continuous rating. It will cut-in on a 12V system at the same rpm as the coarser-wound item does at 6v, which is why they're quite good things.
I have one bike at std 6v (perfectly OK), another at 12v using a standard 10A dynamo, and one at 12v using fine-wound 5A bits. Both OK too. Living in the country where lots of tickover with the lights on isn't a feature, the standard '6v' dynamo with a solid state regulator at 12v (a DVR2 these days, but a JG when they first came out many years ago) is my favourite and long-proven combination.
To your concern about durability, that dynamo has done 20 years and loads-a-miles (my weakness) with only brushes and bearings being changed. It will support Hothands grips for soft middle-aged hands (32W) plus a 35W halogen light etc, or a 60/55W searchlight otherwise. Which neither of the other options would do as comfortably. None of these dynamos has given a moment's trouble in recent years. I put this down, quite simply, to the excellence of the modern regulators available, which don't allow the field coil to be over-fed (a main cause of armature failures).
As to stripping teeth on belts (the original issue), I can only say that after initial teething (J) troubles with SRM pulleys and tapers a while back, my belt itself has now done 20,000 miles and I haven't given it a second thought. Even better ones may now be available from Dynamo Technologies.
I like dynamos. I prefer them at 12v, but above all I like them with decent solid state regulation - and with a magneto doing the really important thing of guaranteeing locomotion!
Bill

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Re: Lack of charge - REASON FOUND!
« Reply #6 on: 31.03. 2011 21:23 »
I've run the SRM belt system with the dynamo chamber so full of oil it was coming out of the cork seal around the dynamo (DAMH it's too embarrassing ) and it still charged and the belt did not incur any damage.
I was running six volt but with 45 watt halogen bulb
All the best - Bill
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Offline alanp

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Re: Lack of charge - REASON FOUND!
« Reply #7 on: 09.04. 2011 14:41 »
Sometimes you need the patience of Job to run these bikes.
I've replaced the knackered/toothless belt drive to the dynamo with a 15mm wide set and the voltage output is hardly better, as seen on the ammeter and measured at the dynamo (i.e. green/yellow together and voltmeter from them to earth).
I reflashed the dynamo for positive earth. Still no joy.
Even though I knew the volts were down, in desperation I tried 3 different makes of electronic regulators and of course I was wasting my time.
I took the dynamo apart to see if the armature had hit the field coils (as per SRM suggestion for why the teeth went awol) and all is well including the brushes and comm. and bearings.
It seems to me that something is wrong with the dynamo and the knackered/toothless timing belt drive was coincidental!!! How about that chaps?
So, the dynamo will be off to a local dynamo/magneto wizzard on Monday to persuade it to start behaving itself!
Anyway here's a photo of the 15mm wide dynamo drive.
I'm going into the garden now to relax and replace my white 'garage' skin with a sun tan (hopefully).
Alan
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Online trevinoz

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Re: Lack of charge - REASON FOUND!
« Reply #8 on: 10.04. 2011 02:51 »
Sounds like your armature is shot, Alan.

   Trev.

Offline alanp

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Re: Lack of charge - REASON FOUND!
« Reply #9 on: 20.04. 2011 15:43 »
Sounds like your armature is shot, Alan.

   Trev.

Good call Trev!
The armatures shot.
I need the bike tonight for our Fish and Chips run so have fitted a Wassell armature to get me going. I don't know what their quality is like but I need to ride!!!
My wizard is going to rewind my original armature to have as a back up.
Cheers
Alan
Member of the 'Last of the Summer Wine Club - Jennycliff'.

Offline Topdad

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Re: Lack of charge - REASON FOUND!
« Reply #10 on: 27.05. 2011 12:18 »
Good afternoon everyone, I'd get intouch with Paul Goff 01494868218 he sells arange of led bulbs that go right on and take min wattage therby allowing higher wattage at headlight regards Bob  not associated with him other than as a satisfied customer .
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