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talbot
United Kingdom
718 Posts |
 Posted - 14/09/2006 : 18:44:35
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I have raised this issue before but never really pursued it. I managed to get hold of an alternator from a Kawasaki 1000 cc motor bike. After cutting the mounting lugs off I was able to turn the aluminium case (fits a Myford easilly) so it was a snug fit in the original vertical dynamo (field coils removed) What I must do now is make a top and a tail shaft to connect the alternator shaft to the gear and fork. If the alternator bearings are removed there will be plenty of room to drill counter bores and weld to the alternator shaft. This will allow the original dynamo bearings to be used and the conversion will be totally invisible. Before I do any more work though I would appreciate comment on the potential output from the alternator, will it work at MMM revs, will it work anti clock and will the solid state controller sense the current requirement and adjust the amps in sympathy. The controller is inside the casing. My test alternator cost ú8 - a little less than the ú1500 I have been quoted by a dynamo / alternator reconditioner. If anyone is interested I can send digitals of all the bits an pieces.
Cheers
Jan t |
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Nick Feakes
USA
3376 Posts |
Posted - 22/09/2006 : 13:01:09
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Hi Jan
alternators will work clockwise or anticlockwise. The voltage regulator does just that - there is no current sensing in an alterantor - the alternator is self limiting in this respect. Before you do too much work it might be worth finding out how much current the alternator produced in its original duty - I would guess 10 - 12 amps but I am sure the internet would provide the answer. You then have to mount the rectifier assembly somewhere where it will stay nice and cool - else it won't last long! I suspect this might be the stumbling block.
I have been trying to put the lucas bulletins on the site but the file is too big. I will try splitting it in two or uploading the file directly if I could only find where the file goes!
Nick |
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Pat B
United Kingdom
66 Posts |
Posted - 25/09/2006 : 15:15:24
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********** LATEST UPDATE *********
On the recommendation of Wood Auto Supplies I purchased a different regulator (P/N VRG 355) which, in their opinion, is better suited to a non-vented dynamo.....as in my application.
On the recommendation of DMS Technologies (the battery manufacturer) I need to set the regulator to provide 14.5 - 14.7 volts to the battery. The battery then regulates the amount of current it needs.....that's why they call it a "self regulating" battery, I am told!
However, things just don't seem to be that simple. Wood Autos recommend a maximum current of 9 amps. Any more and you risk over-cooking the dynamo ! A fact well known to most Triple-M'ers. However, 9 amps (going by the Ammeter) is not enough to provide 14.5 volts to the battery.
It would therefore, appear to be a choice of setting-up the regulator to either protect the dynamo and not supply enough juice to the battery to maintain a full charge or set the regulator to provide sufficient charge to the battery but risk over cooking the dynamo.
There doesn't seem to be a happy medium that satisfies both. Is this correct ? |
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Nick Feakes
USA
3376 Posts |
Posted - 25/09/2006 : 21:12:00
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Hi Pat
there appears to be some confusion in your post - setting the voltage regulator will regulate the volts - it will have no control over the current (in fact the higher voltage setting will drive more current through the lamps - demanding more current from the dynamo).
As far as the battery goes - a certain voltage setting of the regulator will control how fully charged (and not overcharged) the battery gets. Even lead-acid batteries are self regulating in this respect - as they become fully charged their terminal voltage rises so reducing the charging current (provided the supply's voltage is regulated). Now if your battery is fully charged no charge will show on the ammeter, and that is normal. Remember the ammeter only shows the current going in or out of the battery. So if the generator is supplying all the load the ammeter will show zero. However, if the generator is unable to supply the total load, the battery will have to contribute and the ammeter will show a discharge.
I am assuming the regulator you have has 2 bobbins under the cover - in which case it will not regulate the current from the dynamo. If it has 3 bobbins it can limit the current. Set up the voltage regulator first and then short the voltage regulator contacts (to stop it regulating) and adjust the current bobbin contacts to limit the current to 8 amps. Thus set, the dynamo will produce the set voltage until the load on the dynamo reaches the set limt (8 amps in our case) and then the dynamo voltage will fall to maintain the current at the set limit. Hope that is clear
Nick |
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talbot
United Kingdom
718 Posts |
Posted - 26/09/2006 : 18:07:52
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I posted to this topic recently about converting to an alternator but since I don't understand solid state technology I am now back to dynamos. Someone mentioned that a Beetle dynamo could be converted for use in a MG so I bought one from ebay. Even though it has an input and output shaft the armature is simply too long so that's ú8 wasted. It's a pity since the quality of the Bosch unit is first class. I then found a Lucas C40 dynamo from my MG B days. The manual rates this at 22 amps. I have now made a new square bottom end plate out of aluminium and bushed the shaft to take the original gear - a simple job. The top is not so easy though since the shaft isn't long enough. I am now part way through making a top end plate with a proper, larger bearing with an internal diameter that will take the cam drive fork boss - exactly like the rear of the crank shaft. This will place tge fork in exactly the right position. The only slight complication is making a new fork - I will have to pay to get an internal key way cut. Before I waste any more time can someone comment on the use of the C40 dynamo and associated 3 bobbin control unit. I must add that the C40 has holes in the end plates and a fan behind the pulley - mine won't have any of these but I could cut apatures in the main casing - facing the block for invisibility.
Cheers
Jan T |
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Nick Feakes
USA
3376 Posts |
Posted - 26/09/2006 : 23:11:03
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Hi Jan
this is available commercially. As to how much current it can safely deliver - the cooling is a factor but it can probably deliver more current safely than the original as the insulation etc is probably better. You will have to try it and see - I would have thought 12A is probably a safe place to start. Let us know how you get on
Nick |
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bob
United Kingdom
335 Posts |
Posted - 20/10/2006 : 20:21:14
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Is anybody able to tell me if I have a 3 brush or 2 brush system?
The little box that the dynamoe wires seem to go into have
Type 12v , MF/2, RX and F3036 written on them? |
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Nick Feakes
USA
3376 Posts |
Posted - 27/10/2006 : 20:03:02
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Bob
the only certain way to tell is to remove the cover that is over the dynamo brushes. Have a look in the right hand side and see if you have a thin carbon brush (about 1/16" thick) and check that the brush holder has a wire connected to it. In this case you have a three brush system. If the thin brush is missing or not connected then you have a 2 brush setup.
Nick |
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