How to test the generation side of the DynaStarter

[AustHaflinger]

Got access to the brushes but can only get one out. No trouble moving the spring and lifting the brushes but the connector wire has to be unscrewed but I can only get one undone. With the other two, the torque required to unscrew the connector is greater than the flimsy mounts can sustain and they are likely to break off. I need to think a bit more on this - maybe some penetrating oil then some way of supporting the mount.

This is the one brush I was able to remove.

They are all worn the same amount and sit flush with the top of the little fitting they slot into - so OK but I would like to replace them.

So does the plate at the end (see pic) come off? I have removed the four small bolts and it moves but does not come off.

What else do I need to look for?

Thanks

Garry

[heinkeljb]

The end plate should come off, but as the end of the commutator is in a bearing which is in that end cap, it might need some sort of puller or atleast a pair of screwdrivers 180 degrees apart to slowly lever it off.
I think you really should get the fan off as trying to rebuild the brushes part is going to very difficult inside the Dynastart body. You should make sure the commutator is nice and round and the copper segments are clean. also that the insulation between the segments is below the level of he copper segments where the brushes rub.

To remove the fan, you obviously have to take the nut off. There is a hole in the fan which is designed to take a rod, this will then lock against a rib on the dynastart body. This locks the shaft from rotating. Make sure you have the Dynastart in a big enough vice. You could also put a rod through the holes where the brushes are to provide additional locking against the body and shaft of the Dyanstart turning whilst you apply enough torque to undo the nut. I use an 18 inch breaker bar and even that you have to apply quite a lot of effort too. Soaking it with PlusGas (dismantling fluid) for a long time before hand should help. It is a normal Anticlockwise thread to loosen the nut.
It obviously has not been taken off for a very long time and has probably got some electrolytic action between the metals bonding it the threads to the shaft.

Taking the brushes out, soak the screws / threaded parts with PlusGas, then have a second pair of hands to use a pair of pliers to hold the fixings whilst you unscrew the screws.

Hope this help Gary.

John

[heinkeljb]

Just re-read you post Gary,

If a rattle gun is not moving the nut, I suggest you try heating the nut. When I first took the nut off Lurch's Dynastart just after I bought him, it was very tight. I had an 18 inch breaker bar with the correct sized socket, and if I remember correctly, I still had to put a bit of tube on the handle of the breaker bar - I don't remember it being a very long bit of tube, but it did provide the breaker bar with a bit more leverage.
The next issue you will have if the nut is on that tight is getting the fan off the shaft! Soak it lots, the shaft is straight with a key way so getting a puller on it will probably be essential. Constant pressure and then a sudden shock - just like taking steering ball joints apart, should (that's a nice word), get the fan off the shaft.

John

[AustHaflinger]

Thanks John - all great advice, I will give it all a try today.

Re the bushes I guess I need to get them from Haflinger Technik unless some of Aussie viewers have a local source.

Cheers

Garry

[heinkeljb]

I think they are a reasonably available item. I would try a local starter motor repair place in case they can provide local input. You know you can get them from Haflinger Technik if you really can't find them locally.

There're a Bosch part after all.

John

[AustHaflinger]

I think they are a reasonably available item. I would try a local starter motor repair place in case they can provide local input. You know you can get them from Haflinger Technik if you really can't find them locally.

There're a Bosch part after all.

John

Haha - you are spoilt living in the UK - I live in Canberra - the capital of Australia - no local rewinders or repair places local - I would have to send it to Sydney - 350km away.

I must have scared the dynastarter yesterday - because today the fan nut just came off with no effort as did the fan and the stator.

Even the screws that hold the brushes' connecting wires even undid.

All looks OK - so i will just put new brushes in and see what happens.

When it is all stripped down, it looks like any other generator.

Cheers

Garry

[AustHaflinger]

Well I tried a few places including a place that specialised in Beetles and drew a blank on the bushes - I ended up at my local auto electrician and he had a book of Bosch bushes but the Haflinger one is not in it. I gave him the Bosch part number of the dynastarter and he found it in his system but you can only buy a complete unit and not the brushes - he took the measurements of the brush and my telephone number and is going to investigate further.

I was discussing my overall problem of not getting 13.5v charge into the system and whether the issue could be the generator or the Bosch electronic regulator (a direct replacement for a VW Type 1 vers) and I showed him this pic of my reg to ask if he had issues with them.

He said they were fine and was explaining how to test inputs and outputs on the reg - basically about 14v on the top left contact (+ from gen) , about the same on the bottom right contact (regulated + to battery) and said that if I was not getting the same voltage at the battery there there could be a wiring issue between the reg and the battery.

Then he noticed the fuse just to the right of the reg - he said that they notorious for not keeping contact and that could be the problem - intermittent contact. During my exploration work I had identified that fuse as being dodgy and had replaced it with a 30amp blade fuse but not actually tried everything with it in - so that is probably what my issue has been.

Anyway my current bushes are not completely worn down but are getting close to it so I will have to wait for a new set - so hopefully all will be good afterwards - and I have learnt all about the dynastarter

Thanks for all the input, has been informative.

Garry

[AustHaflinger]

Well I think I am a pretty bright and intelligent sort of a person who does have a little experience tinkering. One philosophy I have is that when something breaks 90% of the time it is something simple and to investigate the easy stuff before the hard stuff.

Well with this low voltage issue I have been having I did not follow my own advice - last year I developed low voltage and replaced the electronic voltage regulator $80. Ran OK for a few months and the same problem came back - assumed my dynastarter was burning out the regulator despite all voltage checks on the dynastarter being fine. Bought a mechanical voltage regulator on the assumption that it was more robust but it requires different wiring in the vehicle to what the Haflinger has, so another $80 but not wasted as I can use it in my Landrovers.

When sorting the wiring for the mechanical regulator I noticed the fuse that takes the power from the regulator to the battery was a bit feral so I replaced it with a 30amp blade fuse - at this point the should have come on but it stayed definitely off.

Back to the dynastarter and I pulled it out and dismantled it. I ordered a new set of brushes from Haflinger Technik which arrived yesterday. While waiting for the brushes to arrive I went to my local auto electrician to see if I could get some brushes which he didn't have and I showed him a pic of the electronic regulator as it had been fitted previously - and he spotted the dodgy fuse straight away and said the one I had has a history of failing and not letting the green steam through - it was then the came on and I proudly told him I had already identified that and replaced it - I didn't tell him that the dynastarter was unnecessarily in a million bits scattered across the garage floor.

So new dynastarter brushes in today, reassembly and re installation - the old brushes were OK but worn down about 3mm.

On start - yep got 13.8v - 14.6v at the dynastarter, 13.9v at the output side of the regulator and 13.8v at the battery.

Moral of the story - when looking at electrical issues - check the fuses first before you start pulling stuff apart - it saves time and money.

Oh an I guess I am not as smart as I thought I was.

Garry

[AustHaflinger]

Yep been driving around a bit - all is good now getting a consistent 14v to the battery. Such a simple thing but I now know all about dynastarters and their operation, something new to me.

Cheers

Garry

[heinkeljb]

Glad it was something simple, but obviously a good idea to dig into the Dynastart as well - brushes have a service life and if you had no idea of when they were changed you will no idea when you need to look at them again. I think it is 12000 miles but the manual will be more accurate. Fuse holder obviously is subjected to heat and vibration so after 40 years is allowed to fail!

John