Different starter question

[Alex.L]

Hi,
Long time reader but never posted.

I'm trying to convert a starter motor as shown in the guide on this site. But my motor looks different than the one in the guide.

Instead of opposite brushes, mine are paired up.
So two are connected to each other and the to solenoid and two are ground.
I was thinking I'd keep the ground in the case, how would I go about wiring up the other brushes? One lead on each and then switch them for reverse?

Thanks for your time!

Edit: Or I'm thinking that it's opposite brushes that should be plus and minus(ground)? So that it's every other + and -.

 

[landuse]

I have never really dealt with starter motors, but I do know that they are not totally suited for a kart application.

Someone will help you soon though

 

[itsid]

Hi Alex,

Why would you want to alter the commutation?
So stick with the way it was!

Also make sure that ALL brushes are properly insulated against the case!
if you want reverse (flipping + and -)

Even if you do not need reverse or don't care about it too much,
make sure to get the best possible connection between the power source and the brushes.
You should really have two identical terminals for the two armature wires IMHO
it's okay to have the case participate.. it's not okay to use it as 'part of the connection'

'sid

 

[Alex.L]

Hi Alex,

Why would you want to alter the commutation?
So stick with the way it was!

Also make sure that ALL brushes are properly insulated against the case!
if you want reverse (flipping + and -)

Even if you do not need reverse or don't care about it too much,
make sure to get the best possible connection between the power source and the brushes.
You should really have two identical terminals for the two armature wires IMHO
it's okay to have the case participate.. it's not okay to use it as 'part of the connection'

'sid

Hey Sid,
Thanks for your reply!
Will consider the insulation, thanks for the tip.
I do want reverse in this case, but I'm afraid I'm not following you after "two identical terminals".

I tried taking better photos to show what I mean. That the brushes are bunched up, on one side it's 2 positives and on the other there is 2 negative/ground.

I've only worked with motors with two brushes before and that's easy when it comes to wiring.

What I meant with the case comment was that I'd rather have two cables coming from the case than three.

Edit: the first pic are the two ground brushes and the second pic are the two positive brushes(as I see it)

Edit2: How would I wire it without changing the commutation? I would like to remove the solenoid.

 

[itsid]

What I'm saying is..
I don't know how the brushes have been wired originally..
and whatever you do you should keep that exact same pattern!

six brushes are four brushes are two brushes no problem at all
it appears the two on the first pic are interconnected (and have always been), so that's great..
Now it's important to know if the brushes (and thus the coils) are paralleled or serialised
That's easy to find out actually..

Is the interconnected set of brushes connected to ground (parallel set up)
or is one of the remaining two? (serial set up)
(can't tell if the second set with the wire is interconencted or not.. appears so.. but hard to tell with the rubber grommet hiding the important bit)

So I'm assuming you have a parallel set..
the one with the lead (previously positive)
was connected to the solenoid
and the other set was case grounded.

But still that's an assumption..
could be just one brush in the second pic connected to the wire and the other to ground (serial) *shrugs*
you can surely find out

IF it's a serial conenction, you just need to remove the brush connection from the case
and break it out to a terminal (as the other brush is)
if it's a parallel connection, you need to remove the case conenction of the set in the first pic and break that out in a similar fashion to the set in the second pic.

that's what I mean by two identical terminals.
you do not want one wire to be noteworthy longer or a of different gauge wiring,
in order to keep the connections as symmetrical as possible.

'sid

 

[Alex.L]

What I'm saying is..
I don't know how the brushes have been wired originally..
and whatever you do you should keep that exact same pattern!

six brushes are four brushes are two brushes no problem at all
it appears the two on the first pic are interconnected (and have always been), so that's great..
Now it's important to know if the brushes (and thus the coils) are paralleled or serialised
That's easy to find out actually..

Is the interconnected set of brushes connected to ground (parallel set up)
or is one of the remaining two? (serial set up)
(can't tell if the second set with the wire is interconencted or not.. appears so.. but hard to tell with the rubber grommet hiding the important bit)

So I'm assuming you have a parallel set..
the one with the lead (previously positive)
was connected to the solenoid
and the other set was case grounded.

But still that's an assumption..
could be just one brush in the second pic connected to the wire and the other to ground (serial) *shrugs*
you can surely find out

IF it's a serial conenction, you just need to remove the brush connection from the case
and break it out to a terminal (as the other brush is)
if it's a parallel connection, you need to remove the case conenction of the set in the first pic and break that out in a similar fashion to the set in the second pic.

that's what I mean by two identical terminals.
you do not want one wire to be noteworthy longer or a of different gauge wiring,
in order to keep the connections as symmetrical as possible.

'sid

Thank you again for a very educational reply!
Ah, I misunderstood what you meant by commutation. I've never considered changing the layout of the brushes, I might have been unclear about that.

It's a parallel connection, the "positive"brushes are only connected to the breakout lead and isolated from the case and brush mount by rubber.
The two grounded ones are connected to the metal plate in the middle which in turn is connected to the brush mount and case.

Thanks again for the explanation about identical terminals!
That's what I was thinking of doing all along.

So I'll separate the ground brushes from the case and then use two cables to break out both the positive and the negative brushes(exchanging the present positive lead and using same guage wire and length on both connections).

 

[mckutzy]

I'm curious as to why this came to this amount of disassembly, for questioning of the wireing...
I've seen in some cases there's a jumper, with the extra set of brushes...

So bigger question what was this fror/from originally?

 

[Alex.L]

I'm curious as to why this came to this amount of disassembly, for questioning of the wireing...
I've seen in some cases there's a jumper, with the extra set of brushes...

So bigger question what was this fror/from originally?

I think it's from an older Volvo, but don't really know as I was given it.
About the disassembly. I more or less had to if I wanted the brushes to stay on the commutator. And also, I didn't know the state of it before hand. Good thing though as all the grease had solidified and/or was absent. I also had to drill out the screws on the solenoid because of rust.
But I tried it before all this and it worked. And I like taking things apart for learning and pure curiosity.

 

[Alex.L]

And I just realized something. I'm guessing it's on or off running a starter motor? Not sure what kind of controller would handle the power. Or is there any way to limit the current drawn by the motor?
If I hooked it up with, say a 40A controller, would the controller limit the current or would it fry?

Looked it up online and it seems to be a 2.2kw motor. It's a Bosch 0 001 109 252.

 

[itsid]

Yes on or off is all you can pick from..
and
No, anything below a 200Amp controller would just fry..
since the motor will draw the 200Amps if it wants to
and there's nothing you can do about that.

BUT
Motor controllers are limiting however
by modulating the pulse width
(every pulse is still capable of delivering the full 200Amps!)

In order to limit the total output the PWM
can be set to say 25% (by means of throttleposition)
that means for every millisecond the controller is delivering power it's 3 milliseconds off.
(usually it's a microsecond scale depending on microcontrollers pwm bitsize... but 1024bit and 16Mhz are quite usual)
resulting in essentially 550Watts of output power..

A controller capable of delivering 200Amps (yes you need more than just the 183.3Amps !)
can be had from kellycontroller.com

Keep in mind that starter motors are meant to run about 10-12 seconds at full power only
and then usually need a full minute of cool down before you try again.
You can drastically improve that by altering the case
(vent holes, proper bearings if it has bushings and an internal fan if you have enough room to add one)
but still a programmable controller is likely a good idea to limit the max output
to avoid overheating the motor
Many controllers allow for a temp sensor input (to shut down before overheating),
so adding a temp sensor inside the case can give you some extra security protecting the motor itself.
Especially with starter motors I think that's a reasonable idea if the case is already popped open. (and you can get a more or less reliable 2kW or such)

reminds me... many high power starters I've seen use stator coils instead of permanent magnets.
Maybe you can convert that to a SepEx setup, splitting rotor and stator coils
that'd make it a three or four terminal motor alright,
but it gives you better controll (well the controller has more ways to keep the motor cool and reliable)

'sid

 

[Alex.L]

Thank you so much yet again Sid! I haven't got any experience of these powerful motors