Commutator & Rotor

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ChuckLebeda
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Commutator & Rotor

Post by ChuckLebeda » Fri Apr 26, 2019 9:25 pm

I have a 1921 coupe purchased five years ago from an estate. Trying to get it started this winter.

Cleaned electrical system from negative ground on frame through to the spark plugs.
My problem was went I went to start it, it backfired and would not start. To make a long story short, I pulled the commutator and the rotor was all twisted and destroyed. The commutator cap is brand new but the rotor appeared original. So ordered another rotor which I installed and had the same thing happened. Two rotors destroyed. Inside of commutator looks excellent, no damage. Attached is the picture of the cap; is this an Andersen cap and I am putting in the wrong rotor??? The cap has the contact points numbered. Any help on this problem would be greatly appreciated. Thanks! Chuck
Attachments
Commutator_A.jpg
Commutator_C.jpg

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Mark Gregush
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Re: Commutator & Rotor

Post by Mark Gregush » Fri Apr 26, 2019 9:54 pm

Sounds like when it back fired because it was timed wrong or the lever was pulled down, the flapper caught on the contact and got messed up. You need to check your timing. It should be set to fire at No 1 compression just after the piston is on it's down stroke with the lever up. I have found in the past with Anderson timers, you need to watch where the lever is on start up. Sometimes if the engine rocks back they will pull the lever down. Some people love them some swear at them. I am the latter.
You may also need to at this point get the contacts inside reset, they may now be bent out of alignment.
I know the voices aren't real but damn they have some good ideas! :shock:

1921 Huckster
1925 Cut down pickup


Topic author
ChuckLebeda
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Location: South Dakota

Re: Commutator & Rotor

Post by ChuckLebeda » Fri Apr 26, 2019 10:54 pm

Mark: Is this cap from an Anderson timer??
Thanks for your info! Chuck

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Mark Gregush
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Re: Commutator & Rotor

Post by Mark Gregush » Fri Apr 26, 2019 11:01 pm

looks like it, show the outer side.
I know the voices aren't real but damn they have some good ideas! :shock:

1921 Huckster
1925 Cut down pickup

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Mark Gregush
Posts: 1986
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Re: Commutator & Rotor

Post by Mark Gregush » Sat Apr 27, 2019 12:10 am

Might not be an Anderson, but to be sure show the rotor and other side. I can't think of any way that a rotor could be destroyed by back firing. If it was a standard timer with just contacts inside, the rotor would just roll backwards. If it is indeed an Anderson and you are trying to use a roller type, that would be an issue. You would need the flapper type contact.
Attachments
911725.jpg
I know the voices aren't real but damn they have some good ideas! :shock:

1921 Huckster
1925 Cut down pickup

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HalSched
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Re: Commutator & Rotor

Post by HalSched » Sat Apr 27, 2019 12:54 am

You will be surprised how much a new wire harness will improve the operation of the engine. As stated, with that cap U need a flapper, not a rotor. Make sure none of the wires or connectors are grounded because that would give you a backfire.

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HalSched
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Re: Commutator & Rotor

Post by HalSched » Sat Apr 27, 2019 12:57 am

Closer look...That flapper looks like it has a "wheel". That's a good idea


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ChuckLebeda
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Re: Commutator & Rotor

Post by ChuckLebeda » Sat Apr 27, 2019 10:57 am

Here is the side view. Needs an ANCO roller/rotor.
Attachments
Commutator_A.jpg
Commutator_D.jpg

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Mark Gregush
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Re: Commutator & Rotor

Post by Mark Gregush » Sat Apr 27, 2019 11:02 am

That still does not tell us anything. Need to see the insides.
I know the voices aren't real but damn they have some good ideas! :shock:

1921 Huckster
1925 Cut down pickup

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DanTreace
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Re: Commutator & Rotor

Post by DanTreace » Sat Apr 27, 2019 12:42 pm

Anderson timer shell has arms inside, the rotor is a flapper, spring loaded.

IMG_7115 (500x375).jpg
IMG_7115 (500x375).jpg (89.06 KiB) Viewed 1375 times
243609.jpg

The common Ford style timer case has contacts imbedded in a ring, the rotor is a spring loaded roller.
IMG_3734 (800x600).jpg
IMG_3614 (610x458).jpg

Mixing the two is problem.
The best way is always the simplest. The attics of the world are cluttered up with complicated failures. Henry Ford
Don’t find fault, find a remedy; anybody can complain. Henry Ford


Topic author
ChuckLebeda
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Location: South Dakota

Re: Commutator & Rotor

Post by ChuckLebeda » Sat Apr 27, 2019 3:28 pm

First time it was set up this way by previous owner and had never been run. Second time was my fault, should have known.

Fool me once, shame on you. Fool me twice, shame on me!!

Thank you all for your help.

Chuck


Topic author
ChuckLebeda
Posts: 17
Joined: Thu Jan 24, 2019 4:09 pm
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Last Name: Lebeda
Location: South Dakota

Re: Commutator & Rotor

Post by ChuckLebeda » Sat Apr 27, 2019 3:33 pm

Dan:

Did you use spacers between the rotor and the camshaft??

Chuck

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DanTreace
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Re: Commutator & Rotor

Post by DanTreace » Sat Apr 27, 2019 6:31 pm

Chuck

I have used the spacers before. Usually depends on the cam you have, some have shoulders a bit long or short. If too long you can get a rotor with more narrow cylinder. For most times, one or no spacers works. Check the need for spacers by testing the action of the flapper, once you fasten it firmly with the cam shaft nut. Test the flapper so it moves completely free. Any impingement on the front plate will cause the flapper to hang up. Use a spacer to place it away from the front plate.

Normally using the spacers won't interfere with the rotor pin, but....at times had to rat tail file the slot a tiny bit for the pin to fit in snug. The Anderson pin cap is unique, has a good raised edge to clear and retain the pin, and has a cutaway for the flapper action, (i.e. the flapper circle clip and axle) ; if you use a Ford std. pin cap without that cutaway, you can have the flapper hang open or closed. :|

IMG_7109 (640x480).jpg
Bit of high strength grease on the flapper, for lube against the case fingers. This view shows the raised edge over the rotor pin, and the cutaway edge, you can see the flapper axle is free to move, no pinching.

458446.jpg
The best way is always the simplest. The attics of the world are cluttered up with complicated failures. Henry Ford
Don’t find fault, find a remedy; anybody can complain. Henry Ford

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Mark Gregush
Posts: 1986
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Re: Commutator & Rotor

Post by Mark Gregush » Sat Apr 27, 2019 10:25 pm

Don't know but there must be more to this story then what is being told. If you tried to run a roller(?) in an Anderson and the roller got wiped out twice, I am still going to say the timer will need service because changes are good the contacts are now bent out alignment. That changes the cylinder to cylinder firing time.
In your first post your not sure what kind it is then the jump to needing spacers? Are there some PM's going back and forth leaving the rest that are trying to help in the dark?
I know the voices aren't real but damn they have some good ideas! :shock:

1921 Huckster
1925 Cut down pickup

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