Detector issue

[speir01]

Hello all,

I have an issue with a recent detector rebuild, and need some input. I rebuilt an old spare detector i have, replace all cams but the OOR, and all the controllers were in fine condition. New cams, new shaft, new key.

I installed it to test it to make sure it was ok. I had late movement of the flag (yes, detector was in time, I checked, checked, and checked again.) where the moving deck would not move, just scissors. I cycled to 90' strike, to find that the strike cam follower was not to the low of the cam. so I pulled the detector and installed the old one to get the machine back operating. I set it at 90' on the bench, strike cam follower is just on the lip of the high of the cam coming to the low, and the strike controller is in the low of the cam.

I am under the impression that I have a bad cam, as the the timing cam was ordered as a new part.

Thoughts would be appreciated guys.

Thanks

[Steve Stafford (JBEES)]

The strike controller actually drops into the low of the selector cam at 85 degrees. It remains there through 95 degrees or so.

How did you determine that you are at 90 degrees on the bench? I measure this by the strike cam follower being in the low of the timing cam. Don't use the selector cam as your guide. That might be what is throwing you off. Try this...place the main shaft at 0 degrees by placing a 1/4 inch punch through the timing holes and look at the strike cam follower and it should be at the tip of the high dwell of the timing cam. That will verify that the cam is good or bad. Take a picture of the strike cam follower and post here and we can help you determine if it is correct.

[speir01]

IMG_20120604_114434.jpgHere it is at 0'

IMG_20120604_111822.jpg
And here at 90'. I bolt it to a spare 1:1 plate, and this is how I determine 90' on the bench. I can also assure you that this was where the roller sat at 90' in the machine as well.

[JACKO]

The cam looks correct, did it match with older one? I have always pulled detectors @ 90' strike to see strike cam follower in low dwell as you stated earlier, and that works for me. Looking at pictures, I just do not think assembly is not quite at the degree the 1 to 1 plate is stating. Whenever I had problems with detector rebuilds, was when I had unknowingly mixed toes with rollers, or the detector disc was wrong for the toes or rollers, if those happen to be the same. Hard lessons to learn, and never forget!

[Roscoe]

Speir:
Did you put the pin in the gear at O as Steve suggested or you just going by the line and degree markings. The pin method would be the only accurate method of determination.

[Wookie8662]

In the first picture, the detector is not at 0 degrees, it looks to be one tooth retarded.
The D shaft selector has not yet cleared the blocking lever for the strike cam follower.
The cam slope angle should "point" at the center of the cam follower bearing.

I install all my detectors at 0 degrees, and use this method to time them.
My other mechanics insist on snapping off the pin on the timing tools for the detector, so I stopped buying them.

[MASTERMIKE]

Man,
If you put the pin in at zero id sure say that cam is off, something is....
Mike

[speir01]

sorry for the delay, I was off last week. yes the pin was in at 0'.

the issue is resolved, the cam was off. the keyway was off about 1/32", resulting in close to a 1/4" difference in the position of the cam.

Nothing like your first detector rebuild having a faulty new part... lol.

[SoCalTom]

Nothing like your first detector rebuild having a faulty new part... lol.

Just because a part is new doesn't mean that it's perfect. (I have received brand new deck cables that were made too long.)