Exploring the distributor

[Pietenpol]

Trying to delve a little deeper into the distributor and would be interested in everyone's thoughts on my observations. I realize that this is all basic knowledge to most of you.

Starting from the back at the clutch where the trip lever meets the clutch plate. Basically no built-in adjustment so I consider the trip arm to the clutch as an area to leave as-built. The half moon with the rollers flip the trip arm up and thru spring aid down as pins trip the fingers. I've noticed the smoother deliveries are when the bottom roller is just barely off the carriage or touching ever so lightly. This is adjusted by the rod or cable between the fingers and the half moon. The carriage sliding across the rollers needs to be parallel to the trip rod so the rollers of the half moon maintain the same distance to the trip arm no matter where the dizzy arm is extended. The only place to adjust is the lower front roller. The adjustment point to the pivot point (rear lower roller) remains constant. The pivot point to the half moon changes as the arm extends and retracts. When the arm is extended adjusting the front lower roller has a minimal effect, when it is retracted the same change is much more drastic (basic geometry). I've heard many times to watch if the trip arm to clutch moves at all when sliding the carriage but I believe the half moon to be the better place. Watching to see if the roller spacing changes.

Based on these thoughts I've been trying this method to adjust my rollers.

With the carriage extended I set my bubble on the trip rod. Then I move it to the carriage tube and match the bubble by adjusting the front bottom roller. Extend the carriage completely and use the rod/cable from the fingers to get the bottom roller on the half moon just barely off the carriage tube...or touching just barely. Retract the carriage completely and note the spacing of the bottom roller on the half moon. If it is more than it was in the front then the front roller is too high and vice verse. Make sure the carriage is seated against the top roller when you check this. Once you have the same alignment of the half moon roller to carriage tube no matter where the arm is then adjust the top rollers to your preferred tightness. Some like it loose but I would think nothing more than a slight drag. I also check the top half moon roller when completely retracted to see if it hits the pan at all. If so I give the half moon a little bend away from the carriage.

[Pietenpol]

Noticed a typo..

Trying to delve a little deeper into the distributor and would be interested in everyone's thoughts on my observations. I realize that this is all basic knowledge to most of you.

Starting from the back at the clutch where the trip lever meets the clutch plate. Basically no built-in adjustment so I consider the trip arm to the clutch as an area to leave as-built. The half moon with the rollers flip the trip arm up and thru spring aid down as pins trip the fingers. I've noticed the smoother deliveries are when the bottom roller is just barely off the carriage or touching ever so lightly. This is adjusted by the rod or cable between the fingers and the half moon. The carriage sliding across the rollers needs to be parallel to the trip rod so the rollers of the half moon maintain the same distance to the trip arm no matter where the dizzy arm is extended. The only place to adjust is the lower front roller. The adjustment point to the pivot point (rear lower roller) remains constant. The pivot point to the half moon changes as the arm extends and retracts. When the arm is extended adjusting the front lower roller has a minimal effect, when it is retracted the same change is much more drastic (basic geometry). I've heard many times to watch if the trip arm to clutch moves at all when sliding the carriage but I believe the half moon to be the better place. Watching to see if the roller spacing changes.

Based on these thoughts I've been trying this method to adjust my rollers.

With the carriage extended I set my bubble on the trip rod. Then I move it to the carriage tube and match the bubble by adjusting the front bottom roller. Extend the carriage completely and use the rod/cable from the fingers to get the bottom roller on the half moon just barely off the carriage tube...or touching just barely. Retract the carriage completely and note the spacing of the bottom roller on the half moon. If it is more than it was in the front then the front roller is too high and vice verse. Make sure the carriage is seated against the BOTTOM front roller when you check this. Once you have the same alignment of the half moon roller to carriage tube no matter where the arm is then adjust the top rollers to your preferred tightness. Some like it loose but I would think nothing more than a slight drag. I also check the top half moon roller when completely retracted to see if it hits the pan at all. If so I give the half moon a little bend away from the carriage.

[Toby]

The distributor is the part of the machine that makes very little sense to me, and I certainly have one or two that run like total garbage. I'll try your method this week and see how they improve. The manual instructions read like Greek, so thanks for a clearer account!

Toby

[8270king]

Here is how it should go:
1. Make the carriage tubes parallel to the tip tube - adjusting the eccentric rollers
2. Adjust the trip arms so that you get a good index at all positions
3. Be wary if you get the trip arm too tight the bottom of the stop blade can lock into the pinion teeth

[pinfeed]

The top front roller is for adjusting parallel. The top rear and bottom front are for tension. There is no parallel adjustment for these two rollers.

[Toby]

How tight do you make the nut on the clutch? This is the one that the spring rests on. Does the torque on that nut need to fall within a certain range? How is the distributor affected by over or under tightening that nut?

Toby

[Pietenpol]

The top front roller is for adjusting parallel. The top rear and bottom front are for tension. There is no parallel adjustment for these two rollers.

I refer to the rear rollers as the pivot point. As to the front rollers according to the book they are adjusted as a set for parallel. My procedure is close to the book procedure but I use the half moon as a reference to get it as parallel as possible and it seems to work quite well for me. As to earlier post....this is the way I do it. I'm sure there are quite a few other mechanics out there that have their own method and many others that go strictly by the book. Whatever works for you should be the way to do it.

[Pietenpol]

How tight do you make the nut on the clutch? This is the one that the spring rests on. Does the torque on that nut need to fall within a certain range? How is the distributor affected by over or under tightening that nut?

Toby

General consensus seems to be 3/4 to a full turn to start. The 6 to 10 move is the hardest on the clutch.. too loose and the distributor will stall between the 6 and 10 positions... too much and it will cause stalling or failure to index.

[smurtland]

I usually use the spring to tighten the nut. It gets you a little more than finger tight but does not over tighten.

[Tassie_tech]

As King said, make the carriage tubes parallel to the trip rod by adjusting the eccentric rollers. I have even run a fourth eccentric at times to get extra adjustment if needed. I like the rollers tight enough so there is no play in the tube in between them but loose enough so that I can still turn the rollers without the tube wanting to move back and forth.
I run the trip/stop blades as low as possible without getting drag on the nylon on the clutch backing plate, I find this makes for good clean indexing every time.
I run the cable just tight enough that it will lower the trip blade past the clutch plate tab in every position.
I just nip up the nut on the clutch so that it is firm but not overtight and as pie said 3/4 turn on the spring and work from there but a good general starting point.
Those are some of my methods but everyone has their little quirks and whatever works is the best method imo.

[Grit]

has anyone ever noticed that in the back row the white nylon rollers are not fully over the trip tube? more specifically I've seen many failures to index because the rollers were laterally too far out to move the trip tube enough.

I found out that the front and rear posts on the distributor frame are actually offset to cause this and wonder why they are not inline with each other?

[NeverSeenThat]

I adjust the eccentric rollers with the high spot of the front roller towards thre front and the high spot of the rear roller towards the rear of the machine (pivot AWAY from each other). This tends to make the a longer distance between the rollers which gives more support to the dist carriage. Also when these rollers start to wear, the carriage will develope sideways, or lateral movement which will cause intermittent problems.

[Grit]

I added spacers behind the rear eccentrics to bring them back inline with the front eccentrics. this keeps the center of the white rollers over the center of the tube and I do not have the issue with the trip cable linkage rubbing the inside track on the indexing cam. I still don't understand why they are offset though.

[MarkyB]

I added spacers behind the rear eccentrics to bring them back inline with the front eccentrics. this keeps the center of the white rollers over the center of the tube and I do not have the issue with the trip cable linkage rubbing the inside track on the indexing cam. I still don't understand why they are offset though.

Done this with a few in the past, dont know if its a bad cast or not, but it sure makes them run better!

[Mark_S]

When building the clutch after i put the worm and front plate on about 2/3 of the way. I tighten the nut finger tight, plus a little. Then I turn the front plate as far as it will go. This way there is no danger of the worm moving out when fitting the front plate. It's just the way I was shown, and easier for the new guys. Less chance of moving the worm out when turning the front plate.