XS650 Clutch Worm Actuator Rotation Guage (degree wheel)

TwoManyXS1Bs

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XS650 Clutch Worm Actuator Rotation Guage (degree wheel)

This is a companion piece to the XS650 clutch actuator experiments:

Clutch worm actuator experiments and tidbits
Clutch worm mod testing
Clutch pushrod experiments and tidbits
Clutch cable experiments and tidbits

I've been using a homemade dialgauge adapter to measure worm actuator plunge depths:

Clutch worm depth dialgauge-post90
Clutch worm depth dialgauge-post91
Clutch worm depth dialgauge-post92

But making that dialgauge adapter is a bit involved, so here's a little project that uses simple household appliances and kitchen utensils. Should keep you occupied while snowed-in.

The XS650 clutch worm actuator rotates to create the lateral movement that pushes the clutch pushrod, about 0.0035" per degree of rotation (about 0.003" for the different pitch MikesXS worm mechanism). The amount of rotation can be measured with a homemade degree wheel to estimate how much pushrod travel might be achieved (minus cable and mechanism slack). The amount of rotation is partially influenced by the length of the worm actuator arm, which can be anywhere from 1.2" to 1.8", depending on worm model. The amount of rotation is also influenced by the clutch cable, which, depending on brand and condition, can stretch at different rates.

Pic #1 - Here's what you'll need.
ClutchGuage01.jpg


A 1:1 scale printout of pic#2, cutting board, knife, scissors, ruler, stupid glue.
1/2" rubber tableleg bumper(s). This will press fit on the worm adjuster screw locknut.
(The XS locknuts came in 13mm and 12mm sizes, but the tableleg bumpers will fit on either.)
A 3/16" hole punch, or if you're skillful, an x-acto knife to carve the holes for the #10 machine screw.
A #10 machine screw, about 1" long, #10 fender washer, #10 nut.
A plastic food container lid, like that found on a tub of cottage cheese, either the 4.6" diameter lid, or the 5.3" diameter lid.

Pic #2 - Degree wheel templates, in JPG format.
XS650 Clutch Guage.jpg


Inch scaling lines run down the side and bottom so you can print, measure, and adjust the printer scaling as needed to get true 1:1 scale.
The large fan-shaped degree wheel doesn't need to be scaled, its angles remain the same regardless of scaling.
If you don't have access to a printer, there's an alternative method demonstrated here.
 
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Pic #1 - Here's two different sizes of food container lids, large 5.3" diameter at the back, smaller 4.6" diameter at the front.

ClutchGuage02.jpg


Unfortunately, camera parallax makes the front one look larger.
Two of the printed templates are designed to be simply glued to the edge of the chosen lid.

Pic #2 - The 4.6" diameter lid has a 367 mm circumference, very close to 1mm = 1 degree of angle.

ClutchGuage03.jpg


Using a fine point sharpie marker, you can simply roll the edge of the 4.6" lid around a metric ruler, and make your matching degree marks with the sharpie.
 
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Pic #1 - Cut or punch a 3/16" hole smack-dab in the middle of the rubber bumper.
ClutchGuage06.jpg


Pic #2 - Parts to make the fan-shaped degree wheel. Shove the screw into the inside of the bumper, fit the degree wheel, washer and nut.
ClutchGuage07.jpg


This works fine using just paper. You may choose to pre-mount the degree wheel (well, ...fan) on card stock, construction paper or sheet metal.

Pic #3 - Assembled, ready to go. You can glue the 'fan' gauge to the rubber bumper if you want it to be more permanent.
ClutchGuage08.jpg


The exposed threads of the screw are used as the handle.
 
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Pic #1 - Remove the clutch adjuster cover and shove your new degree wheel onto the adjuster nut.
ClutchGuage09.jpg


A reference pointer needs to be fitted, aligned with the '0' degree mark. A piece of masking or painter's tape, with a drawn straight line, works fine.

Pic #2 - I have the adjuster screw backed-out a couple of turns here, to measure the full free/unstrained worm actuator rotation, here about 20 degrees.
ClutchGuage10.jpg


At 0.0035" per degree, this would be about 0.070" of worm travel.
 
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Pic #1 - Here, the template is being glued to the edge of the 5.3" lid.
ClutchGuage11.jpg


Pic #2 - Punch or cut a 3/16" hole in the middle of the lid. There's a little raised dot in the middle of the lid that will guide you. Cut away excess parts of the lid.
ClutchGuage12.jpg


Pic #3 - Assemble same as the 'fan' gauge, glue optional. Ready to go...
ClutchGuage13.jpg
 
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Pic #1 - Remove the clutch adjuster cover and shove your new degree wheel onto the adjuster nut, facing up.
ClutchGuage14.jpg


A reference pointer needs to be fitted, aligned with the '0' degree mark. A piece of masking or painter's tape, with a drawn straight line, works fine.

Pic #2 - I have the adjuster screw backed-out a couple of turns here, to measure the full free/unstrained worm actuator rotation, here about 20 degrees.
ClutchGuage15.jpg


For the Yamaha worm, At 0.0035" per degree, this would be about 0.070" of worm travel.
For the MikesXS worm, At 0.0030" per degree, this would be about 0.060" of worm travel.

This gauge wheel can be left on for short riding experiments, since it's readable from the riding position.

Using my stock `71 XS1B, here's what I've found for clutch action while riding around:

2°-3° (0.007"-0.010") - Cable slack
3°-5° (0.011"-0.017") - Feathering/engaging zone
5°-9° (0.018"-0.032") - Difficult finding neutral
10°-up (0.035"-up) - Easy finding neutral
14° (0.050") - Max travel I'm getting with a 1.68" worm arm length
20° (0.070") - Max travel with adjuster backed-off 2 turns (non-engaging)

Since the MikesXS worm has a shallower thread pitch, requiring more rotation compared to the factory Yamaha worm, multiply the above angle values by 8/7 to get the corrected travels.

Hopefully, this will be a very easy way to check worm actuator rotation. No need to remove pegs, shifter and sidecover.

Enjoy your project...
 
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Fantastic info 2M as always !!!!!! as well as the follow up info as where the clutch does it's thing... something we did not know thank you !
so there seams to be plenty of travel in the stock worm gear to get the job done....it would be really interesting to see the results of others having trouble finding neutral.... you don't have that trouble,...after all you have made up a PERFECT bike there,... it's one of a kind !
but a great bike for seeing what it SHOULD BE !!!!! LOL
thank you for your hard work ! well done !
....
Bob........
 
Thanx, Bob. I just noticed that this is one of my older threads, was working on a primitive tablet and didn't know how to get the pictures imbedded properly in the posts. So, updating this thing now...

Well, the forum software won't let me edit post #1.
EditError.jpg


But, the other posts are fixed...
 
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Don't that figure ! !
I hate it when a program HELPS me ! but then again if they didn't I'ed really be stuck because I can't keep up with all the changes any more...I quit trying back in the 1990's ! LOL
......
Bob......
 
2M, when i sign in on here, (i use firefox), i always get a notice warning me this is not a secure connection Here is an example of the warning box
, Secure connections.png
 
Just read this with great interest and thoroughly enjoyed the detailed instructions to make the home made degree “fan”. Things like this make me smile and be happy that I have my XS and am part of this great community. I’m involved with other groups for boats, cars and other models of bikes and this forum is hands down the best I’ve seen. Thanks to all for your contribution and educating others. Greatly appreciated!
 
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