Yamaha CR-600 - Tuning Knob Won't Go Back On

[t_munz10]

Hi All! Hoping you guys can help me out here.

I've been fixing up an old CR-600 for a work friend and I've got it just about all done. Sounds great, everything works again, and now I'm putting it back together.

The tuning knob will not slide back onto the shaft to the same depth it was at before (only about half a cm off, if that). You can see an indent where the set screws were previously tightened to. I've tried lubing it with some deoxit and using about as much force as I can muster. I'd normally be okay with just tightening it a little further out, but it's actually barely too close to the faceplate and I can't get the set screws in.

Calling it quits for the night, but hopefully there is some suggestions by the time I'm home from work tomorrow.

Cheers!

 

[Watthour]

A knife file used carefully can be run along the damaged/distorted shaft to remove the burrs.

Try using anti-seize compound instead of DeOxIt as the lubricant, and it would be good to use some of the compound on the set screws as well since the steel wil have a tendency to stick in the aluminum over time.

 

[dzkfraser]

Hi All! Hoping you guys can help me out here.

I've been fixing up an old CR-600 for a work friend and I've got it just about all done. Sounds great, everything works again, and now I'm putting it back together.

The tuning knob will not slide back onto the shaft to the same depth it was at before (only about half a cm off, if that). You can see an indent where the set screws were previously tightened to. I've tried lubing it with some deoxit and using about as much force as I can muster. I'd normally be okay with just tightening it a little further out, but it's actually barely too close to the faceplate and I can't get the set screws in.

Calling it quits for the night, but hopefully there is some suggestions by the time I'm home from work tomorrow.

Cheers!

Yes, good thing you called it quits, frustration can cause you to do stupid things, like eyeing that hammer in the toolbox

 

[Skywatcher]

like eyeing that hammer in the toolbox

^^^^

 

[Skywatcher]

Hi All! Hoping you guys can help me out here.

I've been fixing up an old CR-600 for a work friend and I've got it just about all done. Sounds great, everything works again, and now I'm putting it back together.

The tuning knob will not slide back onto the shaft to the same depth it was at before (only about half a cm off, if that). You can see an indent where the set screws were previously tightened to. I've tried lubing it with some deoxit and using about as much force as I can muster. I'd normally be okay with just tightening it a little further out, but it's actually barely too close to the faceplate and I can't get the set screws in.

Calling it quits for the night, but hopefully there is some suggestions by the time I'm home from work tomorrow.

Cheers!

As Watthour says, remove the burrs on the shaft and it should slide right on. They are raised areas caused by the set screws pushing the metal out the sides. You can actually feel them running a finger across them. I usually remove all burrs before putting the face plate on where there is lots of room.

 

[t_munz10]

A knife file used carefully can be run along the damaged/distorted shaft to remove the burrs.

Try using anti-seize compound instead of DeOxIt as the lubricant, and it would be good to use some of the compound on the set screws as well since the steel wil have a tendency to stick in the aluminum over time.

Awesome, thanks a bunch! I'll give it a go tonight and let you know how it works out. It's like every problem I run into, someone on here has run into before.

like eyeing that hammer in the toolbox

I honestly considered wrapping a cloth around a hammer and giving it a whack. Good thing I didn't want to wake anyone, eh?

 

[Skywatcher]

Awesome, thanks a bunch! I'll give it a go tonight and let you know how it works out. It's like every problem I run into, someone on here has run into before.



I honestly considered wrapping a cloth around a hammer and giving it a whack. Good thing I didn't want to wake anyone, eh?

I would skip the anti-seize compound because it is very messy, and really not necessary if the burrs are removed.

 

[t_munz10]

I would skip the anti-seize compound because it is very messy, and really not necessary if the burrs are removed.

Thanks everyone for the replies. Took the faceplate off again and removed the burrs. Took quite a bit of filing, but it slid on nicely eventually! Adjusting the idling current and mid-point voltage now, before everything goes back in the case.

 

[Skywatcher]

Thanks everyone for the replies. Took the faceplate off again and removed the burrs. Took quite a bit of filing, but it slid on nicely eventually! Adjusting the idling current and mid-point voltage now, before everything goes back in the case.

It's amazing just how much a little set screw can distort a shaft. That's why it is important to not over tighten screws.Glad it all worked out in the end.

 

[Watthour]

I would skip the anti-seize compound because it is very messy, and really not necessary if the burrs are removed.

At the least, apply some anti-seize to the set screw so that it doesn't fuze into the aluminum. I JUST NOW finished drilling one out and tapping the thread back through (with a roll-form tap) to avoid having to step to the next size screw. I was thinking about this thread the entire time.

 

[Skywatcher]

At the least, apply some anti-seize to the set screw so that it doesn't fuze into the aluminum. I JUST NOW finished drilling one out and tapping the thread back through (wil a roll-form tape) to avoid having to step to the next size screw. I was thinking about this thread the entire time.

I add a drop of clear silicone grease to the threads, then wipe off any excess. Aluminum galls easy and makes steel set screws "stick" in the threads. Either way, a thread "treatment" is good.