Can you FREEZE A push in rubber bumper, to

Duane Remick

AzB Gold Member
Gold Member
Silver Member
make it a little smaller insert diameter.
i have a replacement bumper- oversized though"
can push in bumpers be properly machined-reduced in diameter?????
THANK YOU
 

Ssonerai

AzB Silver Member
Silver Member
I set them up in a cheap import spindex, in a collet, and reduce them on a surface grinder.
Any grinder would work, so long as you can get a spindex clamped or mounted, and a way to "nudge" it toward the wheel with some control.

I use mist coolant running obviously wet, and you can't hog or it will grab and spit the rubber out of the collet.
However, it is a relatively quick process with steady gradual infeed or down feed. (depending on orientation of spindex to grinding wheel

36 AlO wheel, as open structure as possible, even induced porosity if available. Wheel hardness is irrelevent in this case, but mine are mostly I or J.
46 grit, same specs as above, will also work.
 

HawaiianEye

AzB Silver Member
Silver Member
make it a little smaller insert diameter.
i have a replacement bumper- oversized though"
can push in bumpers be properly machined-reduced in diameter?????
THANK YOU
I don’t remember who or where, but I was told that when I had a bumper that was too big for one of my cues.

I was told that it could be frozen and then reduced.
 

Ssonerai

AzB Silver Member
Silver Member
I was told that it could be frozen and then reduced.

I tried that so long ago don't remember what the rubber application was, but it was useless AFA a home freezer.
Reason i went to surface grinder,

Usually when that is mentioned on machinist sites, they mean "with liquid nitrogen". Can't recall if i ever tried with dry ice - do remember getting a chunk left over from one of our club ice-cream stands, and doing experiments with it. But think that was mostly cryo- for steel. At least dry ice is cheap to try, if you still have an old school ice house locally.

smt
 

cueguy

Just a repair guy
Silver Member
make it a little smaller insert diameter.
i have a replacement bumper- oversized though"
can push in bumpers be properly machined-reduced in diameter?????
THANK YOU
I have turned them down just using a HSS bit (very sharp) in the lathe and it worked fine when at a tourney and no other options ;-)
 

Canadian cue

AzB Silver Member
Silver Member
If you have a router mounted to your tool post you can use mounted stones the same as you would use in a die grinder to shape bumpers. I have done a few. The hard part is holding the bumper, I have built jigs to hold them or depending on the style of bumper you can mount them on a mandrel.
 

DaveK

Still crazy after all these years
Silver Member
I tried that so long ago don't remember what the rubber application was, but it was useless AFA a home freezer.
Reason i went to surface grinder,

Usually when that is mentioned on machinist sites, they mean "with liquid nitrogen". Can't recall if i ever tried with dry ice - do remember getting a chunk left over from one of our club ice-cream stands, and doing experiments with it. But think that was mostly cryo- for steel. At least dry ice is cheap to try, if you still have an old school ice house locally.

smt
Maybe try something like SuperCold spray:


For something small like a bumper it might work, and you can re-apply while the bumper is still chucked.

Dave <-- not a cuemaker but has used SuperCold when debugging electronic circuits decades ago
 

Dave38

theemperorhasnoclotheson
Silver Member
Maybe try something like SuperCold spray:


For something small like a bumper it might work, and you can re-apply while the bumper is still chucked.

Dave <-- not a cuemaker but has used SuperCold when debugging electronic circuits decades ago
Have used it for that also, and it works great for removing gum, so I think it would be an option for a bumper
 

whammo57

Kim Walker
Silver Member
why not just bore out he butt to accept the bigger bumper........... I use bumpers that have a .620 stem and I bore the hole to .600........ a nice tight fit.... sometimes I use a little wax on the stem to get to go in................

Kim
 

Ssonerai

AzB Silver Member
Silver Member
If you have a router mounted to your tool post you can use mounted stones the same as you would use in a die grinder to shape bumpers. I have done a few. The hard part is holding the bumper, I have built jigs to hold them or depending on the style of bumper you can mount them on a mandrel.

I wonder if that might be the ultimate?
Because if you have a pad center for the TS, it can be brought up against the outside end for even more support?
For that purpose, even a flat/round piece of say phenolic with a dimple, for a regular pointy ball bearing center, would work.

Big advantage for me with the surface grinder, though, it coolant - keeps the abrasive from gumming up. Right grit on lathe/router might be resistant, too. Or stop and clean if it starts to clog.

why not just bore out he butt to accept the bigger bumper..

Because sometimes the wall thickness of socket would be compromised, in the cue-maker's opinion. Depending rubber size, cue dia.

Because sometimes the shape and exact proportion of the rubber just adds that last little bit of elegance. :)
(Hey, i still don't have any eye whatsoever for making "fancy" cues & decoration. It's just beyond my imagination level. But i think my eye is pretty good for proportions :) )

smt
 

JoeyInCali

AzB Silver Member
Silver Member
What are you trying to reduce ???
The stem or the bottom ?
I've reduced 1" screw-on rubber bumper down to 7/8 OD . I just made a jig to screw it on and then chuck that jig.
Did not need freezing . But, I used a 4-flute carbide end mill on a Makita router . The end mill is freaking sharp .
If you are going to use a lathe bit, good luck .
 

Tommy-D

World's best B player...
Silver Member
Back in the day Bill McDaniel made me a jump cue butt that would not only fit Schon shafts but looked like the front end of an STL-1.

He was actually finishing it up when I picked it up. One of the things he did was take a smaller than normal bumper that still used a 8-32 cap screw and mounted it on a Delrin rod. With the lathe on,he pulled out a 1" wide diamond grit nail file,and ground the bumper to size and shape that way. Tommy D.
 
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