R-8 spindle cleaner

[kwoodhands]

My mill has an R-8 spindle. Yesterday I had trouble removing an end mill holder. Tried tapping the bolt with a dead blow hammer as I usually do. After about 6 or 7 blows I went and got an 8lb sledge hammer. I gently tapped the bolt and the holder dropped down. I assumed the problem was with the holder as it was a 3/4" holder that I rarely used. I set the holder aside figuring I'll look for burrs later on. Make a long story short ,the spindle is the problem because other holders gave me the same problem.
There are no burrs that I can feel in the spindle. May just be accumulated oils, dust etc.
I found a website that showed how to make an R-8 spindle cleaner. Pretty simple, the holder is made with 6 flutes that hold strips of felt or leather. A solvent that removes oils is first dabbed on the spindle. The spindle cleaner is held into the spindle while the mill is running.
So far I have made the tool from Acetal and slotted it in 4 places. Glued 1/8" thick cork in the slots. I will trim the excess cork tomorrow. I plan to run the mill without charging the cork with rouge or whatever. This should help to clean and remove the solvent, I haven't decided what solvent to use. I have acetone, paint thinner, lacquer thinner and naptha on hand. Also have spray cans of Goof Off and PB blaster.
Hope this works, mike

 

[stevehuckss396]

if it doesn't help try wrapping a short screw driver with scotch-brite and stroke that up and down a few times. Then lay the tip of the screw driver on the taper lightly and move the screwdriver up and down and feel for burrs. do all that while it is running of course. If you feel a burr it is probably a small chip that got smashed between the collet and the taper. find that spot with a small file and try to knock down the high spot and repeat.

 

[kwoodhands]

if it doesn't help try wrapping a short screw driver with scotch-brite and stroke that up and down a few times. Then lay the tip of the screw driver on the taper lightly and move the screwdriver up and down and feel for burrs. do all that while it is running of course. If you feel a burr it is probably a small chip that got smashed between the collet and the taper. find that spot with a small file and try to knock down the high spot and repeat.

Thanks Steve, what I did was make the cleaner from acetal and milled a 1/8" wide x 3/16" deep slots.
I did not have felt or leather on hand and used 1/8" cork instead. I glued it up with wonder glue yesterday and today I trimmed the excess. Sprayed WD-40 in the spindle and then held the shop made cleaner in the spindle while it was running. After about 1 minute, probably less I stopped and tried a holder in the spindle. I knew immediately that what I did worked because installing the holder was also a PITA before cleaning. Holder went up easily ,tightened the drawbar and released the holder with one tap from a dead blow hammer. I tried another holder to make sure, good results .
There is a website, maybe You Tube ,not sure that shows how to make the cleaner. MSC wanted $214.00 for a plastic R-8 cleaner. McMaster Carr similar pricing.
mike

 

[len1042]

There is a small key in the spindle that engages the collet when the collet is inserted. Make sure the cleaner does not get snagged on the key. The problem you are experiences may not be from dirt but could be caused by the key being damaged.
Len

 

[petertha]

As len1042 suggests the key is basically a dog point set screw on many mills. If it is extended too far, it can can start interfering with the key way groove. Often its 2 set screws, the dogpoint as mentioned & another to hold that set position. They can loosen over time or become worn/damaged. Depending on your mill, you may have to remove the end cap. I made a makeshift pin wrench because some of the spanner wrenches don't quite fit.