BOSCH Colt Trim Router Maintenance

[TDA]

Thanks for the info Bill.

I wonder about the originally bearings as everyone I know that has replaced them has gotten better runout and noise then new. These specific ones made less noise and gave better runout then the original (from .0008 to .0004 measured from the taper of the colt). Don't get me wrong I'm not doubting your information I'm just wondering what the originals are like if these are not intended for use in this kind of system and seem to do better. If you ever get a look at the originals I'd appreciate any info you might gleam from them.

Also, as long as I'm picking your brain. As I understand it the SS they are using is 440C with HRC of 58 and the chrome steel is 52100 with a HRC of 62. Now admittedly my only experience in Rockwell C scale and wear is in blades but that's not a lot of a delta. Does 4 points in a Rockwell C scale make that large of a difference in bearings?

[BillK]

John,

Yes, the four point difference is very big. Rc 62 would be about right for this size bearing and 52100. Rc 58 would not be acceptable for this size and 52100.

Rc 58 is actually a little bit high for 440C bearing steel. Most specs. Would call for a max of Rc 55.

Comparable life data would show a significant difference between the two steels and the same size bearing.

As for the difference in runouts, I believe this is attributed to the radial play. Although the steel is the same throughout the bearing, temperature differences in the system may produce different growth rates lowering that difference when cool as the system warms to operating temperature. For proper selection you really need to know shaft and housing sizes and tolerances and their materials.

BillK

[Bob]

Back to the basics...
I want to replace the bearings on an old Colt. How do I remove the bearing from the lower aluminum housing on the router? Not the one on the armature. That one is easy.
But the one that stays stuck in the bottom end of the housing?
I thought it would be a good idea to ask before trying my bearing extraction tool, aka the big honkin' hammer.
Thanks,
Bob

[REG]

I'm headed to my second brush replacement and now I want to change the bearings, since there is certainly a lot more "rattle" coming from the Colt. I don't want to buy the economical grade that Colt provides so looking at the links that John posted is very helpful but I was wondering if anyone actually bought these bearings or ones that could be recommended to install in the Colt.

Bob, hopefully by now you found a way to pull the bearing in the housing. I have a small puller that should do the job although I have to dismantle to puller to install the puller fingers to fit into the shaft opening.

Any recommendation for a direct bearing replacement for the Colt would be greatly appreciated.

Bobby

[Bob]

Bobby,
Nope, no one who has removed the bearing has told me how to do it yet.
Bob

[REG]

Bobby,
Nope, no one who has removed the bearing has told me how to do it yet.
Bob

Bob, I have the luxury of having two Colts. the puller I have is a kit I got from Harbor Freight but I will try with conventional tools (like a bolt and nut jig). I haven't pulled my bearing yet, I did test the fit of my puller to see what I was in for. I want to wait until I get the new bearing before I pull the old one. I will try to share the process (success or failure) in a post here.

Bobby

[Bob]

Bobby,
I'm in the same boat as you. I have three Colts, so I'm in no hurry. I look forward to hearing about the results of your bearing extraction adventures.
Bob

[REG]

Bob, I spilt the Colt to remove the bearings. I went backwards removing the top cover (VSD speed dial area) first when I should have removed the collet pieces first. Remove the collet and there is self locking nut (#15 on the parts diagram) that comes off the spindle. Bosch has a special tool for this to reach into the 4 holes, I tried snap ring pliers first, no go - so I used a good set of needle-nose pliers. That did it with some effort. It is threaded on the same way as the collet, you just unscrew it off. Now you can remove the end case. That takes some working but careful wiggling will coaxe it off. On my Colt, the tail bearing came out of the housing, it is pressed onto the shaft of the armature. Now removing the aluminum (collet side) case required the same wiggling, but being more careful since removing the armature from the aluminum case has tighter clearance due to the fan. The collet bearing is not pressed but rather kept in place by the locking nut (#15) and a spring retaining clip on the other side (which can be left on the armature). That bearing (#13) simply pushed out of the aluminum housing. The opposing bearing (#14) had to be pressed off the shaft. I basically fashioned a "collar" out of 1/4" flat bar steel and pressed it out on my bench vice. Careful to note that the to casing houses two ring springs to absorb armature slop. One of my rings showed considerable dampening wear.
Also, in my findings, most sealed bearings are rated far less rpm than the max unload speed of the Colt.
The collet bearing (#13) is a sealed bearing, the opposing end (#14) is just shielded. Bearing numbers are:
6002RS (#13)
627-2A (#14)

Bobby

[Bob]

Bobby,
Thank you for an excellent description of this procedure!
Now, it's off to work I go...
Bob

[Bob]

Just a quick update...
By following these directions, I was able to remove the bearings with no problem from an old Colt. When the time comes to replace bearings in a newer Colt, I don't think there will be any problems.
Bob