kirkpoore1
Established Member
furnace":3kvbykn1 said:Thanks Simon. It is on "your" rebuild thread that we are now posting! I found it when searching for info on bearings for my BAOS.
I read the details of your bearing refit and had a couple of questions.
Did you insert the (cold) bearing in the (hot) cast iron housing, and then attach the combined (hot) units to the (cold) shaft? (Option 1)
Or did you put the (hot) bearings on the (cold) shaft and then attach the (hot) housings to either end of the (cold) shaft? (Option 2)
You talk about doing Option 1, but show a picture of the naked bearings in the oven.
You talk about scribing the cutter shaft to relocate the bearings accurately, but both the shaft and the housings appear to have shoulders against which the bearings would seat, thus determining the overall width. Thoughts?
I can determine no play in the cutterblock even using a dial gauge, yet it sound really groany when running. I would have expected it to run pretty quietly given such a stable mass and quality bearings. Is the noise you can hear from yours primarily motor noise, or does the cutterblock make a racket as well?
BTW, fantastic rebuild job. I hope you've got the fence down now and are enjoying such a fine beast.
Kind regards
Mark
Mark:
I wish I could see Simon's pictures, but they're blocked here. Anyway, your bearings will be a press fit on one item (probably the cutterhead) and a slip fit on the other (the housing). You'll need the temperature differential on the press fit side. It's best to use an arbor press to put the bearings on, but since I don't have one I go with the freeze inside/heat outside technique. To heat the bearing, I set it on an incandescent light bulb for 30-60 seconds, while the shaft (or cutterhead in this case) would be in the freezer for up to an hour. Be ready to wipe off any frost that condenses on the bearing seat after you take it out of the freezer. You can then tap the bearing into place using a hammer and a pipe. The pipe must be sized to press ONLY on the inner race of the bearing to avoid damaging the bearing. As you noted, usually there's a shoulder that the bearing needs to press against.
Put the bearing(s) on the cutterhead. The assembly should then slide into place in the housing. If the housing is clean and undamaged, you should need no more than light taps to get it into place. If it's not going, back off and examine the housing for obstructions. When you take it apart, take pictures so you know exactly how it goes back in. In particular, there may be some spacers or a spring washer on the non-pulley end. Those need to go back into place correctly.
There is some pucker factor when you do this for the first time, but really it's not very hard. You'll do just fine.
Kirk