case temps

[angelo c]

wondering why the large discrepancy in bearing mounting temps with the 200t... never really noticed the suggested bearing install temp of 459 deg where every other case is usually around 350 ?
ideas ?
@lone wolf

 

[lone wolf]

wondering why the large discrepancy in bearing mounting temps with the 200t... never really noticed the suggested bearing install temp of 459 deg where every other case is usually around 350 ?
ideas ?
@lone wolf

I dont know why they say that either way will work fine so will no heat work.

 

[lone wolf]

You working one on one now?

 

[angelo c]

You working one on one now?

Yeah...was bored..had one in a box so long I didn't remember what was wrong with it...so I figured "why not start all over" with it

 

[cookies]

best guess without having it infront of me is case thickness and its webbing being more robust, possibly a different metal blend for strength since its a small foot print design.

 

[angelo c]

best guess without having it infront of me is case thickness and its webbing being more robust, possibly a different metal blend for strength since its a small foot print design.

Kinda funny how it's almost the opposite...and the bearings have a nylon retainer ..they are different bearings than most other stihls and the cases have the least "tight" tolerances. The bearings almost plop in, as Wolfie said, with minimal heating. Only reason I was concerned was the inner case surfaces were really dark after I heated them to manual suggestions...ain't doing that again

 

[Robin Wood]

Arent those roller bearings?

 

[lone wolf]

Arent those roller bearing

Yes they are.

 

[Robin Wood]

Yes they are.

Probably it needs to be squeezed more to take the slack from rollers

 

[av8or3]

I’ve come to love roller bearings.

 

[av8or3]

Just this weekend I installed new rollers in a 143 I’m building. I use a tabletop oven big enough to hold engine cases. I set the case in so the roller will fall out on its own. I set the temp to 275 degrees and after about 15 minutes the bearing falls out. I then go to the fridge and retrieve the new one, take the case out and pop in the new one. Repeat for the other side. After installing the new bearing I set the case outside to cool as quickly as possible to reduce the possibility of cooking the roller cage. 275 probably won’t hurt it, but I do it anyway.

 

[av8or3]

On the 200T the bearings won’t fall out on their own. I heat them for 20 min at 275. Then I push them out using an Arbor bench press and a socket. Heat them a bit more and using the press, push in the new ones.

 

[Robin Wood]

Just this weekend I installed new rollers in a 143 I’m building. I use a tabletop oven big enough to hold engine cases. I set the case in so the roller will fall out on its own. I set the temp to 275 degrees and after about 15 minutes the bearing falls out. I then go to the fridge and retrieve the new one, take the case out and pop in the new one. Repeat for the other side. After installing the new bearing I set the case outside to cool as quickly as possible to reduce the possibility of cooking the roller cage. 275 probably won’t hurt it, but I do it anyway. View attachment 1048777View attachment 1048778

Damm nice work there mister!
Contrary to popular belief, poly cage can withstand some serious heat

 

[angelo c]

On the 200T the bearings won’t fall out on their own. I heat them for 20 min at 275. Then I push them out using an Arbor bench press and a socket. Heat them a bit more and using the press, push in the new ones. View attachment 1048779

I heated the pto side to 450ish and the bearing needed a Lil push with a wooden dowel and a lil hammer love. Heated the ignition side to 350 (like every other saw I've ever done) and it still needed a lil love tap er two to "drop out"
Funny side note....every set of bearings I've ever installed felt smoother than the ones I replaced...no matter how new they supposedly were...must be mental ? Old bearings always feel crunchy