Crank bearing installation question

[StihlEchoingHusky]

There is no weakness with proprietary nylon bearings, they have been around for 27 years in Husqvarna saws, 351 was the first model to get one.
Nowadays they are the first choice in professional saws, hobby saws get traditional metal cage bearings!

I never did say there was actually anything wrong with them. It's just In my mind plastic+ something that spins as fast as it does +the heat from combustion just doesn't seem right. Granted there is peek which if I'm not mistaken is a insulator for high voltage lines as well as insulator for a heating elements both small and large.

 

[Tor R]

I never did say there was actually anything wrong with them. It's just In my mind plastic+ something that spins as fast as it does +the heat from combustion just doesn't seem right. Granted there is peek which if I'm not mistaken is a insulator for high voltage lines as well as insulator for a heating elements both small and large.

In terms of appearance, the newer ones look like peek, while the old ones look like pei.
Now, it's probably not exactly the exact material.
The crank bearings are upgraded relatively often as newer plastic materials are introduced.

I can only speak for the Husqvarna 5xx series, where the crank bearings must be all the way to the bottom of the bearing pocket, there is little wiggle room for the crank sideways.

We can mount as we want, I know that with a heated crankcase and cooled bearings, the bearing will reach all the way to the bottom without filling the pocket with magnesium shavings.

 

[Stump Shot]

Heat until it smokes or the back of the case half is too warm to hold onto.

Then it just drops right in.

Nothing to it really.

 

[furb]

I am one of those that would heat the case, put down the torch and then grab it by the hot spot not thinking and instantly wondering why I didn't have any gloves on....


I have a new to me toaster oven in my shop, I will have to give that a try!! Welding gloves...welding gloves...welding gloves....have to remember the welding gloves!!

Screw all that. Use the one in the kitchen and assemble in the dining room. The snacks are closer.

 

[Tor R]

I use the oven in the kitchen, goes faster than baking a pizza.
Short distance to the freezer is also a bonus lol
The only downside I've seen is that plastic parts have to be disassembled before baking!

 

[Outback]

Yea, you have to pull the plastic. I have an oven in my barn. I leave the cases in the oven for 30 minutes, sometimes more so it bakes the oil out the case. I don't think the wife would appreciate the fumes. I have a chest freezer in the barn too. I assemble the cases out there and then take them to the shop. They are cool when I put the oil in and do final assembly. I learned along time ago that good redneck game is to maintain your pile of broken machines where the wife can't see them from the windows of the house. The less she see's or smells the less she thinks about it.

I read somewhere that the nylon cage has less friction than the steel cages. Plus they pop out of the bearing easy. I've got a 562xpg in a box that's waiting for a rebuild. When I do it I'm going to swap ceramic balls into the bearings to see how that works out. Plastic and ceramic should be the lowest possible friction and thus heat generated.

The plastic bearings are rated to 110 to 120C. They are constantly cooled by fuel flowing through. If the bottom end of your chainsaw is hitting 230 to 250F you got problems.