Testing A Raisman Platt Crankshaft In An MS660

[Mastermind]

The crankshaft broked off on this here saw.









Brian killed it......but Jon is fixing it.

Using one of these.





Weedeaterman sent the crank. Great fellers there....believe that.

Weedeatrerman

Brian is gonna mill with to try and kill it.

Oh........I'm porting it some too.

 

[fastLeo151]

You weren't kidding when you said it broke, what caused that to shear off?

 

[Mastermind]

Rusty and stuff in there.



Tools.......yep, gotta have em.

 

[Mastermind]

More tools.......I think Jon is showing off his tool here.

 

[Mastermind]

We collect broked crankshafts.....

 

[Mastermind]

Now the crank has been centered and the bottom is complete.

 

[Mastermind]

 

[Mastermind]

Moving to the muffler....

 

[Mastermind]

Meanwhile on my end of the shop........



This may seem like a lot of work to test a AM crank.......but hell how else will we know if this brand is good or not?

More tomorrow.

 

[Mastermind]

You weren't kidding when you said it broke, what caused that to shear off?

Ain't got a clue......he was milling with it, but that's no sweat normally.

 

[fastLeo151]

What temp are you shooting for with the heat gun? I may try that.... my misses doesn't love when I use the oven.

 

[Trx250r180]

Ain't got a clue......he was milling with it, but that's no sweat normally.

Ive talked to a few timber fallers,a few of them have had the same broken crank problem same spot,i think doug fir and low rakers does it,too grabby and snap


And Jon,you do very nice work, would you like a 084 to work on ?

 

[Mastermind]

What temp are you shooting for with the heat gun? I may try that.... my misses doesn't love when I use the oven.

Hot enough?

You sorta just get to the point after doing a few that you know when it's ready.

Jon can split a bottom end and have it cleaned and back together in an hour or so.

Did you notice that he has a junk oil pump for a stop?

 

[Mastermind]

Ive talked to a few timber fallers,a few of them have had the same broken crank problem same spot,i think doug fir and low rakers does it,too grabby and snap


And Jon,you do very nice work, would you like a 084 to work on ?

It looks weird here.....

 

[Mastermind]

And Jon,you do very nice work, would you like a 084 to work on ?

He's done with them damn OH84s.

 

[RandyMac]

inboard clutch fail

 

[Trx250r180]

I don't think the cylinder cover has ever been off this saw,am i seeing things or will a 461 coil bolt to that hole below the coil ?

 

[spacemule]

Is it just my imagination, or does the dark in the center indicate the crack has been developing for sometime, and finally last held and broke around the perimeter?

 

[Rudolf73]

Tensioning a hot chain (incorrectly) and then letting it cool and shrink could also have bad effects on the crank... maybe.

Don't mind me just thinking out loud.

 

[tdi-rick]

Is it just my imagination, or does the dark in the center indicate the crack has been developing for sometime, and finally last held and broke around the perimeter?

Now I'm not trained in failure analysis, nor am I an engineer, just a mug mechanic but it looks like the crack has propagated from around the 2:00 o'clock position from a stress raiser of some sort.

Now it could start as Rudi suggested, or the lead or start of the thread (threads are notorious for this, particularly cut threads if the tool is a little blunt) or just some sort of notch, and grown from there.