bmp01

My first saw. Was half dead from the auction house (this is in the era before ebay if anyone remembers that). Think the replacement Stihl 18" bar was sub 30 quid at the time. Apologies, off topic somewhat...

Magnetise the end of the T27 bit .... ?

"it was cutting really well..." "reving great..." "never run better..." Happens so often, unfortunately it looks like you had 3 warning signs. Before you strip the saw down better pressure and vacuum test to see if there is anything to learn. Do some searching online for what is involved and decide if you're up for it. But also note you dont always find leaks through cold pressure testing,... the way you've described it could easily be crankseals leaking badly once hot. Not much to loose now, its a good time to learn.

Eh, wot ye say, some one call ? Still here, only fix and tune my own saws generally though. Whats the situation nemcc ?

Thanks Rob and sorry for show response. I'll look into those points tomorrow, 'peening' on drive link is an interesting one.... its the non-loaded side of the drive link ? Wonder if that is same across the whole chain or local to the failure, there is other damage that surely came from the links bashing into each other as all came to a abrupt halt. I'll check. New clutch and rim (Oregon brand) were fitted at the same time this chain was fitted. Bar was dressed at the same time. Bar is used Sugihara, it was on the saw when I bought saw secondhand (previous chain was well used at that point).....nose sprocket has a question mark over it, likely to be worn, I'll check.

Wasn't a facebook advert in Rugby by any chance.... just curious....

Not really the time to punt for an ebay special is it.... Oregon rolls of chain come with presets and tie links, 40 off pairs per roll so I'm told, NewSawChains sell their surplus. Other route is to buy a bag of Oregon presets and a bag of Oregon tie links by their part nos from likes of L & S Engineers but by then you're well past the price of a new chain. The guys in the States are better supported in this respect. In my case the failed link appears the same as the NewSawChains supplied link which I'm told is Oregon....but.... there is a marked absence of the word I Oregon stamped on the preset or the tie link. Wonky's picture above (second one with one half broken) looks the same too.

That is the plan, new joining links are here. Now I need to know how best way to DIY fit new link, not convinced the spinner is best way anymore... Looks like that's cracked through the preset (looks just like the 'spinned' finish of a new preset).

Spot on - exactly that.... Plus there has to be clearance between the rivet and the tie strap in order to assemble but its a good thing if there is no clearance once the rivet if finish formed. No wonder joining links are the weak point.

Thanks for the comments AJStrees, trigger_andy, openspaceman. Openspaceman - Interesting observation regarding rivetting technique. ... enlightening even..... Ok, well the failure happened in an instant, engine revs went skyward that was the first I knew. No half measures - one length of chain rather than a loop. I used to look at failed bits of engines, searching for clues as to what went first so I'm reasonably in my comfort zone in anslysing the bits. I found fatigue patterns on the preset link which tells me it had a crack in it that was opening (and closing) each load cycle, with crack growing over thousand of cycles. The tie link has pinged, the material was stretched to the point of snapping. The remaining bit of tie strap is a cock-in-a-sock fit on its rivet, this could have happened in the failure but there is no sign of that . So the conclusion is the preset cracked first, crack grew and finally broke, tie link followed shortly there after. But why? If the rivetting is done well - so lots of pressure as well as rolling of the head - its likely the pin through the tie link is expanded within the tie link as well...so it takes up any radial clearance between the two parts. No clearance means the tie link can do useful stuff like taking its share of the load in the chain. Conversely, poor rivetting leaves radial clearance between rivet and tie link, so tie link cant take any load - the preset link does all the work, continually bending back and forth and fatigues. So the redneck use a hammer for rivetting rather than the pukker rolling tool doesnt seem so bad after all.... 😨😀

Just once so far. I have some joiner links arrived today. But also wondering about new chain if its going to break often from now on. Chain and bar not getting hot but they do look 'dry' to the point that after each plank I run the saw out of the wood to ensure chain is thoroughly oiled. Its oak that's been down for 5 years or so, still damp in the heart wood though. Auxillary oiler would be an advantage...

Newbie to milling question about chain life really. Would you expect to get the full tooth life out of a chain used for milling or is it typical to bin the chain after say a 1/2 or 2/3rds tooth wear ? Let's assume no chain damage through its life, just wear. Reason for qu - I've busted an Oregon 75DPX chain where the chain has been used for milling the majority of its life. To be honest it doesn't owe me anything, for the cost of the chain I've milled a good deal of oak. But well ye know the chain teeth still look very servicable and the links still feel pretty tight. Power head is a tuned up Husky 395XP, chain is Oregon 3/8 regular, chamfer cutters, ground to 15 degrees. Chain did see some metal a while back but very minor just dulled the teeth and quickly fixed with routine file sharpening. Failure was through the preset joining link which always makes me suspicious. I'll see if I can find a picture.... Thanks for any input.

I'm torn between 'cheeky fecker' and justifying the experiment statement along the lines of real life experience .... valued by manufacturers ,... blar, blar Think we'll go with 'cheeky fecker'

Nice one. I use the Stihl Super already, no complaints to date. I'll not worry so much about it hanging around in saws.....

Thanks for that last bit - useful home experiment 👍 Can we assume your experiment was undertaken in shed type conditions ie cold (winter) and hot (summer) ?

I read it that it was heat from the outer surface of the twin wall within the plaster board duct - which is fair game IMHO, providing some thought and precautions go into it. Opening up the twin wall obviously not a good plan... no point discussing .... Can OP clarify intentions ?

I'd be checking your repair shops claim before going too much further, not saying they are wrong but I'd be wanting to know what the evidence was to draw the conclusion they did. Pull the exhaust off and have a look at piston - that's easy enough. Did the saw stop unexpectedly - you said it wouldn't restart. If it has trashed the piston I would have expected it to stop running by itself. When I rebuilt the top end on my secondhand 395 (lots of hours ) I did the crank seals as a precaution. Sure enough the flywheel side had been leaking, lots of muck on the bearing cage on that side, lucky to have got away with it I guess. The only other thing - emptying fuel is good plan but make sure you then run the saw until it's dry otherwise you are just leaving fuel in the carb to evaporate away.

More likely its the thing the electric motor is attached to and the job its doing. I mean - I dont imagine these people just switched on their electric motors and just sat there holding 'em all day 😃 (maybe some did...) Macpherson got it right - manufacturers cant quantify vibration in use, too many variables.

I'm still of the view that the vibration of an electric motor spinning by itself is insignificant to almost every thing else in the real life cutting wood situation. I think the chain and vibration due to cutting is the key to it. When you consider the guide bar is isolated on the petrol chainsaw (it being mounted to the engine which itself is av mounted to handle) where as the guide bar is directly mounted to the handle on an electric saw. In this case only the flexibility of the plastic handle can dampen the vibration. There isnt much weight in the handle to help either. As an aside, I witnessed a sharp chain with uneven tooth lengths gave a good deal of vibration at the handle, which disappeared once tooth lengths were evened up (MS201T, sensible high chain speeds, wire spring av).

Nope... Must be vibration of the teeth cutting the wood though - its certainly not from the elec motor.

Thanks for that, there's one going cheap nearby might be worth a punt then.

Anyone got a view on the Lidl electric saw ? Think it's sold as 2.4kW which ought to be enough, no idea about chain speed though. Anyone played with one?

Can you come up with a way to drive the oil pump without the clutch in place or engine running? I'm thinking battery drill and an adapter or rubber drive drum (like the rubber drum you have in a demel kit for the sanding drum). Blank off the outlet to the bar, as youve done already. Spin the pump and look for leak. ...

Yeah....but.... The outside of the bar is what it is. It's the inside working bearing you need to see but of course you can't. The only thing you might gleen some info from is the sprocket (not the nose assembly but the actual sprocket), so chain off and inspect down to the root of tooth form. Look for coloured steel indicating heat. I'm guessing your planning on running it anyway. 1) Cross cutting would be a safer way to assess the nose sprocket assy and build confidence. 2) Your milling attacement is still too close to the nose bearing IMHO. There is a void just back from the bearing, where the sprocket teeth would run. CIamp into solid metal back from this void.