sharping help !

[jeepmedic]

Hi !

I am having some chain sharpening issues...

I have a timber tuff chain grinder with a 3/8" wheel. I have been learning by trial and error how to sharpen my own chains, follow the directions, have all the angels set properly, grind @ 30* as noted on the chart for the stihl chain (3634
26 RM3 67) I am running.....have a Stihl 290 saw.

I can get them pretty sharp, the chains throw the little square perfect shavings like a new chain, but they only last about 10 minutes and then dont cut worth a darn anymore.

The chains have only been sharpened about 4 times, and I have not filed the rakers yet.

On an brand new factory chain I can cut about 3-4 cords no problem...and I am very cautious about rocks and keep it out of the dirt, cutting mostly fresh box elder right now.

What am I doing wrong ????

 

[scottr]

Not filing the rakers.

 

[Simonizer]

Need some pics to sort you out bro.

 

[jeepmedic]

Im still new to this whole thing....

Do I need to be filing rakers every time I sharpen the chains then ?

 

[Dan_IN_MN]

Im still new to this whole thing....

Do I need to be filing rakers every time I sharpen the chains then ?

No....only when they are not allowing the cutter to 'take a bite'.

View attachment 229761

 

[Whiskers]

How dirty is the wood you're cutting? The chain could be sharpened perfectly fine, but if you're running it in dirty/sandy wood it won't stay sharp very long. Filing the rakers will get you a bigger chip, but not prolong the cutters sharpness. Were you getting more life out of other chains in the same wood?

As far as adjusting/lowering rakers, I check them with a gauge every couple time I sharpen a chain and lower when necessary. If you keep sharpening a chain and never lower the rakers, the chips will get smaller and smaller until you're just making saw dust or.

 

[jeepmedic]

I am cutting fresh box elder that I have fell myself (super clean). I am super careful to not get the chain into any dirt/sand. I cut 8 truckloads on one factory new chain out of the same batch of trees...when that chain started to dull I switched to one of the chains I sharpened.... literally on the same tree limbs...and a few minutes later not cutting.

I like the above pic of the rakers. I will check them tomorrow.

I will try and post pics tomorrow as well.

Thanks !

 

[mountainlake]

Not filing the rakers is right, a lot of new chains come with the rakers a bit too high and after a couple of sharpenings thier way high. Steve

 

[Sagetown]

1st thing I would do is touch-up the Rakers with a flat file. Just ease across the tops no more than two strokes, and do not bare down, just lightly. Reason is, if you take off too much the teeth will grab and make cutting very rough.

My concern is the 10 minutes you say and it quites cutting. Does the bar and chain get so hot that you can't touch it? If that's the case, the chain may have lost the temper (hardness), and when it hits the wood it dulls rapidly.

 

[jeepmedic]

My concern is the 10 minutes you say and it quites cutting. Does the bar and chain get so hot that you can't touch it? If that's the case, the chain may have lost the temper (hardness), and when it hits the wood it dulls rapidly.

It does get really hot and will smoke at the time it stops cutting. I think you hit it right on the head. The second its starts to smoke is when it stops cutting, and I stop as well. I bet I am overheating the chain when I hit it with the grinder, along with not filing the rakers correctly.

I never thought of that...

 

[Guido Salvage]

Learn to hand file and I bet your troubles go away. You may want to start with a jig in order to get the proper angles, but over time you will be able to freehand.

I suspect you are holding the grinder to the chain too long, thus losing the temper in the metal. Post up a picture of a chain you have done and we can tell you more.

 

[Dan_IN_MN]

1st thing I would do is touch-up the Rakers with a flat file. Just ease across the tops no more than two strokes, and do not bare down, just lightly. Reason is, if you take off too much the teeth will grab and make cutting very rough.

My concern is the 10 minutes you say and it quites cutting. Does the bar and chain get so hot that you can't touch it? If that's the case, the chain may have lost the temper (hardness), and when it hits the wood it dulls rapidly.

It does get really hot and will smoke at the time it stops cutting. I think you hit it right on the head. The second its starts to smoke is when it stops cutting, and I stop as well. I bet I am overheating the chain when I hit it with the grinder, along with not filing the rakers correctly.

I never thought of that...

Link to temps required to change the hardness of steel: Tempering Steel

I don't think it's getting that hot...

 

[J.W Younger]

Something to look at is where the top and side plates meet. This area should be flat . If its not the cutter won't get a good bite and pull out untill the raker stops it. If the cutter doesn't get a good bite it will skid over the wood and heat the chain causing it to soften and push the nose down. Next time look with a magnifing glass before and after sharpening to make sure the point of the cutter is the highest point. If there is any turn down the cutter will have to be filed or ground back more.
Don't forget to check the rakers.

 

[Fred Wright]

I don't trust myself with motorized chain sharpeners. Have always filed by hand.

That was a learning curve... I wrecked a chain by improper filing. And I was having the same symptoms as you describe. It would cut great for a few rounds then make powder. If the angle and pitch aren't right, it will not cut for very long.

I agree, if the teeth are superheated when grinding they'll lose their temper and won't hold an edge.

If the rakers are too high, you won't get much shavings when starting. High rakers won't necessarily cause a chain to cut for a few minutes then stop. It will either cut from the git go or it won't.

Dunno if it'll work with a Stihl chain loop or not... but I've had very good experience with a chain filing gauge that Husky offers. It clips on the chain and has little rollers that the file rides on. Your angle and pitch are right every time.

Hope it helps.

 

[Sagetown]

If your bar is getting too hot and you don't have a bar oil adjustment, you may want to consider doing a home remedy at I did.

 

[Sagetown]

I milled out a channel on the bar beginning at the point where the oil contacts the bar and ending at the bar's oil hole. I did this on both sides of the bar. As the oil is pumped onto the bar it flows directly down the channel into the bar oil hole where the chain drive links picks up the oil and carries it into the bar groove. Does a great job for me.

 

[mad murdock]

Learn how to properly hand file. You will get more use out of a chain and you will have a sharper chain, IMO. I have been running saws in the woods since 1977 and the old round file with properly adjusted raker height is the best way to care for saw chain. The only exception is carbide chain or the carbide impregnated chain. For that you need to grind sharpen. As far as chain bar friction goes, proper amount of bar oil and making sure you periodically clean bar grooves and oil passages is a must.

 

[andydodgegeek]

I use the husqvarna file guide I bought from Bailey's on my stihl chains and they work great. I rarely use my Oregon grinder, I get sharper chain by hand. If your cutter turns even a little bit blue you overheated it with the grinder. You have to take off very small amounts at a time with the grinder. Good luck.

 

[IthacaMan]

I only use a grinder on my chains. The trick is to adjust the grinder, so that you only take off enough material to make the where the grinding wheel touches the tooth shiny again.Also I found that when I adjusted my grinder to the stihl chain spec sheet, the wheel does not conform to the grind on a brand new chain.So what I did was adjust the grinder to perfectly match the factory grind on a brand new chain,now when I touch them up they come out just like a new chain.I am able to touch them up several times before I file the rakers. Check to see if the way your grinder is set now matches the factory grind on a new chain.uttahere2:

 

[oldfortyfive]

I used a file for years and finally got an electric a couple years ago...should have bought one when I got the first saw. It is a rare individual that can sharpen with a file as consistantly as even a cheap electric. I adjust the sharpener to match the tooth. Bottom line is the chains work much better than me or my friends had been doing with a file. I don't let a chain get very dull. Seems like the rakers only need grinding about every 6-8 sharpenings.