Thread: Trouble with keeping blade sharp

I find in dry Balackwood that is about all you get out of a chain, i carry 2 or three chains and touch them up with a file or 12 volt sharpener maybe twice, change chain then grind them all at home on an electric chain sharpener.

I also use skip tooth chain sharpened at 10 deg.

Cheers

Originally Posted by Les Caddaye

Obviously still a newbee, I'm currently slabbing some fairly dry Red Box, its about 25" in diameter and 7ft long, my trouble is that one slab is enough to dull the cutters such that I can't or shouldn't attempt a second. This is quite painful as you have to remove the saw from the mill to sharpen the chain. I'm running a Stihl MS660 on a Westorford mill using Stihl 10 degree chain. Is this normal? or am I doing something wrong?

Sounds close to normal to me, although I would expect to get two 7ft slabs from one sharpening. I touch up about every ~30 sq ft in hardwood and every 65 sq ft in softwood.

Questions for you:
How long is your bar
What sort of chain is it (regular, semi skip, single skip, double etc)
What is your raker depth
What is your gullet width
How do you sharpen.

If you can post some close up pics of your sawdust and a chain cutter side like this, I can help diagnose any cutter problems


I know what you mean about trying to sharpen on the Westford, its the same on the Granberg
This picture shows the problem as I see it. The left hand side mill is the granberg and the RHS is my home made mill.


The left hand side cutters can be filed from the underneath of the mill but the cross bar handle on conventional mills is too close to the bar so it is very difficult or impossible to use a file from the top of the mill. It's pretty clear to see the cross bar on my mill is much higher and further away from the bar so there is room to get in behind and file.

On my buddy Hud's Westford we use Ladder log rails for every slab.

This keeps the bar far enough away from the cross bar handle so it can be sharpened using a file.

An alternative is to you loosen the mill uprights and pull the bar away from the mill, but doing this for every slab is a PITA.

The other way is to use a 12V dremel style sharpener.

You can then sharpen all the cutters from one side but then you need to tote a 12V battery around with you if you go bush.

That sharpener is what i use and just run it off the car/ute battery. Only takes about 3 minutes to touch up a 36 inch bar with single skip chain.

I find when i try to get the second slab (dry blackwood) out of the chain you get 1/2 or 2/3 through and really regret not sharpening it, same goes when you think you can get 2 slabs from a tank of fuel. This is something you learn as you go, normal is sharpen/touch up every time you fuel. I find you work this out as you open the log where the slabs are not as wide as in the centre.

Cheers

Originally Posted by Calm

That sharpener is what i use and just run it off the car/ute battery. Only takes about 3 minutes to touch up a 36 inch bar with single skip chain.

I have a portable 12V HD battery jump pack that I carry in the van behind the drivers seat but I still prefer to use a file and can touch up a full comp chain on a 42" bar (68 cutters) in under 5 minutes ( I have timed myself and pushed myself to do it in 3 minutes but I'm not in a race or in a hurry). I like to hear the file cutting the metal cutter and I also have my eyes reasonable close to the chain so I can watch the edge glint. When the file starts to scrape rather than cut it's time to tap the swarf out of the file. The 12 v sharpener does a good job but the main reason I use a file is because I feel I have a bit more control, and for me chain sharpening is a more peaceful quite time in contrast to the roar of the engine cutting time. Who says milling doesn't have a Zen aspect to it !

I find when i try to get the second slab (dry blackwood) out of the chain you get 1/2 or 2/3 through and really regret not sharpening it, same goes when you think you can get 2 slabs from a tank of fuel.

Yep and Yep

Heh Bob, What is that slippery thing under the log in the big Picture? Damien

Originally Posted by goodwoody

Heh Bob, What is that slippery thing under the log in the big Picture? Damien

Ha! I posted that pic (as is - no description) on a yank forum last Jan to see what they would say and it worked a treat. I had dozens of PMs and postings for about 3 days asking me what they hell it was. In the end I said we put the snake there deliberately to keep the littler ones away and some of them bought it! A day later the thread was pulled for being too controversial

Originally Posted by Calm

That sharpener is what i use and just run it off the car/ute battery. Only takes about 3 minutes to touch up a 36 inch bar with single skip chain.

I find when i try to get the second slab (dry blackwood) out of the chain you get 1/2 or 2/3 through and really regret not sharpening it, same goes when you think you can get 2 slabs from a tank of fuel. This is something you learn as you go, normal is sharpen/touch up every time you fuel. I find you work this out as you open the log where the slabs are not as wide as in the centre.

Cheers

Exactly what I'm finding, get thru 1 slab OK, refill with gas and oil, but only get a 1/3 or 1/2 way thru and decide things are a tad blunt. My biggest problem is I don't like stopping. Guess I'll be taught an expensive lesson soon.

If your only getting one slab out of dry Blackwood I'm guessing I'm doing alright with the Red Box as I'm guessing it a bit denser.

Thanks for the feedback Calm

Originally Posted by BobL

Sounds close to normal to me, although I would expect to get two 7ft slabs from one sharpening. I touch up about every ~30 sq ft in hardwood and every 65 sq ft in softwood.

Questions for you:
How long is your bar
What sort of chain is it (regular, semi skip, single skip, double etc)
What is your raker depth
What is your gullet width
How do you sharpen.

If you can post some close up pics of your sawdust and a chain cutter side like this, I can help diagnose any cutter problems


I know what you mean about trying to sharpen on the Westford, its the same on the Granberg
This picture shows the problem as I see it. The left hand side mill is the granberg and the RHS is my home made mill.


The left hand side cutters can be filed from the underneath of the mill but the cross bar handle on conventional mills is too close to the bar so it is very difficult or impossible to use a file from the top of the mill. It's pretty clear to see the cross bar on my mill is much higher and further away from the bar so there is room to get in behind and file.

On my buddy Hud's Westford we use Ladder log rails for every slab.

This keeps the bar far enough away from the cross bar handle so it can be sharpened using a file.

An alternative is to you loosen the mill uprights and pull the bar away from the mill, but doing this for every slab is a PITA.

The other way is to use a 12V dremel style sharpener.

You can then sharpen all the cutters from one side but then you need to tote a 12V battery around with you if you go bush.

Thanks Bob, your helping me heeps, I'm running 30" bar, normal non skip chain, I'll take some photos tommorow as its dark now and I prefer natural light to take that sort of photo. I hadn't touched the racker's prior to the post but I have now. Its been sharpened once by machine ($50 special from you know where), twice by hand (which I think I prefer, just seems to get a slightly better edge) and now by 12V grinder like your Granberg, I can use that whilst its on the slabbing attachment though I've never been a big fan. I have some experience with saws in that I've been cutting firewood and fence posts for 25 years but have just recently started slabbing, there's something about starting off with a log of wood and ending up with a table just using basic tools that I have in my shed.

Cheers

For that size log in Red Box, I'd say you're doing well to get one slab without sharpening.

Touch the chain up between slabs and your on your way

I usually cut to 8' convenience and trailer size, mostly with a 3' bar on an088. I find that one cut is good on dry ,seasoned Yellow Box, but you really regret not spending the 5min on sharpening when yo are 2/3rds thru the second cut.

Originally Posted by BobL

Sounds close to normal to me, although I would expect to get two 7ft slabs from one sharpening. I touch up about every ~30 sq ft in hardwood and every 65 sq ft in softwood.

Questions for you:
How long is your bar
What sort of chain is it (regular, semi skip, single skip, double etc)
What is your raker depth
What is your gullet width
How do you sharpen.

If you can post some close up pics of your sawdust and a chain cutter side like this, I can help diagnose any cutter problems

See pics attached, hope I get this right, haven't posted pics to this site before!!!

Originally Posted by Les Caddaye

See pics attached, hope I get this right, haven't posted pics to this site before!!!

The orientation of the photos of the cutters is good but see if you can get in even closer (as close as you can and stay in focus). Also I need to know what size your chain is (404 or 3/8). Assuming its 3/8 I get a nominal raker height of about 0.048 "+/- 10% which is consistent with the gullet width of 0.47" ie ~1/10 . Having a higher mag photo would help me work that out a bit better.


At first glance
1 Your cutters look like they do not quite have enough hook
2 the rakers have too flat a top, one even looks like it is sloping the other way
3 you could clean you gullets out a little more.

What does all this mean
1) Adding a little more hook will enable the chain to self feed so you should not need to push as much. If the chain is sharp and you have to push hard to get the saw to cut then this is not right, you should be able to lean on it gently and it should grab and cut.

This picture (from page 71 of the Oregon chain handbook available at Oregon® Maintenance and Safety Manual: Saw Chain, Guide Bar, and Drive Sprocket ) shows examples of your cutter, and the other two extremes of too much hook (8) and not enough hook (9).



Your cutters are tending towards too little hook (9). This tends to scrape the wood instead of cutting it. Too little hook is not an unusual problem with the 12V sharpeners - are you using a guide with the sharpener?

Unfortunately adding more hook won't improve your chain sharpness longevity. In hardwood too much hook can be worse since it will go blunter quicker. However your overall cuttings speed should improve a little with a little more hook. Too much hook also leads to grabbier chains. I prefer slightly more hook as I know I will have to sharpen by the end the slab anyway and the chain self feeds on a slope meaning I hardly have to push. I get that little extra hook by using the recommended 13/64" file in a 5/32" guide. Of course the chain is a bit more grabbier and can bog the saw down, but that is something you learn to cope with.

2) Flat top rakers will grab wood and add unnecessary friction and load to the powerhead. The rakers need to be rolled over. Most people don't realize that rakers actually penetrate into the wood to create the cutting angle. With really hard or dry wood the penetrate very little so the rakers need to be dropped further OR the rakers need to be filed more pointy (some people file them almost triangular) or a combo of both. Your raker depth appears good (ie 10:1 gullet width to raker depth) but is negated by the flat topped rakers. Flat topped rakers will reduce cutting speed meaning the cutters need to take more passes to cut the same wood meaning cutters will go blunt faster.

3) This one won't make any difference in 24" wide really hardwood because there is little chance of the gullets completely filling with sawdust, but if you mill a little wider it will. Keeping the gullets as clear as possible helps the sawdust escape behind the bar so cleaning these out will help.

From what I can see the sawdust looks surprising good . As others have already said your chain going blunt in the wood you are cutting is no surprise but those things above will at least make the cutting a little easier on you and your saw.

Originally Posted by BobL

The orientation of the photos of the cutters is good but see if you can get in even closer (as close as you can and stay in focus). Also I need to know what size your chain is (404 or 3/8). Assuming its 3/8 I get a nominal raker height of about 0.048 "+/- 10% which is consistent with the gullet width of 0.47" ie ~1/10 . Having a higher mag photo would help me work that out a bit better.


At first glance
1 Your cutters look like they do not quite have enough hook
2 the rakers have too flat a top, one even looks like it is sloping the other way
3 you could clean you gullets out a little more.

What does all this mean
1) Adding a little more hook will enable the chain to self feed so you should not need to push as much. If the chain is sharp and you have to push hard to get the saw to cut then this is not right, you should be able to lean on it gently and it should grab and cut.

Bob,
Thanks for the feedback, have resharpened since with a file but I'll take your advice.

1. Had inadvertently sharpened with a 9/32 stone (wrong) but this may explain the lack of hook, grinder does have a guide attached to unit but only very simple..

2. I've always just flattened off my rakers (followed stihl book), but I'll try as per your instructions on the rakers.

3. I used to clean gullets out but I've just gotten lazy, again, I'll go with your suggestion and see how I go. May not be slabbing for a while now as I have enough stock for the next 2 projects.

Chain is 3/8 Stihl. Haven't taken photo as I have already resharpened and saw is at Sop getting 1st service.

I like your slabbing attachement, I gather its home made, do you produce them for sale or do you have plans your willing to part with??

Cheers

Originally Posted by Les Caddaye

1. Had inadvertently sharpened with a 9/32 stone (wrong) but this may explain the lack of hook, grinder does have a guide attached to unit but only very simple..

That's all you need,

I like your slabbing attachement, I gather its home made, do you produce them for sale or do you have plans your willing to part with??

Yes it is home made. There are no plans to make them as they would be too expensive compared to other Alaskan mills. Maybe if I lived in the US I'd consider it. The are no plans but if you search for BIL mill you will get more than enough info about it.