Grinding chain loops and the difference between left and right hand cutters..

[Sidecarflip]

Some thing I've found interesting and that is, when sharpening (grinding) customers chains, there is always a difference between the left hand line of cutters and the right hand line, almost always.

Not something you'd see with hand filing but when machine grinding them and the repeatability of machine grinding, I almost always see a difference in cutter tooth length and have to reset the machines between the right side and the left, which I've been doing, but my question is..

Should I grind them all to a uniform length (left side and right side) or just reset the machine to allow for the difference, so long as the cutters are uniformly sharpened and if so, would it make a difference in overall cutting performance?

I guess my issue is, if say the left hand side cutters are ground and I switch to the right side and the cutters are quite a bit longer, I'd have to remove way more cutter to get them uniform (left and right balanced). I do check cutter length prior to grinding with a set of dial calipers and almost always there is a difference.

I really dislike removing excessive tooth material because it shortens loop longevity and chain loops are expensive today, at least Oregon and Stihl loops are.

These are all professional tree company (Arborists) chain loops. I don't sharpen consumer chains at all, except my own. Kind of a value added thing for me as I grind chipper knives mostly but I've been getting saw chains lately as well.

I need some opinions, do I grind the left side and reset the machine's) for the right hand side or grind them all evenly and remove a lot of tooth material in the process.?

I use Diamond Abrasives CBN wheels exclusively and not the stone wheels so heating teeth (and destroying the temper) is a non issue.

 

[user 122190]

I've always found it interesting and a mystery as to why one side is always shorter then the other. I figure it is because I sharpen better on one side then the others. I don't recall this being the case when I use to sharpen using a bench grinder.

As far as getting them the same size, I wouldn't bother. It's the rakers that determine the cutting performance. Same raker depth, same cutting performance.

 

[Del_]

On a machine grinder I'd straighten that **** up.

Especially for a customer who likely won't understand about depth gauges making the difference and will only see an obvious error.

Plus once equalizing tooth length the depth gauges are a breeze to make all the same height using a machine grinder.

Hand filing with a progressive sharpening measuring device is another story. But that is a pro move, IMO.

 

[Sidecarflip]

I always set the raker (depth gages) 0.020 below the leading edge of the sharpened tooth unless the it's not required. and on the low pro chains (in tree top handle saws), I'll not cut them at all. Nice thing about machine grinding or should I say a not nice thing is the tooth discrepancies show right up because the grinding machines are very accurate in depth of grind.

Dropping the dept gages (rakers) too much only causes a chain loop to require more power to cut wood and the chance of kickback is also increased and I don't need my customers getting hurt.

 

[chipper1]

AS Del said, set them all the same for the situation you describe.
If the hook is set properly, there ain't nothing in Michigan that you'd need a raker set a .020 with the proper power. I wouldn't set them to anything less than .025 and that's just a good starting point for cutting hardwoods on a newer chain, anything filed/ground back I set mine progressively as that's how they should be set.
Honestly, I find it hard to believe that after cutting with a new chain anyone comes back after having the rakers set at .020(or not set at all), especially if the cutters are different lengths .

Edit; personally I don't care if the cutters are the same length for my chains, guess I'm a pro according to Del .

 

[Sidecarflip]

I only drop the depth gages if they are proud with the cutting edge of the tooth after sharpening. Only time actually and I have a dedicated grinder just for that and again, a CBN wheel.

 

[Sidecarflip]

Far as Michigan is concerned, my customers work 3 states, Michigan, Ohio and Indiana and I have no idea where they go, they go to where the jobs are.

 

[chipper1]

I only drop the depth gages if they are proud with the cutting edge of the tooth after sharpening. Only time actually and I have a dedicated grinder just for that and again, a CBN wheel.

It's still wrong.
CBN wheel changes nothing about setting the depth gages other than if you have the angles set properly(ie the hook is proper), then you should be setting them to .025 or lower when a chain is new, and at least .035 when a chain is nearing the end/close to the witness marks.

Far as Michigan is concerned, my customers work 3 states, Michigan, Ohio and Indiana and I have no idea where they go, they go to where the jobs are.

Been to all of them, and go to them all weekly, same wood...
I'd still say the same as above.

 

[Del_]

It's still wrong.
CBN wheel changes nothing about setting the depth gages other than if you have the angles set properly(ie the hook is proper), then you should be setting them to .025 or lower when a chain is new, and at least .035 when a chain is nearing the end/close to the witness marks.

Been to all of them, and go to them all weekly, same wood...
I'd still say the same as above.

Spoken like a pro!

 

[Philbert]

Grinding wheels are round. Unless perfectly centered over the vise, you will hit one side of the chain with a different part of the wheel circumference than the other.

In addition to cutter length, you may see differences in depth of cut, etc.

These are more noticeable with smaller diameter wheels (any type).

Better grinders have adjustments to center the wheel, but this has to be made if the wheel wears (conventional, vitrified) and the diameter changes, or when different wheels are swapped in and out.

I compensate in the way I grind (*this takes longer to describe than to actually do*);

- set up and grind all the Left cutters, as desired;

- rotate the vise and grind one, ‘test’, Right cutter;

- hold the test cutter back-to-back with any Left cutter, and note any differences in length, depth, profile, etc.

- make any adjustments needed, and grind all the Right cutters.

When I am doing a lot of chains, I can usually predict the compensating adjustments needed. Might take a few small adjustments when first trying this.

Philbert

 

[Philbert]

Not something you'd see with hand filing but when machine grinding them and the repeatability of machine grinding, I almost always see a difference in cutter tooth length and have to reset the machines between the right side and the left

I see MUCH more variation with hand filed chains.

Often, completely different angles, and very different lengths, due to people being stronger on one side or the other.

Philbert

 

[pdqdl]

Some thing I've found interesting and that is, when sharpening (grinding) customers chains, there is always a difference between the left hand line of cutters and the right hand line, almost always.

Not something you'd see with hand filing but when machine grinding them and the repeatability of machine grinding, I almost always see a difference in cutter tooth length and have to reset the machines between the right side and the left, which I've been doing, but my question is..

Should I grind them all to a uniform length (left side and right side) or just reset the machine to allow for the difference, so long as the cutters are uniformly sharpened and if so, would it make a difference in overall cutting performance?

I guess my issue is, if say the left hand side cutters are ground and I switch to the right side and the cutters are quite a bit longer, I'd have to remove way more cutter to get them uniform (left and right balanced). I do check cutter length prior to grinding with a set of dial calipers and almost always there is a difference.

I really dislike removing excessive tooth material because it shortens loop longevity and chain loops are expensive today, at least Oregon and Stihl loops are.

These are all professional tree company (Arborists) chain loops. I don't sharpen consumer chains at all, except my own. Kind of a value added thing for me as I grind chipper knives mostly but I've been getting saw chains lately as well.

I need some opinions, do I grind the left side and reset the machine's) for the right hand side or grind them all evenly and remove a lot of tooth material in the process.?

I use Diamond Abrasives CBN wheels exclusively and not the stone wheels so heating teeth (and destroying the temper) is a non issue.

Yes. The cutters should be ground to the same length.

You will also find that this error in your grinder can be corrected by adjusting the clamping plate closest to the grinder pivot away from the pivot point.

Here is what is happening: your clamping mechanism, if it is like most of the ones I have seen, is in a fixed but adjustable position. The clamping side compresses the drag link towards that fixed side. If that fixed point is not truly in the center of the chain grinder, you will set your grinding point on the first side you have chosen, but when you grind the second side, the "mirrored image" grind is positioned incorrectly because the clamp is not properly centered.

Now this gets particularly complex because there are five different thicknesses of drag links you might encounter, and then there are varying amounts of wear on different chains. If you really want a perfect grind, you should adjust the chain clamp to center the chain, rather than just snug it up the right amount.

Alternate method: adjust your clamping mechanism for the most common chain guage that you encounter, and then make small adjustments to your stop point to compensate for the error between right and left side cutters. They should be equal in length.

PS: I think the automatic clamp on the better Oregon grinders has the fixed side furthest away from the grinder pivot.

 

[pdqdl]

I've always found it interesting and a mystery as to why one side is always shorter then the other. I figure it is because I sharpen better on one side then the others. I don't recall this being the case when I use to sharpen using a bench grinder.

As far as getting them the same size, I wouldn't bother. It's the rakers that determine the cutting performance. Same raker depth, same cutting performance.

That doesn't quite work for a bench grinder setting. Most guys set the depth guages the same, and run it through the machine. Longer cutters will then have greater clearance, and the chain will cut crooked. If you compensated for the cutter error by grinding the left and right side depth gauges accordingly, then you'd probably be ok. Too much work though!

Just adjust your clamping mechanism to properly center the chain!

 

[pdqdl]

AS Del said, set them all the same for the situation you describe.
If the hook is set properly, there ain't nothing in Michigan that you'd need a raker set a .020 with the proper power. I wouldn't set them to anything less than .025 and that's just a good starting point for cutting hardwoods on a newer chain, anything filed/ground back I set mine progressively as that's how they should be set.
Honestly, I find it hard to believe that after cutting with a new chain anyone comes back after having the rakers set at .020(or not set at all), especially if the cutters are different lengths .

Edit; personally I don't care if the cutters are the same length for my chains, guess I'm a pro according to Del .

.025 for homeowner saws, .030 for pro-saws. .025 is ok for a pro-saw, but looses a great deal of performance when it gets a little bit dull. .030 is for the guys that are willing to not bear down on the saw when it is really a keen edge, and then when dulled a bit, it will keep cutting.

Inadequate clearance on the depth gauges can really piss off the homeowner, because even a little bit dull, it quits cutting. Then the user brings it to a shop that give a little more clearance, and the sharpening seems to last longer due to the increased clearance on the depth gauges. I try to have that discussion with my customers, so that they will be aware of what is happening.

As mentioned previously, .035 works better on a really worn chain. I have always thought that might be due to the fact that the greater distance from the cutting edge to the depth gauge gives the cutter more leverage to pivot the cutter link backwards away from the wood. That's just a guess, however, since I've never read any research on that topic.

 

[huskihl]

Your grinder isn’t set up properly if the teeth aren’t the same length. A grinder will always be more accurate and consistent than freehand filing.

 

[pdqdl]

- set up and grind all the Left cutters, as desired;

I always do the right side cutters first.

Most chainsaw operators are not left handed, and cut from right to left. Most of them are too damned lazy to bend their knees and get close to the ground for a horizontal cut when dispatching underbrush and small trees.

This puts the right hand cutters closer to the ground than the left, and this is the side that is usually the dullest.

 

[HumBurner]

I only drop the depth gages if they are proud with the cutting edge of the tooth after sharpening. Only time actually and I have a dedicated grinder just for that and again, a CBN wheel.

I file with a G-106b.

I drop the depths first, if needed, then sharpen the teeth. If the depths need a lick or two more, so be it. I generally know where my leading edge will end up at before I start.

As many have said, know the profile you want to end with before you even put file to tooth.

With hand filing, you can also tailor the hook and gullet shallower or deeper, temporarily avoiding having to touch the depths.

 

[Sidecarflip]

CBN wheel changes nothing

Aluminum rimmed CBN wheels won't destroy the temper in a cutter due to overheating. Why I use them that and you never need to dress them, just clean them occasionally

I get a kick out of this forum, I asked a simple question and off the thread goes into never-never land.

I'm done here. My question was answered and that is all I need to know.

 

[bwalker]

Your grinder isn’t set up properly if the teeth aren’t the same length. A grinder will always be more accurate and consistent than freehand filing.

Setting up a grinder to grind perfect on both side is just as hard as doing the same with hand filing. Most of the cheaper grinders are pretty bad aide to side.

 

[Philbert]

I always do the right side cutters first.

With my grinder, the Left cutters tend to come out a hair shorter than the Right.

I can always take a little more off the Right, if too long, but hard to put more back on.

Just important to find something that works for you.

Aluminum rimmed CBN wheels won't destroy the temper in a cutter due to overheating

CBN wheels can overheat a chain.

It was one of the first things I tried when I bought a pair, several years ago. Also, did not like the finish they produced. Went back to conventional wheels.

Philbert