Unable to get cutters the same length.

[Will the wood chopper]

Hello all.
I am new to this site.
I have been cutting hedge for the last 20 years and have always had my chains sharpened by someone other than me. I decided to buy the oregon 520-120 sharpener. I am having trouble getting the cutters to come out the same length and I need advice.
Thank you!

 

[Philbert]

Welcome to A.S.!

This thread is full of tips and wisdom for most Oregon / Tecomec grinders:

https://www.arboristsite.com/threads/511a-grinder-improvements-tweaks.197073/
Philbert

 

[Philbert]

Two main things to note:

Your grinder (a very nice one BTW) has instructions for centering the grinding wheels over the chain vise, in the instruction manual. This needs to be checked, periodically, as the wheels wear, and change diameter.

The other, is that these are semi-precision machines. My procedure (takes longer to read than to do!):

- grind all the cutters on one side (say, the Left cutters);
- grind one, test cutter in the other (Right) side;
- compare this test cutter, back-to-back, with one cutter from the other side, and adjust grinder settings (chain stop, wheel depth, etc.) as needed.

This becomes ‘automatic’ to me. I do my Left cutters first, back off the chain stop 1/4 to 1/2 turn, lower my grinder head stop the same, and I am usually right on.


Philbert

 

[Will the wood chopper]

Yes sir, I have centered wheel over the vise as the manual states.
I am hoping that this problem is just me not knowing what I am doing yet. I just looked at some chains that I had sharpened at a local shop in Topeka Kansas. They are different lengths from right to left. but I am having problems getting the length the same on one side let alone right to left.

 

[Philbert]

Once you set the chain stop on your grinder, all the cutters on that side should grind to the same length, angle, profile, etc., unless you change something.

Are you grinding with the profiled rim of the wheel, or the side of the wheel ?

For guys new to grinding I recommend taking an old or ‘scrap’ chain, and experimenting with it:

- ‘play’ with every adjustment on the grinder separately, and see what each does to the cutter profile;

- intentionally try to overheat, or ‘burn’ a cutter, then work backwards to see how to avoid that (lots of small taps, no sustained contact);

- place a sharp chain you like in the grinder, with the power ‘Off’, and try to ‘copy’ those angles and settings with the grinder adjustments (and write those settings down);

- profile the rim of the grinding wheel, with the dressing brick, then lightly dress it once oer chain loop, to continuously expose fresh, sharp, abrasive;

- practice, and don’t worry about speed - that will come with experience.

Philbert

 

[blades]

Couple notes: I am not where i can get pics of this, when you run the cutter up to the stop due to the angle of the stop digging into the bottom of the cutter it will cause the cutter to raise up( tilted in relation the vise rails) this will give you uneven cutter lengths. This is the primary cause of the uneven length. Run the cutter to the stop then push down on the cutter and tighten vise. this should solve the problem. Also there is a bit of play in the stop assembly so depending on how hard you pull the chain back into the stop will give variance as well. I do not remeber if the 520 has the adjusment screw for rail slot width at the pinch point of the cam - considering that the rail slot is set for .063 there is a fair amount of movement front to back when tightening the vise on thinner drive links - easy enough to drill and tap to add a set screw ( it is on the back side center of vise).

 

[Rooshooter]

I do the same as Philbert does, grind all my left cutters first, back of slightly and grind one cutter on right and measure length then adjust chain stop & depth height for correct length/height.
I also start out with my chains clean ( soak in caustic soda/water solution and then pressure clean ) this helps stop clogging of the grinding wheel.
Do not grind with a dirty wheel, as the wheel clogs up and turns black on the cutting surface performance drops markedly and will start to burn the cutter no matter if you gently grind, so you need to profile & clean the wheel.
Also I let the grinding wheel " spark out " so you have absolute minimum of sparks, grind all cutters the same way.
If you don't you can end up with cutters on the same side varying by up to .020" - after I sharpen , my cutters left to right are usually within .005"
I usually sharpen up to 30 - 40 chains per week and run three 511A's and a 520.

 

[Will the wood chopper]

I do the same as Philbert does, grind all my left cutters first, back of slightly and grind one cutter on right and measure length then adjust chain stop & depth height for correct length/height.
I also start out with my chains clean ( soak in caustic soda/water solution and then pressure clean ) this helps stop clogging of the grinding wheel.
Do not grind with a dirty wheel, as the wheel clogs up and turns black on the cutting surface performance drops markedly and will start to burn the cutter no matter if you gently grind, so you need to profile & clean the wheel.
Also I let the grinding wheel " spark out " so you have absolute minimum of sparks, grind all cutters the same way.
If you don't you can end up with cutters on the same side varying by up to .020" - after I sharpen , my cutters left to right are usually within .005"
I usually sharpen up to 30 - 40 chains per week and run three 511A's and a 520.

Hello Rooshooter.
When you say " spark out " do you mean to sharpen cutter until very little sparks are coming off cutter?
Also How do you pressure clean the chain?
Thanks.

 

[coffeebrk]

When I'm using my grinder I always put my hand on the top, not the side, of the handle.
This gives me a very consistent and repeatable result.

 

[lone wolf]

Two main things to note:

Your grinder (a very nice one BTW) has instructions for centering the grinding wheels over the chain vise, in the instruction manual. This needs to be checked, periodically, as the wheels wear, and change diameter.

The other, is that these are semi-precision machines. My procedure (takes longer to read than to do!):

- grind all the cutters on one side (say, the Left cutters);
- grind one, test cutter in the other (Right) side;
- compare this test cutter, back-to-back, with one cutter from the other side, and adjust grinder settings (chain stop, wheel depth, etc.) as needed.

This becomes ‘automatic’ to me. I do my Left cutters first, back off the chain stop 1/4 to 1/2 turn, lower my grinder head stop the same, and I am usually right on.

View attachment 1134573
Philbert

And is the chain cutting good even with this?

 

[Philbert]

And is the chain cutting good even with this?

Yes.

I get uniform, sharp, consistent, cutters.

Philbert

 

[Pjohnson]

The more i read about tooth length the more confused i get. Right now my opinion is that it doesn't matter the length of the tooth as long as the raker or depth gauge is set properly for each tooth. I grind all one side the same then the other. I could care less if they are the same. Now set your depth gauge for each side. As long as depth gauge matches the tooth it will cut straight. If you damage a few teeth cut them down as needed and set depth, no need to grind the whole chain down. I know there's two schools of thought about this but this keeps it simple and works for me.

 

[lone wolf]

Yes.

I get uniform, sharp, consistent, cutters.

Philbert

Well, then don't even worry about it. Mine are all hand filed, and the left side is always shorter but works fine . If you had a problem with it cutting rainbows then something needs to be addressed, but in your case not.

 

[Philbert]

The more i read about tooth length the more confused i get.

Couple of things:

- If you use a conventional, fixed offset depth gauge tool, (reasonably) consistent cutter lengths are required.

- When I get in chains that are all messed up (different angles, cutter lengths, depth gauge height, etc.) I ‘even them out’ / bring them back to a uniform condition with a grinder, to ‘start over’.

- If you regularly sharpen with a grinder, you set it up to run all teeth uniformly, and all depth gauges uniformly, not individually.

Hand filing individual cutters, you have a choice to use a ‘progressive’ depth gauge tool.

But, even if different length cutters cut, it does not mean that your chain is cutting as smoothly as if uniform.



‘Jointing’ (height) and ‘setting’ (sideways projection) of cutting teeth is basic in sharpening of any type of saw.

Philbert

 

[sean donato]

Couple of things:

- If you use a conventional, fixed offset depth gauge tool, (reasonably) consistent cutter lengths are required.

- When I get chains all messed up (different angles, cutter lengths, depth gauge height, etc.) I ‘even them out’ / bring them back to a uniform condition with a grinder, to ‘start over’.

- If you regularly sharpen with a grinder, you set it up to run all teeth uniformly, and all depth gauges uniformly, not individually.

Hand filing individual cutters, you have a choice to use a ‘progressive’ depth gauge tool.

But, even if different length cutters cut, it does not mean that your chain is cutting as smoothly as if uniform.

View attachment 1135175

‘Jointing’ (height) and ‘setting’ (sideways projection) of cutting teeth is basic in sharpening of any type of saw.

Philbert

I don't ever set the depth gauges with the grinder for that reason. It's too generic, and I'm not grinding down an entire chain for a few rocked cutters.

 

[Philbert]

I don't ever set the depth gauges with the grinder for that reason. It's too generic, and I'm not grinding down an entire chain for a few rocked cutters.

Took me a little while to learn how to do depth gauges efficiently on a grinder (even started a thread on it!). But if the teeth are uniform, then there is no reason to do depth gauges individually.

As for having ‘a few’ damaged cutters, that is up to the individual. How many? How damaged?

Sometimes, I’ll grind past the damage, on a couple of teeth, and let the other cutters ‘catch up’ over time.

Sometimes, I have spun out and replaced heavily damaged sections of chain.

But when I get a chain that appears to be randomly filed, I am not going to try and figure it out like a puzzle: I bring everything back to a uniform condition.

If it is your own chain, you might have a better idea of what is going on with a specific loop.

Whatever works for folks.

Anyway, the OP’s question was about getting cutters the same length on a grinder.

Philbert

 

[Pjohnson]

Maybe i wasn't real clear i take the minimum off the left side all left same size then do the same with right. For all i know they could be exactly the same i dont measure between left and right. Then set left side rakers as needed and then all the right side. So all left are the same and all right are the same. Usually just a couple swipes with a file on the rakers too lazy to swap wheels. Only time I'd have shorter ones mixed in if i was trying to save a few damaged teeth.

 

[blades]

That likely works ok. Like some others here I do commercial sharpening and do not have time to fiddle on individual tooth vs depth gauge. So to that end I try to get all cutters same length Likely with in a few thousandths. I have a DG6 depth gauge grinder which does both sides to the same height. Fairly quick and easy- beats messing with tooth grinder to do same or hand filing although on those pico pico chains ( .043 drive links, which ya dang near need a magnifying glass to see the teeth and the depth gauges) I end up doing the depth gauges by hand on those with the files.

 

[Rooshooter]

Hello Rooshooter.
When you say " spark out " do you mean to sharpen cutter until very little sparks are coming off cutter?
Also How do you pressure clean the chain?
Thanks.

Hi Will, yes that's correct and as far as cleaning goes I drop the chains in caustic soda/ water mix leave them in for about an hour ( longer doesn't cause problems ) and use my water pressure cleaner to blast the residue off the chains, btw caustic is about the only thing that will dissolve wood gum.

 

[EchoRomeoCharlie]

Doesn't matter in my opinion.

I hand file and do not take cutter length into account what so ever. I sharpen each tooth until it's sharp and remove any dings. If that means removing a ton on one tooth and 2 strokes on another, that's what I do. I use a depth gauge file guide on each and my chains cut straight without any issues. I doubt any of my cutters are the same length. If they are, it's by pure coincidence.

Chains last a lot longer than back when I would sharpen to the shortest tooth too. Which is a nice bonus.

I've had a couple chains that had 3 or 4 teeth completely missing before I felt the rest of the chain was done and retired it. Still cut fine.