Chain Grinder Wheel Experiments

[Philbert]

The bottom of the side plate, where it transitions into the gullet, is quite a tight curve with the 1/8" wheel . . .

OK, I was on my phone and had to keep my earlier reply short.

DEPENDING ON HOW YOU GRIND . . . . .

I have posted this illustration many times. 'Grind as you File: File as you Grind'. If you do this, it is easier to go back-and-forth between a grinder in the shop (heavy sharpening), and a file in the filed (touch up sharpening), which I do.


If you grind like this, you will get a hollow ground top plate cutting edge, and a rounded side plate cutting profile. But a lot of guys take their grinding wheels deeper into the gullets, essentially shaping the top plate cutting edge with the side of the wheel, and the side plate cutting edge in a straight, instead of curved, profile.

90% of the guys following this thread have moved on by now; only the true chain geeks are still following . . . .

You don't really have a choice when using a thinner wheel, unless you want to re-set your chain holding dog and depth adjustment, and do the larger cutters in multiple passes. If you try, you will probably end up with serrated side plate cutting edges (an interesting idea in itself!). What I would really like to see is research from Oregon, STIHL, etc. which would let us know if there would be an appreciable advantage from having MORE widths of grinding wheels available to match all the recommended file sizes (1/8, 5/32, 11/64, 3/16, 7/32, 1/4, . . . ).

As for your asymmetrical wheel edge, aside from the balanced wear issue, I would have a concern about chasing gullets. After I sharpen the edges, I often go back and chase the gullets with the same wheel, and I think that the corner might dig in, in some cases.

Philbert

 

[Philbert]

Personally, I would rather not have to swap wheels over, which I find I'm having to do plenty of, even on my own chains which are picco, 3/8, .404.

That's why a number of guys keep their eyes open for used grinders, and keep 3 set up: 1/8" wheel, 3/16" wheel,
1/4" or 5/16" for depth gauges.

Philbert

 

[KiwiBro]

'Grind as you File: File as you Grind'. If you do this, it is easier to go back-and-forth between a grinder in the shop (heavy sharpening), and a file in the filed (touch up sharpening), which I do.

Thanks but I don't ever hand file in the field - anymore - unless something has gone wrong like I have rocked many chains, or I forgot to bring enough sharp chains with me.
Secondly, in many cases, with many of the people that bring me chains to grind, they are also better off never owning a hand file because they are muppets who couldn't file a chain if their lives depended on it. When they try, they screw it up. When they don't try, they just burn their way through anyway, say a few swear words, and hope the store is open to go buy a new chain.

 

[KiwiBro]

That's why a number of guys keep their eyes open for used grinders, and keep 3 set up: 1/8" wheel, 3/16" wheel,
1/4" or 5/16" for depth gauges.

Philbert

This doesn't subscribe to my de-cluttering KISS mantra, but would be nice.

 

[jakethesnake]

Just curious anyone try putting a "good' wheel on a harbor frieght grinder I have one but if you get a banged up chain you gotta take it real slow I'm new to grinders but when you jack a bunch of chains and need to go in the am you use what ya got

 

[Philbert]

Just curious anyone try putting a "good' wheel on a harbor frieght grinder I have one but if you get a banged up chain you gotta take it real slow I'm new to grinders but when you jack a bunch of chains and need to go in the am you use what ya got

I started a whole thread on those here:

http://www.arboristsite.com/community/threads/hf-chain-grinder-thread.268303/

Better wheels make a big difference, but you have to find ones that fit.

Philbert

 

[bikemike]

I am more of a 'stock' guy. But I should find a way to market my hoard of end-of-life chains to the race guys . . .
View attachment 417936
Philbert

I've run many chains down like that. If it cuts use it

 

[bikemike]

It cut awesome, not grabby at all with the rakers at .030". But that was years ago when I made that one.

I do something similar to some of my chains too. I touch em up often vs waiting till there in no edge left. I like the way my chain cuts through hard or soft wood.

 

[bikemike]

Just curious anyone try putting a "good' wheel on a harbor frieght grinder I have one but if you get a banged up chain you gotta take it real slow I'm new to grinders but when you jack a bunch of chains and need to go in the am you use what ya got

I have a hf grinder that works good now. The wheels sold at menards are a courser grit than the hf brown wheels and take material off quickly. I had changed the angle of attack using the chain rail and it made night n day difference. Only thing I'm not happy with is the degree gauge is not accurate. So I matched up with new chains and scribed new reference lines on the base for 30° 25°. I L post pics of the hf grinder if ur interested

 

[Philbert]

I matched up with new chains and scribed new reference lines on the base for 30° 25°. I L post pics of the hf grinder if ur interested

Post them in the'HF Grinder' thread, mentioned above.

Philbert

 

[Grande Dog]

Howdy,
I didn't realize this was bumped from earlier. If you're going to split hairs on sharpening .325 chisel, 4.5mm would be the correct size file. The problem with using a 3/16 abn is that even though you get the better side plate profile, you're leaving a radius edge on the top plate. You would be better served by tilting the vise. Keep in mind when you tilt the vise, your top plate angle will be about 5 degrees different that what your scale is reading. So, if you like a 25 degree top plate angle, set you scale to 20 degrees. This will take hook out of the side plate, and allow the wheel to get deep enough to were the top plate is totally on the side of the wheel. This gives the top plate a straight chisel edge, rather than a concave edge.
Regards
Gregg

 

[KiwiBro]

Thanks Gregg. Need to get off this gum job and into different species but I can say I'm pretty happy with how the 3/8 chain is performing when ground with the thin wheel even if the transition from side plate into the gullet is a tighter curve than with the thicker wheel. I just can't get as aggressive with the raker angles as I usually do or it isn't as smooth cutting, but that's fine because it still performs well at about 6 degrees from cutter to raker. Anything more and the chatter isn't nice, especially in dry gum.

 

[KiwiBro]

Tried the thin wheel on .325 also and it's fine. So, at this stage, I have just .404 to try it on and if that works out OK, I think if I get a diamond wheel, it will be one to do all. I haven't used the thicker wheel for a while now. I did reprofile my thin wheel more to the shape I mentioned above.

 

[Locust Cutter]

I'll have to bookmark this thread...

 

[bikemike]

I've used a thin wheel on .325 and 3/8. Got to say it looks different but cut great

 

[Mike Kunte]

OK, I was on my phone and had to keep my earlier reply short.

DEPENDING ON HOW YOU GRIND . . . . .

I have posted this illustration many times. 'Grind as you File: File as you Grind'. If you do this, it is easier to go back-and-forth between a grinder in the shop (heavy sharpening), and a file in the filed (touch up sharpening), which I do.
View attachment 482839

If you grind like this, you will get a hollow ground top plate cutting edge, and a rounded side plate cutting profile. But a lot of guys take their grinding wheels deeper into the gullets, essentially shaping the top plate cutting edge with the side of the wheel, and the side plate cutting edge in a straight, instead of curved, profile.

90% of the guys following this thread have moved on by now; only the true chain geeks are still following . . . .

You don't really have a choice when using a thinner wheel, unless you want to re-set your chain holding dog and depth adjustment, and do the larger cutters in multiple passes. If you try, you will probably end up with serrated side plate cutting edges (an interesting idea in itself!). What I would really like to see is research from Oregon, STIHL, etc. which would let us know if there would be an appreciable advantage from having MORE widths of grinding wheels available to match all the recommended file sizes (1/8, 5/32, 11/64, 3/16, 7/32, 1/4, . . . ).

As for your asymmetrical wheel edge, aside from the balanced wear issue, I would have a concern about chasing gullets. After I sharpen the edges, I often go back and chase the gullets with the same wheel, and I think that the corner might dig in, in some cases.

Philbert

Hey Philbert!

You have hit upon something that has been bothering me for a long time now... I always used to hand file with the Stihl gauge - that little job that attaches to the file, but was never quite happy with the results. The last two years or so I've been using my Oregon 620 grinder and getting very consistent results. The two thing which bothered me most was the depth that the grinder wheel is pushed into the cutter, and the specified diameter of the wheel "thickness". So....

1. Why would the manufacturer specify a wheel "thickness"/diameter if he did not want the user to "stop" short and leave a round hole - as you said - file as you grind, and vice versa.

2. If I drop below this specified depth, and then leave a "straight" 60 degree angle on the back of the cutter before the radius begins, the "diameter" of the grinding wheel is actually unimportant...

3. Since recently watching some guys filing free hand on YT, I decided to give it a try. Results were good. However - I don't think anyone in the world can file 100% consistently with the required accuracy to keep each cutter exactly alike. Maybe perfection is not required, and a good cutting result is the proof of the pudding. Think about it - who can judge by eye whether a 13/64ths file is exactly at the correct height? Being out by as little as 1/64th (about 15 thou) will either cause a micro-hook with an angle lower that 60 degrees (if the file is too low) or a "blunt" butt edge with and angle higher than 60 degrees (file too high). Engineers use highly accurate measuring gauges to measure such small differences, yet many "pros" claim they can do it by eye. I'm not convinced. I am not saying that a free-hand filer cannot achieve good results - there are many profession loggers whose chains never see a grinder in their lives.

I know this might sound unclear, so I'll use a drawing....



Looking at both pics:

1. At "A", both cutters have exactly the same angle (for example, 60 degrees)
2. At "B", the top pic has a curve, whilst the bottom pic has a "straight back".

Questions:

1. Does the curved back cut better than a straight back? Does anyone have solid info on this?
2. Should I drop the grinder wheel in only until the wheel produces a "curved back"? This way I can pick up in the field with a file if necessary...

Thoughts please!

Mike

 

[Philbert]

It depends . . .

Might depend on the type of wood, type of cutting, power of saw, etc., etc., etc. 'Square filed' chain has flat cutting edges, but also different angles. The sketches below show a less common, hybrid, 'goofy file' which leaves a flat top plate cutting edge and a rounded side plate cutting edge.

Bottom line: it's up to you. One of the advantages of sharpening your own chain is that you can experiment and find what works best for you, your saw, your wood, and the type of cutting you do. My main point is 'INTENT' - shape the cutting edges intentionally, the way you want them to end up, rather than as an accident of the file/method you use. Choose the cutter profile your want, then choose file and the file guide, or shape the grinding wheel, to get that profile. And if you use both a file and a grinder (as I do, and it sounds like you may too), consider combinations and techniques that work together, so that you are not re-shaping the edges each time.

Philbert

 

[Mike Kunte]

Philbert!

I have used one of your images from above, and modified it slightly to show a worn tooth. Whether using a round file, or using a grinder set to just form a "cup", the gullet bottom (marked "A") will gradually rise up. It will happen in a more pronounced way than the image depicts. Actually, it would form a slightly scalloped "ramp". Do you think this is a problem? I hear a lot of talk about "chip flow", and want to know whether the "bottom" should should be filed down to the original depth.

Mike

 

[Philbert]

. . .the gullet bottom will gradually rise up . . . Do you think this is a problem?

Short answer: 'No'.

If you look at the thickness of the average chip, it barely gets down there. But if you are in a high 'chip flow' situation, it might slow things down a little.

That said, I like to leave the bottom of the gullet flat, knowing that this may be more cosmetic than practical. This is really a separate step from 'sharpening' a cutter. I sometimes do this with a larger diameter file, after sharpening the edges with the recommended file. With the grinder, I back off the tooth positioning dog a half turn or more, lower the grinding wheel head a bit, then 'run the gullets' on each side. On chains where this has never been done, it may take a few passes. Then I set the depth gauges.

I think that some guys get into trouble focusing on how the cutter looks, rather than understanding the business part. Get that top edge, corner, and upper part of the side edge sharp; then go back and make things pretty as a separate step. If you try to do this in one pass (file or grinder) you will not end up with the edges you want.

JMHO

Philbert

 

[chipper1]

OK, I was on my phone and had to keep my earlier reply short.

DEPENDING ON HOW YOU GRIND . . . . .

I have posted this illustration many times. 'Grind as you File: File as you Grind'. If you do this, it is easier to go back-and-forth between a grinder in the shop (heavy sharpening), and a file in the filed (touch up sharpening), which I do.
View attachment 482839

If you grind like this, you will get a hollow ground top plate cutting edge, and a rounded side plate cutting profile. But a lot of guys take their grinding wheels deeper into the gullets, essentially shaping the top plate cutting edge with the side of the wheel, and the side plate cutting edge in a straight, instead of curved, profile.

90% of the guys following this thread have moved on by now; only the true chain geeks are still following . . . .

You don't really have a choice when using a thinner wheel, unless you want to re-set your chain holding dog and depth adjustment, and do the larger cutters in multiple passes. If you try, you will probably end up with serrated side plate cutting edges (an interesting idea in itself!). What I would really like to see is research from Oregon, STIHL, etc. which would let us know if there would be an appreciable advantage from having MORE widths of grinding wheels available to match all the recommended file sizes (1/8, 5/32, 11/64, 3/16, 7/32, 1/4, . . . ).

As for your asymmetrical wheel edge, aside from the balanced wear issue, I would have a concern about chasing gullets. After I sharpen the edges, I often go back and chase the gullets with the same wheel, and I think that the corner might dig in, in some cases.

Philbert

I wasn't following this thread and just stopped in, am I still a chain geek .
One thing I do differently than you from what I read here is to clean the gullets out first, even on rocked/damaged chains and then I sharpen them "like I file".
This way I set the chain up for the gullets and then I will grind until the gullet is clean and then I will go until the tooth is almost sharp on a rocked/damaged chain, then I simply change the depth so it's as I file and sharpen the teeth. The way you describe you will be setting the grinder up twice on each tooth whereas I set up once then reduce the depth, it's very easy and I'm quite pleased with the results.
There is a little ledge left on my ground chains that my file will sit on which makes hand filing a breeze if I choose to in the field. As you were saying earlier in this thread use the witness marks both on the top and sides as it helps to get the "factory proper angle". As the OP was saying he will customize his own chains as do I because the factory proper angle is a more generic setting that will work the well in the most situations, that being said it doesn't work the best in specific situations and can be changed to optimize performance in most cutting scenarios and the chain will out cut the factory proper angle.
I agree sharpening and cleaning up the gullets is a separate step, but they can be more incorporated into the same procedure quite easily.
Hope this is clear and helps someone.