Oregon Micro-Lite 90PX chain sharpening

[Philbert]

I tried a sample of them and they really worked well. The comments from other users were also very positive.

ABN/CBN is what is used on many of the expensive chain grinder wheels, whereas diamond is typically only used for carbide chains.

Philbert

 

[GerrySM]

Thing is, a-BN and c-BN are completely different. Due to its great chemical and mechanical robustness, c-BN has widespread application as an abrasive, such as on cutting tools and scratch resistant surfaces. That's the crystalline form. ABN, or a-BN, is the amorphous form. The crystalline form is an extremely hard, brittle solid. It is of jet-black to silvery-gray color with a metallic luster. One form of crystalline boron is bright red. The amorphous form is less dense than the crystalline and is a dark-brown to black powder.

Crystalline boron, although relatively brittle compared to diamond, is second only to diamond in hardness.

The chemical properties of boron depend largely on the physical form as well as on the purity of samples. Amorphous boron oxidizes slowly in the air even at room temperature, and is spontaneously flammable at about 860°C.

Even if the product you recommend actually has CBN and not ABN (which I suspect, if the reports have been good), it's still, in theory, inferior to diamond (and much more expensive too). Amirite?

 

[Philbert]

Even if the product you recommend actually has CBN and not ABN (which I suspect, if the reports have been good), it's still, in theory, inferior to diamond (and much more expensive too). Amirite?

Not if the diamond falls off due to cheap abrasives or poor quality ($1.25 each? Really?). 'Diamond' is a mineral, but there are different grades. 'Aluminum oxide' is a synthetic mineral, but there are many grades. Etc.

Diamond wheels are not normally used for standard saw chains - they are not 'better' from a performance standpoint. The matrix can fill up with steel, clogging them. 'Harder' is not always better; sometimes it is too brittle.

What I can say is that I tried the stones in the referenced thread, and they performed very well. They sharpened the cutters quickly, and did not wear noticeably or change shape, like the aluminum oxide stones. I do have some fine, inexpensive, diamond dust stones for my Dremel tool, but they are not something that I would use for this application.

If they work for you - that's great.

Philbert

 

[GerrySM]

I'll let you know how the diamond burrs go. They sure seem popular on eBay (>1500 sales!).

I just can't see why those "ABN" stones are so expensive, and why the vendor still only sells them on eBay and not his website, and why the manufacturer seems a little confused about whether he is using ABN (unlikely) or CBN.

 

[CR888]

Filing is about practice, technique and understanding. Just buy some gear and get going and find out what works best for you. What many love and achieve good results with others can't stand. There is a lot of marketing and big claims with many of these products.

 

[SawTroll]

The cutters on 90 are clearly taller than the cutters on 91. It's probably more aggressive filed with the smaller file, but 4.5mm files are like hen's teeth and I never tried one.

Ordering 4.5mm files usually isn't a problem, but don't expect any random dealer to have them in stock - and they usually aren't available in as large packs as some other sizes.

The only other chains I know of that they are recommended are Oregon 30-series chain and Stihl Topic chain in .325 (low profile cutters on standard size chassis). Most of those models have been discontinued for some time, only the rather hopeless 30-series SL safety chain remains.

 

[SawTroll]

Well, I've been using that for several years, and I also thought that a file was the way to go. But when I got the saw back from a service at the dealer it was so much sharper than I am getting it that I started wondering if there wasn't a quicker, better way. So I've bought a set of 4mm diamond stones, and I want to use them with a Dremel or drill to see if it is faster and sharper.

View attachment 519988

If you can't sharpen a chain better than a saw shop with a grinder, something is wrong with the way you file.

Nothing else can get a chain as sharp as a file, provided it is done (fairly close to) right.

 

[GerrySM]

Nothing else can get a chain as sharp as a file

Nonsense

 

[SawTroll]

Nonsense

You are of course entitled to have your own opinion, just don't expect many knowledgeable persons to share it.

There are a lot of gimmicks that can offer some help to those that know nothing about chain sharpening, but not much that helps those that know more....

 

[Chris-PA]

Most of those models have been discontinued for some time, only the rather hopeless 30-series SL safety chain remains.

I didn't even think that was still available. I have a couple of loops of 33SL that I removed all the safety fins from, and I sharpen it with 4mm files (the cutters are getting pretty short). It goes pretty well actually, but I prefer chains that have a narrower kerf.

 

[SawTroll]

I didn't even think that was still available. I have a couple of loops of 33SL that I removed all the safety fins from, and I sharpen it with 4mm files (the cutters are getting pretty short). It goes pretty well actually, but I prefer chains that have a narrower kerf.

I'm not sure if Oregon still is marketing the 33/34/35SL themselves, but at least it has been used as OEM chain by some saw brands until recently.

 

[GerrySM]

You are of course entitled to have your own opinion, just don't expect many knowledgeable persons to share it.

There are a lot of gimmicks that can offer some help to those that know nothing about chain sharpening, but not much that helps those that know more....

I used to spend hours hand-sharpening knives in my large knife collection to a razor's edge, now I use electric tools and get it done in a fraction of the time. I intend applying the same logic to my chainsaws.

By assuming I know nothing about file sharpening, you are living up to your name. I've been sharpening chains with files for many years, with passable results, but the size of the woodchips coming off the dealer-sharpened chain impressed me enough to consider automating, speeding and improving the task.

 

[SawTroll]

I used to spend hours hand-sharpening knives in my large knife collection to a razor's edge, now I use electric tools and get it done in a fraction of the time. I intend applying the same logic to my chainsaws.

By assuming I know nothing about file sharpening, you are living up to your name. I've been sharpening chains with files for many years, with passable results, but the size of the woodchips coming off the dealer-sharpened chain impressed me enough to consider automating, speeding and improving the task.

Even if you have hand sharpened "for many years", your story tells me that you never learned to do it right. When that is the case, other sharpening methods will of course look better/more attractive to you than they really are.

 

[SawTroll]

Removing major damage from the cutters is something at least grinders are effective for in the right hands - but to get the teeth really sharp they need to be hand filed afterwards.

I don't know how well the tool in question is for removing damage. If it is (effective), again hand filing will be needed afterwards, to get the teeth really sharp.

New chain isn't what I call really sharp (even Oregon and Stihl, that usually is best in that regard). A few strokes with a file really is needed (and the rakers need to be checked/corrected).

In other words, machines can be helpful in chain maintenance, so I'm not dismissing (all of) them as useless - but the final touch better be done with a file. You miss something important if you don't learn to use a file properly.

 

[GerrySM]

Removing major damage from the cutters is something at least grinders are effective for in the right hands - but to get the teeth really sharp they need to be hand filed afterwards.

Nonsense. Unless chain chisels/cutters are very different to knives, there is no reason why a mechanised process cannot get the teeth every bit as sharp, and faster.

... again hand filing will be needed afterwards, to get the teeth really sharp.

Again, codswallop. There is no scientific evidence for that at all.

In other words, machines can be helpful in chain maintenance, so I'm not dismissing (all of) them as useless - but the final touch better be done with a file. You miss something important if you don't learn to use a file properly.

You seem to be a believer in, and promoter of, old wives tales. The one about "files are best" is prevalent in chainsaw forums I note, and especially here.

If you

1. work in good, strong light (and for old guys like me, use an illuminated magnifying headset)
2. avoid bluing the metal by using a quick, sensitive touch
3. hold the cutter still with a finger on the back edge (both immobilizes the cutter and alerts you to overheating)
4. watch the top of the cutter as you sharpen — the "roll back" on the top of the chain cutter goes away when sharpening
5. let the stone turn into the top of the cutter, not the bottom
6. move the stone backwards and forwards as you work to avoid creating a "waist" on the stone (changing the diameter of the stone at one point)

...then you will get razor sharp cutters FASTER and EASIER than you can by working with a file.

Miss any of the above points, and you could end up with blunt or de-tempered cutters, and you'll be a candidate for believing old wives tales.

Note: loss of temper means loss of sharpness. Even the sharpest looking cutter, if detempered, will become blunt so fast that it will seem as if it was never sharp. I suspect this is why hand filing is so popular — it's virtually impossible to remove the temper that way.

 

[Chris-PA]

Must be why people who shave with straight razors sharpen them with machines rather than by hand......... Oh wait......

 

[GerrySM]

Must be why people who shave with straight razors sharpen them with machines rather than by hand......... Oh wait......

A machine to sharpen a long, fragile blade like a straight razor (of which I have plenty) would be impractical for everyday use. But they are sharpened by machine at manufacture, where speed counts!

I use an $80 Spyderco ceramic whetstone (and strop) for my straight razors. Slow but effective.

 

[AVB]

I know this is probably off topic but how do electric sharpers work as far indexing (advancing) the cutters to next one? Is automatic or manually done?

Kinda thinking of buying one but hand sharping is the way I have done it for 30 years and have straighten a lot screwed machine sharpen chains. Most times it appears appears to be operators not paying attention to the setup.

I also have found the not all files are good files. Brought a file guide with a file that would even file the cutters the other day. Changed the file and everything worked fine other than takinglonger to get those 60 degree cutters back to 30 degrees. Operator must have never done any rip cuts at all as he said it cut fine.

 

[reedo]

I recently picked up the Timberline sharpener. After seeing the difference between a Timberline sharpened chain, hand filed, and new chain I am a true believer in their product. In my experience hand filing has been a better method when compared to mechanical.

 

[SawTroll]

Nonsense. .....

You betters stop using that word if you are serious about staying on the AS.

You are of course entitled to have your own opinion, but the way you are presenting it leaves a lot to be desired. As your posts looks so far, they raise the questions if you are selling the tools in question, or if you just are a Troll, that wants to stir things up....

That aside, it should be obvious that shaving metal away along the edge (what you do with a file) leaves a sharper edge than ripping metall away with an abrasive rotating tool across the edge. Also, I suspect said rotating tool/bit will wobble slightly, as long as it isn't supported at both ends.