Kinds of grinders/mechanical differences

[Chainganger]

I know nothing about grinders. There seem to be some cheap and expensive ones that act like a chop saw, where the rotating wheel is dropped down unto the stationary cutter, like the cheap harbor freight model.

Others where the rotating wheel is stationary and the cutters are moved into the wheel.

Are there any designed like a sliding miter saw where the rotating wheel is slid into the stationary cutter instead of chopping down on it?

Is one design inherently "better" than another in your opinion? Does one lead to longer cutter life or lead to a lesser chance of over heating the cutter when grinding?

 

[dgeesaman]

Cheap grinders come with cheap wheels, have limited life mechanically, and don't tend to hold accurate angles. But they can work and sharpen many chains.

Better grinders may still have the cheap wheel but are generally faster and easier to use. They can handle a wide variety of sharpening angles.

Silvey grinders hold the wheel still and move the chain, and Silveys are top of the line, but that doesn't necessarily mean it's much better. Since proper grinding technique requires numerous quick touches of the wheel to the chain to keep the chain cool, what matters is if the system will keep the chain cool. It appears to me that both can do that.

Of course regardless of the grinder you can find wheels of various materials and sizes so don't let the wheel become a big factor in your selection, other than to make sure it's not an odd size.

There are two systems of describing the orientation of a grinding wheel to a cutter tooth. The Oregon system (Tecomec/and other brands too) uses 3 angles to set the grinder. The Stihl / USG system uses two angles and an offset distance. Do not confuse the systems. Fortunately they're both able to produce the same basic round grinds and it's fine to use an Oregon sharpening spec on a Stihl chain and vice-versa.

You'll also notice there is such as thing as "square" filing and grinding. No offense, but if you're not already round grinding and filing at a high level, square methods are not for you.

 

[Chainganger]

Thanks! no one has invented a sliding grinding wheel like a sliding compound miter saw? Conceptually I would think it might have some advantages compared to one that does not slide. Just thinking out loud.

Want nothing to do with square grinding for now. In fact, I had a nice square ground chain that I took in for sharpening and the shop (a well known established place) converted it to round when I thought they would square grind it, apparently they do not do that there.

 

[dgeesaman]

What you describe sounds a bit like the Timberline carbide sharpener system.

 

[Philbert]

Is one design inherently "better" than another in your opinion? Does one lead to longer cutter life or lead to a lesser chance of over heating the cutter when grinding?

Lots of ways to sharpen chains. The important thing to consider is what you want your cutters to look like when you are done, and how you are going to achieve that. Modern saw chain was designed to sharpen both the top plate cutting edge, and the side plate cutting edge at the same time, whether using a file or a grinder. It is possible to do a lot of different things using specialty files, guides, wheel grinders, rotary grinders, etc., if you want. Some race guys go nuts with their chains, spending hours for just a few seconds of cutting. Most guys just want their used chain to cut after sharpening similar to how their new chain cut out of the box.

There are even automated grinding machines that are within the reach of a guy with a decent job, and rumors that some of these will be coming down even further in price. They save labor, but are not necessarily 'better'.

If all you want to do is sharpen round ground chains for typical use, there are a number of options on the market, with quality and service life mostly linked to what you pay for.

- What's your budget?
- How much will you use it?
- Expect to find parts and service available for your grinder in a few years?
- Happy with 'standard' settings, or want a lot of freedom to customize angles?

The smaller motors and smaller diameter wheels grind slower - OK for light touch ups on a few chains, but not for fixing heavily damaged chains, or high volume. Grinding wheel quality is critical IMHO. I put higher quality wheels on some cheap grinders, just to experiment, and the difference was dramatic - like the difference between using a sharp and dull chain on just an average saw.

There is also skill required to sharpen chains, that takes a little while to develop. If you view your grinder like a 'chop saw', you will burn cutters even if you paid a lot for it. Sharpening quality and cutter life are more a function of the operator than the tool. That said, better quality tools, including better quality wheels, make the task easier.

Philbert

 

[Chainganger]

Thanks for the thoughtful responses.

I am thinking of getting the Oregon knock off from RUSSO off eBay and a couple of the black wheels from Baileys to start. That grinder has a metal base, looks like a better motor and may be more stable than the HF type grinders.

 

[Philbert]

I spent a bit of time looking into, and experimenting with, the black (resinoid) wheels. Basically, the abrasive grit is held together with a glue/binder ('resin') instead of being fired ('vitrified') like the more conventional wheels. The resinoid wheels are similar in construction to the metal or masonry cut-off wheels used in chop saws, and they give off the same type of smell. I like to do my grinding outside, if possible, to keep the dust and sparks out of my shop, which is used for other things. Using the resinoid wheels outside is not a problem, but note that the smell and extra dust generated could be an issue indoors.

Generally, these wheels appear less likely (but still possible) to 'burn' a cutter, and leave less of a burr on the outside. They are also less expensive than vitrified wheels at Bailey's.

Some additional comments, including impressions from others in this A.S. thread: http://www.arboristsite.com/community/threads/resinoid-grinder-wheels.256733/

Whatever you go with, take some time to develop the skill necessary to grind well. Take some scrap chain and play with it. See how different angle settings affect the cutter shapes. Intentionally overheat some cutters to see what it takes, and what it takes to not do that. Read through some of the other threads on how to use a grinder. Good luck!

Philbert

 

[KenJax Tree]

I know where there might an Oregon 410-120 for sale soon.

 

[Philbert]

I know where there might an Oregon 410-120 for sale soon.

You have to give it a fair shake first . . . . !

Philbert

 

[Brian Simonseth]

I know where there might an Oregon 410-120 for sale soon.

I'm going to look at a 520-120 tomorrow morning

 

[KenJax Tree]

You have to give it a fair shake first . . . . !

Philbert

One day I'll get back around to it but for now it's hand filed

 

[Brian Simonseth]

I'm going to look at a 520-120 tomorrow morning

Next weekend it's coming home with me

 

[KenJax Tree]

Next weekend it's coming home with me

Good luck