Thread: Cheap chainsaw grinder sharpener

I bought one of those cheap *rse grinders off of E-bay. They do work and providing that you take the time to set them up properly and use only the lightest touch they will give you repeatable results but at the expense of taking off A LOT of material. I bought it because although I am capable of learning how to sharpen by hand it will be a skill I'll exercise once a year maybe.

However, after sharpening my chain to its safe wear limit way too quickly I got rid of it and bought a set of those little diamond sharpeners (by Eze-Lap I think) that fit into my Dremmel. This gives me a happy compromise between the hand skills required to get the right angles and dangles and the use of a power tool to do the work which doesn't compromise the effort involved in setting everything up. And chains last longer!

If I was a pro chainsaw user I'd learn how to do them by hand so they can be touched up in the field and have them professionally sharpened regularly.

I agree that grinders can take too much off and then chains don't last as long. It is possible to learn how to adjust the grinder to take a bare whisker off every time but it takes time to learn that skill especially if you only occasionally use the grinder. The problem is reduced if you only have one chain and you can incrementally adjust the grinder every time to suit that chain. However this is not so easy when the grinder has to be constantly adjusted to suit different chains. If you have two old chains practice alternately grinding each chain until the minimal amount is removed and this will give you the practice you need in setting up the grinder for any chain.

My experience is that the majority of sharpening problems are not the cutters but failure to set the rakers correctly.
Most raker gauges are designed to set the raker a constant amount (25"') below the cutter which is fine when a chain is new but completely wrong once more than about a quarter of the cutter is filed away. The more the raker is filed the even lower the raker needs to be.

A simple rule of thumb is that the raker depth should be 1/10th of the gullet width. So when a cutter is new the gullet is typically 0.25" so the raker should be 0.025"
But when the gullet is 0.5" the raker depth should be 0.05"

My experience with occasional chainsaw users buying grinders is that they are somewhat disappointed when the grinder doesn't fix their cutting problem. When I tell them to show me their rakers they are all over the place and always way too high for the state of the cutters.

Perhaps if you thought of them as depth gauges rather than rakers then this might help when keeping the cutters above the depth gauges. I have seen beautifully sharpened teeth virtually not touching the wood because the rakers are too high. however as a depth gauge they indicate how much wood the tooth must cut.Worth a tryBrosh

I gave away my cheapie and got a half decent one (usually ~$180), but even with that I line it up with the teeth to just miss, then bump it and the minor flex just touches it and sharpens perfectly. The only time I took it to my local chainsaw joint they took off 3mm

Cheers guys! I only have one chain at this stage, planning on buying another at some point, just in case I bust one out in the bush.......

i am am thinking a 909 might be the go, I have a hedge trimmer in the same brand and it works a treat, reminds me of the old GMC stuff! Works perfectly twice a year, every year!

Thanks for the info on the rakers, how often should I check them? I am cutting Jarrah only, a few ute loads over winter.

I think it would be worth my while getting the grinder, and only using it a couple of times a year?

Most of the cheap chain saw grinders are little more than ruubbish the frames bend and the tolerences are not able to be adjusted to a aceptable level therefore they will just eat the chain away, if you want something decent then you need one of these
http://www.oregonproducts.com/pro/pr...er_520-120.htm you won't get much change out of $600

Originally Posted by dai sensei

I gave away my cheapie and got a half decent one (usually ~$180), but even with that I line it up with the teeth to just miss, then bump it and the minor flex just touches it and sharpens perfectly. The only time I took it to my local chainsaw joint they took off 3mm

+1 for what Neil said, I find enough flex in the unit to just touch the side of the wheel lighlty on the tooth and use an upward motion, removes very little material, I dont use it every sharpen just when I feel the angles are getting a little off or I need to set a new angle for milling etc.

Just use a file...jump in and do it. Let's be honest, even if you are a bit off, its not going to make a difference when cutting firewood. We're not talking about how precise everything needs to be for slabbing, just firewood.
Like Bob said, rakers are the main demon I tend to knock 3 or 4 file passes off them from factory chain, then tend to give them 2-3 passes every 3rd file. Having said this I've got the ponies to rip through just about anything - 395xp running 24" bar with 3/8 chain that has 1/3 of the teeth ground out, so effectively the 395 is only pushing 16" bar all the time.

Originally Posted by Spelunx

Thanks for the info on the rakers, how often should I check them? I am cutting Jarrah only, a few ute loads over winter.

It depends how "optimised" a level you want to operate at.

This is how I operate
The reason I don't use a grinder is because I touch up my teeth after every tankful of mix. Just 2 swipes of a file in a file guide usually does it - the key is to "remove any cutter edge glint".
The rakers get a couple of swipes every 3-4 tanks of mix. If not enough chips and too much dust is being made the rakers might get a couple more swipes

Every 2 days of use I rotate the bar and dress the bar if required.
At this point I swap chains, touch up the cutters and check some of the raker angles with an Digital Angle Finder.
If my field protocol has been working I don't usually have to touch the rakers, usually I do - 3-4 swipes is usually all I need.
I never worry about cutter length because the constant raker angle takes care of that.

This means my cutters are never really blunt and the raker settings are always close to optimum.
This minimises the load on my power heads which will hopefully prolong their lives.

Some operators like to run their chains until they are blunt and then swap chains - this means they need a supply of spare chains. I can touch up the cutters on a 42" bar faster than I can swap the chain out. Swapping chains out would mean I would need ~10 chains a day which would be a PITA to manage.
Running a chain until it is really blunt increases the load and temperature on the power head. I have a temperature gauge on one of my power heads and can see the temperature increase as the chain gets blunter.
Running a chain to bluntness means more metal needs to be removed to remove the glint on cutter edges.

For dry hard firewood cutting I would do the same as above.

I think it would be worth my while getting the grinder, and only using it a couple of times a year?

I wouldn't bother for a couple of times a year. Get your rakers sorted and see how the chain cuts then decide whether you need a grinder or not.

Cheers guys!

I have run three tanks of juice through, and sharpened it in the bush a couple of times, and back home in the vice twice. The first time I took it out I fudged up by cutting through a log, and not realising I had hit gravel on the other side! That blunted the chain real quick..... I am finding I get a reasonable edge at home, with some practice it seems to cut very well for the first tank of juice in the bush. I cant seem to get a good edge on it after that though. I guess it is just practice.... I am also looking into one of those stump vices, see if I can get a better edge without the saw moving around all over the place. I just propped it on the back of the ute, but even after a cuppa, the saw was too hot to get a decent grip on it!

Anyway, I have gone away from the idea of purchasing a cheap grinder, for now, I will see how my hand filing goes, and take it from there.

Cheers

Originally Posted by Spelunx

Cheers guys!

I have run three tanks of juice through, and sharpened it in the bush a couple of times, and back home in the vice twice. The first time I took it out I fudged up by cutting through a log, and not realising I had hit gravel on the other side! That blunted the chain real quick..... I am finding I get a reasonable edge at home, with some practice it seems to cut very well for the first tank of juice in the bush. I cant seem to get a good edge on it after that though. I guess it is just practice.... I am also looking into one of those stump vices, see if I can get a better edge without the saw moving around all over the place. I just propped it on the back of the ute, but even after a cuppa, the saw was too hot to get a decent grip on it!

Did you do anything about checking the rakers?

You definitely need to make the saw stable.
A useful field vice is a stump, then do this https://www.youtube.com/watch?v=CoNDVKdQX_A
The guy's chain in the vide is blunt but the vice is nice - also you can use a clamp instead of a wedge.

If you want a chain diagnosis post a flat side on photo of a couple of cutters.
Like this.
The angle shown by the red lines should be 6º or greater but not too great or the chance of kickback is increased.

FYI 909 is the new brand of GMC (Global Power Brands) who also own Triton.

Cheers BobL!

No, I haven't checked the Rakers, as the chain is brand new, I was going to leave it for a few more tanks.

The Stihl filing kit came with a raker guide and file, which looks easy enough to use.

That stump vice video is a doozy! Talk about creative. I think there might be a way of using the hard plastic case the Stihl dealership chucked in, to keep the saw steady when I am filing.... need to get out bush again and experiment!

Regards

Originally Posted by Spelunx

Cheers BobL!
No, I haven't checked the Rakers, as the chain is brand new, I was going to leave it for a few more tanks.

If the cutters have been sharpened 4 times it's time to swipe the rakers.

I even swipe the rakers on new chains before I use them.
The gullet on new 3/8 chains is 0.25" and the raker setting is 0.025"
This translates to a raker angle of 5.7º whereas I like to use 6.5º
This small difference in angle really turns a new chain from "nice" to "Oh Yeah".
In softwood 7.5º is possible, and 8.5º is possible with a big saw on softwood and this is "Holy crap" territory.
Now nothing is for free and there will be increased vibe and greater need for bar maintenance but it sure makes sawing a lot more fun.

The Stihl filing kit came with a raker guide and file, which looks easy enough to use.

That raker guide is a constant depth guide which will produce an ever decreasing angle until the chain will be producing more dust than chips.

That stump vice video is a doozy! Talk about creative. I think there might be a way of using the hard plastic case the Stihl dealership chucked in, to keep the saw steady when I am filing.... need to get out bush again and experiment!

The other clever vice is the one mounted to a sort of Z shaped piece of SHS and plugs into the Square section tow bar socket.