HF chain grinder

[KE4AVB]

Just what I thought, another mostly useless machine.

I finally thought I try one since a lot customers were bragging about these chop saws. Carefully sharpen a 3/8 std chain on an Echo 60cc saw. Took it out for a test run. Boy what crappy sawdust produced by it. Then I went and hand sharpen the chain. It was like the difference between night and day. Glad it was $21 with the discount as it will spend of the time in the back corner of the shop unused except those chains that were harden by someone using one these grinders in the first place; unless, I throw it away. If this the results that most of the other grinder produce then it is a waste of my time and money to buy one of the more expensive units.

Just my opinion but I can do a lot better job hand sharping.

[bgsengine]

If it allowed you to set the angles correctly and grinding to the correct profile, most any grinder can do an excellent job, but if you cant adjust for top plate angle, correct depth (for cutter profile) and a correctly shaped grinding wheel (using dressing brick to get the correct shape for the chain being sharpened) then they'll almost always give a crappy result. Most of the time, grinding wheel is re-dressed every 3-5 chains - use the smaller 1/8 wheel for low profile chains , the 3/16 wheel for larger chains (1/8 wheel used where you may use up to a 4.5mm file and 3/16 wheel for where a larger file would be used)

Although a 3/16 wheel can be dressed down to a slightly off-center profile instead of changing out to a 1/8 wheel... but then you'd have to re-dress again for bigger chains (goes through a grinding wheel fast) - Best grinding wheel are the "ruby" (red color) ones which run cooler (we also use the ruby wheel on blade grinder for mower blades)

[KE4AVB]

The angle setup is the cutter angle which for the chain I sharping was 25 degrees. It appeared to sharpen correctly but it just would not produce the results that I am use to with my hand filing. But it was better than the rocked chain that would not cut hot butter. To me it was the hook that was cut right more flat than I get with my round files. Maybe it me. At least I didn't overheat and harden the chain to where I couldn't sharpen it otherwise.

I really would hate to buy a $300 Jolly grinder and get these results which is something I was considering before this; now I don't know.

[bgsengine]

It takes some practice and an "eye" for the important angles - a grinder is not gonna give the same "hook" as a file will - I first learned chain sharpening on a grinder when I worked for another shop, and they never were well known for good quality sharpening - wasnt until I worked with my brother in Logging and learned to file by hand and then studied the oregon book (they still have that page in their big forestry catalog) and learned how to draw an imaginary line from the top plate to the bottom (with a file you get a "hook") and note how the top and bottom of the "hook" are a right angle to the chain links (straight up and down) and from that line measure your angle of the cutter "edge" - Same principle with a grinder but the profile it leaves behind will be different.. a well dressed grinding wheel may leave a more "flat" hook but the actual cutting edge should get that nice angle to it.. As I would tell anyone getting a new grinder , save up some scrap saw chains to practice on and learn how to tell just by eyeballing the finished grind when the cutter is sharpened right - have to study the chain from the top and from the side both but once you can "see" the cutter is done, it gets much faster and easier - one of the more common reasons the chains get hardened is trying to grind too fast and not having a clean chain (caked on wood and bar oil insulates things and holds in heat) - some real bad chains may take 2-3-4 passes to get them sharpened .. but once you can visualize how far you have to grind (or file) to get a sharp edge on the chain it's easy enough to show the customer while they are right there and sell them a new chain if their old one is gonna be like 10% left "It'll only take one more sharpening and then it's junk - time to think about a new chain"

[KE4AVB]

Then it is just me then as it did fairly nice job considering it took me 5 passes to remove the rocked leading leading off. I did all cutter each and then readjusted for the next passes. It look very off to me because that flattening of the hook. I did have the blade making just to bottom of the gullet so at I was cutting those tie straps.

I learned to hand file long ago (over 40 years ago) well before I ever of the chain grinders. I probably will always prefer hand sharping over the grinder as flat hooks won't seem to self feed as well. That is the problem with the carbide chain I got, no hook just a flat angle grind.

[KE4AVB]

I do have question though. Why is the grinder disc size different from the normal files that do the same job? I would thought it would have been 5/32, 3/16, and 7/32 grinding discs. I probably know why and it has to do the entry angle ie lack part of hook on the top plate.

Edit: Darn it I think just answered my own question.

[bgsengine]

I do have question though. Why is the grinder disc size different from the normal files that do the same job? I would thought it would have been 5/32, 3/16, and 7/32 grinding discs. I probably know why and it has to do the entry angle ie lack part of hook on the top plate.

Edit: Darn it I think just answered my own question.

Yup. that is pretty much it - Some of the better grinders have an adjustable entry angle but the curring edge angle is pretty much done with the side of the wheel , while the rounded "nose" of the dressed wheel creates the gullet and avoids hitting the tie straps.. it just wont have the same finished profile as a filed chain..

Wait til you get someone in with the relatively rare square ground chain (for hand filing there's a 6-sided triangle file used) - I used to sell (and sharpen) a lot of that and sold lots of the files.. but when the logging business started to die out in this area, so did all that specialized work.. No idea really how one might go about shaping the grinding wheel to make a good grind on those though.

[KE4AVB]

Wait til you get someone in with the relatively rare square ground chain (for hand filing there's a 6-sided triangle file used) -

I know I may have forgotten a lot but anyways don't a triangle have only three sides? Might need to explain this to me as if i remember correctly hexagon is the 6 side item.

Hmmm, maybe it is a double triangle setup like the double square sockets I got.

[bgsengine]

Wait til you get someone in with the relatively rare square ground chain (for hand filing there's a 6-sided triangle file used) -

I know I may have forgotten a lot but anyways don't a triangle have only three sides? Might need to explain this to me as if i remember correctly hexagon is the 6 side item.

Hmmm, maybe it is a double triangle setup like the double square sockets I got.

Imagine a triangle file (the kind that you might use to sharpen a crosscut handsaw as used in carpentry) but with the sharp corners (3 points) ground flatter - or put another way , its a sort of hex file but 3 sides are about 3/32 " wide while the other 3 sides would be around maybe 5/32" -3/16" wide - if you can get the picture from that you'd be pretty close to the file I'm referring to.

The saw chains were actually square ground - the top cutting angle was quite a bit sharper - chains like that would be very easy to dull quickly if they hit anything BUT wood , but cut through wood like a hot knife through butter (and I cut myself many times just lightly bumping the chain tooth, where any other chain, wouldn't have scratched me) I am not at all sure if they even make the chain (or the files) any more, but maybe a search on someplace like Bailey's might get you results.. I still have one of those files in my toolbox , but haven't used it in something like 20 years or so I dont think.. it has been a *very* long time since I saw any of those chains..

Ah Ha - yes here we go - Pferd tri corner files http://www.baileysonline.com/Chainsaw-C ... s-Each.axd Damn! 13 bucks EACH .. I should have kept those 2 boxes I had leftover instead of just giving them away.. 2 dozen of those files.. makes a pretty penny at that price

[KE4AVB]

Now I similar files in my mini files that I use for various projects. I going to need some ones those as I have lost a few and dull a few.

I use the Pferd brand files here and they hold well unlike those Oregon files I was using before. Even those that I thought I ruined on the Mac 610 chain still file good as used one yesterday. Like all files they will dull from use but I usually get about 10 heavy filing of 18-20 chain loops.

As for cutting myself I make that mistake every once a while here on chains while sharping, just bumping is enough to do it. Even some the new Timber Ridge chains I sell will cut you handling them if you get careless.

Haven't tried the square filing. As for it dulling quickly other then wood I some trees here that dull chains quickly enough now. Some bark like rock laiden yet the wood itself fairly soft. I might it just to learn how in case I ever run across one. Lots loggers in the area as two or three sawmills rather close by. I have been seeing some semi and full skip setups plus a hand full of rip chains.

Instead of the Pferd 17081 you could use the 17082 which flat file version which is little easier to use for beginners and double as a raker/depth gauge file. From profile image of the flat file version it wouldn't be hard to reshape the grinding discs to match by forming a matching v-tip. You would need one the flat files to work from to get the shape right.

Now viewing this image be careful of the optical illusion. The sides are evenly v-shaped.