Making a depth gauge/raker grinding fixture

Single wing nut screw locks it down in a hurry for easy, quick adjustment for various sizes.



Tore it all down and painted the mild steel so it won't rust. reassembled and looks even better.



I can use this set up for 10 - 22 inches



This will do 16 - 32 inches.



This will do 20 - 48 inches.

 

Put the first chain on the 028 and was actually surprised that I noticed a difference. Much smoother than before. I did not resharpen the chain as that was all ready done on the initial test, just evened and rounded the rakers.



Some did not clean up so it can only get better if I use this all the time. I set this chain for .030 depth cut. Some fines in there but I'm pretty confident it will change when I get a complete, even grind.



So far so good as this chain was probably about 1/2 to 2/3's gone.

Heading out now to try a Picco chain which will be a different wheel dress.

 

Here is a not to scale drawing of what Stihl RS has for it's rakers. .210 Radius with an .030 cutting depth. I dress a ..020 flat into the wheel and shoot to have no more than .010 on the raker itself.



This is how Stihl .042 Picco is set up. Again, not to scale. There is a .015 straight wall on the far right before you hit the strap. .025 cutting depth. I'll attempt to duplicate this now. Not on the drawing but they use a .350 radius on these rakers



First thing I do is set my radius dresser to .350 above centerline. I use a chisel diamond and have set this dresser up after I got the machine. This system makes it easy to get what you want without having to use gauge blocks.



Diamond set so we are ready to proceed.



This will be easy as I want the total width of the radius to be .250. I just get a .250 wide wheel so no side dressing is needed. First I touch off on the front side.



Then I zero out the Y axis.(infeed)



Then I swing the dresser arm 180 degrees and touch off on the backside of the wheel.



Here is that number.



On this readout I hit Y then CL (centerline)

 

This automatically splits it in have to where if I now dial to zero, I'm in the very center of the wheel. Handy feature for numerous things.



Dialing into zero, I'm now in the center as you can see.



My centerline is off .031 if you do the math from Stihl's set up so I move off that amount to dress the wheel.



Swinging the dresser arm 180 degrees, I go down till it has dressed as much as it can. Then zero out the downfeed. You can see here it is off center now



Now i'll set the position of the wheel to the raker. I'll go the long way so you can see how the math works. First I dead wheel to the edge of the cutter.



This is the number there. Now I have a reference to work from.



Now if I add 094 to the previous number, that will put the centerline of the dress over the tip of the centerline of the cutter.



This is the number there. Now I have a reference to work from.



Here you can see that it looks like they are in line.

 

Now I minus .270 from that number and this should put me where I need to be. I know you don't have to do these steps but I'm just showing the reasoning as to how/why you do it.



With this done my infeed is set and looks correct. Now we are ready to grind. This process looks like it takes a lot of set up when in reality to very quick to do.



This chain is a little over a 1/3 gone and rakers need adjusted. I ink it up prior to grinding to show removal.



Reground to original spec.



I double check with a gauge and write my downfeed number down. I simply reindex, clamp dial up and back down to this number on every one.



Here's checking it with a gauge. they all repeated very well.



Someone asked about then weight. as it sits right here it is 23 pounds.



Put the chain on the saw and ready to try it out.



Using a 192 rear handle and happy to say the chain cut like a new one. No chatter and smooth cutting with very nice speed. Saw basically self feeds as it should.

 

Nice consistant heavy chips with very little fines.

Thanks for following along and hope you got something out of it other than I'm nuts! I now have something that will make this job enjoyable to do and all at the cost of missing a few football games. Okay in my book.

 

Can you retrofit a digital readout to my Oregon grinder?

 

I'll leave you to do that thread!

 

Now you need to figure out a fixture so you can convert your surface grinder into the sweetest square grinder ever.

 

This!

 

School me on square grinding. I've heard of it but don't know anything about it. What angles and such?

 

I'm to dumb to foller all dis fancy stuff. But it sho is mity purdy! Gussen I'll just keep using my Timberline sharpener and hitting dem rakers wit da file. Don't gotts no trouble putting a tree on hit's side purdy quick like.

 

Looking at your list you seem to like more than is needed too.

 

I'm not even remotely qualified to school anyone regarding square grinding.

Paging SquareFile Moparmyway mdavlee

 

Squared cutters can drop cut times by 20-30%.........sometimes more.

Latest PS work chain for the Ohio chain race

 

Is there a thread anywhere that explains it or is this a "ancient Chinese secret" grind?

Normally if I grind into a strap, like what it looks like in the second pic, they tend to break. Always open to learning new stuff.

 

Ancient Chineese secrets and all .........
Square filing chains | Firewood Hoarders Club

I wouldnt go that deep into the straps normally, but that chain is for the Ohio chain race.



You do some real nice work in that shop of yours !

 

The basic concept is simple. Chains have a vertical cutting edge (side plate) and horizontal cutting edge (top plate). When ground/filed with a round tool, the cutting edge angles vary all over. It's a compromise between simplicity and speed of sharpening against optimal cutting geometry. With "square" sharpening, you're holding a consistent cutting angle on each edge. For timbersport events there is no other competitive option. For pure cool factor its a winner of course.

Even if I developed the skill, I doubt I'd bother because I simply don't spend enough time with my chain in the wood for a 25% speed increase to matter. Yes, speed is nice but I have a grinder already and I can't remotely justify more investment in time and tooling. In fact I switched from full chisel chain back to semi-chisel just so that I'd have less dulling, and that loss in speed was a non-issue.

If full chisel chain isn't enough, and you want to convert wood from log to chips as fast as possible, you should look into square sharpeneing.

 

Thanks for the link. I looked through all the posts and got some info. With a surface grinder, if it is just straight walls we are dealing with it would not be that difficult to do all of them exactly the same. I could use my existing fixture by kicking it sideways with a sine bar and kicking it up on a magnetic sine plate. Slip dress the bottom of the wheel and it would be there. Dealing with to angles at once is the kicker as they effect each other. They make compound sine plate where you can set both angles at once but one has to be "adjusted". Meaning if you want a 30 on one plane and 40 on the other, you just can't put those build ups in as it won't be true. One will be less.


Compound sine plate pic attached


I did not see the "perfect" angles by anyone so it seems to be an open playing field on that. I may play around with it sometime but if anyone wants to share what their top cutting angle(looking down at the top of the cutter) and their Backcut angle is it would give me a place to start.

One question though, does square cut dull quicker in comparison to round cut?