Sharpening Stihl full chisel vs semi chisel with grinder

[memory]

I have an Oregon 511a grinder that I just used to sharpen 2 Stihl chains. One is a full chisel 33rs 84, the second is a semi chisel 33rm 84, these are 25" chains. Both were sharpened with the same angles, 30-60-0 and same wheel, I use CBN wheels. Nothing was changed in between sharpening the first chain and second chain.
Is it just me or does the semi chisel not have enough hook to it compared to the full chisel? Why would that be the case? I have not got the chance to put either of them in wood yet. The pic on top is the full chisel.

 

[Duane(Pa)]

Semi tooth is shorter. It will need ground lower to get some hook. I highly doubt you will be satisfied with the way it cuts as pictured.

 

[Mike Kunte]

You may be surprised how little hook you really need. Having said that, it does look rather little. But first cut with it before worrying about "looks".
It's quite common (and even recommended) to switch to a smaller file size when nearing the end of a cutter's life. This will help encourage more hook. However, unless you have a CBN wheel with a thinner profile, you can't really replicate this with the grinder.

First check how it cuts before making changes. Let.us know the result.

My 2c

Mike

 

[Wood Doctor]

The problem I run into when the cutter gets this small is that the grind stone starts digging into the back stop that holds the cutter in position. So, I either hand file it or just pitch the chain. Small cutters tend to give me the creeps. They can break off too easily under load.

 

[HarleyT]

Small cutters tend to give me the creeps.

 

[HarleyT]

I have an Oregon 511a grinder that I just used to sharpen 2 Stihl chains. One is a full chisel 33rs 84, the second is a semi chisel 33rm 84, these are 25" chains. Both were sharpened with the same angles, 30-60-0 and same wheel, I use CBN wheels. Nothing was changed in between sharpening the first chain and second chain.
Is it just me or does the semi chisel not have enough hook to it compared to the full chisel? Why would that be the case? I have not got the chance to put either of them in wood yet. The pic on top is the full chisel.

View attachment 942986View attachment 942987

What size wheel are you using? You also might do the 10 degree tilt for the full chisel.

 

[chipper1]

Add a little hook, by filing them a bit more with a smaller file as that wheel is too large/wide for that semi-chisel, and leave the rakers a bit high at first.
Semi-chisel typically needs a bit more hook than factory to feed well in harder wood from my experience. But too much hook and the rakers to low will bog a saw, so take it easy on them.

 

[memory]

What size wheel are you using? You also might do the 10 degree tilt for the full chisel.

I am using a 3/16 diamond wheel

I will try this chain next time I am out cutting wood and see how it does.

Ty all for the help so far

 

[HarleyT]

Yeah, try the tilt feature on the chisel chain too.

 

[memory]

Yeah, try the tilt feature on the chisel chain too.

I have never used the tilt feature but may try that next time especially on the semi chisel

 

[HarleyT]

I have never used the tilt feature but may try that next time especially on the semi chisel

It is meant for the full chisel.

 

[dsell]

When you tilt the vise, watch the angles close from left to right. Mine is fine flat, but off tilted.

 

[Hinerman]

I have an Oregon 511a grinder that I just used to sharpen 2 Stihl chains. One is a full chisel 33rs 84, the second is a semi chisel 33rm 84, these are 25" chains. Both were sharpened with the same angles, 30-60-0 and same wheel, I use CBN wheels. Nothing was changed in between sharpening the first chain and second chain.
Is it just me or does the semi chisel not have enough hook to it compared to the full chisel? Why would that be the case? I have not got the chance to put either of them in wood yet. The pic on top is the full chisel.

View attachment 942986View attachment 942987

As the cutter gets shorter, change your angle from 60 to 55, maybe even 50, to get more hook. I think 60 does not create enough hook anyway, at any stage of the cutter. Everybody has their own preference though.

Your chain does not look like it would cut well, but last a long time. There are trade offs for changes in cutter geometry.