Stihl USG chain grinder angles... Question for those running one

[max88]

Hi Guys & Gals!

I have a question regarding the Stihl USG chain grinder. As far as I know, the markings for the side plate angle (referred to in the manual as the A-scale) show the zero degree setting at the top, i.e. the 12 o'clock position, or when the wheel is vertical. This setup is different from the Jolly/Tecomec/Oregon grinders, which have the 90 degree setting at the 12 o'clock position. Am I thus correct in assuming that in order to get a side plate angle of 60 degrees on the USG, that it has to be set at 30 degrees?
On the Oregon, it's as simple as setting the scale to 60 degrees.

The reason for my question is that I have a friend who has the USG, and has recently added a CBN wheel to his grinder collection. He called me to say that his CBN wheel is contacting his depth gauges on the way down, so I suggested to him that he set the A-scale to 30 degrees (90-30=60). He is hesitant to set it at 30 degrees, because the manual stipulates a 40 degree setting. This just does not seem right to me. Could someone clear this up for me please? Surely the 40 degrees in the manual results in a 50 degree side plate angle. This is waaaay too acute... especially considering Stihl calls for a 60 deg angle on the RS chain, and even steeper 75 to 80 deg on the RM and Duro chains...

Regards,

Mike

Hi Mike
Any news on this issue ?
I just ordered some CBM wheels from Baltic Abrasive and a Stihl USG. I can see from you tube videos that there is very little clearance with the raker. Perhaps thats why the original wheels from Stiehl are flat on the side facing the raker. To me it looks like the angle is not correct. But a German engineer making a math error is not very likely. I hope i will be able to get a god result doing like you proposed with setting the A angle to 30 degrees.
Regards from Denmark
Max

 

[max88]

Just saw in another post where a guy had measured the angle, that 30 on the A Scale is equal to 60 degrees on the wheel. Like its measured on the Oregon grinder. So the Stihl chart which states the A angle should almost always be set at 40 degrees much have been made by a German after some beers.
That also explains that some guys would get a very over aggressive tooth and that the CBN wheel can't get past the raker.
Im not that worried anymore. i will set the A angle to 30 for a Full chisel chain like the RS Stihl and not do what the still chart tells me to.

 

[Mike Kunte]

Just saw in another post where a guy had measured the angle, that 30 on the A Scale is equal to 60 degrees on the wheel. Like its measured on the Oregon grinder. So the Stihl chart which states the A angle should almost always be set at 40 degrees much have been made by a German after some beers.
That also explains that some guys would get a very over aggressive tooth and that the CBN wheel can't get past the raker.
Im not that worried anymore. i will set the A angle to 30 for a Full chisel chain like the RS Stihl and not do what the still chart tells me to.

Max!

Thank you so much for this info! This is exactly what I was trying to establish! I was certain that there was an error somewhere, and that the 40 degree angle was incorrect! I'll be sure to pass this message on to my friend, who can now grind with confidence! The Germans definitely had too much beer that day!

Regards,

Mike

 

[Dennisthemenace]

sJust saw in another post where a guy had measured the angle, that 30 on the A Scale is equal to 60 degrees on the wheel. Like its measured on the Oregon grinder. So the Stihl chart which states the A angle should almost always be set at 40 degrees much have been made by a German after some beers.
That also explains that some guys would get a very over aggressive tooth and that the CBN wheel can't get past the raker.
Im not that worried anymore. i will set the A angle to 30 for a Full chisel chain like the RS Stihl and not do what the still chart tells me to.

Exactly what I did, after a lot of head scratching

 

[Ed Mullen]

I have found that 55 degrees head tilt on my Oregon grinder occasionally ticks the depth gauge on Stihl chains.

When they say 40 degrees in the chart, it must be the complementary angle, meaning 50 degrees on the Oregon grinder. I'll have to try that - it might just be enough additional head tilt to sneak past the depth gauge.

That chart also specifies 15 degrees up/down tilt, and I'm not aware of any other grinder (other than theirs) which goes past 10 degrees. Also, this contradicts their manual sharpening guidance which recommends flat.

The 30 degree sharpening angle is about the only consistent guidance I've seen for Stihl chains.

 

[isaaccarlson]

I used 30/60/10 for years. The chains cut ok, but not as well as filed. I was grinding chains tonight and decided to try 30/50/10 to replicate the hook angle of new chain. It looks to be very close, but not quite as extreme as new hook, and the wheel did barely touch the raker on new chain. I am using the 3/16 wheel on .325 chain.

I have seen different numbers from stihl over the years, but they have changed cutter profiles also.

 

[Braintree]

We're both running Baltic Abrasives CBN wheels. They cut cleanly, quickly, and they keep their cool!
Mike

Mike would you have a order number for the Baltic CBN wheel 3/8 & .325?Thanks in advance. Paul

 

[Mike Kunte]

@paul,

I'll take a look in the garage. Which grinder are you using?

 

[Braintree]

@paul,

I'll take a look in the garage. Which grinder are you using?

USG…I have two of them.I wise I had the square grind attachment.Ya take a look at what you have thank you

 

[Mike Kunte]

USG…I have two of them.I wise I had the square grind attachment.Ya take a look at what you have thank you

Here is the link to the item:

https://lapidarywheels.com/cbn-wheels-for-steel-chains/150-pitch-38-404-5-34x78-cbn.html


Here is the description:

Our Super Abrasive CBN chainsaw chain sharpening wheels achieve superior ground surface finish. They are suitable for professional and private use. They are preshaped for perfect fit, have aluminum core, last very long.

Will work with most chainsaw sharpening machines like: Oregon 511/510, Stihl, Timbertuff/Upright, Maxx/Pro-750, Efco, Tecomec,Northern/Wall or Bench Mount, Jolly, and others.

Outside diameter: 5 3/4" or 146,05 mm

Bore diameter: 7/8" or 22,23 mm

Free bushing included to reduce bore size from 7/8" to 12 mm

For chainsaws with pitch: 3/8, .404

Please make sure this wheel fits your machine before buying.

NOTE: For steel chains only, NOT for carbide tipped chains

 

[Braintree]

Here is the link to the item:

https://lapidarywheels.com/cbn-wheels-for-steel-chains/150-pitch-38-404-5-34x78-cbn.html


Here is the description:

Our Super Abrasive CBN chainsaw chain sharpening wheels achieve superior ground surface finish. They are suitable for professional and private use. They are preshaped for perfect fit, have aluminum core, last very long.

Will work with most chainsaw sharpening machines like: Oregon 511/510, Stihl, Timbertuff/Upright, Maxx/Pro-750, Efco, Tecomec,Northern/Wall or Bench Mount, Jolly, and others.

Outside diameter: 5 3/4" or 146,05 mm

Bore diameter: 7/8" or 22,23 mm

Free bushing included to reduce bore size from 7/8" to 12 mm

For chainsaws with pitch: 3/8, .404

Please make sure this wheel fits your machine before buying.

NOTE: For steel chains only, NOT for carbide tipped chains

Mike,thank you for the information.I order the .325 see how it goes with.Item # LPFIQKRAR

 

[Mike Kunte]

Mike,thank you for the information.I order the .325 see how it goes with.Item # LPFIQKRAR

Hey, Braintree! Did you ever test out the Baltic Abrasives wheel? Would really like to hear your take on it!

Mike

 

[Braintree]

Hey, Braintree! Did you ever test out the Baltic Abrasives wheel? Would really like to hear your take on it!

Mike

No Mike I have other iron in the fire at the moment.When things slow down a bit. I will report back. Thank you for asking though. Paul

 

[larasea]

I have wrestled with these angles with my Oregon grinder for the past two years. I have ground chains at different angles and have settled on the following for Stihl chains: RS 55/25/10, RM 50/30/0. I'm to the point where I hand file unless I rock a chain and then I grind it.

Stihl in a recent email recommended the following for Stihl USG: "The A angle on the USG is set to +40 degrees, the B angle on the USG is set to -15/+15 degrees, and the C angle is set to -30/+30".

Further, the last column on the Stihl chart points to an angle of 60 or 75 depending on the chain. According to Stihl, this is the end product angle of the tooth after grinding. This information was received during a followup phone conversation. This is not the head tilt angle on your Oregon grinder according to Stihl technical services representative.