Depth Gauges on a Grinder?

[Philbert]

One of Those Subtle Things . . .

. . .I keep in my left hand a tool to firmly bottom out the link while clamping the vise and also to steady the tooth while grinding. The tool is like an awl with a slightly curved point. This eliminates any chatter and keeps the tooth rock-solid when the wheel makes contact. . .

This is a very subtle, but important tip!. I tried it today when sharpening a chain - used my finger to press down the rear of each cutter before locking the vise, and it held rock solid. I realized that the chain positioning dog on my 511A slightly lifts up the rear of the cutter when it butts against it. Worth the cost of membership in A.S.!

The cutter chatters less, so I am sure that I get a smoother, more cosnsitent grind. It slightly changes the angle of the cutter and the resulting edge, but this is only by a degree or two, and not something that is likely to make a difference.

Thanks.

I am going to re-post this, with credit, in one of the grinder sharpening threads.

Philbert

 

[Philbert]

Slow But Steady

OK, tonight I was able to do the depth gauges on a 114 DL loop of 3/8 STIHL chain without burning a single depth gauge!

Key Points:

- the chain was clean (as it was before);
- the wheel was freshly dressed (as it was before);
- the chain did not have the triple-humped-tie-straps * (I think that this was a key factor);
- the depth gauges only needed a little bit taken off * (I think that this was a key factor);
- I was very patient and took very light taps;
- I periodically adjusted the chain stop dog to move the depth gauges to different parts of the wheel.

I am still much faster with a flat file. But now that I know that I 'can' do it, it is something that I can play around with, and maybe increase my speed.

Thanks for all of the helpful input.

Philbert

 

[dsell]

Someone on this site taught me to cut the left rakers, turn the chain around and cut the right rakers so that the raker is always closest to the back of the grinder. This works excellent, more safe, and you don't have to adjust the depth from left to right rakers.

 

[Philbert]

Someone on this site taught me to cut the left rakers, turn the chain around and cut the right rakers so that the raker is always closest to the back of the grinder. This works excellent, more safe, and you don't have to adjust the depth from left to right rakers.

Galde mentioned something similar in an earlier post:

. . . After grinding the left gauges I reverse the chain to grind the right gauges. . . .

I'll have to play with this a bit more, as the chain positioning stop can be an issue when running some types of chain backwards in the vise. But there did appear to be some differences between Right and Left depth gauges, due to the amount of 'set', and where the wheel hits each side. Approximately 1/4" offset between R and L depth gauges on a loop of 3/8" chain I just measured.

Philbert

 

[dsell]

Galde mentioned something similar in an earlier post:



I'll have to play with this a bit more, as the chain positioning stop can be an issue when running some types of chain backwards in the vise. But there did appear to be some differences between Right and Left depth gauges, due to the amount of 'set', and where the wheel hits each side. Approximately 1/4" offset between R and L depth gauges on a loop of 3/8" chain I just measured.

Philbert

My Oregon 511 vise holds the raker better for grinding when it's closer to the back of the grinder. The other way is like trying to cut wood backwards with a circular saw. I use my chisel backstop for a marker when the chain is reversed. I think it ends up over the center of a rivet.

 

[lambs]

wheel for depth gauges

Philbert asked what wheel I am using.....it's a 1/4 " vitreous wheel from Oregon. I generally set it at about 80 degrees so it puts a little slope in the depth gauge, and after hitting them all, I pull the chain through the vise again rounding off the front edges with a flat file. I've learned this is easy and quick, particularly if you position the depth gauge you are filing right at the end of the vise where the link in front is already turning down from the vise.

I'm a little curious about the possibility of bluing a depth gauge. Seems to me it really doesn't matter since it isn't doing any cutting.

Am I missing something here guys? Thanks.

 

[Philbert]

I'm a little curious about the possibility of bluing a depth gauge. Seems to me it really doesn't matter since it isn't doing any cutting.

That's what I thought at first. Quickly learned that it hardens the depth gauge just like the cutter - a file won't touch it afterwards. Had trouble just rounding them over, and had to clean them up with my bench grinder.

So, it might not be that big a deal if you will always be adjusting them with your grinder, and if you don't round over the leading edges. But it's better if you don't.


Philbert

 

[MCW]

I know this is an older thread but I just saw one of Philbert's other posts linking to it
What people can also do for depth guage profiling is buy an 8mm round profiled wheel made to sharpen 3/4" harvester chain. With a dressing stone you can shape it however you like and tailor it to suit your wants/needs/thoughts etc etc (brace yourself for sh*tloads of dust). 8mm is about as wide as you can go on Tecomec style grinders before clearance becomes a problem and 8mm is wide enough to cover the whole raker in one pass - standard raker wheels pull up "just" short in width, particularly with .404" chain and some of the newer, wider, low kickback style rakers.
The 8mm wheel wasn't my idea but from another chainsaw business I visited and I have personally never done it as I went ABN/CBN.
The biggest problem I have seen however with standard wheels and especially wider wheels taking off a lot of metal is dust. Dust was the main reason I went to ABN/CBN style wheels. I was sick of blowing black snot out of my nose for days after a good grinding session. With the Dinasaw wheels basically the only particles coming off is metal and they do not seem to float around in the air unlike other particles that fly off of standard wheels - any small particles that will not break down and make it deep into the lungs are doing you damage (silica for example). Steel dust from cutters will rust away (the chrome won't however).
On another note I have never seen excessive heat cause a problem on rakers, unlike cutters. I quite often give my rakers a hiding with the grinder and even leaving them blued has had no detrimental effects on wear, even in our dirty hardwoods. This is certainly not something you want to do on cutters however

There are apparently a few manufacturers in the US that can make a cyclone type wheel from a steel blank with the edge coated in CBN. They'll make any size you want. I have one for my 3/8 pitch chain and my 511a pulls it just fine. You can always blue a cutter if you don't pay attention, but the cut outs in the wheel and the resulting breeze greatly reduce that risk.
It's not an especially cheap solution, but you get a wheel that also never needs to be dressed, will probably grind 1500 chains, and can be sent back and recoated when the finish finally wears down. If you routinely sharpen a lot of chain in the same pitch, it's a good option.

The ABN/CBN wheels are excellent.

I have a 7mm ABN/CBN Dinasaw wheel for my Speed Sharp Auto grinder for using on depth guages. It has a flat profile but in hindsight I should have listened to Greg Costin from Dinasaw in Australia who offered to make a concaved profile wheel to accurately match the rounded depth guage from a new factory chain.
Of course I knew better Not...
Out of interest the 3.5mm, 4.5mm, and 7mm Dinasaw wheel I have all cost the same and there was no extra cost in getting a custom profiled wheel.
Also with the recoating don't be fooled by the cost savings - recoating one of these wheels recently (my 4.5mm one) cost me around AUD$200 (remember that there is two way postage) when a new wheel was AUD$230. When my 7mm depth guage wheel needs recoating I'll simply buy a new one with a concaved profile

 

[dsell]

The dust messes with my nose and I don't know if its the iron or the wheel. I've been using a 3M dust mask when I grind and I don't have that problem. My Dad died of lung cancer and my father-in-law lost a lung due to cancer, so I try to be careful.

 

[Philbert]

Dust was the main reason I went to ABN/CBN style wheels. I was sick of blowing black snot out of my nose for days after a good grinding session. With the Dinasaw wheels basically the only particles coming off is metal and they do not seem to float around in the air unlike other particles

Here's a 'solution' for collecting the metal particles. Saw this at Ron Kunz's (TreeMonkey's Dad) shop at a GTG a while back:



This is an inexpensive welding magnet. Old speaker magnet should work too, although, I recommend keeping the guards on the grinder Suppose that you could also save the metal filings up for recycling?

Philbert

 

[madhatte]

I figured out a pretty good way to use the Silvey 510 for grinding rakers.

From the manual; "Depth is lowered .020" per revolution of depth adjustment knob". This is a useful baseline for generic raker depths -- find the depth to the working corner and turn the knob down to the desired depth. However, I still prefer progressive raker depth, so what I do instead is file a single raker using a Husky or FOP gauge AFTER first grinding the cutters on BOTH SIDES.

What I do next is to lower the wheel until it just contacts the filed raker, using the depth adjustment knob. This sets the depth I will grind the rakers to. When grinding rakers, you want to follow the logic opposite that of grinding the cutters; that is, you want to grind from inside out. This prevents the hardened chrome from trying to pull the cutter into the wheel and changing the depth. It's OK to push the bur to the outside on the raker -- it's not cutting anything so it won't affect operation. I find that modern "comfort" chains have wide enough rakers that I have to make two passes to cover the entire width of the raker. Be advised that you will have to set the cutter back far enough that the pawl will want to miss the rear corner, so you will occasionally have to set it by hand to keep the raker under the wheel rather than the cutter.

After two passes in each direction, there's often a small hump in the middle of the raker left when the wheel missed a spot. The chrome is usually already peeled back from that spot, so it's just a matter of one bump from a hand file to knock the hump down to the same height as the rest of the raker, and then another bump on the front to re-shape it to the original profile. This should not be at all difficult if you've taken care to not blue the steel. The Silvey turns much slower than Oregon (and Oregon-alike) grinders, and uses a larger wheel, so it's much easier to avoid bluing.

I have used this method, somewhat modified, on the Northern Tool grinder as well, but find that the ergonomics and precision of the grinder are sloppy enough that my results are satisfactory at best. The Silvey grinder does a much better job.

 

[Justsaws]

"Brace yourself for a ****load of dust."

MCW, that right there is funny. Well done, perhaps a bit of an under statement though.

Probably should be printed on the side of all grinding wheels and on the actual grinders as well.


Philbert, bend a sheet steel backing plate for behind the grinder and put the mag on that. Put a bottom or trough on it. Make it so you can remove it to clean up.

Start saving for life size mag n doodle boards, or chemistry projects.

 

[Philbert]

Philbert, bend a sheet steel backing plate for behind the grinder and put the mag on that.

Again, that was not my set-up. Belonged to TreeMonkey's Dad.

I do my grinding outside, if at all possible. I did put some aluminum tape on a few parts of the grinder where the grit tends to build up, just to make clean-up easier. If I did if full time, I would invest in a fireplace vacuum, or some other type of dust collector that works with grinders. Would probably also invest in those fancy wheels that MCW raves about.

Philbert

 

[Philbert]

I think that the low-kickback humps have been a key problem factor for me - not with filing, but with grinding. Filing has just been faster for me. Might try to order one of the Total Fireball resinoid wheels and see how that goes. Probably won't get to it until the weather warms up a bit.

Thanks again for everyones input!

Philbert

 

[Philbert]

Resinoid wheel.

Can only find the following resinoid wheels for my Oregon grinder:

Total Fireball TL66-R (3.2mm / 1/8") - 1/4, 3/8 low pro, .325 pitch

Total Fireball TL64-R (4.7mm / 3/16") - 3/8, .404 pitch

Can't find a 7.9mm / 5/16") for 3/4 pitch or rakers. Anybody know of one?

Philbert

 

[Philbert]

OK, Tecomec appears to offer a range of hardness grinding wheels for the Speed Sharp / Jolly Star / Oregon 511a type grinders. Looks like they have to be imported 20 at a time.

For some reason I am unable to load this link. But go to Tecomec (www dot Tecomec dot com) , select 'Products', 'Chain Saw Accessories', and click on the photo of the grinding wheels. (Clicking on the Italian or British flag will change the page language into Italian or English).



Philbert

 

[dsell]

Wouldn't that heat the chisel up a lot more?

 

[Philbert]

Wouldn't that heat the chisel up a lot more?

I'm trying to learn here, so I am open to anyone who has experience with this.

My understanding is that there are a few different components to a grinding wheel (aside from size):

- the type of abrasive (aluminum oxide, silicon carbide, ceramic, etc. - and each has different grades);

- the size of the abrasive particles (analogous to 'grit' on sandpaper - e.g. 80 grit is coarser than 120 grit);

- the type of bond (what holds the abrasive particles together).

Together these determine:

- how fast the wheel cuts;

- how smooth a finish it leaves;

- how long the wheel lasts.

In one of the earlier posts, it was suggested that a 'softer' wheel would cut faster and heat up the cutter less, but not last as long (?)
I was interested in trying one on rakers, due to the problem I was having. I could only find the Total Fireball resin bonded wheel as an alternative, and only up to 3/16".

Philbert

 

[galde]

A local dealer had several Mole Mab 5 3/4" depth gauge wheels on his clearance table for a price I couldn't pass up so I bought all of them. They measure 0.325" thick, and that is what I now use for depth gauges.

 

[Philbert]

Finally got around to trying this again. Similar situation: had a lot of chains to do, many with neglected depth gauges. Clean chains; same dressed wheel; worked fast this time !? Might have been like 'the shanks' from that "Tin Cup" movie, where you just need to do it?


(NOTE: not encouraging anyone to grind drunk!)

The STIHL triple low-kickback humps were part of my problem. My Oregon 511a grinder grips the drive link adjacent to the cutter, but does not grip all of the drive links in the vise. So, when grinding the depth gauge, the 'tail' of the adjacent low-kickback hump would rotate back and chatter. Then it would pivot forward, with a tail higher than the depth gauge. This was contributing to the bluing problem, and left me with humps higher than my depth gauges.

I was able to control this when filing the depth gauges. Taking a tip from Galde I used a screwdriver to hold the front of the humps down when grinding - this made a world of difference. A little tricky when holding them from the back - I held the screwdriver in my right hand and tapped the grinding head with my left. Need to make one of those hooks that Galde described.



Rounded over the depth gauges on a ScotchBrite wheel, and everything looks pretty..

Philbert