Has anyone modified their CatClaw?

[kelLOGg]

to a 4 degree tooth angle? My 2002 model has 8, 10, 12 and 15 degree stamped on it and I would like to modify it. I have always used 10 degree, but for my next logs I am going to start using 8. I don't think the range of motion of my model will go much lower than 8 but without a way to measure the angle in such a tight space I can't be sure. Has anyone done this?
Bob

[barbender]

I just go past the 8° index hole and clamp it down for 7°. Someday I may get serious and drill and tap some holes :

[Chuck White]

I normally sharpen at 10° and if I'm going to get into a little hardwood I keep 2 blades sharpened at 8°.

If you are thinking of trying for 4°, you may even have to move the pivot point and not just the tilt of the grind motor.

[4x4American]

Yes I did I drilled and tapped for 4° and 7°.  I'll have to go take a video of how I measured it to explain better, but pretty much I just eyeballed it up, the rock to the blade, and then clamped, drilled, and tapped.  Once you change the degree you have to square the rock to the grinder, cause it will move outta square.

[kelLOGg]

Once you change the degree you have to square the rock to the grinder, cause it will move outta square.

I didn't understand that. The grind rock is mounted to the motor shaft so why would it move out of square? A video would certainly be nice.

To go to 4 deg I would probably have to cut some parts but I wouldn't try to change the pivot point.
Bob

[4x4American]

I don't understand why it does either, but whenever you change the degree you should always check the rock for square.  They wouldn't give you a squaring tool if it always stayed square!  I didn't change the pivot point, just where the stops are at.  Had to drill a new slot for that clamp type unit to so that the head would go low enough for 4° grinding.  I found that for 7° it was close enough to just set it on the clamp unit's bolt and then tighten it down. 

[YellowHammer]

I have modified mine to do WM 9° and 4°, without any special issues.  The easiest way to set the four degree angle is guess, make a test grind, then use a machinist protractor to measure the angle that was cut in the band and readjust.  The screw in clamp can be used to hold the head at the new angles, or a set of vise grips.  Once the angle is correct and the face angle is exactly right, drill and tap a hole to insert the shoulder bolt that supports the head at the correct angle, no different than than any other angle setting.

If you are trying to exactly duplicate the WM 4° profile and gullet shape, (I did) then it's best to grind a cam to work with the current rock profile, instead of having to reprofile the rock to match the gullet, or profiling another rock just for that angle.  This way the rock is never changed, and the rock remains the same for all the angles.  Once the cam is custom hand ground and right, all you have to do is just simply adjust the angle, switch cams, and start grinding. 

Grinding the cam is not a big deal, it's important to realize that as the cam rotates around, if it's too high, then it drives the rock up.  So it's all about cutting the cam down in the correct spot. I've tried different ways, but he easiest is with a sharpie pen.  Slowly get the cam spinning so it just barely, and I mean barely, grazes the tooth face.  Watch the rock cycle a few times, then watch the cam, and during the rotation, mark the high spot on the cam where the rock comes off the band gullet. Then take a file or grinder and take that high spot off. Repeat about a couple dozen times, never being too aggressive.  In a while, the cam will be perfectly profiled so that the rock always just touches the face and gullet and you now have a custom cam. 

[4x4American]

^^^smarty pants...

I might try and grind my cam that way..

[bandmiller2]

Very interesting Hammer, I've thought about it but don't believe minor changes in the gullet amount to much. I use the timberwolf cam and all bands regardless of brand conform to it, after a couple of grindings. I have done the same with Simonds cam and had the same good results, really its sharp and set that carry the mail. One old pharts opinion. Frank C.

[kelLOGg]

Thanks, YM. Your technique for changing the angle sounds straightforward.

Measuring the angle is more of a challenge for me. I have a Starrett #19 protractor but the short height of a tooth doesn't leave much to contact the arm of the protractor limiting my confidence in the measurement. I am thinking about using a broken band in the sharpener, turning the cam off and lowering the grind rock deep into the band to give more height for an angle measurement. Unfortunately, I just recycled 5 broken bands. If I'm lucky maybe I'll break a band this week.

What technique do others use to measure the angle?
Bob

[Ga Mtn Man]

I use one of these on my home-made grinder:



 

[ely]

I have not modified my cat claw except I did put a piece of tie wire around my depth adjustment to keep it from backing off. I use the 8 degree setting for everything I sharpen... it seems to work well for me.

[Ox]

I also modified mine to get 7 and 4 degrees and 4x4 already said everything I would have said about it.  I used an inexpensive angle finder with a magnetic base and just took my time.  I measured the platform the motor sets on at 8 degrees to check if it was accurate with my angle finder, found it was, then moved on from there.  Not difficult, just time consuming.  I tend to sharpen mostly at 7 degrees.  Next year when I get into more red pine I'll be trying 4 degrees to see if I can get flatter cuts through the knot rings on these trees.

[bandmiller2]

Kellog Bob, give or take a degree is hard to tell. I use an accurate LS Starret protractor head, base on the bottom of the band and with a white background leave a little gap from the front of the tooth to the ruler easy to tell within about half a degree. Frank C.

[4x4American]

I started to take a video today but ran outta memory 20seconds in.  Once I get more memory on my phone I'll do it again.  I can post what I took so far you can kinda get an idea just gimme a little bit

[Magicman]

I ran out of memory sometime this morning too.     :D

[YellowHammer]

Very interesting Hammer, I've thought about it but don't believe minor changes in the gullet amount to much. I use the timberwolf cam and all bands regardless of brand conform to it, after a couple of grindings. I have done the same with Simonds cam and had the same good results, really its sharp and set that carry the mail. One old pharts opinion. Frank C.

Your opinion carries a tremendous amount of experience behind it so it's more like a fact,  :P and I agree that a sharp band with good evenly set teeth are all that's needed and it's hard to tell the difference.

But there's just something magic about a 9° WM band in cherry, and I cut a lot of big cherry... I can feel the difference, even different from an 8°.  Not saying they don't cut well, but that 9° in cherry is special, just like finding another gear in a sports car or using a favorite rod. 

I've read several favorable posts of yours on the Timberwolf bands and cams and I need to give them a try. 

[fat olde elf]

Yellow Hammer: You are absolutely correct about Frank C. I called him just to hear his New England accent.....He speaks with authority..

Kellog: My Cats Claw is older that yours because I bought it on the Sawmill exchange several years after we got our MP 32 mills.  I just clamp it 7 degrees for most sharpening.  My sharpener was marketed by Suffolk but it has all the Cooks labels on it. Love sharpening bands and making sawdust. Happy days............. 

[4x4American]

So IDK what's up with uploading a video, but I'll describe it best I can.  I just did it by intuition, there's really nothing to it.  The hardest part is figuring out where you want it.  Once you figure out where you want it, pin it.  What I did was put a new, known 7 or 4° blade on the grinder, clamp it, and run it around with the finger until I get the grind rock coming down just a sliver in front of the tooth face.  Make sure rock is square at this point.  Then I rigged up a bright magnetic light behind the rock and watched for the light.  I used a pry bar to move head around.  Kept the 1/2" bolt snug so that it would stay when I pryed it.  Once I got it to where I wanted it I stuck an F clamp on it and double triple checked everything then drilled and tapped a hole for the now stop.  For the 7° angle I found I just took the stop out and let it sit on the clamp.  For 4°  you have to drill/tap a new hole for the clamp because there's not enough clearance, Clarance.  I slid it over a bit and cocked it sideways and that seemed to work for me.  That's how I did it, it doesn't have to be perfect, just close.

[bandmiller2]

Thanks guys, Timberwolf sold Cooks cats claw sharpeners for years I have some cams with TW's name on them. don't know if they still work togather. A case in point about cams. My best sharpening customer brought a box of Cooks magnum bands yesterday 1"x.055 he was thrilled with them  very stiff and stable in the cut. He also brought a new cam for them (like I said good customer) that was sent with the bands. I found  the 7/8" timberwolf cam to be a much better fit in fact almost perfect. He was telling me their are two flavors of the magnum bands stiff like he had and a more flexable one for longer flex life. The ones I sharpened seem to hold their set well. Frank C.

[kelLOGg]

Thanks to the replies in this thread I was able to add 4° and 6° to my sharpener. Thanks. guys.  I put an old band in the jaws and elevated it ~3/8" so I could get a deep cut with the grind rock. Then I lowered the motor assembly to the lowest point, fixed it in place and slowly ground into the about 5/8" to 3/4". Such a deep grind gave me more confidence in measuring the resultant tooth angle. This grind gave me an angle of 4° so drilled and tapped it. I then drilled and tapped a hole midway between the 8° and 4°, made another deep grind; it measured 6°. 8)

I can't post pics with the old computer I am using so I will continue later when my computer gets repaired.
Bob

[Banjo picker]

I haven't done any thing to mine yet, but if I see some pictures..... ;)  Banjo

[YellowHammer]

Thanks to the replies in this thread I was able to add 4° and 6° to my sharpener. Thanks. guys.  I put an old band in the jaws and elevated it ~3/8" so I could get a deep cut with the grind rock. Then I lowered the motor assembly to the lowest point, fixed it in place and slowly ground into the about 5/8" to 3/4". Such a deep grind gave me more confidence in measuring the resultant tooth angle. This grind gave me an angle of 4° so drilled and tapped it. I then drilled and tapped a hole midway between the 8° and 4°, made another deep grind; it measured 6°. 8)

I can't post pics with the old computer I am using so I will continue later when my computer gets repaired.
Bob

That's great, glad it worked out.  Also remember that a sharp tooth looks like this with a sharp chisel edge, sharp corners, no burn.


Not this, with dull edge, rounded corner, a little tip burn.  Not one of my best attempts.

[Nomad]

Thanks to the replies in this thread I was able to add 4° and 6° to my sharpener. Thanks. guys.  I put an old band in the jaws and elevated it ~3/8" so I could get a deep cut with the grind rock. Then I lowered the motor assembly to the lowest point, fixed it in place and slowly ground into the about 5/8" to 3/4". Such a deep grind gave me more confidence in measuring the resultant tooth angle. This grind gave me an angle of 4° so drilled and tapped it. I then drilled and tapped a hole midway between the 8° and 4°, made another deep grind; it measured 6°. 8)

I can't post pics with the old computer I am using so I will continue later when my computer gets repaired.
Bob

That's great, glad it worked out.  Also remember that a sharp tooth looks like this with a sharp chisel edge, sharp corners, no burn.


Not this, with dull edge, rounded corner, a little tip burn.  Not one of my best attempts.

     Good pics, YH.  First pic, perfect.  Second pic...  Nah.

[4x4American]

I have a hard time getting my cat claw to give me a square corner on the inside set teeth.  I can get the other teeth just about perfect.  Any advice?