why did i wait so long to do this? cbn grinder wheel

[Bibbyman]

Welcome to the Forum Tommone.

Tell us more about yourself.  I'd make a guess by your replay you have some lengthy experience in metallurgy.





About the Wood-Mizer CBN grinder;   The blade advance does pause for just the smallest part of a second in the grinding cycle when the CBN wheel hits bottom.  The cam has a flat spot on it for a couple of degrees. 

If you study close the picture above, you will see the cam has two yellow marks that I have put there to more easily spot this flat in the cycle so I can adjust the wheel depth to the gullet.  I cycle the blade advance until the wheel falls into the gullet (grinding wheel not spinning) and then check by eye for fit and turn the wheel by hand to check for contact.

The CBN wheels from Wood-Mizer cost right at $200.00 each.  I've not seen any other full contour CBN wheels available. 

I've exchanged some e-mail with the Wood-Mizer blade people about the use of a water based coolant or at least some non-petroleum based coolant.  They say they've tested other coolants and found it shortens the life of the wheel by 2/3s.   This leads me to assume the useful life of the wheel would be even more reduced if used without any coolant or wash.

[bandmiller2]

Bibbs,you have sharpened with boath are the CBN bands sharper or no different from the stone[rock] sharpened ones.Thanks Frank C.

[amberwood]

Bibbyman.I use the WM PLCBN sharpener, the 240V version of your Shop series. I use a 50:1 mix of water/white oil rather than the WM recommended oil. Heaps cheaper and cleaner to work with, plus it does not turn to sludge when the air temp gets down closer to zero. You need to run the pump flat out and drench the wheel and blade to keep the wheel from gumming up with metal.

DTR

[tommone]

hilltop 366    i agree  motor HP could be a problem if using a full width steel bodied Woodmizer CBN wheel  on a low powered machine but then again the momentum of the heavy steel wheel may keep the speed up much like the flywheel in a car but could damage the bearings and even the motor electrics. On the  other hand upgrading  the motor could help  . Either way it could be an expensive mistake.

[Hilltop366]

Hi Tommone and welcome!

I suppose a few light grinds might work, but then it would take much longer. You would also want to check out the required rpm for the cbn wheel.

I noticed on the wm link Jeff posted that the wm shop series grinder with the 1/2 hp motor will sharpen up to the .045 with a single pass, the .050 & .055 blades require 2 or more passes, which makes me think that 1/2 hp would be the least you would want.

[Bibbyman]

Bibbs,you have sharpened with boath are the CBN bands sharper or no different from the stone[rock] sharpened ones.Thanks Frank C.

It's been many years since I sharpened with the stone grinder.  The DoubleHard blades were not available then and I was running them on a manual LT40 with 18 hp engine.  So there is no "apples to apples" comparison.   But I'd have to say the blades I sharpen today with the CBN and dual-tooth setter are far better than the ones I sharpened on the stone grinder years ago.

Years ago we got a free coupon from Wood-Mizer to get a box resharpened at their service center.  After Mary used them, she didn't want to use the blades I sharpened.  So we started sending the blades to resharp and eventually sold our grinder and single tooth setter. 

She hasn't fussed about the blades I've sharpened on the CBN equipment so I guess that's proof that they are better.

The blades I've sharpened with the new CBN equipment have proven to saw well.  At least most of them.  A week or so back we ran out of blades I'd sharpened and broke into a new box of 7 DoubleHards.  We used five new blades and then I got caught up enough to sharpen a bunch of the old ones again and we started using them.  I feel most of the blades I've sharpened sawed just as well as the new ones.  The new ones often saw smoother and probably longer before change on average.

Another thing I've noted is how many times I've sharpened these blades.  Some have had 1/8" ground away and still cutting good!  I'm sure I'd never have gotten that many resharps on the blades back when I was using the rock grinder. 

I think the CBN wheel is making a much smoother grind and leaves almost no burr. 

[tommone]

Hi r.man and thanks for welcome. According to the members map I appear to be the only forum member from Ireland. We do have lots of castles ,stone fences and walls etc but generally we are a modern country with access to the same good and bad things in the world as you do. We are about 10% forested compared to over 30% for US and Canada . Mainly Beech and Scots Pine. The UK is similiar. According to Woodmizer there are about 1000 Woodmizer machines in the UK and Ireland  plus others from Timberking etc but the members map only shows 19 members in that area. Thats what I meant when i asked why so few member from Europe? I am involved in a timber orientated business but can't say too much about it in case I occur  the wrath of Moderators. Most of my experiences have been with major mills in UK and Ireland but over the last year have been involved with quite a few people with portable mills here and I find they have similiar issues as the big guys in the lumber business. My main knowledge base would be superabrasives ,blades and Stellite. The portable sawyers are now getting to grips with CBN  and will probably start looking seriously at Stellite tipped thin kerf bands soon. Quite expensive at the moment but greater sales will definitely reduce prices over a period of time as happened with the majors in europe . This raises another question--- is the forum restricted to people with an interest in small mills only or open to contributions from major mill  personnel.? These guys would have enormous experience in many departments and I am sure would have advice ideas and solutions to help out many forum members.          
                                                               

[Peter Drouin]

Just bought all the  new CBN equipment it works the balls  8) 8) 8) 8)any one want to by the old stone grinder and tooth setter ;D

[Chuck White]

Peter; List your sharpener & setter in the "for-sale" section, here on Forestry Forum.  I'm sure it won't be there long.

Lots of people looking for them.

[Bibbyman]

Just bought all the  new CBN equipment it works the balls  8) 8) 8) 8)any one want to by the old stone grinder and tooth setter ;D

What'd ya' get?

[bandmiller2]

I'am sure the adaptable Cook's cats claw could have a dwell cam and CBN wheel with coolant,hint hint Tim. Frank C.

[Peter Drouin]

All wm . thay keep me working I keep them working you know all wm parts too. 8) 8) 8) 8)

[tommone]

Hilltop366 thanks for welcome. CBN wheel speed is an interesting subject  as it is known that CBN grinding wheels last longer the higher the peripheral speed.I suppose over a period of time sharpening motor speeds will go up to to accommodate this advantage. Hopefully it will not result in increased cost to the buyer.

Hi Tommone and welcome!

I suppose a few light grinds might work, but then it would take much longer. You would also want to check out the required rpm for the cbn wheel.

I noticed on the wm link Jeff posted that the wm shop series grinder with the 1/2 hp motor will sharpen up to the .045 with a single pass, the .050 & .055 blades require 2 or more passes, which makes me think that 1/2 hp would be the least you would want.

[tommone]

Thanks for welcome Bibbyman .great idea with the yellow marks on the cam!!I am not a metallurgist but have been in the R&D business nearly all my life . Picked up a few things along the way from metallurgists chemists etc.
Enjoying the discussion and opinions on coolant and CBN. Pure oil is the best coolant for CBN long life but has disadvantages of cost ,fumes when grinding and thickness at low temperatures as stated by Amberwood. But it is the best to prevent steel particles from sticking to the CBN grit particularly at heavy infeeds. On the other hand 2 to 5% solution oil in water will do the job. Keep an eye on the CBN surface and clean occasionally with a soft dressing stick. Don't ever use pure water as you will end up with a weak solution of Boric Acid which won't do any one any good.

[eireog68]

tommone i am originally from county carlow and i am going to say its because there is not many woods left over there even the last sawmill in carlow is gone according to my parents. there might be more woods by you but for how long.

[tommone]

tommone i am originally from county carlow and i am going to say its because there is not many woods left over there even the last sawmill in carlow is gone according to my parents. there might be more woods by you but for how long.

Hi Young Ireland nice to hear from you.The forest area in Ireland has actually increased over the last 20 years due to sensible replanting but maybe not in
Carlow. There is a major mill in Carlow called Murray Timber,used to be called Deacons. Maybe your parents know of it. Slainte tom.

[paul case]

a little update here.
i have sharpened 84 bands (14'6''  7/8'' tooth spacing) to date and the wheel is still working as well as when i started. i notice no wear on the side that gets used the most and no change in tooth hook angle. no build up either. good so far. pc

[paul case]

well,
at a 115 i started noticing the wheel burning the tip of the tooth. so i have turned the wheel around to use the side that was away from the tooth before.
if we get 85 out of the second side the wheel would cost $.0475 per sharpening. i didnt try to keep track on the grind rock type but i wasnt real happy about having to dress the stone for every blade or 2. the cbn wheel stays the same.  pc

[LeeB]

How much differrence is there in the profile from one side to the other?

[paul case]

none. this wheel is only 1/4'' thick and is rounded a just about like the bottom of the gullet on both sides.
i am real impressed with how well this works. i will replace this with another just like it when it wears out. pc