TimberAx Knives

[Tony Puckett]

I was wondering what the folks who run the TimberAx head do to sharpen their knives. There has to be a better way than what I am using. I touch mine up two or three times on the machine with a side grinder and then take them off to sharpen and reset the angle. I cannot find a machine shop in the area that will do them for what I consider an affordable price ($450.00 to mill 12 -9" and 2- 4" knives). I currently use a 12" table top disk sander with a 40 grit disk and the table set to the correct angle. I keep them cool with a bucket of water so as not to over heat them. It takes about 15 to 20 minutes per blade to get them sharp at the correct angle. Any help or suggestions would be appreciated.

As the knives have gotten older they don't stay sharp as long. Has anyone had any experience re-hardening the blades, or case hardening the flat side of the blade so as to make them self sharpening. Years ago my dad and granddad used to case harden the flat sides of rotary mower blades, plow points, etc. to make the blades self sharpening. They used a case hardening powder.

I do have two sets of knives so I can operate during the day and sharpen at night.

 

[JDPN]

Grinding is an expensive operation. Dressing and diamond wheels, coolant, and grinding stones aren't free and the machines themselves can be really freakin expensive, depending on what kind of grinder.

 

[JDPN]

Oh here's some advice. get some sort of hand grinder and grind them on the machine as shown on the loftness website on the side where the features are.

Loftness >TimberAx > Specifications

Maybe this straight grinder
http://www.dewalt.com/us/products/tool_detail.asp?productID=158

 

[Tony Puckett]

I looked at the link for the grinder you posted. I have never seen a grinder like that. Have you used one, and how do you hold the angle consistant.

I can't tell what type grinder they are using on the Loftness website.

I will look into different types of grinders.

Tony

 

[Robbie Hegwood]

I never removed my blades for sharpening. I used a 9" craftsmen grinder with a norton 3x disc. They can be bought at Home Depot. You should have a small gauge for the angle.
Also milling them takes off too much material.
Option A, new alloy blades from loftness, they do hold a edge longer
Option B, I know a guy local to me (Mcdonough) who made mine. A whole set for $700.00.

PM me if you need further info.

Robbie

 

[john_bud]

Kasenit will case harden most low alloy steel, is that what you were thinking of?

jb

 

[Tony Puckett]

Thanks for all of the info.

Tony

 

[Terra Firma Scott]

7 inch angle grinder with the NORTON 3X disc here.ps-thanx robbie..I also built a small riser to park the machine on so that im sharpening at chest height or so..Ive found slow speed is better...rotate the head back as to expose your blades as best possible..Flip the chains back and out of the way..Lock the drum with the alignment holes and pin on the left side as you face the front of the head.."Blip" the grinders trigger and move the grinder fast across the face of the blade..I usually "pull" the grinder working from left to right..Its not as perfect as when they are NEW but they will be sharp and the knives dont really care when they are eating all that wood...as long as you dont grind in one spot too long and change the edges profile...and may create a balance issue...FYI-Your forearms will feel it after doing a set....I seem to get a full day of cutting with mine..possibly 2 but all depends on what your into...I like to run a day and touch em up after for the second day...If i hit rock or wire or bricks ,etc then it takes a bit of cleaning up the edge....

I think it just takes some time and practice...dont think you ever get them perfect.....hope this may help..

 

[Gamma]

I looked at the link for the grinder you posted. I have never seen a grinder like that. Have you used one, and how do you hold the angle consistant.

I can't tell what type grinder they are using on the Loftness website.

I will look into different types of grinders.

Tony

It almost looks like some kind of car paint buffer to me.

 

[Tony Puckett]

I will go to Lowe's and see if they have the disk. We don't have a Home Depot in Statesboro. DO they come in different grits? If so what do you use.

thanks,
Tony

 

[allaboutmowing]

I never remove my blades either I actually sit on the floor with the head tilted all the way back and grind with a regular dewalt angle grinder, the straight grinder in the link would not work due to the angle. I now sharpen my blades either daily or after every job. It is quicker and the jobs go much faster with sharp blades. As for the angle on the blade I just eyeball it and it works fine, its not a perfect science, and you really now you done something when you finish.

 

[deniscimafinc]

Hello Tony,

We are a manufacturer of brushcutter-chippers where the cutting tools are also fixed knives, as on the Loftness machines (see www.deniscimaf.com).

What we supply our customer with every machine is a grinder made from a Komatsu Zenoa RedMax handheld brushcutter. We do the modification ourselves.

However, what is mostly important is the type of grinding disc. For our knives, the ones we ship with the grinders are for stainless steel sharpening. If it's not specified to be for stainless steel or harder material, it becomes too long to sharpen. Other than that, what you actually prefer to use to spin that disc is up to you...

On our blades, the angle of attack is important. Our studies showed that the most efficient angle of attack was within a range of only 6 degrees, so it's important to stay in that range to keep best productivity. I'm guess Loftness came with similar conclusions, and that they can supply you with a sharpening gauge similar to the one we send along with our grinders.


Hope this helps!


Frederic