Another thread with blade questions

Redhorseshoe · September 13, 2020, 04:43:54 PM

I've been using the WM 7/47 blades and have really liked them so far. I started sawing some dry juniper and am getting these blade marks. The blades are cutting fast and flat but just leaving these marks. I'm wondering if you all think a 4 degree, or other band, would help with this.

Magicman · September 13, 2020, 04:51:59 PM

You hit something with that blade.

Redhorseshoe · September 13, 2020, 05:05:17 PM

That wouldn't surprise me, that board was the worst of the worst and one of the last I sawed. The others weren't that extreme but still had more blade marks than usual.

JoshNZ · September 13, 2020, 05:11:19 PM

Can't get a better answer than that from anyone better than that. I've seen that on my timber and figured as much.

Would you swap out the blade @Magicman , if it were still cutting alright and you're producing rough sawn anyway?

Redhorseshoe · September 13, 2020, 05:11:33 PM

Here's another one, this is more typical.

Magicman · September 13, 2020, 05:29:46 PM

Quote from: JoshNZ on September 13, 2020, 05:11:19 PMWould you swap out the blade MM, if it were still cutting alright and you're producing rough sawn anyway?

It's not cutting/sawing alright and swapping out the blade depends upon the use for the lumber and who for and how the lumber will be used. You may can find and straighten the offending tooth/teeth, but it probably will never saw smooth.

In my instance I am always sawing for a customer which means that there are two people to satisfy; Me and the Customer, so the blade would probably be discarded.

Tom the Sawyer · September 13, 2020, 06:18:44 PM

That is what I refer to as a rogue tooth. When I have had that pattern I have found at least one tooth will be out of set, usually around 5 thousandths over.

WV Sawmiller · September 13, 2020, 06:29:19 PM

Lynn,

I don't sharpen or set my blades - I send them back to WM for Re-sharp. Do you mean discarded or would send back for re-sharp? I assumed the blades would be re-set when resharpened and this would fix this problem. Al I making a wrong assumption?

JoshNZ · September 13, 2020, 06:37:12 PM

My sharpener checks the set with his fingers, tells me it's fine and it never goes near a setter lol.

Total bs, hence I'm in the market for my own setter.

Magicman · September 13, 2020, 07:35:14 PM

Howard,I don't have any always/never rules.

If a blade shows those kinds of marks I will already know when I hit metal, etc. and the customer is billed $30. I'll inspect the blade and if teeth are damaged and I don't feel that they can be restored to saw smooth, yes I will discard them.

Saw blades are expendable items and I try to never send marginal blades back to ReSharp with the hope that they can/will be restored.

terrifictimbersllc · September 14, 2020, 06:42:01 AM

It is a good practice when putting on a new blade to check both sides of the first cut. If smooth then you know that kerfy marks came from cutting those logs not from having teeth out of set when you put it on.

I had 3 blades cutting "kerfy" on Saturday's job that I took off and did not charge the customer for. My usual feeling is that the blade hit something, but not sure enough to put it off on the customer. In this case I was sawing dirty little logs some of which had holes in them and could easily have picked up gravel.

I doubt ReSharp will/can de-set teeth. Pretty sure they use BMT250 setter.

I can use my setter to check set and correct by hand when I have a snaggletooth sawblade. Did it yesterday. Took me about a half hour with the blade, going around manually first one side then the other. I don't usually spend this much time on a blade but was in a leisurely mood. Not having good luck with my "desetter" now that I have begun using 055 blades.

Chuck White · September 14, 2020, 07:29:09 AM

The ReSharp at Hannibal has rollers (similar to mine) set up and the blades are deset to a certain point, then reset and sharpened!

Taking a tour of the resharp a few years ago is what gave me the idea to have mine made!

terrifictimbersllc · September 14, 2020, 07:51:14 AM

That's helpful info, didn't realize. Good on them.

WV Sawmiller · September 14, 2020, 08:29:06 AM

Chuck,

That is the way I thought they all did them and deset then sharpened and reset all the teeth when resharpening.

YellowHammer · September 14, 2020, 08:53:53 AM

If its a new, still sharp band, lots of times I will turn everything off, and spin the band by hand real quick and look for the bad tooth. Sometimes its pretty obvious because there is still a sliver or piece of whatever you hit still hung on the tooth. So pick it off with your fingernail or a screwdriver. If its over bent or over set due to the hit, flatten it out with pair of pliers and turn it into a neutral tooth. If you can't find it in about a minute, put on a new band if want a smoother cut, or just get back to cutting with it still on.

Mossy Chariot · September 15, 2020, 10:27:33 AM

Great and timely information from you all - Thanks!!!

I generally saw with 4° blades but decided to order a box of 747s. When I put the first one on and started sawing SYP, it left a saw mark just like Redhorseshoe's first picture. My initial thought was at least one tooth set out too far. So, I changed the blade out for another new one. To my surprise, the exact same result. At that point I was about to decide I did not like 747s. The 4° blades always cut very smooth but leave a lot more sawdust on the boards. After reading this thread, I will look a little harder to see if I can spot a tooth set out to far. The box of 15 bands was a little beat up when delivered. I guess it is possible that some very rough treatment in shipping bent a tooth on several bands.

Tin Horse · September 15, 2020, 12:49:35 PM

Mossy Chariot. Did you increase the feed rate? I found the same issue with white pine. I almost doubled the feed rate and the cut is good. So far I'm happy with them. My first try with the 747's. Just wish I had help with lumber coming off the mill now at a faster rate. No issues with accuracy either.

Mossy Chariot · September 15, 2020, 05:53:37 PM

I did adjust the feed rate both up and down without it getting smoother on the first band. Thank you for suggesting that @Tin Horse . I'll try that again if I don't find a "rogue tooth."

Tin Horse · September 15, 2020, 07:02:42 PM

I'm curious of the opinions between the 747's and the turbo 7's from some of the more experienced users here.

terrifictimbersllc · September 15, 2020, 07:59:26 PM

Turbo 7 .055, 1-1/2 pretty much cuts everything for me. I tried two 747s they cut good too, but wasn't doing anything where I could tell a difference. I did hit small metal with one of them, this stripped teeth off that I thought would have survived if it were the turbo 7. Fair amount of metal strikes I can recover the blade with little work with the turbo 7. Didnt see a reason to switch to 747.

YellowHammer · September 15, 2020, 08:15:59 PM

I agree, the 747's were more fragile and didn't have any advantage over Turbos.

As far as a rogue tooth, it's definitive if it it directly follows your feed rate, so that the slower the feed rate, the closer the scratches are, the faster the feed rate, the further apart.