4 degree vs turbo 7

[Magicman]

This is simply an observation on my part, not a degree war.

I have been exclusively using T7°'s for a couple of years with no regard for whatever log species I was sawing.  (I let attrition eliminate my stash of 10° blades long ago.)  OK, so what's up now?

The job that I am presently sawing so far is all SYP, which includes some very knotty logs with some of the knots ranging up to ~6"+.  I had a partial box of 4° blades so I said "what the heck".  The 4° blades are sawing very well but the blade life suffers.  I am having to change blades more often and using 3 blades where I normally would use 2.  The less blade angle introduces more scraping that allows the 4° blade to saw straight but also dulls it quicker.  More scraping equals more dulling.

So now what?  I'll run out of my stash of 4° blades next week and will be back to sawing with my T7's while the 4° blades go to Resharp. 

[YellowHammer]

I agree.  I have let all my other blade angles go extinct over time and just replace them with Turbos (not the 747's).

I haven't seen any species I can't saw well and fast with a sharp .055" x 1.5" Turbo, and lots I can saw with a dull one. :

I hate to admit it, but I leave my bands on longer than I should and sometimes switch species rather than change the band.  Is the band getting dull near the end of a whack? I'll finish the session with a few soft maple logs, cherry or maybe some basswood.   :D   Then turn the mill off and come back the next day and put on a new one.  

[WV Sawmiller]

   How is the comparison between the performance on those knots? Do the 4* blades saw through them straighter than the T7's? Do the T7's want to rise on the knots? I am phasing out everything except my 4* blades and have tried a few T7s but likely did not give them a fair eval. You have more hp than I do too.

[Southside]

Yup - guilty of the same thing YH.  "Oh I can finish this log" before changing the band....about that time I am looking at each board hoping to not see the wave of "nope should have changed the band earlier".   :

[Bruno of NH]

I have been sawing lots of hemlock and spruce as of late.
Not much bigger than 20" on the butt .
I have been using turbo 7° in .042 x 1.25.
It's fast and true lumber is a result. On the spruce if I flood it with blade lube they cut for a long time .
Lube dosen t matter much on hemlock it's wet and no pitch.
I used 4° in the past on spruce and I agree that they cut flat but dull much quicker. 
When the logs freeze in a few weeks all other bands get put away till spring.
I only use frost notch bands in the winter or I wouldn't saw at all. 1.25 × .050.
They only last one maybe 2 sharpening. They only cost $18.00 per band delivered to the mill.
I didn't like the turbo 7° at first but have they now have a place in my operation. 

[Bruno of NH]

The 747's cut nice but dull much to quick for me.
The tall tooth might be why maybe ?

[barbender]

I'm still running standard 7°, I never have tried the Turbo. I suppose I should. I only tried one 4°. I know Magic saws em and leaves em, but I've gotten to the point when sawing my own that if the knots are so big it causes sawing problems, I know the lumber will be junk as well. Some of our white spruce that has big knots, you can pull the board of and break it just setting it over your knee, you don't even have to try.

I usually don't mill much in the winter as that's our busy time out in the woods. I am planning on keeping it rolling this year though, I'm sure I'll have some teething issues😊 I may have to try some frost notch blades.

YH, I've been guilty of going out searching the yard for some easy sawing wood when a blade has lost a bit of its edge, too😂

[SawyerTed]

I have used 4° blades mostly but have 45 or so Turbo 7s that I haven't been using.  I'm reaching the end life on some of my 4° blades and will need to settle one way or another.  What I probably should do is to saw with both sometime to compare the results. 

[ladylake]

 I buy my blades at 10° and sharpen to 4°.  The sharpened 4° cut straighter longer than the new 10° blades.  I'm not even going to try blades with pointy teeth that cant take a metal hit.  I did try Cooks super sharp with the pointy teeth once years ago , didn't saw as straight as the Simonds I was running and a metal hit ruined 1 of the 2 blades I tried . Steve

[Magicman]

How is the comparison between the performance on those knots? Do the 4* blades saw through them straighter than the T7's? Do the T7's want to rise on the knots?

Howard, either will saw knots when then are sharp and both will wave when they get dull.  The T7's stay sharper longer and hands down will remain my go-to blade.  I only have 5 more sharp 4° blades and will be glad when they get dull so I can go back to those "pointy tooth" T7's because they allow me to saw faster and have no species preference.  I only tried this sorta experiment because I had that partial box of 4° blades and got tired of kicking it aside.  I suppose that after they are resharpened I can resume kicking it.  :

I have no desire to "chase blades" so I have not and do not intend to even try the 747's.  

[kelLOGg]

My opinion is that discussions about tooth angle should involve engine horsepower. On my low power mill (16 HP) I plan to always use 4° on everything. If I had 30+ HP as do most hydraulic mills it would be a different story. There, 7 to 10° angle teeth are a plus. Comments?

[barbender]

There's more to the story than just hook angle. Tooth height, back angle, set, blade thickness...to be honest, good ol' 10° blades of all brands have given me good service, they all seem to have a similar middle of the road profile. I'd shy away from blades that have the tall pointy teeth with a low horsepower mill (like the WM 747). I'd say the same if it was a 1047 or 447 as well😁

[Southside]

There is a member on here who has had good success with T7's on a 13 HP mill, can't remember who.  Cut width will play a major factor in success as well.  I started running 1.5" turbos on my LT 35 with a 25 HP gas engine, which is completely outside of what should work.  The difference?  I use it as a re-saw to make clapboard siding, so the width of cut is 7".  Performance is impacted by a wide range of factors. 

[caveman]

I do not saw as much as a lot of you on here do but the turbo 7's, which I was so excited about using, did not deliver the mail in longleaf pine (12-14" heartwood) or the live oak like I had hoped it would.  The 4° and regular 7° have been performing well for us.  Lately, we have been buying 7° and having them sharpened to 4° (the guy who sharpens for us has a 4° grind on his wheel).  I have not used the .055 x 1.5" 7°'s.  They may do better in what we saw than  the .045, 1.25" turbo 7°'s that we got when we brought home this mill.  If I were sawing cypress all the time, I would probably order 10° or 13° blades and run wide open.

It is really gratifying to fly through a cant but we spend much more time sorting, stacking, drying and sterilizing than we do sawing.  I would much rather saw flat, accurate lumber than saw fast.

If I were running a lower horsepower mill, I would exclusively run 4° blades.

Recently, we sawed some longleaf with a resharpened 1.25 x 4° blade, put it on the rack to be resharpened, trashed a new 1.5, 7° in pecan with hardware, reinstalled the 4° to cut over 30 live oak tree cookies and then sawed three pecan logs with it, expecting to trash it - all dead flat.
4° would be my go to if I could have only one.

[YellowHammer]

caveman
For what it's worth, I tried Turbo 7's, .045 x 1.25 in my old LT40 and just hated them.  I didn't even finish the box, and tossed them.  They wandered and left disagreeable streaks on the boards.  

I later tried .055 x 1.25" Turbos on my LT40 and they were much better, and would cut as fast as I could push the the mill.  However, they were very hard in my drive belt, and I had to tighten it much more frequently.  I eventually settled on a mix of 7's and Turbos.

With the LT70 I tried a couple boxes of most everything I could get my hands on, and by far, with this mill, the .055 x 1.5 Turbos were head and shoulders above anything else I tried, including the new 747's.  The only exception was the two carbides I tried, they cut very flat and true, and for a long time.  

[Larry]

First, I don't run a debarker which makes a difference.

I tried the .045 1-1/4 T7's when they first came out.  They cut fast and true until they started to dull and I got waves.  The reason I think is that extra deep gullet doesn't leave enough meat in the body of the band to make it run true.  Next I tried the .055 1-1/4's and the 1-1/2's.  The wave problem was solved but the bands were expensive and they broke early compared to the .045's.

Next I tried the Kasco 7's with the same geometry as the T7.  I picked 1-1/2 .050 bands which WM doesn't offer.  It's difficult to get them to wave, but I can still do it if I really push them when they are dull (abuse).  They run nearly as long as the .045's before breaking and the cost is reasonable.  These Kasco 7's are by far the best band I have ever used.  I'm using them everyday cutting hardwood slabs from 20 to 32" wide.

[Andries]

I don't saw much cedar anymore, but when I do, the WM 7 degree bands are good.
Elm. ash and oak are on the mill most weeks, and a lot of those city trees have high metal content. The Kasco 4 degree works well on the hardwoods, and doesn't quit after hitting an embarrassing amount of metal.
I'm with Caveman, milling is a 'material handling' exercise.
Most days I'm on my own. 
The time spent taking sawdust out of the log isn't the biggest part of my day

[mudfarmer]

My lt15 is 10hp diesel, ordered a box of blades at purchase time. Went to pick it up and they asked me what kind of blades I wanted?? I was ill prepared and asked them what they recommended. Don't do that :D :D :D :D :D :D :D They "recommended" (salesman'd) me into a box of 747s. So far working OK but do seem to start to dull and wave faster than the 10*s do in all species I have cut (white pine, hemlock, hard maple, soft maple, elm, black cherry). Probably would not recommend for low hp mill but don't have anywhere near the experience you folks do. Note to self, don't get overwhelmed and remember to study before quiz time

[barbender]

I really don't understand why Woodmizer is pushing those things so hard. I get an email almost daily, "Woodmizer 747, they fly through everything you saw". I just don't understand, aren't they making the same profit if they sell a box of 10's, instead of a box of 747's etc? My experience is that they are not in any way the "do all" blade they are marketing them as.

[terrifictimbersllc]

If, for me,  there's a do-all blade so far in the Wood-Mizer lineup, it is the 7 turbo.

I converted to 7 turbo for my last 4 years with a 42 Kubota, 158"  1-1/4" .045, and continued with them in 195" 1-1/2 0.055 with 55 Yanmar. In both cases the 7 turbo saw everything I encounter flat and fast as can be except for very knotty spruce, which takes some strategy to break down to narrow width first.

The 747's, I only tried two of them, sawed fine, but one of them got wiped out completely by a medium nail strike a 7 turbo would have survived. I didn't see any reason to switch to them.

[Bruno of NH]

The 747 tooth sticks out and says , break me please.

[SawyerTed]

I guess I'm sawing with T7s tomorrow since this is my 4° wheel.

I was getting frustrated with my 4° bands.  Now I know why - there's nothing left to sharpen the tooth face.  Too many attempts at recovering metal strike blades  🙄 


 

 

[ladylake]

I really don't understand why Woodmizer is pushing those things so hard. I get an email almost daily, "Woodmizer 747, they fly through everything you saw". I just don't understand, aren't they making the same profit if they sell a box of 10's, instead of a box of 747's etc? My experience is that they are not in any way the "do all" blade they are marketing them as.

Advertising.   Steve

[Patrick NC]

I haven't tried turbo 7s on my mill yet. I probably will at some point, but so far I'm really happy with Kasco 7s. Seem to work good in everything from cedar to white oak. Cut some knotty yellow pine today and sawed straight in that too. 

[barbender]

I've been running a box of 7° Kascos I got from Cutting Edge. They are the milder ones, I don't know what they're called but Richard said they were better if you weren't pushing your saw full tilt all the time. They are a good blade and cut great in the wood I saw.