Wood-Mizer 7X39 .055 Turbo Blades

[Magicman]

I had never used the Turbo blades so as a courtesy WM sent me 10 to trial while sawing the wwsjr project.  Since I was steadily sawing small ERC logs for three days, I chose to continue using 10° Resharps since the only problem with sawing ERC is dulling.

Hookpilot and logs2lumber both used the Turbos Monday & Tuesday and reported favorable, but both of them experienced a blade to break Monday morning, and not in the weld.  Maybe they will chime in and add more of their thoughts.

The first Turbo that I put on Thursday AM left marks like a tooth out or a burr which went away after the first SYP log and it sawed smoothly thereafter.  I would not recommend them for smaller HP sawmills, because with 20"+ logs, they were all that I wanted, and I was sawing just above the point where my RPM's would drop off.  If/when the RPM's dropped, blade marks would be evident.  I do not know whether it was the Turbo profile or the .055's but the blade did not wave with 3"-4" Pine knots. 

I do not want to be cluttered with an arsenal of different blade profiles, but adding these for those big old knotty SYP logs seems to be OK, but 4° .055's probably would serve just as well.  I will judge these further when I get them back from Resharp.

[Sixacresand]

Lynn,
I will be the uninformed one and ask ???:  What is special about the Turbo blade? 

[Dave Shepard]

Deep gullet, and lots (.039") set.

[Magicman]

Yup, the wide set and deep gullets really put a load on the engine.  I could immediately tell the difference.   

[Rachiano]

The .039 is not the set...it's the back angle of the tooth. Actually it's 39.5. Works great on higher hp mills. Think WM recommneds at least 35hp engine. They do cut fast due to the deeper gullet carrieng out more sawdust. I set mine at .025 for medium hardwood although I use the .045 thick blades.

[Kbeitz]

Wow.....
To think that I set my blades to .012

[logs2lumber]

I have a 51 cat on my mill and cutting cherry and the oak with that blade was great cut smooth. I did have a blade break like Magicman stated but it was also  pretty dull i was in the middle of finishing the last 2 cuts and thats when it broke.  I did saw some pine with it but i dont recommend that for soft wood. all in all it done well in hardwood and cut smooth.

[customsawyer]

Deep gullet, and lots (.039") set.

It does not have .039" set. The 7°/39° is in reference to the tooth hook angle and the back angle of the tooth. The set is pretty much the same as most any other WM blade. The welds have been a problem for some of us that use this blade and push them hard in a "production mode" type of sawing. There has been a few other problems with some of these blades but it is a quality control issue and not the blades fault.

[rooster 58]

Yup. I have turbos breaking at the weld, even new ones that have only run an hour or so. But they are still a fine blade. They've worked well in dead hickory

[Dave Shepard]

Then what is the set? My 10s come back from ReSharp at .030. I saw a lot of white pine with the turbos.

[4x4American]

The teeth are tall on the toibos, well either that or the gullet is deep.

[customsawyer]

The set is normally in the .024- .027 range.

[bkaimwood]

I run the 7/39 turbos in .045", not .055". I'm into my 4th box now, run a diesel, run them hard, and have never broken one. I've never had them sharpened yet, but its time to start sending some out. Maybe that will make a difference? They cut everything great. They leave striations if you feed too slow. They have heavier exit frey. The only issue or concern I've had is sawing spruce. Despite heavy tension, I still get some waves on tough logs...of course worst when opening a log, bark sawing. Stuff gets wavy fast as soon as they start to dull. I have a 9 degree to try, but have never run anything else. I don't see the need, or I don't know any better??? I have 2 hickory logs to saw, haven't sawed any yet...also wondering how they'll do in frozen logs?

[terrifictimbersllc]

Deep gullet, and lots (.039") set.

It does not have .039" set. The 7°/39° is in reference to the tooth hook angle and the back angle of the tooth. The set is pretty much the same as most any other WM blade. The welds have been a problem for some of us that use this blade and push them hard in a "production mode" type of sawing. There has been a few other problems with some of these blades but it is a quality control issue and not the blades fault.

I was going to question this too....039 would be a huge set.  I have 4 CBN wheels for WM blades marked 10/30, 9/29, 7/34, and 4/I forget.  The second number corresponds to the back angle of the tooth as the grind wouldn't have anything to do with the set.    Expecting that the turbo wheel would say 7/39.

[customsawyer]

I think you are right that the wheel would say 7/39. I sharpen mine to 4/39 with the rixsaw wheels. If you roll these blades and sharpen to a 4/39 it makes one fine cutting instrument. It will cut flat and true. The guys I talk with up north sharpen to this profile and just lower the set a little bit and they are able to cut frozen logs to problem. I think they lower the set to have less sawdust on the boards for when they are grade sawing. I don't have to do that so I run .025-.028 set year around.

[MartyParsons]

Hello,
I think we set these 7/39 to .028.

Do you know what blade strain is? Think about putting a .038 thick blade on the mill tighten to 2500 on the gauge. Then put a .055 blade on the mill and tighten the tension to 2500. Which blade would stretch more? 

I like to tighten the .045 blade as far as the gauge will go or strain the blade. I don't use the .055 blade much because I can not strain the blade as much as I would like.

I guess my point is if you have a LT40 or LT50 and have enough hp to strain the blade and use the an aggressive hook angle then tighten the blade and saw.

We have been running the 7/39 blade .045 even on the 19 hp LT15 and it works well. You can not cut wide cuts but if you saw 8 to 12" width then you will be ok. If you are sawing wide cuts you will need to change the blade to a different hook. I like the 9 degree for the lower hp mills and wide cuts.

Lots of owners are running the 7/39 in winter and tough woods like Hickory with great results.


Hope this helps.

Marty

[gmmills]

    The differences between the standard 7/34 blade and the 7/39 Turbo blade are quite easy to see with naked eye. The turbo gullet depth is significantly deeper .330 thou compared to the 7/34  .295 thou.  There are no less than 10 local bandmills in my area that use the 1 1/2"  .055  7/39 Turbo exclusively.  Work great in all our hardwood species. Actually did saw some hickory last week and these blades performed great.

     In frozen or extremely dry logs, I also change the blade profile to a 4/39 with a Rixsaw wheel just as Customsawyer does. This allows me to only purchase one blade profile for all my cutting needs.

     The only issues we have seen with this profile have never been attributed to the profile itself. These issues are a direct result of poor quality control in the blade manufacturing facility. These issues range from poor weld joint alignment, dull blades right out of the box, new, to actual failure of the weld joint itself. I have, just this past week, seen a blade weld broken in a brand new box of blades. Yes, new, still retained in the box. I do have a picture of this.   In the last couple of months the issues have become more prevalent. The weld failures are not acceptable. If the welds are fused and annealed properly the blade will fail somewhere other than the weld joint.  These issues have been brought to WM attention and hopefully be rectified soon.  If not , many of us will be looking for another blade supplier.   

    As Customsawyer stated, if they are rolled flat and sharp they are one fine cutting instrument. To date, for our application, theses blades out perform any other blade profiles that are out there.   
   

[Hookpilot]

I was cutting Cherry with a 44hp LT50 and ran into the same pattern MM did with it looking like a tooth out of whack. I called him over and the next pass I started at the speed I had been cutting then he motioned to me to increase my speed (didn't need to increase much) and I did until the engine started to strain. At that point we found the blade cutting smoothly and when I backed it off just a touch it was a bit wavy again. The first blade lasted about 4 1/2 hours, may have cut 1,000 bf as I was making stickers and 3x3s as well. On the last pass as I was returning the head I got about a quarter of the way back down the log and the blade broke. I normally don't disengage the blade when I return.

The second blade lasted about twice as long and at this point I was into some pine logs. It did a good job with straight cuts and no teeth marks until it started to dull then I noticed it not doing quite as good a job around the knots so I changed it out.

All in all good blades but as has been said I think the key is to have plenty of power to run them. It could also be I am still reasonably new to this and just need better technique.  :laugh:

[Magicman]

WM was originally sending me .045 blades and I had them changed to .055.  After reading Marty's reply above, it appears that I made a mistake.   :-\

[Dave Shepard]

I run .045s at work with a 33 hp Kubota. I prefer the heavier bands, so I got a box of .055s for my mill. I've always run .055s on mine, but this is a first for Turbos. I'll report back if I have any trouble.

[Magicman]

I will Resharpen the dull .055's but I will not replace the broken ones.

[sandsawmill14]

i tried the turbos on the s&w with 30 hp electric worked fine but were hard to pull in the 20"+ wide cuts broke 3 out of 10 on the first box  havent ordered a 2nd box ;D

[MartyParsons]

Hello,
We have many customers using the  7/39 blade. Very little issues with blade breakage. Weld breaks are different than gullet brakes. .055 blades have less flex life than thinner blades. If you are running .055 blades then you need to shorten your run time to achieve longer band life.
I talked to a customer last week with a LT15 with blade breakage issues at the gullet. They were running the blade for days before changing. When I explained the run time should be about 500 to 800 bd/ft on a .045 blade there was silence on the phone. They said they would try to change the blade more often. I thought they should change the blade at least twice in a 8 hour shift from what they described. Communicating what needs to happen and why can be interesting. They lady said there were three in the family working at the mill all day sawing at least 10 logs a day. I asked them how many bd/ft they had sawn.  She was not sure. I asked how many packs of lumber have they produced, she said they had sold two trailer loads.
This information adds to the questions. How big was the trailer? How large are the logs? How long are the logs? What kind of wood are they sawing? And more and more. I enjoy spending time resolving issues. The sad thing is when they dont call and we do not get a chance to help when they get frustrated, some even give up.

Hope this info helps!

Marty

[Magicman]

We did not have any blades to break in the weld.  I contribute our breakages to (1) logs2lumber was pushing a dull blade trying to finish the last couple of logs, and (2) Hookpilot does not idle his mill on gigback which significantly increased the blade run time.

[dustyhat]

Marty parsons maby thems some big logs there sawing lol. never have tryed woodmizer blades , are the very costly and can i buy a couple at a time to try?