CBT?

[einsteinjon]

Hi all,

Was hoping to be enlightened with your experiences/knowledge of the Busse CBT. I recently got a Battle Saw, but have yet to use it. I am wondering, is the CBT strictly a weight saving things while adding strength, with the focus being making a more efficient chopper? In other words, will a CBT grind excel at things other than chopping?

My main use of big knives tends to be having some fun processing wood from cleaning up my backyard...I have a lot of overgrowth, dead trees, yucky looking trees, etc. This involves chopping, batoning, limbing, etc. With the CBT I am primarily wondering about batoning, and the CBT maybe getting caught up and slowing the process. Any thoughts from you folks having used the Battle Saw or other CBT knives?

Also, what is the consensus around here about grinding out the CBT to make the knife smooth? Would that compromise the strength too much? On my Battle Saw the first 1/2 inch or so from the edge seems to be a little thicker than the CBT above, and I am wondering if that would cause the knife to get stuck in something. So my thought was grinding it all out smooth but I'm not sure how that would go.

Or will the CBT excel as is? Just looking for thoughts before I start using her!

Appreciate the help!

 

[PeteyTwoPointOne]

I'd say, it may knock down some resistance especially batoning thru dense, tight and tough stuff.

Kinda like a cheese knife.

But I haven't noticed any discernable difference. The biggest game changer for me batoning and processing wood is satin finish sprayed with PAM. I've FELT the difference there for sure.

CBT may be lighter...I haven't searched the stats...but I don't count ounces when I pack big BUSSES-- it just doesn't make that much of a difference to me when I'm already committed to packing a 10 or 12 inch blade.

If I have to go with most bang/buck/weight ratio-- it's B8 all the way on days I want to move light & faster.

Having said that I love the way CBT looks. So I'm a big fan.

Here's my Saw...she had some lovely CBT under the paint and THERE IS a noticeable difference in the stripper v. the painted blade!

It is VERY EVIDENT with the teeth...the bite is REAL!

I notches a pine 2x4 like nobody's business.

FWIW, I think a Competition Finish Battle Saw straight from Wauseon would be a SMASH HIT!

 

[Robdude]

Awesome pics Petey!!

 

[Fonedork]

I think it’s supposed to help prevent the blade from sticking actually. Besides lightening it I guess.

If you’re deciding between using it as is or using it after you grind it down, might as well use it as is now and check out the CBT performance.

 

[bullpin]

Those are some really good pics bro.

 

[zmbhntr]

I used to really like CBT, and it certainly does look cool. That being said, as I understand it, CBT is traditionally how the blade looks after milling but before it gets a major belt sanding; therefore, blades released with CBT have a lot less labor involved than blades without CBT (and therefore a good amount of cost savings as well). Think about it, the the new mistress looks like a knife pretty much straight off the CNC mill, and really the only thing that needs much manual work done on the blade is the edge itself. I'm not trying in any way to be anti CNC here at all, I'm just trying to keep it real. If CBT makes INFI more affordable it's a good thing for most people.

In terms of performance I have used a Moabolo with and without CBT, and the Moabolo without CBT performed significantly better than the Moabolo with CBT (chopping wood). Mileage may vary of course, and my understanding may be off base, but that's how I understand it and that's my actual real world experience. At the end of the day any knife can have its shoulders thinned out behind the edge, have a screaming edge put on, and be a significantly better chopper than it is stock. This could of course have some negative effect on edge durability depending on the sharpening angle, how much material is removed, etc. etc.

 

[AZTimT]

The CBT is designed to maintain, or exceed strength while saving weight. They are fairly unique to Busse and do not come in LE satin offerings, but they look good and perform amazingly well. If that also provides a cost savings, even better. I had a show special .25 CGFBM I scored at Blade that was full flat grind without the CBT's and it was much heavier in hand than the regular CBT version. The difference was significant enough that I could not see myself ever using the non CBT version and sold it off.

If the OP really wants to grind off the CBT to lighten up and thin out the primary grind that is up to him, but it is not something I would do to an INFI Battle Saw. Maybe a BG Battle Saw as it is not going to be quite as desirable long term.

The MOABolo differences make it questionable as to how much the CBT effects performance vs. more likely difference between a .34"-.36" full flat grind primary angle (thinner wedge) and a .38" CBT saber grind primary angle (fatter wedge).

 

[zombieassassin]

I personally am not a fan of CBT blades, that being said....it makes them look so much cooler. Faster too....but from my experience, a smooth, stripped and polished blade with Pam or WD-40 works like nobodies biz as someone stated above....p2.1

 

[nydude]

My understanding was that it was a pretty straight forward way to increase lateral strength while saving weight.

Also, I'm not a maker but I don't think it's less work at all. It seams like they would have to start with more metal and do more work. Also, I think CBT blades are a little more expensive... ultimately guessing here though.

 

[Crosier]

I used to really like CBT, and it certainly does look cool. That being said, as I understand it, CBT is traditionally how the blade looks after milling but before it gets a major belt sanding; therefore, blades released with CBT have a lot less labor involved than blades without CBT (and therefore a good amount of cost savings as well). Think about it, the the new mistress looks like a knife pretty much straight off the CNC mill, and really the only thing that needs much manual work done on the blade is the edge itself. I'm not trying in any way to be anti CNC here at all, I'm just trying to keep it real. If CBT makes INFI more affordable it's a good thing for most people.

In terms of performance I have used a Moabolo with and without CBT, and the Moabolo without CBT performed significantly better than the Moabolo with CBT (chopping wood). Mileage may vary of course, and my understanding may be off base, but that's how I understand it and that's my actual real world experience. At the end of the day any knife can have its shoulders thinned out behind the edge, have a screaming edge put on, and be a significantly better chopper than it is stock. This could of course have some negative effect on edge durability depending on the sharpening angle, how much material is removed, etc. etc.

So if I’m understanding this correctly, CBT is how the blade looks after it’s first cut(CNC) and making it any other type of grind is more work?

 

[Jerry Busse]

CBT is much more expensive than grinding the bevel. It does however make for a stronger blade.

When we grind a bevel, the blank is full-thickness and only the outer profile has been CNC machined.

My recommendation is that you take your Battle Saw out and "beat it like you stole it".

If it doesn't light your fire, then grind away!

Make it yours my friend!

Jerry

.

 

[einsteinjon]

Thank you Jerry! My main concern was that if I ground it then it would be too thin/weak, but glad to hear otherwise!

 

[zmbhntr]

Very interesting info indeed, thanks for responding Jerry. I know for sure that some other makers use their mills to machine the blades down so that they don't have to spend as much time manually grinding, which enables them to make more knives in less time (especially if they are a one or two man show); some of them even have the step down milling marks which if you squint hard enough look CBTish. As is true many ways, Busse is different from the competition.

 

[Crosier]

Thanks for the clarification Boss!

 

[Salival]

I have 2 MOABOLOS, one each.
Chopping > FFG
Splitting-batoning > CBT
Destroying, prying, open a car in two, fighting an army or haevy armored zombies > CBT

The FFG is also a bit lighter (0.38 vs 0.35), so it fatigues the arm less.

The theory behind is, that the grooves will make the blade bend less; so with an identical mass the CBT blades will be stiffer....... anyway, even to bend the FFG you'll need some inhuman strength....

Answer get both.

 

[einsteinjon]

Thanks for that Salival...interesting to hear at least with the Moabolo it is FFG for chopping and CBT for batoning. I was thinking it would be opposite!

 

[Currawong]

I have 2 MOABOLOS, one each.
Chopping > FFG
Splitting-batoning > CBT
Destroying, prying, open a car in two, fighting an army or haevy armored zombies > CBT

The FFG is also a bit lighter (0.38 vs 0.35), so it fatigues the arm less.

The theory behind is, that the grooves will make the blade bend less; so with an identical mass the CBT blades will be stiffer....... anyway, even to bend the FFG you'll need some inhuman strength....

Answer get both.

To my eye (I could be wrong) my CGFBM with CBT looks like it has an overall convex grind. So in the part of the blade between the CBTs and the blade edge the bevel angle will be greater on a CBT knife than on an FFG one. This would make it a worse chopper but a better splitter than FFG from factors unrelated to the presence of CBT (i.e. from basic blade geometry). Separate from that the presence of CBT would add stiffness, but would not affect performance in any other way apart from there being less binding.

A truer comparison, that would show the difference made by just the CBTs on performance in chopping or cutting (etc) would be between a CBT and a normal convex-ground blade.

Does this sound right?

 

[AZTimT]

Jerry's feedback is very interesting and in line with what I have suspected for a while. The machining to make the outer convex profile on a CG NMSFNO, FSH or NMFBM is often still visible when the coating is removed. You can also see it between the edge and CBT grooves on most stripped CBT blades as well in those fine little grooves that can be sanded off with a little bit of work.

In regards to the two different MOABolo performance: Skinnier blades with narrow primary angles almost always chop better than a fatter blade angle of similar (or even heavier) weight, that's just how geometry works. We see that with 1311 performance keeping up with an FBMLE or similar sized blade at nearly double the weight. Conversely a fatter wedge will split wood better as it can spread the grain of the wood apart faster. Fun stuff.

Along those same lines, that is the same reason that a very pointy Russian AK74 5.45 round outperforms on penetration through wood compared to the much more blunt tipped 5.56 round. I have even shot 5.56 FMJ bullets loaded in a 5.45 x 39mm case to confirm the performance difference with my own testing, just to make sure that the same powder, weight, velocity & primer were used to eliminate other variables for science... and fun. The difference was over 4 inches of penetration on average that the 5.45 bullet outpenetrated the 5.56. For someone who lives in the woods, that is good info to know.

 

[AZTimT]

To my eye (I could be wrong) my CGFBM with CBT looks like it has an overall convex grind. So in the part of the blade between the CBTs and the blade edge the bevel angle will be greater on a CBT knife than on an FFG one. This would make it a worse chopper but a better splitter than FFG from factors unrelated to the presence of CBT (i.e. from basic blade geometry). Separate from that the presence of CBT would add stiffness, but would not affect performance in any other way apart from there being less binding.

A truer comparison, that would show the difference made by just the CBTs on performance in chopping or cutting (etc) would be between a CBT and a normal convex-ground blade.

Does this sound right?

Yes and no. On an INFI CGFBM the CBT's stick out from the primary bevel, so they do actually increase friction at the depth where they start. All of the other CBT models since have recessed grooves so they can actually reduce friction surface. But otherwise your theory seems sound.

 

[Salival]

To my eye (I could be wrong) my CGFBM with CBT looks like it has an overall convex grind. So in the part of the blade between the CBTs and the blade edge the bevel angle will be greater on a CBT knife than on an FFG one. This would make it a worse chopper but a better splitter than FFG from factors unrelated to the presence of CBT (i.e. from basic blade geometry). Separate from that the presence of CBT would add stiffness, but would not affect performance in any other way apart from there being less binding.

A truer comparison, that would show the difference made by just the CBTs on performance in chopping or cutting (etc) would be between a CBT and a normal convex-ground blade.

Does this sound right?

That's true.

The difference in performance between my 2 blades comes mostly from the geometry.
If the blades had identical thickness, the FFG would still chop better, since the CBT one has a saber grind, so a more obtuse geometry.
If the CBT where FFG I guess it would be a even match.... maybe a slightly smoother penetration form the nonCBT (even more if satin or with some WD40), but the CBT one will shine when it comes to not get stuck, especially in fresh and dense wood.

I think that the stiffness is important in the long run, I mean, it's realy hard to break a Busse, even more a fat model... but less bending less chances to get a plastic deformation.