Ultralight Saws

Wouldn't the pressure created to keep the blade stiff put too much lateral pressure on the carbon and snap it. I'm prolly saying things wrong.

I'll be interested to see what your testing shows. Good idea… I just wonder

After snapping two prototypes of the bow saw at the joint I have heavily reinforced the longer tube that inserts into the shorter handle tube. Internally it has a thin steel tube with a solid fiberglass plug about 4" long. And the longer tube is actually two tubes, one epoxied over the other. I have loaded it with over 50 lbs. of force along the axis of the blade and it has held up so far. If I can't get the 24" blade tight enough to work I will try a 21" blade by reducing the length of the handle and making the angle between the blade and the long tube more acute, so that more of the force from tensioning the blade will be compressive down the tube instead of bending at a right angle at the joint:

The engineering terms are "tension" and "bending moment."

Tension would be pulling the long tube away from the handle. Compression is pushing the long tube into the handle. Tension on the blade will compress the long tube into the handle. The smaller the angle between the blade and the long tube the more the tension of the blade will translate to compression instead of bending moment on the long tube.

Very interested in your UL saw experiments. Watching with anticipation. Where are you finding aluminum and steel tubing of just exactly the right ID and OD? Good find. Is there any way of making the connection point between the two tubes, a metal-to-metal connection point, perhaps of aluminum?

Also: when grinding those pruning-style pull saws, tell me you have wrapped the blade in a wet towel before you grind. It will help you keep the blade's temper during grinding.

Delmar, I will be sure to post my results. It may be a few weeks till I'm able to machine the aluminum fitting for the butt end of the handle and the tensioning screw.

Finding the right size aluminum and steel tubing has been a matter of some luck and some reverse engineering: I use standard 1/2" and 3/4" aluminum tubing and cut the tapered fishing pole and golf shaft to fit. There was about 6" of tapered steel tubing at the end of the particular golf shaft I cannibalized, and the fiberglass plug was from the fishing pole, both of which happened to be the right size. There has also been some hand work slightly enlarging inside diameters where things were too tight, and copious amounts of epoxy where things were a little too loose.

I thought about trying metal-to-metal at the joint but I would have needed to use 5/8" aluminum tube for the inserting end of the long carbon tube and, given the 3/4" size of the aluminum tube I used for the receiving part of the joint, there wouldn't have been enough metal left if I enlarged the hole through it to receive the 5/8" tube. If this design doesn't work, I have my eye on a beefier salt water fishing pole with larger diameters than the one I happened to have at hand, which would let me up-size all of the aluminum tubes.

Good to know about the wet towel. I will do that going forward. Fortunately I don't think the blades got too hot, as I was able to hold them about 1"-2" from the spot I was grinding, and when it got too hot for that I air-cooled the blade with the breeze coming off the adjacent 6" wire brush wheel.

You're doing a heck of an amazing fabrication job, given you're not using a lathe or a mill!

I recently ordered a custom small Sawvivor that can take 12" hacksaw blades, and it arrived sized wrong (close, but would not take the standard hack blade). So I had to do a bunch of customized machining to get it to work, but now it's the bee's knees; can cut metal, woodwork (fine) or pruning (rough), given the correct blade. And very light for its skillset.

While working on (and with) the saw, I really grew to appreciate the articulated setup of the hinges. Your nesting design is better for space savings and weight, but have a look at the Sawvivor hinge anyway; it's a thing of beauty, very stout. Maybe a nudge to get you thinking about square joints rather than round ones.

If I were fabbing your saw, I'd certainly try to sleeve all the ends. Regarding the corner connection, perhaps with a "tongue and groove" type fitting would work well. The "tongue" can be thinned out in one dimension so it doesn't get so thick, (rectanglish,) and might uncomplicate the "round into round" issue you're having. On the downside, that would require a square hole to fit into, which would require broaching if you didn't find some other workaround.

I don't have problems with pinned or screwed connections. People generally denigrate them, because then you have a pin or screw you can lose, rendering your saw into spare parts. That's true, but, this is BPL, where you must behave thoughtfully. I don't mind screw together field equipment.

Sheath? Especially for those pruning saw blades.

Weight of said sheath will be?

Buck saw.. http://www.qiwiz.net/saws.html

For the pruning saw blade sheaths I use a combination of a report binder spine over the teeth, and thick card stock paper with duct tape reinforcement at the edges. Weight is .7 oz for both.

For the bow saw I use two report binder spines over the teeth and a couple of "hair scrunchy" rubber bands to hold them in place, then everything goes in a long, slender cloth pouch I cannibalized from a tenkara fishing rig. Weight is .8 oz.

Those buck saws are awesome! 3.95 oz for 15" and 8.8 oz for 24". That is ultralight. I'm curious how the blade is connected. The picture on the web site is fuzzy, but it looks like a loop or loops of wire. Do you know?

Now I have a weight goals for my bow saws. Thanks for the link.

"The picture on the web site is fuzzy, but it looks like a loop or loops of wire. Do you know?"

Split-rings.

Watch the video.

I'm not going to give the answer away. I suggest you buy one and support another BPLr. The saw works great.

Full disclosure, and a good price too.

I have the Little Buck and can confirm that it's a very nice and useful saw. T It's pretty secure once all tightened up and I've cut through 6" branches with it before, just need to be careful not to stress it too much while sawing. I agree on supporting a fellow BPL'r.

I can re-weigh mine tonight, but my spreadsheet says 5.0 oz (with the tyvek envelope) so it's a bit heavier than what the site lists it at. You do have to have a way to cover the blade when it's in your pack, the envelope works well but there are likely lighter ways to do it.

Just carry the blade and use green wood for the bow:
http://www.raymears.com/Bushcraft_Product/791-Bahco-23-24-Raker-Tooth-Hard-Point-Bowsaw-Blade-24-inch/

I keep reading this as "ultralight straws" and think, seriously? Might as well shave some weight by shaving your head/all body hair.

Haha.

Are wire saws any good? I bought one for a buck on STP just to have around, buy have never used it.

“Are wire saws any good?”

Depends on the wood.

Dry is ok.

Wet not so much.

Got a Lot of time and strength?

I like the blade-only-green-wood idea, but how do you cut the piece of green wood from the tree and the blade mounting slots in the end? I guess this would be a LNT (Leave No Trace) no-no.

>"Might add well shave some weight by shaving your head/all body hair."

Voyager, the first around-the-world, without-refueling flight gained 11 miles of range because Jeana Yeager cut her waist-length to shoulder length beforehand.

>"Are wire saws any good? I bought one for a buck on STP just to have around, buy have never used it."

If there's something you HAVE to cut – a stick to the right height for a tarp pole or split, an arm pinning under a boulder, . . . they're good for that. If I was going to be making dozens or hundreds of cuts because my primary stove was wood-fueled, then I'd want something else.

"Just carry the blade and use green wood for the bow:
http://www.raymears.com/Bushcraft_Product/791-Bahco-23-24-Raker-Tooth-Hard-Point-Bowsaw-Blade-24-inch/"

That is more difficult than it sounds and it takes time. It's a skill worth knowing and trying out but not a practical way to save weight.

David,

Do you mind if I ask which pruning saw from which the 10.5 blade came from? Do you have any plans to sell any of these?

Thanks

Derrick

Derrick,

I got the 10.5" saw blade from a generic hand-held pruning saw at Orchard Supply Hardware. The 15" blade I'm waiting to receive is a replacement blade Fiskars 9333 that I ordered from Amazon for $10.55.

I do think I will sell the saws, once I have perfected them. The lightening holes are a PITA to drill, and dull even cobalt bits after just a few holes, but I have Drill Doctor on the way to resharpen the bits frequently. I also intend to try grinding slots with a small abrasive wheel, perhaps a Dremel, since the blade steel is so hard.

In the spirit of multiple uses, I will also sharpen the back edge of the blade to make a knife out of it too.

I'd like to see them for sale ;-)

"Are wire saws any good?"

None that I have tried. :-(

What I have purchased and used is the Pocket Chainsaw.

http://www.campingsurvival.com/pochsawofacu.html

It weighs 5 ounces in the can so it is a bit heavy compared to the "straight" saws. Substituting another container could save some weight.

I used it to clear out a small tree stump next to my fence at home and was impressed at how well it worked. I used some small pieces of 1/2" PVC pipe inserted through the rings as handles. I also dual used it as a "rock" in my bear bag throw line pouch on my last hike which kind of abused the container. ;-)

FWIW The only real use that I had for my saw was as a throw weight. I was able to process my firewood using my hands and leverage between two small trees growing close to each other. Splitting wood could easily be accomplished by batoning with my knife. But I also never really needed to split my firewood either.

Party On,

Newton ;-)

"FWIW The only real use that I had for my saw was as a throw weight. I was able to process my firewood using my hands and leverage between two small trees growing close to each other. Splitting wood could easily be accomplished by batoning with my knife. But I also never really needed to split my firewood either."

In my experience, the wood that you can break through leverage is usually older and cracked which allows moisture to get in it. I usually go for wood that hasn't been dead for too long, standing or pieces propped up vertical to find dry wood. That stuff you can't break by hand easily. Pretty much the only time I carry a saw backpacking is in wet weather where I don't want to mess around. It makes things much easier and faster, just cut and split, cut and split instead of messing around with damp twigs.