Author Topic: Buzz Saw  (Read 18524 times)

Offline gunna

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Re: Buzz Saw
« Reply #30 on: February 13, 2015, 07:45:39 AM »
Just thinking Brian, the wood of those "broom" trees will be pretty dry and hard, ie difficult to cut across the grain with a small "low-powered" saw. Perhaps you might have to source some green timber from tree prunings or similar.

Ian.

Offline Ian S C

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Re: Buzz Saw
« Reply #31 on: February 13, 2015, 12:27:54 PM »
If the "Buz Saw" wont do the job, perhaps something like this will, a junior hacksaw blade, and a 5 watt max power Stirling Engine. A saw similar to this could be built using coping saw blades, or some times a wood cutting blade can be got for the Junior hacksaw frame.
Ian S C

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #32 on: February 13, 2015, 05:49:57 PM »
Went down street this morning and invested a whole $11.87 on a blade.  ---And by the way, the blade is 0.036" thick at the hub area. The carbide teeth are .063" wide.

Offline Tennessee Whiskey

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Re: Buzz Saw
« Reply #33 on: February 13, 2015, 06:34:21 PM »
Brian, digging this one also. I'm thinking a finer pitch blade is going to be best for the broom tree wood, like a finishing cut blade.  That one is an ali cutting machine   though, as well a good rough cut wood blade. .

Eric

Offline jonesie

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Re: Buzz Saw
« Reply #34 on: February 13, 2015, 07:15:11 PM »
hi Brian you could also use a fine tooth slitting blade in what ever size and thickness you have. jonesie

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #35 on: February 14, 2015, 09:21:38 PM »
That's enough building for one day. I have enough assembled now to test run this thing. No point in spending time on the frame if the saw doesn't cut the way I want it to. I am not terribly impressed by the "look" of the sawblade. I think a slitting saw would have been closer to the look of a real buzz saw blade. Oh well, I only paid $11 for this blade. If it cuts okay, I probably won't change it.


Offline Brian Rupnow

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Re: Buzz Saw
« Reply #36 on: February 14, 2015, 11:25:10 PM »
The blade most definitely cuts!!! It cuts very well too, and doesn't seem to put any strain on the mill.  Probably tomorrow I will jerry rig the blade and arbor up to some kind of stand and drive it with my side valve engine just to be absolutely sure. Assuming the test is successful, I think I will bolt  two pieces of 1/4" plate together and cut out both sets of frames at the same time. Since both frames have material to be cut away from the 'inside' of the perimeter, I may use my sabre saw with a metal cutting blade to cut away most of the inside material, then finish up on the mill. I can cut the outside of the frames with my bandsaw, then clean up on the mill.

Offline Ian S C

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Re: Buzz Saw
« Reply #37 on: February 15, 2015, 11:42:52 AM »
I think you are going the right way with the tooth size, if you went too small(scale of a full size blade)you might have a problem with the teeth getting clogged up.
Dremmel, and Proxon make much smaller blades.

Ian S C

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #38 on: February 15, 2015, 02:32:51 PM »
News is not good this morning!! Saw is jerry-rigged to side valve engine. My first problem was keeping the darned belt aligned so it wouldn't fly off as soon as the saw came under load. Many of the partial cuts in the wooden dowel are a result of the belt flying off as the saw reached the heaviest part of the cut. Then when I finally got things moved around to where the belt wouldn't fly off, the engine just ran out of power and stalled about half way thru the "log". I have to ponder this now for a while. I think the sawblade at 1/16" wide is too wide for this set up. Or--the pulley on the saw is too small and needs to be bumped up in size. I didn't want to do that, because I am trying to keep the saw pulley the same size as the saw hub so the log doesn't rub on the drive belt. Or--I need a more powerful engine. The likeliest bet, and the least work for me, is to find a thinner saw blade. As I said in an earlier post, those blades come in 3 packs, which I didn't look at. There may be a thinner, finer toothed blade in the 3 pack. I will investigate this tomorrow. EDIT---I just tried a 1" balsa "log" and the saw goes thru it like poop thru a goose!!!
« Last Edit: February 15, 2015, 03:27:50 PM by Brian Rupnow »

Offline Jasonb

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Re: Buzz Saw
« Reply #39 on: February 15, 2015, 04:26:05 PM »
Brian, I think you may want to up the size of the engine pully as the blade RPM are not likely to be high enough, take a look at the other side of that cross cut rig I posted earlier and the pully is very large compared to the one on the shaft. Should also help make it "buzz"

I wonder if a 4" x 1/32" slitting saw would be an option with a lowish tooth count.

Have you crowned the pullies a sthat will help keep the belt tracking in the middle.

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #40 on: February 15, 2015, 07:27:35 PM »
Jason---There is substance to what you say, however, the greater differential there is in pulley size, the more mechanical disadvantage the engine is running at. I am running a 2:1 ratio right now. If I upped it to 3:1 as your picture shows, my engine would be at an even greater disadvantage.  I will play with saw blade thickness first. Many of the buzz saws that I have seen pictures of have a flywheel attached to the end of the saw arbor. I may have to consider that also.---Brian

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #41 on: February 15, 2015, 07:49:56 PM »
Time for some "outhouse math". I just googled it, and linear blade speed should optimally be 150 foot per second. My engine is running at 1500 RPM.  My blade is 3.375" diameter running at approximately 3000 rpm. 3.1416 x 3.375=10.6"=0.88 feet per revolution. 3000 RPM divided by 60=50 revolutions per second.   50 RPS x .88 feet=44 linear feet per second. Jason you are right--Looks like my sawblade should be turning almost 3 times faster than it currently is, unless I have bumbled the math.---Brian
http://joneakes.com/jons-fixit-database/2226-at-what-speed-should-my-saw-blades-spin-

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #42 on: February 15, 2015, 11:16:10 PM »
Makita also sells a 44 tooth blade which has a center hole to fit the saw arbor I made. (The blade I have, which is VERY aggresive has 24 teeth.) I will call tomorrow and order the 44 tooth blade.---There is a picture of it in the link.
http://www.amazon.ca/Rockwell-RW9232K-VersaCut-Circular-3-Piece/dp/B005BTM0YE/ref=pd_cp_hi_1

Offline Brian Rupnow

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Re: Buzz Saw
« Reply #43 on: February 16, 2015, 09:25:29 PM »
And that, my friend is what a whole days work looks like!! Both end frames are finished, the 1/4" diameter cross ties are finished, and I have put a 1 degree crown on the pulley to help keep the belt on it. All the stores are closed here today for a provincial holiday, so I couldn't order my new blade. All the companies I normally do business with are closed today, and wife is at work, so I played all day in my shop!!


Offline Brian Rupnow

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Re: Buzz Saw
« Reply #44 on: February 17, 2015, 01:50:58 AM »
I have decided that the buzz saw really needs a base which can be screwed or bolted to the table-top for actual running. So--the clearance holes which were originally called up in the underside of the endstands have changed to  #5-40 tapped holes, and a 1/4" thick baseplate has been added to allow me to firmly attach this saw to my test bench for running.