# Buzz Saw



## Brian Rupnow (Feb 9, 2015)

In days of old, when knights were bold--and chainsaws hadn't been invented----People still had to saw logs up into 16" lengths for "stove-wood" to burn in the kitchen stove, or the box-stove for heating. Although this could be done with a cross-cut saw (I sweat even thinking about it), to get enough wood cut up to last all winter, most people used a tractor driven "buzz saw". This was generally a 36" or so diameter circular saw, fitted to one end of a shaft which had a flat faced pulley on the other end. The saw was driven by a flat belt from the tractors power take off. The saw and bearing supports stayed stationary, but a "swing cradle" attached to the same supporting frame had a place to lay a four foot length of log on, and was pivoted near the bottom so the cradle and log could be  swung into the saw blade to cut off a 16" length of "firewood", then the log was advanced by hand and swung in again to cut off another length. I know from experience that you could cut a prodigious amount of wood in a day, and if you didn't keep damned good awarenes of where your hands were at all times, it would cut a hand off just as quickly as a piece of log. Since I have already designed and built a sawmill and a wood splitter (and even though they were separated in time by about a century) I am thinking of building a "buzz saw" to add to my collection of engine driven models. I just did a bit of internet searching, and there are commercially available circular saw blades 3 3/8" diameter with a 15mm center hole, which would just be about right for sawing up 1" diameter broom trees into 1 1/2" lengths---for the wood splitter, of course. I don't want to build anything for a while now, but you do have to admit, it would fit right in with my other "forestry" themed models.---Brian


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## Swifty (Feb 10, 2015)

Hi Brian, I am so wary of circular saws that I don't even own a proper one, but I do have a small saw with the small dia blade that you mention. I needed to cut through my decking to reach a pit drain, so the little saw fitted the bill, just checked the blade size, 76mm dia x 1,2mm thick with a 10mm hole, it is also carbide tipped. The small width of these blades will help with the power required to cut through the broom trees.

Paul.


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## Cogsy (Feb 10, 2015)

My dad has a buzz saw at his property. We last used it about 5 years ago. It used to have a 48" blade but it developed a crack and he had it professionally reworked to about 36" to eliminate the crack (a very long time ago).

I hated the thing and always expected to either die or lose a limb when we used it. I much prefer my chainsaw (although that's caught me out majorly a couple of times as well). It just feels a lot safer.

But a mini one would be very cool to see.


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## Brian Rupnow (Feb 11, 2015)

Here we go!!! That's a 3 3/8" diameter Makita wood-saw blade, with 3/8" diameter shaft and all frames made from 1/4" aluminum plate, the cross ties between end-frames are 1/4" diameter round. and the log tray angle is 1 1/4" x 1 1/4" x 1/8" aluminum. The "log" shown is 1" diameter. There is no welding anywhere.


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## rodw (Feb 12, 2015)

Go for it Brian. I have used the tractor mounted version in your first picture. When the saw was lifted on the PTO for travel, the geometry disengaged the drive belt which went slack. The spinning saw blade was very close to your ear when in the drivers seat which was very disconcerting! She would bounce a bit at the top of the travel and it scared the bejesus out of me first time! Of course sawdust and wood chips were flying everywhere.

My father used to remove his belt and strap his leg to the upright when cutting firewood so he could engage the table without using his hands. We thought he was mad! But he did have all of his fingers when he passed away.

We also had another fixed mount circular saw which had a sliding table on roller bearings doused in a thick coating of grease. We just backed the tractor up and hooked up the flat belt. But we had to double handle the logs and bring them into the wood heap where the saw table was. You can add that one to your project list too!

The PTO saw made the job much easier. The circular saw was much faster than a chainsaw so we'd cut logs down to manageable lengths and cut to woodbox size with the circular saw.

What we called a buz saw was quite different. Some called it death on wheels







I remember they were made by Mobilco. Fortunately Dad got rid of his when I was about 4 so never had to pilot one!


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## rodw (Feb 12, 2015)

You can make a whole collection of sawmills Brian. This kind of thing is similar to the bench saw i was describing.


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## Brian Rupnow (Feb 12, 2015)

There have been a hundred different ways to hook up circular saw blades to machinery since they were invented. The one I modeled is what I grew up knowing as a "buzz saw". Thank you for taking the time to answer my thread and for the pictures.---Brian


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## Brian Rupnow (Feb 12, 2015)

Surely, someone-somewhere has built a model buzz saw!!! I can't find a link to one on google. Does anybody else know of one?


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## Brian Rupnow (Feb 12, 2015)

Hang onto your hats---Here we go---


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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)




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## Brian Rupnow (Feb 12, 2015)

To print any of these drawings, click on the actual drawing on your computer screen---That will take you to Photobucket. Choose "download" option from upper right corner. This will download the picture, then you can print it on whatever size paper your printer has. Good Luck!! Let me know if you build one. I take no responsibility for cut fingers!!!---Brian


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## Brian Rupnow (Feb 13, 2015)

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.


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## Brian Rupnow (Feb 14, 2015)

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.


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## Brian Rupnow (Feb 14, 2015)

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.


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## RichD (Feb 14, 2015)

Brian,
My Grandparents (Mom's side) had 50 acres up in the mountains and lived up there full time. He used a 1936 Graham automobile with an angle drive rear differential (one side cut off on the passenger side). The blade ~24" maybe bigger, was mounted to a flange directly off that short side. It had a wooden sled mounted on the back of the bare car frame where the wood was placed for cutting. The sled had a long piece of rubber inner tube running to the throttle. 2nd gear, low engine speed was how he used it when cutting. It's still up there last time I looked. I'll have to take a ride up there this spring and take a couple of pictures.

If I remember right the car was my Father's High School car before. I might be wrong about the year but the pictures will tell the story when I post them.

Rich


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## Brian Rupnow (Feb 15, 2015)

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!!!


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## Brian Rupnow (Feb 15, 2015)

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-


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## tornitore45 (Feb 15, 2015)

> and doesn't seem to put any strain on the mill



I am not surprised, I have a similar blade 5" a bit less that 0.062 kerf and use it on the mill to cut aluminum 1" thick with no problem other than a racket.  I do not own any kind of power metal saw.  I cut 1/2" aluminum on the 10" table saw almost 1/3 as fast as hardwood,  teeth clenched all the way tough.


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## tornitore45 (Feb 15, 2015)

Your blade is roughly 1:10 scale of a 34" blade; such full scale blade would have a thickness of 5/8" and most likely bog down the full scale engine as well.


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## Brian Rupnow (Feb 15, 2015)

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/dp/B005BTM0YE/?tag=skimlinks_replacement-20


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## Brian Rupnow (Feb 16, 2015)

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!!


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## Herbiev (Feb 16, 2015)

Wife works on a provincial holiday and you play in the shop. I love it 
Looking forward to the test cuts.


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## Brian Rupnow (Feb 16, 2015)

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.


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## Brian Rupnow (Feb 17, 2015)




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## Brian Rupnow (Feb 17, 2015)

There we have it with 1" diameter log. Carriage swung out to receive log and carriage swung fully in to cut position. All I have left to build is the "swing limiter strap". I ordered a new fine toothed blade this morning.


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## Brian Rupnow (Feb 17, 2015)

I'm finished!!!  The bar which limits the amount of "swing out" of the log carriage is finished and installed. Now I have to be honest with you---I've built a lot of models of many different things in the last five years. This, however, is the only model I have built that actually frightens me a bit.  The original buzz saws, were horribly dangerous. People worked with them every day, and let me tell you---You had to be VERY aware of where that saw blade was and where your hands were at all times. It was unusual, but grizzly accidents did occasionally happen with them. ------------And this little saw is no different!!! I own a skill saw, a sabre saw, a chainsaw, a table saw, and a bandsaw.--I am very aware of the safety requirements when using them, and fortunately I still have all of my fingers. I will put a new fine tooth blade on this model saw, will power it up long enough to make a video of it working, and then will sigh with relief when it goes up 'on the shelf" with all my other models!!!


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## ShopShoe (Feb 18, 2015)

Brian,

There are more modern versions with blade guards.

http://www.newhavenpower.com/Woodsman250_Buzz_Saw.html


But, I do understand your model to be a version of what most people had through the years.

I have enjoyed this project and I may build it myself some day. (Like yours, to look at.)

--ShopShoe


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## Brian Rupnow (Feb 18, 2015)

If I have done this correctly, this link should get you a download of all the drawings.---Brian
http://www.mediafire.com/download/qaq9xdu4i1cqcsq/MODEL_BUZZ_SAW.zip


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## Brian Rupnow (Feb 18, 2015)

The "broom tree" I showed was actually a piece of 1" diameter wooden dowel from the lumberyard. They said that it was kiln dried poplar, but it seems to be harder than any poplar that I have experience with. I tried to buy a 1" softwood (pine or spruce) dowel, but wouldn't you know it, they don't carry softwood dowel!! Not to be outdone by adversity, I grabbed a couple of short pieces of spruce from my "wood scrap pile" (yes, I have one of them to) and made my own 1" softwood dowels. This yielded a nice little pile of 'cord-wood" to try out with my buzz saw when the new blade arrives.


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## Herbiev (Feb 18, 2015)

If you use two different coloured woods you could make a set of checkers :hDe:


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## Brian Rupnow (Feb 18, 2015)

Now THAT my friends, looks like a buzz saw blade!!! 44 teeth and only .028" thick. With any luck, tomorrow will see a buzz saw party!!!


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## Brian Rupnow (Feb 19, 2015)

And this my friends, is the end. I had a hard time to find an engine that would run the saw without bogging down in the middle of the cut, but finally used one of my faithful old hit and miss engines. This lends even a bit more authenticity to the video, because the hit and miss engine was the engine of choice for many buzz saws.  I probably won't use this saw again, because it is amazingly dangerous, just as it's full size ancestors were. It does work, and does indeed cut the logs, albeit more slowly than the full sized buzz saws with much more powerful engines did. If you build one of these, beware--they don't know the difference between a finger and a log, and will happily saw through either!!
[ame]https://www.youtube.com/watch?v=DKiX6ESTaV8&feature=youtu.be[/ame]


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## Cogsy (Feb 19, 2015)

Awesome work (as usual) Brian. Does this complete your woodshop now, or do you have another interesting gizmo to model for us?


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## Brian Rupnow (Feb 19, 2015)

Cogsy--I'm tired of modelling for now. I can't think of anything I want to build, and really, I have been on the forums too much this winter. Think I will try and lay low for a while now.---Brian


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## ShopShoe (Feb 20, 2015)

Brian,

I really like your videos when you have everything hooked up together. The saw is certainly working well.

Thanks for all your work.

--ShopShoe


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## Swifty (Feb 20, 2015)

Another great model, you deserve to have a break Brian, enjoy it.

Paul.


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## chrsbrbnk (Feb 20, 2015)

Kind of a side note, full size buzz saw blades and the larger scale ones  have no forward rake on their teeth so as not to grab  just sort of a safety surprise kinda thing   there's some pretty decent videos on you tube about blade sharpening


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## barnesrickw (Feb 20, 2015)

Now you need a log splitter.


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## Brian Rupnow (Feb 20, 2015)

barnesrickw said:


> Now you need a log splitter.


You've been away for a while, haven't you!!!
http://www.homemodelenginemachinist.com/showthread.php?t=24070


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## barnesrickw (Feb 20, 2015)

Brian Rupnow said:


> You've been away for a while, haven't you!!!
> 
> http://www.homemodelenginemachinist.com/showthread.php?t=24070




Yep, that was the subject of my post a few days ago.


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## bazmak (Feb 20, 2015)

Although its a model and replica of past machines its still as dangerous as
 any other saw.Put a perspex guard on it.It wont spoil the look
but any future demos especially with grandkids would be far safer
Regards barry


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## Brian Rupnow (Feb 23, 2015)

Baz--This is the only model I have built which scares me. I probably won't do any more demonstrations with it. I know it works, I've made the video. It can live on a shelf now for the rest of it's days.--Brian


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## bazmak (Feb 23, 2015)

Even sat on a shelf motionless it can still give a nasty cut to curios little fingers


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## gartof (Feb 23, 2015)

Holy living in a padded room Batman!!


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