# Powered hacksaw



## savarin (May 23, 2020)

I'm thinking of building a powered hack saw (not 100% certain but maybe)
I've read the gingery version (bit flimsy in my opinion) watched plenty of youtube versions.
A lot of then only use around 2" max stroke of the saw blade which seems to be a waste to me.
what is the maximum length of stroke for a 12" saw blade?
I'm thinking that if the saw almost touches the vice edge on the forward stroke then that vice edge almost reaches the middle of the blade on the back stroke then just short of half a saw blade length of material could be cut.
Am I wrong in my thinking?


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## projectnut (May 23, 2020)

Have you considered purchasing an older commercial power hacksaw like a Kasto, Racine, or Peerless?  I picked up a Racine 66W-2 a few years ago for far less money than it would have taken to build one.  It uses standard 14" power hacksaw blades, can cut 6 5/8" flat or round stock, has 2 blade speeds (100 spm and 140 spm) and has a 1 hp motor.  Mine still has the original "patina" in that I don't turn my machines into show pieces, just functional tools.

In our neck of the woods you can get them for next to nothing.  I paid less than $200.00 for mine and all it needed was a good cleaning before putting it to work.  Here are a couple pictures of the machine, and a link to a Racine brochure with the specs.  Blades are available from several industrial vendors, and on eBay.  If you go to eBay have patience.  There are several vendors asking $10.00 to $20.00 per blade.  I have been able to find 75 blades with tooth configurations from 3 tpi to 14 tpi for less than $3.00 each.









			https://ozarktoolmanuals.com/wp-content/uploads/pdfcatalogs/Racine_1957.pdf


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## savarin (May 23, 2020)

It may be just me but it always seems that here any old machinery is sold for its weight in gold.
For $200 I would be there like a shot


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## Winegrower (May 23, 2020)

Opinions vary, but i think a HF band saw would be faster, maybe cheaper and more useful overall.


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## C-Bag (May 23, 2020)

savarin said:


> It may be just me but it always seems that here any old machinery is sold for its weight in gold.
> For $200 I would be there like a shot


It’s all about location because here they seldom come up and are usually in $6-800 range. And are not in usable shape. And I agree with Winegrower, for the $$ it’s hard to beat the HF bandsaw for really close to that same $200.


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## Downunder Bob (May 23, 2020)

Unfortunately here in Australia we don't have harbor freight or any other of your big box hardware stores. Second hand power hacksaws are quite rare here and usually expensive also the blades are expensive whereas bandsaw blades are reasonably priced and easy to get.I think Charles best bet would be the Hafco BS-5V band saw that I have It's made in Taiwan and is reasonably good quality. Although it's sold as a horizontal blade saw, I found it quite easy to modify to a vertical blade saw. and am quite happy with it


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## matthewsx (May 23, 2020)

Or in Aus perhaps a Rong Fu (forum sponsor) bandsaw.

But, how much of a challenge do you want and how important is it to be able to watch the machine work whilst enjoying a cold beverage. 

Lots of us build stuff that we could have bought cheaper but when you build something yourself from scratch there's a certain amount of pride that just doesn't come from modifying someone else's stuff. If you have the time, tools and inclination why not build one from scratch. When you NEED a tool to get a job done then go the most expedient route. If you merely WANT a tool and have the time and ability to make it yourself I think the answer is clear.

As for the original question, it would seem that building it yourself you could easily make the reciprocating mechanism adjustable and experiment with different stroke lengths. Heck, you could probably even build a servo driven CNC power hacksaw if you wanted. 

There's probably a reason why commercial versions have limited stroke length, (most likely all the original designers are long dead so it'll be hard to ask them) but their reasons may or may not be valid for your uses. 
I say go for the DIY build and document it here.

John


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## savarin (May 23, 2020)

squeezing the cash for new from the financial controller will be a hard sell but filtering it out over a period of time whilst building something is easier.
Do I really need one? The majority of work I have done to date would have benefited greatly but I have no real idea of what future projects are in the pipeline. All I know is I have to build something, it keeps me sane.


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## Mitch Alsup (May 23, 2020)

In any event the stroke length for a 12" blade will be:: 12 minus maximum size object you want to cut.


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## Aaron_W (May 23, 2020)

I don't know why, but it seems like power hacksaws only use about 1/2 the blade, with about 1/3 actually cutting. I recently got a 12" and it is only rated to cut 4x4". 
I really can't see a reason why it couldn't use almost twice as much blade as it does, but it seems like all of them follow this "rule" so there is probably a reason for it.

I've seen some plans for a hacksaw in an old popular mechanics magazine that used standard hacksaw blades. I'm guessing those plans are out there on the internet as an alternative to Gingery if you don't like that design.


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## projectnut (May 23, 2020)

If you NEED a power hacksaw and want to build it have at it.  However if you just NEED a saw, I would go the bandsaw route.  The bandsaw is far more efficient, and relatively easy to build.  

Being in the rust belt I regularly find quality commercial grade equipment for minimal prices.  In most cases it's not even worth considering building something because good machines can be had on a daily basis for half or less than what it would cost to build something comparable.  I can start using a commercial machine within hours or days of bringing it home, not weeks or months.  When I "need" a machine it's usually for a job in progress or one that needs to be completed by a certain date.  

I purchased the power hacksaw a few years ago when I had several big jobs in the works.  The saw was the choke point on several of them.  I must admit with all that was going on at the time it did take a couple weeks to disassemble, clean, move to the shop, and reassemble.  It's worked great since the day I plugged it in.  It is used as a backup when the bandsaw is busy.  In the scheme of things I would say it does less than 20% of the saw work in the shop.  So far the only expense beyond the initial purchase price has been  a static phase converter (on sale for $49.00), coolant ($22.00), and blades $2.75 x 75= $206.25).

I found this one on the local Craigslist with an asking price of $350.00.  When I went to look at it the owner said "don't be scared of the asking price, If you're interested I'll give it to you for $200.00 minus the money in gas it took you to get here.  I was a bit shocked at the offer and asked why the difference in price.  He said he wanted it to go to someone who would actually use it, not  scrapper.  After a short inspection he loaded it in my truck and I was on my way.


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## silence dogood (May 23, 2020)

Savarin.  Check out the "Simple Power Hacksaw for Small shop" by Edgar T. Westbury.  Also Hemmingway kits that you can buy  a kit or just the plans.   The pdf even shows you how to build the saw without having to use castings.   I don't think that Savarin would have any problems building a power hacksaw.  After all, this is the guy building a precision telescope.  
I understand your concern about your concern since most of the cutting will be confined to a small portion of the blade when cutting small stock.  Just add a block on the fixed side of the vise  now and then and your stock will be cut on a different part of the blade.


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## projectnut (May 23, 2020)

On a commercial saw like the Racine in the pictures of my previous post, the back half of the vise can be moved.  Generally it's moved for angle cuts, but both bolts can be loosened and the plate can be moved forward about 4".  This will allow you to use a different section of the blade.  The only downside is that the back plate then has to be squared to the blade.  When in the farthest back position it is automatically squared.

I think you'll be surprised how long one of these style blades lasts.  In the shop where I worked we had a similar saw.  That one had a 4 speed gear box for different blade speeds, but other than that was identical.  Our shop was a prototype shop, not a production shop.  However the saw was busy almost all day every day.  Guessing it was busy 30-35 hours a week a 4 tpi blade would last about 6 months.  That's between 750 and 875 hours of cutting on a single blade.


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## silence dogood (May 23, 2020)

projectnut said:


> On a commercial saw like the Racine in the pictures of my previous post, the back half of the vise can be moved.  Generally it's moved for angle cuts, but both bolts can be loosened and the plate can be moved forward about 4".  This will allow you to use a different section of the blade.  The only downside is that the back plate then has to be squared to the blade.  When in the farthest back position it is automatically squared.
> 
> I think you'll be surprised how long one of these style blades lasts.  In the shop where I worked we had a similar saw.  That one had a 4 speed gear box for different blade speeds, but other than that was identical.  Our shop was a prototype shop, not a production shop.  However the saw was busy almost all day every day.  Guessing it was busy 30-35 hours a week a 4 tpi blade would last about 6 months.  That's between 750 and 875 hours of cutting on a single blade.


This is why I suggested a block (squared). You don't have to adjust the jaw.  I did not realize that one can get about 800 hours of use out of what I assume is a commercial blade.  I'm just a retired old guy that likes to make things. Every day I learn something.  Thanks.


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## savarin (May 23, 2020)

silence dogood said:


> I understand your concern about your concern since most of the cutting will be confined to a small portion of the blade when cutting small stock.


I just wondered why virtually all examples on youtube of home made powered hacksaws only have such a tiny stroke, it seems a bad design fault.
I knocked up a simple 3d version to see if there was a reason and couldnt find one, just less than half the blade stroke seems to be fine.
Maybe its the lack of oomph in some of those attempts.


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## Downunder Bob (May 24, 2020)

The max stroke of a hacksaw is of course slightly less than half the length of the blade, so for a 12" blade lets say about 1/2 of 11" = 5 1/2" stroke maybe less, to get this stroke we need a crank wheel of 11" dia.. So the machine is starting to get rather large and also will require more HP. perhaps this is why many machines are designed with only a 4" cut thus reducing the crank wheel to 8"dia. and also reducing the HP all of this adds up to less cost.

I have used many different power hacksaws, mostly heavy industrial models with 14" blades. during my working life, and that experience taught me that there had to be a better way, so when I wanted a power saw I very quickly decided to have a closer look at a band saw and soon liked what I saw. A new, small, out of the box band saw is a lot more compact, easier to set up and somewhat cheaper than a power hacksaw. I can see a slight advantage of a power hacksaw in a heavy industrial setting, but generally not for hobby use.

Small hobby type band saws usually start at 5x5 or 4x6, So straight away they are more capable than most hacksaw type. Many are fixed speed which is always too fast or too slow, depending what you are cutting. Some of the better small hobby type band saws have variable speed. My Hafco has a fully variable speed motor which gives me slow enough to cut really hard tough steels like car axles, and will also go fast enough to cut Al and I even use it for cutting fire wood, although it could be faster for cutting wood it works quite well

I have been amazed at the variety of blades available for this little saw, even a special blade for cutting wood. Finally with a band saw you get to use all of the blade. it always used to irk me to throw away a blade that was still perfectly good for 3/4 of its length. A broken band saw blade is not a problem just rejoin it, if after many breaks or it develops a bad section just add a new piece in there. Also band saw blades tend to run cooler so there is less need for cutting fluid/coolant and I only use it when cutting really difficult steels.


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## Downunder Bob (May 24, 2020)

savarin said:


> squeezing the cash for new from the financial controller will be a hard sell but filtering it out over a period of time whilst building something is easier.
> Do I really need one? The majority of work I have done to date would have benefited greatly but I have no real idea of what future projects are in the pipeline. All I know is I have to build something, it keeps me sane.



Charles, while I'm quite sure you are very capable of building a power hacksaw, and I would not be surprised if you came up with one that could cut more than half the length of the blade. i think your time is far better spent building your amazing projects. I'm also equal;ly sure that that with careful manipulation of the budget you will soon have the funds to buy a small band saw. Even explaining to the accountancy dep't than being able to cut your own material will save you money in the long run. And it will no doubt pay for itself within, a few months, a year at the most. That is what I did.

Good luck Charles, BTW as soon as the borders are open I'm heading up your way, I'll give you enough notice to get the beers cold. It will probably take me a month to get there as I have a lot of people to see on the way.

And yes, building or repairing even modifying something keeps us sane. I have always said that the original designer / builder of any machine did not build as good as it could have been, price always comes into it. Everything is always built to price, with design and function coming in a poor second, thus every machine can be improved.


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## savarin (May 24, 2020)

I look forward to that Bob, keep safe and whats your favorite brew?


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## silence dogood (May 24, 2020)

I have an old Miller-Knute hacksaw that needs to be restored.  It seems to take a  12" blade and has a 4" stroke.  The vise is missing so I don't know for sure how wide the stock it can handle.  I looked up the Hemmingway kit specks.  It takes a 10" blade. The stroke is adjustable from 2" to 3 1/2".  The wider the stock, the smaller the stroke.  It did not say what size stock the vise will hold.   The only thing that I can figure is that if you put in a wide chunk of steel and forget to narrow  the stroke, you will have a crash .


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## Downunder Bob (May 24, 2020)

savarin said:


> I look forward to that Bob, keep safe and whats your favorite brew?



Actually not much of a beer drinker, but when in Qld on a hot day I can put up with a XXXX gold or two, I think it is from memory.

 Mostly I drink Bourbon and Cola, sugar free of course, and or red wine, but don't worry I will have plenty with me. An old mate who used to live on Maggi Island brewed his own It was a Coopers brew kit, but he did modify it some, we drank a bit of that in the day, as we lolled about his pool.


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## Larry$ (May 24, 2020)

I've got one of the 4x6" Chinese metal cutting bandsaws. Mine has the brand Delta on it, but Chinese/Taiwanese? I've had it for over 25 years. Been OK, not perfect. You need to do some adjusting to get it to cut square. Blades are common size & widely available in many types. On things that are going to take a few minutes to cut I just go do something else. Although you can use it in the vertical it is pretty limited due to the small throat opening. It doesn't take much space, is cheap, blades are cheap and it does work up to its capacity OK.  If I had the $ & space, I'd get something bigger. I cut aluminum on a 17" woodworking bandsaw. Fast, don't need to change blades.


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## Downunder Bob (May 24, 2020)

Larry$ said:


> I've got one of the 4x6" Chinese metal cutting bandsaws. Mine has the brand Delta on it, but Chinese/Taiwanese? I've had it for over 25 years. Been OK, not perfect. You need to do some adjusting to get it to cut square. Blades are common size & widely available in many types. On things that are going to take a few minutes to cut I just go do something else. Although you can use it in the vertical it is pretty limited due to the small throat opening. It doesn't take much space, is cheap, blades are cheap and it does work up to its capacity OK.  If I had the $ & space, I'd get something bigger. I cut aluminum on a 17" woodworking bandsaw. Fast, don't need to change blades.



Hi, if it doesn't say made in Taiwan on it, it probably isn't. The Taiwanese are very proud of their superior quality and always promote it.


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## projectnut (May 24, 2020)

Downunder Bob said:


> The max stroke of a hacksaw is of course slightly less than half the length of the blade, so for a 12" blade lets say about 1/2 of 11" = 5 1/2" stroke maybe less,* to get this stroke we need a crank wheel of 11" dia.. So the machine is starting to get rather large and also will require more HP. perhaps this is why many machines are designed with only a 4" cut thus reducing the crank wheel to 8"dia. and also reducing the HP all of this adds up to less cost.*
> 
> I have used many different power hacksaws, mostly heavy industrial models with 14" blades. during my working life, and that experience taught me that there had to be a better way, so when I wanted a power saw I very quickly decided to have a closer look at a band saw and soon liked what I saw. A new, small, out of the box band saw is a lot more compact, easier to set up and somewhat cheaper than a power hacksaw. I can see a slight advantage of a power hacksaw in a heavy industrial setting, but generally not for hobby use.
> 
> ...



I would agree that to accomplish a longer stroke the saw would need to be fairly substantial in size and weight.  The Racine 66W-2 has a 17" x 48" footprint, uses a 1 HP, 1,200 rpm motor, and weighs in at a little over 600 lbs.  With all this size, weight, and power it still only has a stroke of 5"


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## Bi11Hudson (May 24, 2020)

Without a "horse in this race", there's not much I can have to say on the subject. What little saw work I do is with a PortaBand (Milwaukee). What comes to mind after reading the entire post here is my shaper (Atlas 7"). Both the length of stroke and relative position of the cutter are adjustable. And within limits, speed.  It seems simple enough to attach a hand hacksaw to the ram in place of the cutter and have a power hacksaw. Crude but functional.

There are limitations, of course. But the overall concept looks to be viable. Even Gingery's shaper has adjustable stroke. It should be simple enough to adapt an existing system to what is needed. I'm not advocating building a Gingery shaper. Just using the same concepts for adjustable stroke. There would be practical limits to the stroke. Wouldn't want the blade retainers to smack the work. But to adjust the stroke for full use of the blade on small work would be a perfect fit for a shaper. 

As a retiree with no serious work to accomplish, I have the option, and time, to build what I want, when I want it. And the time to sit and think through the concept. Even if it costs more than modifying an existing machine. Just for the satisfaction of "creating" something that no longer exists at a reasonable cost and availability. Like the other comments, if there is a paying job hanging, go the most expedient route. But just for personal satisfaction, think about it.

.


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## projectnut (May 24, 2020)

One major difference between most "homemade" power hacksaws I've seen and commercial models is that the commercial ones raise the blade on the return stroke.  This helps keep the blade from wearing out prematurely.  Also Most (but not all) commercial models cut on the backstroke.  That is when pulling the blade toward the rear of the machine.  The rear half of the vise generally has 2  bolts securing it in place while the front half only has 1.  With 2 bolts the rear half is more solid and less prone to move at an angle with the force of the blade against the stock


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