Why do both power hacksaws and bandsaws exist?

[choochoo_balooParticipant @choochoo_baloo]

What are the pro's and con's of (strictly for metal use) bandsaw vs power hacksaw?

I notice that the only RTR saws available from the usual machinery suppliers nowadays (at least for the home user) are bandsaws. However there are (e.g. Hemingway) kits for power hacksaws. Why is this?

Thanks in advance.

[choochoo_balooParticipant @choochoo_baloo]

[PlasmaParticipant @plasma]

I guess it's a bit like why the shaper became less used, one stroke of a reciprocating machine is just a waste of energy. Returning the blade or cutting tool to its start position wastes time which in a production environment costs money.

A band saw cuts continuously, no wasted effort or time. The steel firm I use has bandsaws that cut huge steel bars so capacity is not an issue.

I use a power hacksaw as i can afford a cuppa as it cuts, blades are cheaper and easier to change.

I also have a shaper which takes it's time but produces a surface finish far better than either of my milling machines.

[Roderick JenkinsParticipant @roderickjenkins93242]

My guess is that new technology made flexible blades with HSS teeth a reality and thus suitable for cutting steel at high speed. The reciprocrating saw becomes old and slow technology.

Rod

[Ian S CParticipant @iansc]

It's easier to build a power hacksaw at home than a bandsaw, I;v done it, it's gone now, replaced by a bandsaw.

Ian S C

[choochoo_balooParticipant @choochoo_baloo]

Is there any advantage to either for e.g. parallelism of the cut? I've read posts where owners of the ubiquitous 6×4 bandsaw have spent ages tweaking theirs to obtain a parallel cut.

Edited By choochoo_baloo on 17/03/2019 00:44:56

[HopperParticipant @hopper]

Bandsaws are probably cheaper to manufacture too. No shock loading from reciprocation and interrupted cut so the whole mechanism can be lighter duty, from the framework through to the reduction gearing. Those old power hacksaws are solid heavy lumps of cast iron that you bolt to the floor and leave in place. Modern bandsaws can easily be moved about the workshop as needed.

[thaiguzziParticipant @thaiguzzi]

Posted by Plasma on 16/03/2019 22:48:51:

I guess it's a bit like why the shaper became less used, one stroke of a reciprocating machine is just a waste of energy. Returning the blade or cutting tool to its start position wastes time which in a production environment costs money.

A band saw cuts continuously, no wasted effort or time. The steel firm I use has bandsaws that cut huge steel bars so capacity is not an issue.

I use a power hacksaw as i can afford a cuppa as it cuts, blades are cheaper and easier to change.

I also have a shaper which takes it's time but produces a surface finish far better than either of my milling machines.

+1. Wot he said.

[thaiguzziParticipant @thaiguzzi]

Posted by choochoo_baloo on 17/03/2019 00:44:36:

Is there any advantage to either for e.g. parallelism of the cut? I've read posts where owners of the ubiquitous 6×4 bandsaw have spent ages tweaking theirs to obtain a parallel cut.

Edited By choochoo_baloo on 17/03/2019 00:44:56

Yeah, that's because a generic Chinese 6×4 is the bottom of the barrel. You do not get these problems with industrial/professional grade bandsaws not made down to a price.

I have a power hacksaw, pre war Denbigh, i have a shaper.

If i had the space and money no object i would sell the donkey saw and replace with a nice bandsaw – far more efficient.

However, the shaper will never be sold………. far too useful. And fun to use………

[JasonBModerator @jasonb]

For hobby use the bandsaw also has the advantage that you can use it vertically to cut sheet, try doing that with a power hacksaw.

[Brian GParticipant @briang]

Cooling may be worth considering. After each tooth of the bandsaw passes through the metal it has plenty of time to cool before re-entering as perhaps 90% of the blade is shedding heat. In contrast a hacksaw blade spends its return stroke passing through the bar it is cutting and only gets a short time at each end of the stroke to cool.

Having said that, I certainly don't have room (or the need) for either a bandsaw or a full-size donkey saw, so a compact powered hacksaw is more attractive. (I have Myfordboy's drawings and a spare motor, but need to get a round tuit, until then the cold saw or a "manumatic" hacksaw will have to do).

Brian

[John HaineParticipant @johnhaine32865]

Apart from kits, does anyone make a commercial powered hacksaw nowadays? I suspect the answer to the question is that power hacksaws are left overs.

[Brian GParticipant @briang]

Posted by John Haine on 17/03/2019 08:11:28:

Apart from kits, does anyone make a commercial powered hacksaw nowadays? I suspect the answer to the question is that power hacksaws are left overs.

Seig still list one: **LINK** . I would imagine that in many countries being able to use standard hacksaw blades is quite useful.

Brian

[Robert Atkinson 2Participant @robertatkinson2]

Big professional ones still exist too

http://www.zoro.co.uk/shop/power-tools/power-hacksaws/ajph200-hydraulic-hacksaw-machine-400v-3ph/p/ZT1028546X?

Lot of money £6000-£18000 for a saw though!

Robert G8RPI.

[Mike PooleParticipant @mikepoole82104]

I just love the way my Rapidor chugs along, without a doubt a decent bandsaw is a more efficient machine but I would rather watch a traction engine than a modern diesel tractor. The donkey saw is an indulgence that gets the job done in a pleasurable way.

Mike

[David George 1Participant @davidgeorge1]

At a place that I worked at we had both a band saw and a power hack saw. the band saw was mostly used on smaller pieces and any angle work but the power hack saw had a 3ft by 3..inch deep by 3/16" thick blade and it would cut straight no waste and as it was powered down would rip through a 24" piece or steel in no time.

David

[Mick B1Participant @mickb1]

As a youngster, I laughed the first time I saw a power hacksaw. I'd seen and operated bandsaws before, and the power hacksaw looked just like a mechanised version of a human sawing arm, as old-fashioned as some piece of Victorian agricultural machinery.

Of course, then I knew little of cost/reliability/floorspace exchange curves, and I guess I'd quite like one now – except I haven't really the space even for that.

Looking at t'internet, it seems that circular cutoff saws are more-or-less superseding them.

[John ReeseParticipant @johnreese12848]

Power hacksaws are rare today in industrial applications. The blade is only cutting less than 50% of the time. Bandsaws cut 100% of the time. Power hacksaw blades are thicker than the equivalent bandsaw blades so they waste more metal.

In the home shop it is a different story. Hacksaws are fairly easy to build from scratch or from kits. Bandsaws are bulkier but are more veratile, many can be used either horizontally or vertically.

[SillyOldDufferModerator @sillyoldduffer]

Extended blade life is an important advantage of bandsaws compared with hacksaws:

1. Bandsaw blades have more teeth than a hacksaw and all teeth work equally. In contrast, hacksaw teeth wear tend to badly in the middle of the blade and very little at the ends.  Quite wasteful.
2. Bandsaw teeth have far more opportunity to cool down after they've taken a cut. In consequence they resist wear for longer.
3. Hacksaw teeth are pulled backwards over the work after each cutting stroke, which tends to blunt the teeth, and keeps them unnecessarily warm. Bandsaw teeth only move in the one cutting direction.

A power hacksaw has some advantages. Apart from the machines slightly smaller footprint, hacksaw blades are standard workshop items and rather cheaper than bandsaw blades. Hacksaw blades are also much easier to change, which is handy when a larger or small tooth per inch would suit a particular job. Blades can be swapped quickly to match different metals (brass vs steel) or profiles (pipe vs solid.)

Dave

Edited By SillyOldDuffer on 17/03/2019 16:05:35

[Mick B1Participant @mickb1]

At least some and maybe all of the power hacksaws I've seen had a hydraulic(?) mechanism to lift the blade on the backstroke so a not to drag it over the work.

The blades were always much wider and thicker than standard hand hacksaw blades. Once worn out, the all-hard-HSS type tended to be cut up, bound with tape and ground sharp as box cutters.

[Pete WhiteParticipant @petewhite15172]

Taking hobby use are we? So a nice old cast iron machine, can be had for small money compared to a light weight or expensive? band saw. Time is not an issue is it? Auto cut off, means you don't have to watch it, if you can stop yourself. lol.

I have two donkey saw, I am booked in for therapy soon, think I might be a collector or hoarder, one needs to go, but that is a good way of eliminating time on a wasted stoke?. lol.

For the equivalent of a vertical band I use an angle grinder with a thin disc, works for me.

[PatJParticipant @patj87806]

I use a Portaband for cutting metal by hand, both straight and curved cuts, generally on thinner material that does not need to be clamped.

For cutting heavier pieces, I have an inexpensive generic horizontal bandsaw, but it does not cut straight, and it not very reliable.

I wanted a machine that would cut larger pieces unatttended, and something heavy duty enough that it would never stop working or need adjustment.

My solution was to buy a Marvel No.2 draw-cut hacksaw.

I am going to change the motor from 3-phase to 1-phase (I don't want to use a phase converter or VFD).

There is a video of someone online that has the exact model, and he rebuilds it, so that will be a great help with changing the motor. I am missing a few tensioning parts, but I can fabricate those.

The cost was $400, and about 2/3 more for shipping, but I think it will work out well, and it does not seem to have much wear and tear on it.

I will post some photos in a minute.

I don't know this individual, but he does a good job on rebuilding his Marvel.

He is what we call in these parts a "Good ole boy", but he has talent.

The part of the video at 4:37 makes one want to yell "Just Say No to Crack !!".

https://www.youtube.com/watch?v=ifF3fUBjEYg

Edited By PatJ on 17/03/2019 22:57:25

[PatJParticipant @patj87806]

Here is the saw I purchased.

It does turn off automatically.

The lever on the front has been sheared off so I will have to cast a new one in gray iron.

It seems to be rather a beast of a saw, but I often cut up large pieces of gray iron scrap to use for the foundry.

 

 

 

 

Edited By PatJ on 17/03/2019 23:00:12

Edited By PatJ on 17/03/2019 23:01:13

[thaiguzziParticipant @thaiguzzi]

Posted by SillyOldDuffer on 17/03/2019 16:03:36:

Extended blade life is an important advantage of bandsaws compared with hacksaws:

1. Bandsaw blades have more teeth than a hacksaw and all teeth work equally. In contrast, hacksaw teeth wear tend to badly in the middle of the blade and very little at the ends. Quite wasteful.
2. Bandsaw teeth have far more opportunity to cool down after they've taken a cut. In consequence they resist wear for longer.
3. Hacksaw teeth are pulled backwards over the work after each cutting stroke, which tends to blunt the teeth, and keeps them unnecessarily warm. Bandsaw teeth only move in the one cutting direction.

A power hacksaw has some advantages. Apart from the machines slightly smaller footprint, hacksaw blades are standard workshop items and rather cheaper than bandsaw blades. Hacksaw blades are also much easier to change, which is handy when a larger or small tooth per inch would suit a particular job. Blades can be swapped quickly to match different metals (brass vs steel) or profiles (pipe vs solid.)

Dave

Edited By SillyOldDuffer on 17/03/2019 16:05:35

1. Most power hacksaws LIFT the blade on the return stroke.

In fact all the ones i've come across do.

2. Have you seen the price of current power hacksaw blades? Cheap they are not. And certainly not to be confused with a std hand held hacksaw blades.

[HopperParticipant @hopper]

And if you want the good quality Starrett etc power hacksaw blades they are very pricey. And easily broken if a bit clumsy dropping the blade onto the job to get started. (Don't ask me how I know this!)

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