Small power hacksaw, how fast should it cut?

[projectnut]

It would be nice to see a few pictures of the saw, or even better a short video. I don't think I would have the patience to use a saw that took 5 hours to make a cut on something that small. The last time I used my Racine power hacksaw I was cutting some 1/2" x 2" stock. I started getting impatient when it took over 2 minutes for each cut.

It sounds like what you're attempting to cut is close to it's capacity, but if it fits in the vise the saw should be able to handle it. Vises are generally sized so the machine will be able to cut whatever fits in it even at a 45* angle. Mine will cut 6" stock at a 45. but uses every inch of the blade to do it.

Power hacksaws usually have either a hydraulic down feed or a sliding weight on top of the saw frame that can be positioned to add more or less force against the material. I don't have a specification blade pressure on a power hacksaw, but my bandsaw is supposed to have a working pressure of 6 psi against the material. The hacksaw has an adjustable dial to increase hydraulic pressure against the material. The dial goes from 1 to 10 (IIRC) but I don't have any specifications that define the pressure at each setting.

A quick search for "10" hacksaw blades didn't produce anything with less than 18 tpi. It sounds like your machine was designed to use standard hand hacksaw blades. Even then finding 14 tpi seems to be difficult.

 

[MrWhoopee]

You are truly a patient man!
Go buy an HF 4x6, then pretty up the hacksaw and put it on a shelf.

 

[ericc]

One way to test the down force is to try a smaller piece of aluminum. If this works, you probably need more pressure on the stroke. You can also try pushing down on a stationary part of the cutting mechanism with a broomstick. If you have a tpi problem, get a coarser blade. You can often come upon large full hard HSS blades which are really coarse. A well equipped metal shop will be able to work around the problem of the blade being a little too long. I have an ideal one, but it is in my scrap box. All the teeth in the middle are stripped out, but a zip wheel would make short work of it and there are plenty of good teeth at either end.

 

[WobblyHand]

You are truly a patient man!
Go buy an HF 4x6, then pretty up the hacksaw and put it on a shelf.

What is sad is that I have one. It's out in the garage, surrounded by too much stuff. It isn't that fast either, as I recall, but it must be lots faster than that hacksaw. I will drag it out of the garage somehow, or make it more accessible.

 

[WobblyHand]

One way to test the down force is to try a smaller piece of aluminum. If this works, you probably need more pressure on the stroke. You can also try pushing down on a stationary part of the cutting mechanism with a broomstick. If you have a tpi problem, get a coarser blade. You can often come upon large full hard HSS blades which are really coarse. A well equipped metal shop will be able to work around the problem of the blade being a little too long. I have an ideal one, but it is in my scrap box. All the teeth in the middle are stripped out, but a zip wheel would make short work of it and there are plenty of good teeth at either end.

Think it needs more down force or pressure on the stroke. I have seen the units that have an adjustable weight, but this guy doesn't have that feature. As for blades - one could modify a longer blade. I can cut it to length. How does one drill a hole through it? Carbide drill?

 

[WobblyHand]

It would be nice to see a few pictures of the saw, or even better a short video. I don't think I would have the patience to use a saw that took 5 hours to make a cut on something that small. The last time I used my Racine power hacksaw I was cutting some 1/2" x 2" stock. I started getting impatient when it took over 2 minutes for each cut.

It sounds like what you're attempting to cut is close to it's capacity, but if it fits in the vise the saw should be able to handle it. Vises are generally sized so the machine will be able to cut whatever fits in it even at a 45* angle. Mine will cut 6" stock at a 45. but uses every inch of the blade to do it.

Power hacksaws usually have either a hydraulic down feed or a sliding weight on top of the saw frame that can be positioned to add more or less force against the material. I don't have a specification blade pressure on a power hacksaw, but my bandsaw is supposed to have a working pressure of 6 psi against the material. The hacksaw has an adjustable dial to increase hydraulic pressure against the material. The dial goes from 1 to 10 (IIRC) but I don't have any specifications that define the pressure at each setting.

A quick search for "10" hacksaw blades didn't produce anything with less than 18 tpi. It sounds like your machine was designed to use standard hand hacksaw blades. Even then finding 14 tpi seems to be difficult.

I'll take a picture tomorrow. Honestly had no idea it would take so long. I've cut other smaller stuff before and it was slowish, but not like this. This unit seems like a bottom end homeowners model purchased 40+ years ago. There's no hydraulics, and it doesn't have a sliding weight. I have seen the sliding weight type hacksaws before.

I bought a few 14 TPI blades from McMaster, it was the coarsest they had in a 10 inch length.

What's silly on my part is I have a 4x6 saw, but it is not accessible. After this experience, I'm going to make it accessible. Might even drag it down the basement to my shop. This prolonged cutting experience has motivated me to find a better way.

 

[Aaron_W]

Think it needs more down force or pressure on the stroke. I have seen the units that have an adjustable weight, but this guy doesn't have that feature. As for blades - one could modify a longer blade. I can cut it to length. How does one drill a hole through it? Carbide drill?

I've never tried to drill a hole in a hacksaw or bandsaw blade but I believe the body of the blades are usually just steel, the only hardened part is the edge by the teeth.

 

[Hozzie]

Get a decent blade for the HF saw and it will run right through that Aluminum.

 

[ericc]

A bi-metal hacksaw blade is not full hard, but a power hacksaw blade is often solid HSS. A carbide masonry drill might drill through, but it has to get hot. It would be better to use a solid carbide spade drill made from a broken endmill. The way I first did this was to braze a tab on to the end of the hacksaw blade made out of mild steel. It can have a hole pre-drilled in it.

 

[MrCrankyface]

I've cut and drilled several blades made for power hacksaws without problems.
I use cobalt drills though so slightly stronger than regular HSS, just apply some oil and go slow.
Should allow you to buy 12" blades or whatever and modify to fit.