Restoring a power hacksaw

[evan-e-cent]

I mentioned to an engineering friend that I was going to the "Men's Shed" to use their electric hacksaw. He said he has one that he never uses because he orders all his stock cut to length. Is he gave it to me. The thick layer of dirt was testament to the fact that it had not been used for decades. I didn't take a photo until after cleaning the thickest layers of dirt. I tried to buy some orange epoxy paint but could not get anywhere near the right colour. So I used the Epoxy Ultra-Blue that I had used to paint my Boxford lathe and drill stand. So now they all match.



Here it is cutting the 80mm diameter stainless steel bar that I used to make the ball turning attachment that I posted today. Apparently in South Africa they call this a "Strongarm".

Cast into the arm is "HAWKINS CH-CH". The abbreviation CH-CH is for Christchurch in New Zealand. I did some research and found that Hawkins Foundry in Christchurch was advertising this kind of equipment from 1932 to 1946. He was the maker of postage franking machines and NZ was one of the first countries in the world to use the system starting in 1905.

In the last photo, at the bottom you can see a white pill box. It contains a microswitch. the bar through the middle is spring loaded to push up. There is a larger sleeve on the shaft that turns the switch off then the blade gets to the bottom.

Originally this had some kind of lifter mechanism to raise the blade on the backstroke. It would have been hydraulic, but it is missing and I have not yet made a replacement. It also needs a guard on the belt and moving parts.

 

[evan-e-cent]

I am new to Hobby-Machinist. I posted a long reply with photos of a hacksaw I restored, but there is no sign of my post after 24h. I wonder why??

 

[evan-e-cent]

Oh as seen as I submitted the question the post appeared like magic!

 

[evan-e-cent]

My hacksaw (seen above, first with its original orange paint and later in blue epoxy) has been working quite well. I still haven't replaced the blade lifter mechanism which I assume was a simple hydraulic ram that lifted the blade on the backstroke. The gear wheel that drives the crank mechanism has a cam cast on its inner face, which would have operated the lifter, moving it about 1/8 to 1/4 inch with each stroke. I have added a heavy weight at the end of the moving arm to apply downward pressure. This works but the blades wear out fast, and tend to chatter, especially cutting the 80mm diameter stainless steel. I have been thinking about the easiest way to make a lifter mechanism. So far the easiest solution has been to replace blades frequently! Any suggestions? Right now the saw is still in New Zealand and I am currently in Tennessee so it won't get done immediately!

 

[evan-e-cent]

Thanks Tyler. I now have it mounted on a frame with wheels so that I can wheel it under my work bench in the car garage, and easily pull it out when needed. I use it quite a lot. I haven't worked out a simple design for a hydraulic lifter that I could make in a day or two with my lathe but no mill. Any suggestions?

 

[LX Kid]

View attachment 386772

I mentioned to an engineering friend that I was going to the "Men's Shed" to use their electric hacksaw. He said he has one that he never uses because he orders all his stock cut to length. Is he gave it to me. The thick layer of dirt was testament to the fact that it had not been used for decades. I didn't take a photo until after cleaning the thickest layers of dirt. I tried to buy some orange epoxy paint but could not get anywhere near the right colour. So I used the Epoxy Ultra-Blue that I had used to paint my Boxford lathe and drill stand. So now they all match.

View attachment 386773View attachment 386774

Here it is cutting the 80mm diameter stainless steel bar that I used to make the ball turning attachment that I posted today. Apparently in South Africa they call this a "Strongarm".

Cast into the arm is "HAWKINS CH-CH". The abbreviation CH-CH is for Christchurch in New Zealand. I did some research and found that Hawkins Foundry in Christchurch was advertising this kind of equipment from 1932 to 1946. He was the maker of postage franking machines and NZ was one of the first countries in the world to use the system starting in 1905.

In the last photo, at the bottom you can see a white pill box. It contains a microswitch. the bar through the middle is spring loaded to push up. There is a larger sleeve on the shaft that turns the switch off then the blade gets to the bottom.

Originally this had some kind of lifter mechanism to raise the blade on the backstroke. It would have been hydraulic, but it is missing and I have not yet made a replacement. It also needs a guard on the belt and moving parts.

View attachment 386775

Nice job! I'd like to restore a power hack saw if I could find one at the right price!

 

[caswal]

I found the same powered hacksaw in a scrap pile at my storage lock up, and asked if I could have it. My research appears to show it first appearing around 1961, advertised in papers. The first advert with a picture I found was from 1967, and looks like it was sold up to 1979 or 1980.

Mine lacks its motor. So was wondering if you could give me the specs and pulley size of the motor on yours. So I can find something suitable. The advert says 1/4hp with 3in pulley.

It is currently seized on the rail and the rear pulley is smashed. There are a few booger welds on it, between the base and the motor/crank assembly.

 

[matthewsx]

3” sounds like a reasonable place to start. Probably want a 1750 rpm motor, anything small should work to get started.

Cheers,

John

 

[RaisedByWolves]

3” sounds like a reasonable place to start. Probably want a 1750 rpm motor, anything small should work to get started.

Cheers,

John

Personally on these I would want it to go slower, baybe a 2” or even smaller.

Their a handful when they go too fast.

This is mine as I bought it. Looks to be a 2ish inch and the speed was pretty hood.

No idea why the sound is so bad, but you can see the speed here.