Restoring an old powered hacksaw

[kb58]

To the OP, I had to laugh when your neighbor offered it for "free."

This is the same sort of neighbor who offers seeds to his neighbors, saying "I just can't seem to get these to grow", figuring correctly that pride will take over, the neighbors will grow them, ending up with too many to eat, and end up giving him some "in payment."

In your case, your generous neighbor ends up with someone who has a fully functioning saw, so he'll probably be showing up eventually with this or that to cut, so that you can "show off" the saw to him. Pretty clever on his part... and he doesn't have a big, barely-working saw cluttering up his shop

 

[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!

 

[Ski]

Nice work!

 

[luap]

Figured I'd share my restoration project!
I've always found these old machines quite cool and when a neighbour offered me a defective one for free, I couldn't say no!

This is the machine as I got it, it runs but won't lower the sawblade so you have to manually push it against the work piece, which becomes quite the challenge and dangerous as heck when it's moving back and forth.


The thick bars protruding on the side are from an automatic feed system that's been cut off.
By pure chance I came across a previous owner of this saw and he gave me these two pictures of how it used to look.
View attachment 331838View attachment 331839

At first I was just going to get the downfeed to work again and leave it at that, not spend too much time on it because I have quite a lot of other stuff that also needs doing.
But just trying to understand how the machine is built and what could be the problem, I was already in waaay too deep to not do something more serious.
Just trying to get the downfeed mechanism out I somehow ended up with this after like 14 hours of work ... Many of those were just shoveling out old sludge and nasty cutting oil.


Every little mechanism is completely packed with old grease that is long overdue for a cleanup, this picture was after I scooped handfuls of it out.
View attachment 331841View attachment 331843

Eventually after a lot of beating I managed to get the entire hinge mechanism off and the parts are starting to pile up.
View attachment 331845

One really interesting thing is this motor. It's 2 motors in one, double shafts and everything.
There's a smaller shaft, inside the bigger shaft, powering the smaller pulley.
View attachment 331846

With everything stripped it was time for it to travel outside for some major cleaning.. Quite a big of degreaser, scrubbing and high pressure washer.
By now you can even see that it has some color underneath all the crud.
View attachment 331847View attachment 331848

 

[luap]

Continuing on.
Using a mix of sanders and wire brushes, I got most of the old crud off.


Both sprayed and brushed on a layer of epoxy primer.


And ontop of that a layer of grey polyurethane.
It looks quite light in the pictures, as it hardened it became a bit darker.
I did so many mistakes here that really ****** me off. Stupid mistakes like how I somehow forgot to mask the top and floor, sprayed way too much paint on and so on.
I will have to get back to this and sand down the runs and do a final top coat again.



I did a quick brushjob on the legs, I think the black should constrast nicely.


To get away off from the frustration of the bad paintjob(I don't like painting but I like a good end result..), I started working on the pump which was the initial problem.
To the left you have the "lid" of the main piston and to the right is the main unit I guess.
The big rod on the lid has a smaller rod inside it, and the big piston has a smaller piston inside it that gets act upon from this smaller rod.
Basically as the saw runs, it acts upon the smaller rod, transfering the motion to the smaller piston down inside the bigger piston.


A closer look on the main piston and the smaller rod.


With the bottom taken off the main piston, you can see this smaller piston. I have taken the seals off it for the photo.


Eventually all that was left to take apart was this part on the lid.
Aaand here we find a completely busted seal.
Hopefully this is all that was keeping it from working as intended.
View attachment 331861

 

[luap]

Great job on your restoration.It seems to be the way to go.Im a local too.

 

[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!