Modifying my small power hacksaw

[RichR]

Last year I posted about the little power hacksaw I picked up for $50:

http://bbs.homeshopmachinist.net/threads/64937-Picked-up-a-baby-power-hacksaw

The saw cuts nicely but I decided it could use a few improvements.
The vise was moved 1/2" to the right to take full advantage of the cutting stroke and 1/2" closer to the blade so
it can clamp a shorter piece of stock if needed. Then I started work on a support for the piece that gets cutoff
and a stop for setting the length. First I trim off some excess from a piece of scrap aluminum:


I'm still impressed with how clean the cuts are:

Cutting off one of the pieces I'll need:


Continued in next post ...

[RichR]

Cut completed:

Cutting off the second piece I'll need:

Mounting holes drilled and tapped in first piece:

Mounting holes transferred to the vise and frame:


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[RichR]

Counter boring the top mounting holes:

It fits:

Milling a slot for the hacksaw blade:

Skipping ahead, the second block of aluminum I cut is bolted to the first and two 0.375" holes were drilled through:


Continued in next post ...

[RichR]

Cutting a flat for the setscrew that will hold this rod in place:

The pieces are starting to fall into place:

Turned down the end of a bolt and made a brass plug to bear against one of the rods so I can lock it in place:

Installed:


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[RichR]

When fully extended, the outer edge of the block is about 7.5" from the blade. I still need to attach a small
flat plate to act as a stop using the two upper threaded holes. The large bolt at the bottom allows me to lock
it in place:

Next I need to make a mechanism to support the arm of the saw to make it easier to clamp a piece in the vise:

Cutting the mounting bracket to length:

All the pieces of the puzzle:


Continued in next post ...

[RichR]

This is how they fit together:

The surface this attaches to is at an angle, so we mill the mounting bracket to match:

Drilling the mounting holes:

The original mounting location interfered with the frame for the blade, so I moved the mounting holes to the right:


Continued in next post ...

[RichR]

This is how it supports the arm:

When you lift the arm, the support drops out of the way onto a small piece of angle bracket. This picture also
shows why I had to move the mounting holes to the right:

[Michael Edwards]

Nicely done. I really like this type of project. Take a tool that you have and make it more usable for you.

Also, I have a soft spot for power hacksaws. I have two of them, a Robertson from about 1936, and my replacement for it is a Kasto.

The Kasto takes a 24" blade and will cut 15" a round piece.

Now every time you use that saw, you will appreciate the upgrades.

[Sun God]

Beautiful work on a beautiful little machine.

Can you clarify something for me though - forgive me for the tangential leap - is the blade frame supported solely by that small shaft running in what looks like a bronze bushing? And it's constrained from rotating by the pulley and conrod? What's it's approximate diameter?

Seems like a remarkably elegant design. If it could say, cut an inch of 4140 in 5 odd minutes it would make a very productive addition to my shop.

[velocette]

Hi Rich
Great photos of an elegant machine and your approach that I can improve on this to to make it in even more versatile machine.
Being a dedicated "Power Hacksaw Nutcase" I take pleasure in seeing other users machines and their ideas.
Can I add a method I use for cutting small and odd shapes on a power hacksaw.
Clamp the job to 20 mm thick plate with 8 mm holes drilled and tapped on a 20 by 20 mm grid and grip it in the vice or bolt it in place of the vice.
Happy Hacksawing thanks for sharing

Eric

[RichR]

Thanks for the compliments.

Can you clarify something for me though - forgive me for the tangential leap - is the blade frame supported solely by that small shaft running in what looks like a bronze bushing? And it's constrained from rotating by the pulley and conrod? What's it's approximate diameter?

Yes, the blade is supported just by that 3/8" (0.366" actually) shaft. The bushing might be bronze, brass, or for all I know, maybe just
a piece copper pipe. The OD is ~0.5" and the wall is ~0.068". The connecting rod drives it and holds it vertical. The pulley is 5" OD.

Seems like a remarkably elegant design.

Agreed. Whoever designed it appears to have focused on simplicity and ease of manufacturing.

If it could say, cut an inch of 4140 in 5 odd minutes ...

I've never dealt with 4140, but it will go through a piece of 0.625" 316 SS rod in 5 minutes using an 18 TPI blade.

...it would make a very productive addition to my shop.

OK, now I don't think I like where this is heading ....

[RichR]

Great photos of an elegant machine and your approach ...

Thank you.

Can I add a method I use for cutting small and odd shapes on a power hacksaw.

If you're referring to the piece of L channel clamped in the vise, that was done because the belt is old and starting to slip. When I had it
properly clamped with an extra block in the vise, the blade would stop because the belt was slipping.

Clamp the job to 20 mm thick plate with 8 mm holes drilled and tapped on a 20 by 20 mm grid and grip it in the vice or bolt it in place of the vice.

That's not a bad idea. Truth of the matter is, I already figured that I could clamp odd shaped pieces to the sliding support I added.

[EddyCurr]

Bravo.

.

[RichR]

I decided to clean off all the cuttings that had accumulated on the saw and base. When I was done I felt the base could use a little
sprucing up:


First I used the random orbital sander to get to some clean wood:


Next I wiped it down with some mineral spirits:


And then I proceeded to polyurethane it:

[RichR]

A couple more shots:




All in all I think it turned out OK.