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Kennedy Mini Power Hacksaw

I have one under the bench not used it for close on 25 years. The 2 sliders wore badly and I think it cuts about 5 degree off the square. Was going to put it on the miller and refurbish it but bought a horizontal/vertical bandsaw to tide me over and that has done so well that I never bothered with the Kennedy.
Keep your sliders well lubricated , wire rope/chain lube is ideal. Better than most mineral oils
 
I was lucky to find one of these old Kennedy saw's in good condition. Even though it had the original motor, the reciprical action just seems to be a little too fast for my liking, and there's no realistic way to reduce it. The nice guy I bought it from was retiring, and gave me a tray full of electrically related tools along with it. :)PICT0009 (Medium).webp
 
Gap-Shot said:
I was lucky to find one of these old Kennedy saw's in good condition. Even though it had the original motor, the reciprical action just seems to be a little too fast for my liking, and there's no realistic way to reduce it. The nice guy I bought it from was retiring, and gave me a tray full of electrically related tools along with it. :)View attachment 775440
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Could you not install a rheostat, in line, to reduce rpm ?
 
If a motor has brushes (DC or AC) it can be controlled by reducing the supply voltage. Yes a rheostat would do it as was done in theatres of old, but they were running a very stable and predictable load - light-bulbs. A motor in a tool will have to drive a varying load and still hold the selected speed. To slow it down and yet still provide torque when asked the supply voltage can be reduced with a transformer, or made variable with a special transformer with a variable output - a Variac. Obviously at lower voltage/speed the max torque available will be similarly lower.

An AC induction-type motor's speed can only be realistically controlled by changing the AC frequency (unless the load is very predictable and constant - a desk fan). The motor on the saw looks like an AC induction job.
 
Antos' said:
If a motor has brushes (DC or AC) it can be controlled by reducing the supply voltage. Yes a rheostat would do it as was done in theatres of old, but they were running a very stable and predictable load - light-bulbs. A motor in a tool will have to drive a varying load and still hold the selected speed. To slow it down and yet still provide torque when asked the supply voltage can be reduced with a transformer, or made variable with a special transformer with a variable output - a Variac. Obviously at lower voltage/speed the max torque available will be similarly lower.

An AC induction-type motor's speed can only be realistically controlled by changing the AC frequency (unless the load is very predictable and constant - a desk fan). The motor on the saw looks like an AC induction job.
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Just wondering - my benchtop band saw has a variable speed control, which I believe is a rheostat. 110- 120/V AC.
 
chouchin66 said:
Just wondering - my benchtop band saw has a variable speed control, which I believe is a rheostat. 110- 120/V AC.
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Could be a phase-angle control - a domestic light dimmer is such. I had a small bench pcb drill using that idea but yes it slowed down under load. Thinking about it, my Bosch hand-drill has phase-angle too, built into the trigger movement. Very handy but it slows down on load - If I need slow with torque I cheat, running it at full trigger but off a variac in an extension lead.

Being a nerd can be useful sometimes.
 
Looking at the size of the pulley cover, there doesn't look like there's much scope for altering pulley size - smaller drive and/or larger driven ........ both look at about the limit.
Not up on electrics but.......... If it's a 2 pole motor, a 4 pole motor would halve the speed Shrug tt
 
chouchin66 said:
Could you not install a rheostat, in line, to reduce rpm ?
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Hmm,:unsure: perhaps a common dimmer type switch ? I have a friend who is an Industrial electrician that trouble shoots equipment issues for a large engineering / welding company. I'll ask him when he returns from the motorcycle races on the Isle Of Man.
 
chouchin66 said:
Could you not install a rheostat, in line, to reduce rpm ?
Click to expand...
No, those are for repulsion motors. Never on an induction motor. It will overheat.
Same thing will happen if your wiring doesn't have required ampacity. The voltage drop will cause the motor to run hot
 
Si Titor said:
Kennedy Hexacut mini power hacksaw that will take standard hacksaw blades.

Picked it up last week, cleaned it up lubricated it etc, works a treat!
Just filled up the dashpot with Castrol EP90 oil before I took the video.


View attachment 774994

View attachment 774995


View attachment 774996
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That's a nice machine,i knew an oldschool upholsterer who had one of these in his workshop,he did machine work as a hobby,he specialised in restoring vintage car interiors & horse drawn cart seats etc,his work was absolutely outstanding,i tried to buy the hacksaw from him a few times but he wouldn't part with it,he's sadly long gone now & i've no idea where his tools would have went.

If you ever feel inclined to part with this give me a shout (y)
 
Zed1 said:
That's a nice machine,i knew an oldschool upholsterer who had one of these in his workshop,he did machine work as a hobby,he specialised in restoring vintage car interiors & horse drawn cart seats etc,his work was absolutely outstanding,i tried to buy the hacksaw from him a few times but he wouldn't part with it,he's sadly long gone now & i've no idea where his tools would have went.

If you ever feel inclined to part with this give me a shout (y)
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You see them on ebay now and then and some with postage, but often or not they are collection only.
 
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