Rapidor power hacksaw

[plewlandsbob]

Hi, I have inherited an old Rapidor power hacksaw. I know it came from an old blacksmiths shop on a local farm. It has a large pulley for driving it,using an old style flat belt. I do not have a motor for it, but would like to possibly mount a motor underneath or on the end of it to drive it. What I need to know is how big a motor would be required to drive it and the speed the blade should run at, ie, strokes per minute of the blade.
Any information gratefully appreciatted.
Robert

 

[simon718]

we have one of them in work, will have a look tomorrow see what spec the motor is

 

[wyn]

I have one as well with no motor.

I remember counting how many strokes/min the one in work did, but unfortunately i can't find the info.

The work one had a gearbox to reduce the speed. The one i have reduced the speed via a number of different sized pulleys.

 

[dazzis]

looks like its missing the base, i have one in the shed, im using a small single phase motor(looks similar to the blue one you have on the floor) i had lying around,the original motor on it was huge, one thing i will say is make sure it runs slow almost broke my fingers when i engaged the drive lever with too small a motor pulley, can you do me a favour and snap a close up of the front blade nut and washer, and also any chance of a pic and dimentions of the damper unit as mine doesnt seem to work no matter what grade of oil you put in it, oh n i think about 60 strokes per minute is about right(just wish i could get mine that slow)

 

[graffian]

I have the later rapidor manchester, the casting encloses the motor.
The motor is 1/4hp three phase[I think], so a 1/3 or 1/2 single phase will be fine. I cut steel with a 4tpi blade and it has never stops it.

The pulley is a compound setup, I think it's easy to select another speed.
I think the first stage of the drive from the motor might be a chain?
60 rpm sounds about right.

You need a coolant pump, mine came without one and I ended up with a fuel pump on it. blades last for ages with a coolant pump and not long without.

Front blade nut and washer was nothing special, mine is different to normal as it was in the bin cos the front of the casting was damaged. I made a 'washer' that fits the casting.

Never taken the damper apart so I can't say whats in it, but it does work;-)

I wonder if someones got a stock one with coolant pump could they take a pic for me?

Nice old saws.

 

[wyn]

Here's a couple of pics of mine rusting away nicely. Another one of those jobs that get started and then something more interesting comes up.

This pic is trying to show the clutch engaging mechanism, it has worn "ramps" on the clutch. I started to make new ones but got stuck on how to machine the ramps.

Here is a pic of the nut assembly that holds the end of the blade. The shiney nut and washer are on a stud that is fixed to the arm, this holds the block on so it can move the distance of the slot machined in it.

This pic shows the bottom of the damper rod and the angled tube it runs in sitting behind it. It is approximately 40mm diameter with a slightly curved outer surface as this has to take into account the arc that the saw travels in as it goes up and down.

The "ball" on the bottom of the damper has 4 holes drilled in it, the bottom surface has a thin plate bolted to it that covers the bottom of the holes. The same sort of set up as bike fork internals.

As the arm is lifted up the oil goes through the holes and forces it's way past the plate.

As the arm goes down in cutting mode the oil seeps past the out side of the "ball" and the tube it runs in.

 

[dazzis]

wyn cant see any pics fella

 

[dazzis]

I wonder if someones got a stock one with coolant pump could they take a pic for me?

Nice old saws.

the coolant pump on mine is an old washing machine pump (impelors dead) which was sat on a plate bolted to the leg, cant take a pic as it buried at the mo

 

[graffian]

I pulled the side of mine and took a photo, but I forgot
to bring the camera in;-)
Basically there is as shelf near ground level. the motor sits on slotted rails on the shelf. There is a bearing block with a shaft with two pulleys on it mounted on the shelf. one pulley has a belt going to your big pulley, the other pulley has a belt going to the motor. It's pretty simple. I thought there was a chain involved, but doesn't appear to be.

 

[madkayaker]

has it worn away Wyn?

 

[wyn]

Sorry about that with the pics, don't know if you can see them now.

 

[madkayaker]

looks like a nice old piece of kit

 

[simon718]

i couldn't get anywhere near ours today, was a bit buried

ours doesn't have a coolant pump.... it only gets used for cutting galv pipe, upto about 4", i just stand and pour oil onto the cut

 

[busastars]

Im after a Donkey saw soon, just waiting for one to turn up local on ebay, you can get a working one for around £60. I hate sawing by hand.

 

[graffian]

If you have the room for a big saw ask on the land rover forums, sorry don't remember which one. I asked and someone in bristol had a biggie[18" blade]saw and it came with what was described as a lifetimesupply of blades plus roller supports for cutting material. He wanted £50.

 

[dazzis]

Cheers wyn, i can now see why my hydraulic thingummy dont work

and i can set about remaking the front blade nut, mine currently has a 50 tooth lathe gear on it

 

[wyn]

Another part of the damper i forgot about was this adjusting rod.

The pic shows the threaded rod going through a tapped hole and pushes on the "washer". The rod has a slot for a screwdriver in the top. It just pushes the washer away from the holes to allow more or less oil flow.

 

[Heyden]

Hi:
I haven't got an answer to anyones questions but i have got an old Rapidor power saw (complete and original) for sale.
It is in need of some TLC, good project for someone
Can provide photographs if needed
Cheers

 

[Arsonista]

Can provide photographs if needed

Pics are always good.

 

[fluxcored]

You need a coolant pump, mine came without one and I ended up with a fuel pump on it. blades last for ages with a coolant pump and not long without.

Can't contribute much but just had to thank Graffian for the brilliant idea re the fuel pump.

I'm building myself a power saw and main issue I had is pumping coolant. He just solved that for me!

Regards.