ARROW spring assisted shaper

[Ady1Participant @ady1]

[Ady1Participant @ady1]

I found this on Tonys site and thought "that could be useful!"

The spring "absorbs 50% of labour required by the operator" which must mean that a powered machine doing a job could do the same job with 50% less motor power kinda thing

 

 

Now while 50% is a bit of a stretch(a lot of a stretch) I would be intruiged to know if their system did actually generate any improvements

Does anyone know how their system worked?

Presumably the gain on the forward stroke was countered by the reversing stroke being harder

Anyone ever used one of these spring assisted units?

 

http://www.lathes.co.uk/arrowshaper/

 

Edited By Ady1 on 04/05/2012 10:58:51

[John McNamaraParticipant @johnmcnamara74883]

My guess is the spring is compressed on the return stroke at a moderate pressure. Then on the power stroke the built up pressure is added to the force of the cut. It makes some sense. However the total work performed must be the same. After almost 400 years (B 1642); In the real non sub atomic world Sir Isaac Newton still reigns supreme. Energy must be conserved.

John M

[NobbyParticipant @nobby]

Hi Andi1

I wonder if i could add this to my Drummond shaper ?

[colin hawesParticipant @colinhawes85982]

When I use my shaper I often need to stop the ram on a part of it's travel.The idea of having so much energy stored in a powerful spring seems very dangerous. Be careful! Colin

[NobbyParticipant @nobby]

HI Colin & Guys
On a 36" shaper as colin said to remove metal on a central area of a job I used to shape between 2 slots . My drummond is great for slotting key slots in 5/8" Dia bores. IE gears and collars. I know I should not slappedd wrist Fit a grinding head for light surface grinding . I know it's not a J&S 540

Nobby

[joegibParticipant @joegib]

The spring "absorbs 50% of labour required by the operator" which must mean that a powered machine doing a job could do the same job with 50% less motor power kinda thing

He, he, you forgot to add a smiley.

Turn that machine through 90 degrees and you've got a unit whose operation is essentially the same as a pillar drill with the ram being returned to the start position in the same way as a drill spindle is by its coil spring. A spring is a energy store and it can only output the energy that has first been put into it by you (or a motor). In other words it acquires potential energy (from you) on compression and returns it on release.

As an energy saver its about as much use as recommending that people in an elevated position exploit their potential energy by falling down stairs rather than making a controlled descent.

Joe

[John McNamaraParticipant @johnmcnamara74883]

Hi All I have repeated the obscured by advertising text from my first post

"My guess is the spring is compressed on the return stroke at a moderate pressure. Then on the power stroke the built up pressure is added to the force of the cut. It makes some sense. However the total work performed must be the same. After almost 400 years (B 1642); In the real non sub atomic world Sir Isaac Newton still reigns supreme. Energy must be conserved."

For a human powered machine using a lever it makes some sense to use a spring; It allows a greater force than one person could apply to be added to the power stroke. As long as the lever is returned to the start position (The spring is at its uncompressed state or limit if it is preloaded), before the handle is released there is no risk of the potential spring energy being released suddenly.

I guess the greatest risk is that the ram is stopped say due to too greater cut being put on, after which the operator then moved his hands to the work to make an adjustment to the work and the ram suddenly moved propelled by the spring there could be serious injury.

I guess you cannot protect some of the people all of the time.

Cheers

John

[Ady1Participant @ady1]

My own guess would be that the backstroke would store some energy, so would be 50% harder to do.

 

So, in a perfect world, a 0.5HP motor could do the work of a 1HP motor, but it would do twice as much work so you would get the electric bill of a 1HP motor

 

The motor would compress the spring on the return stroke doing 0.5HP of work

The motor would then begin the cutting stroke doing 0.5HP of work, assisted by the spring which would be contributing 0.5HP of work, giving you 1HP of cutting power

 

All reduced by the vagaries of the real world but hopefully giving you at least an extra 50% of cutting power, so 0.75HP with a 0.5HP motor

 

The spring design would be important, you would want the energy to reach 0.0HP AFTER the end of the cutting stroke, and begin compression to full power on the return stroke.

An air compression system may also work, like when you put your thumb on a bike pump and compress the air inside, anything which stores energy could be used.

 

The best system would be one which creates a constant release of energy across the entire cutting stroke, the above compression storage systems start at a peak and reduce with the distance cut

 

2cents

 

and the ram suddenly moved propelled by the spring there could be serious injury.

On a powered shaper the shaper gearing system would prevent this surge

It would definitely be a risk with a hand shaper though, but you don't ever put your fingers near a tool problem, on a shaper a jam is relieved at the top of the ram by winding back the clapper slide, darwinism would soon teach you to keep one hand on the shaper handle(the human is the gearing system with a hand powered shaper) while the other hand screws back the cutting tool depth.

I recall reading somewhere that a shaper is one of the only power tools which has an operators hand constantly on a moving part it while it works

 

Edited By Ady1 on 06/05/2012 09:15:42

[Ady1Participant @ady1]

An air compression system may also work, like when you put your thumb on a bike pump and compress the air inside, anything which stores energy could be used.

An air compression system would also be safer for tool jams

Tool jams

Stop machine

open air pressure valve

Adjust tool to relieve jam

close air pressure valve

restart machine

[colin hawesParticipant @colinhawes85982]

Not everyone has the strength of a horse so,for a hand shaper, a longer handle should give the best results if more power is needed. Simples. Colin

[NobbyParticipant @nobby]

Hi Colin
Thats a good idea . I will try that tomorrow a peice of tubing springs to mind . I love mine for small fine jobs. In industry they are not used know now high flow milling and cnc finisded them off.

Regards Nobby

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