Boxford 8"shaper

I have a single phase one and I do not notice a speed difference with cut and return stroke.

Looking at the mechanics of the flywheel and the linkage to the ram there is no way different speeds could be achieved.. The thrust of the cutting stroke does slow down if the cut is to heavy. not by design more to do with workload.

Have a look for Whitworth Quick Return Mechanism, and then observe a machine in action through the side door
The effect is more noticeable for long strokes than short, but don't forget to select a lower belt speed, and turn it by hand before running under power.



See also, this article, though there are many others
https://studentlesson.com/definition-applications-components-types-working-advantages-and-disadvantages-of-quick-return-mechanism/

For The Boxford 8", This diagram from the spares site
shows the arrangement of the bull wheel 


https://www.boxford-software.com/spares/NewImages/SHAPER/rocker%20assy.png

Bill

Edited By peak4 on 18/01/2023 01:36:42

Here's a good example of a shaper working backwards

none of them even noticed either

Edited By Ady1 on 18/01/2023 01:43:32

One more comment on the inaccuracy of that animation. Notice how the chips fall into a single pile, rather than spitting all over the workshop!

Yet another subtle geometric titbit is in that animation

The fixed link from the top of the powered pendulum means you can use a hole and pin in the ram

If the pendulum attaches directly to the ram, like in most compact shapers, you need a vertical slot instead of a hole because it describes a tiny arc at the tip (So the pin goes up and down)

My Elliot 10M shaper has an obvious direction arrow on the vee belt drive guard.

Looking at the motor pulley which direction is "normal" CW or CCW ? I will have a look to see if my Boxford has a direction arrow.

I have an Elliot 10m and yes it must run the right way and the geometry does give a slow out, faster return. Also the original motor was a 6pole, giving about 960 rpm, not the more common 4 pole at 1430rpm. Noel.

Edited By noel shelley on 18/01/2023 10:28:27

The forward power cutting stroke is when the drive pin is at the top of the circle because you get more torque when the pin is further away from the anchor/hinge point of the pendulum

It's like opening a door, the further from the hinge you go, the easier it is to move the door

Mr whitworth was a very smart cookie

From the owners manual Installation page

"The motor and countershaft pulley should rotate in a clockwise direction when viewed through the drive compartment door. Machines for single phase electric supply are correctly wired before despatch.
Machines for 3 phase supply can be reversed if necessary by changing over any two leads from the supply"

Here is a useful page for info on shapers generally
https://www.circuitousroot.com/artifice/machine-shop/shaper/literature/index.html

Bill

Brilliant info. My shaper has been going the wrong way since I purchased it 6 years ago. I will swap a couple of motor connections and get it going the right way.

Is it also worth pointing out that the auto table feed should feed on the ram's return stroke, and go 'Click, click, etc' on the cutting stroke? I've seen them wrongly set...

It's worth checking to see that the ratchet on the table feed doesn't also drag the feed screw backwards, so it oscillates, rather than feeding steadily. IIRC there's no built-in provision for adding some friction to the feedscrew's rotation, to prevent this from happening.

Did you get/are you fixing the vertical feed? I had to tighten up the horizontal before I dared turn it on

I think I want to fit a fridge-style, internal light that comes on when I open the octagonal door. I't a bit gloomy in there.

Robin

Yes, as I recall, after fitting the vertical drive gear, I had that problem.
I'm in the house at the moment, but I think I added either a fibre washer, or an O ring, behind the micrometer dial to add some friction to the shaft leadscrew assembly.

Bill

Most shapers will not feed properly just after you reverse the ratchet. The quick and dirty solution is just to move the handle a bit in the new direction to take up the backlash. Once that is done they drive OK, at least all my three shapers do.

John