Can it adjust the fall back of the clapper box?

If so it could adjust either the clearance angle on the tool by slanting the clapper forward. Or by the same method finely adjust the the fallback to give an extremely fine Z axis height adjustment. Just thinking out loud!!

It looks to me like the leadscrew from a lathe cross slide or compound table. The right angle pin at the end would go in a hole in the slide, so that the slide is pulled back and forth when the handle is turned, but the alignment between the screw part and the slide is not too critical. It doesn't look like anything I have seen on a shaper before.

The shaper itself looks like a good machine, and the vice looks like just the bee knees! The gearbox does indeed seem to be ex motorcycle, possibly replacing a stepped pulley for a belt drive. My Dad once used one from a two stroke motorcycle for a drill press, cutting away the engine part first.

John

I reckon you've guessed right with what that screw drives, in those last photos, Jordi.

Why?

Definitions first:

The sliding mass on the shaper is its Ram.

The Clapper-Box is as it says, the hinged block that holds the tooling.

That add-on does not reach the clapper box, and I can't see why you need to limit its return arc. In fact I'd consider that bad practice. You control the tool geometry by grinding it appropriately.

The only time you lock the clapper-box, is when cutting internal key-ways etc. Those are normally draw-cut, necessitating that locking. One way that avoids modifying the machine is to use a tool-holder fitted with a jacking-screw in an extension above the clapper-box top.

So why this accessory?

First what it is NOT. It is not a stroke-limiter – not on a power-driven machine! That is the task of the crank adjustments and nothing should obstruct the ram acting as the crank stroke and relative position give.

Therefore, I think it was intended to give a fine, short-stroke hand feed. Hard to see where that might be used, but one guess is for engraving scales when you'd want to cut only short, fine grooves under close control.

On my Atlas – the ram position is adjusted by a crank on top of the ram and there is a separate locking handle. This adjustment simply positions the ram within it's stroke – and as Nigel states – the actual stroke length is set by another adjustment. This shaper doesn't have the crank adjustment but I assume the ram is simply slid around and then locked in place by the lever on top of the ram – a similar but simpler arrangement.

It does look as if the slot in the new part could be intended to fit under the 'locking handle' but then – if tightened – the ram couldn't move – so I don't see any point to doing that if used as a shaper.

However, if a milling head was substituted for the clapper box, then the shaper becomes a mill and this attachment makes perfect sense as a feed screw.

So I think you should look for some kind of milling spindle to fit it in your box of bits Jordi.

Regards,

IanT

Edited By IanT on 03/04/2019 10:23:39

Well, you could, and I did think that with my Drummond, making a fitting to take a small milling/ drilling -head – mounted directly on the clapper-box stud and set-screw so without permanently altering the machine itself. It would be quite limited in scope, though.

I still think it more likely it was for hand-control finer than the machine itself can give, very possibly as Neil suggests – working to blind ends – but it would be a very slow way to do any sizeable cutting like gear-teeth and splines. If I was to make a compound gear I think if the design allows, I'd rather screw two separate wheels together face-to-face.

If it is possible I'd ask the machine's previous owner but I am aware this may have come from a dealer, or a bereavement sale.

You surely would need to remove it before starting the shaper.

I think Jordi has it right, it is for adjusting the stroke. I will also guess that it is not a manufacturers accessory, but something that has been made by a former owner. It is not that a precise adjustment of the stroke is all that important, it is that it can take a bit of to and fro to get the stroke anything like, and while you are doing it your hands are inside the machine, just waiting for someone to bump the power switch and put you in a world of pain.

Some shapers are easy to adjust…my 18 inch Alba has the screw and bevel gears inside the bull wheel, so it can all be done from the operators side. My 6 inch Ammco does not, but it is a small machine, and it is easy to get the position right, you get the slotted arm in the vertical position and the crank pin will slide up and down easily and stay in the right position while you lock it up. My 10 inch Alba has the same arrangement, but it is not so easy to get it adjusted to a good position, it fights a bit and the rather small door opening gets in the way. So it is easy to see that someone might have decided that a more sophisticated way of adjusting the stroke was desirable.

John