Surface finish

[Clive HartlandParticipant @clivehartland94829]

From my formative years at Tech College the tools on the shaper always had a side ways rake, maybe about 30 to 45deg. They always looked like exaggerated lathe tools and gave a very good finish. I have to say that the shapers were big and had a 10hp motor driving them. The surface of plates always came off with a good finish. So much so i did no further work on the surface and left, 'As is' and it looked good on the finished job. There were no complaints.

A small shaper is like a small lathe and cannot have the rigidity and power to give good finish. Here you have to do all you can to reduce the force at the tip of the tool so tool geometry is very important. I have some old books so will delve in and see what the oldies did with the geometry and report back.

Clive

[_Paul_Participant @_paul_]

Even a lightweight machine like the Adept should produce a better finish than that I know I have one.

The effect looks like surface chatter it’s now a process of elimination to find the cause/s

Some starter questions:

How many strokes per minute are you running at?

Any slop in the clapper box pivot pin?

And a few suggestions if I may:

Your tooling appears to be ground back in such a fashion as to have little support to the cutting edge try a fresh face on the tool and put around 5* positive rake on it try a shape like a lathe knife tool to start.

Before taking your cut tighten one of the gib adjusting screws on the side of the head (not the ram) enough to lock it up solid.

Cut the speed right down.

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Regards

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Paul

[Tony Pratt 1Participant @tonypratt1]

The OP's tool radius is much too large, it wants to be more like a lathe knife tool.

Tony

[Gordon FowlerParticipant @gordonfowler20773]

Thank you again for the replies, I am in the middle of making new T bolts and bearings for the push rod arm (from crank to ram) this was at a slight angle and not running as smoothly as it should be, maybe giving rise to a bit of juddering/vibration. I will as said previously sharpen the tool, however when the ram is disconnected and the machine manually operated the finish is fine. This hopefully indicates a drive train issue, hence my interest in the T bolts and bearings.

Gordon

[Gordon FowlerParticipant @gordonfowler20773]

Sorry to bring this back up, however after much fettling, new bushes etc and changing the drive from belt to worm and wheel.

As above. Also rubber mounting the motor success has been achieved and a good finish can be constantly achieved. The right angle reduction gearbox significantly slows the machine down but enhances the machine.

Gordon

[Ian S CParticipant @iansc]

Is the connection between the gearbox and the shaper solid metal to metal, or do you have a rubber joint (forgotten the name of it) this dampens the starting shock, and the stopping if you get a jamb up. If the gear box is not up to the job, it will let you know—-with a BANG, had that happen with a some what bigger one. Ian S C

[Oompa LumpaParticipant @oompalumpa34302]

Posted by Ian S C on 04/08/2014 12:30:45:

Is the connection between the gearbox and the shaper solid metal to metal, or do you have a rubber joint (forgotten the name of it) this dampens the starting shock, and the stopping if you get a jamb up. If the gear box is not up to the job, it will let you know—-with a BANG, had that happen with a some what bigger one. Ian S C

Oldham coupling Ian. I only remember this because I live near Oldham otherwise I would have forgotten too!

graham.

[Gordon FowlerParticipant @gordonfowler20773]

Gentleman thank you for your concerns. The connection between the motor and gearbox and gearbox and shaper is indeed solid metal, using a shear pin ( split pin ). Which has sheared! This allows a bit of flexibility. The positioning of the g/box, motor was carefully plotted and drilled to get the best line up, allowing for slight flex on the motor mounts. There is no reason why the connections could not be changed to a more resilient coupling in the future, this was after all to prove a point and has worked suspiciously well. The shear pins shear when I am being a little too demanding and the motor vibrations have dramatically reduced as have the strokes per minute. It now does what is asked of it, fairly accurately on rough old bits of metal. Ian taking your advise and experience I will make a gearbox guard.

Gordon

[Ady1Participant @ady1]

Got a description for it.

Engine turning

[Ian S CParticipant @iansc]

Gordon, There is a simple coupling that was used on all the old wringer washing machines, it consisted of a bit of thick walled rubber tube, the type with cloth included in it's structure, a bolt about 3/16" dia through both shafts and the tube. This does all that the Oldham coupling does.

The only guard I'd install is a little tunnel between the gear box and the shaper, and between the motor and the gear box. These could be wood or metal, what ever you have to hand.

Ian S C

[Ian S CParticipant @iansc]

Ooops finger slipped, pushed button X 2.

Edited By Ian S C on 05/08/2014 11:00:33

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