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New to me Ammco 7" Metal shaper

In Kay's Shaper Columns there is a story of a lab machine shop where they had set up a big industrial shaper near the supervisor's desk . Since no one had ever used it there was no problems. But they got a machinist who was skilled in it's use. The big fat chips came off red hot and burned the supervisor's papers. Shapers are fun.
 
Don’t know if it is running backwards, I say it looks to be moving faster moving ahead, then back. Could be a seeing thing, am needing to look see if on forward stroke the eccentric is on the upper half of the bull gear.

It might be helpful to know that there isn't much difference between forward and backward Ram velocity when the stroke is small. That's because the arm ratio isn't much different when the follower is near the center of the bull gear. The difference is MUCH more noticeable when the machine is set to a long stroke.

I think @Dabbler did bit on how and why the speed were different as a pulley/gear/wheel turned.

I found some discussion she did on pulleys but couldn't find anything she did on Shapers.

If you want, I could do an over view of how the geometry drives the velocity difference between the forward stroke and rearward stroke while it's fresh in my mind.
 
If you want, I could do an over view of how the geometry drives the velocity difference between the forward stroke and rearward stroke while it's fresh in my mind.
This has baffled me since this conversation started...how does a mechanically linked rotational mechanism change speeds from one way to another????
 
This has baffled me since this conversation started...how does a mechanically linked rotational mechanism change speeds from one way to another????
If you're not familiar with the mechanism there is a vertical arm hinged at the bottom. At the top the arm is hinged to the ram. Motion is derived by a pin rotating on the bull gear and running in a slot in the vertical arm. When the pin is on the top of the bull gear traveling horizontally it scribing a larger arc than when it is traveling horizontally on the bottom but the rotational speed is the same, so longer and shorter travels in the same time have to be different speeds for the ram.
 
On the 6 and 7 AMMCO Shapers, the Ram is driven back and forth by a vertical arm that is hinge pinned at the bottom and pushes the Ram back and forth at the top. The arm just rocks back and forth as the bull gear slider/eccentric goes around and around. The slider itself is bolted to the bull gear but slides up and down in the arm as it goes around and around on the bull gear.

20250427_135854.jpg

The arm is driven back and forth by the sliding eccentric that is adjustably pinned to the bull gear. The radius that the slider is set at defines the stroke. When it is in the center, the slider merely rotates and the arm does not move and therefore neither does the Ram.

As the radius of the block set point increases, so does the rocking of the arm and therefore the stroke of the Ram increases. At a maximum radius of 3 or 3.5 for the 6 and 7 inch shapers respectively, the eccentric/follower moves in its largest circle which moves the arm in its largest back and forth arc, which moves the Ram through its biggest stroke.

That's the simple part. The more difficult motion to see is the result of geometry.

The Ram always slides back and forth at the top of the arm on the drawing above. But the sliding block moves with the bull gear at a variable distance from the arm pivot. Since the rotational speed is the same, Vt and Vb for the block are the same, but in opposite directions.

However, the speed of the top of the arm depends on how far the block is from the pin. At the top, the Ram moves just a bit faster than the block. But at the bottom (return stroke), the Ram is moving about 5x as fast as the block because of the ratio of their distances from the pivot.
 
Thanks@Susquatch, have to look in to this when I have some time. In the miste of a very large project,for me, these day,( wood, etc.)

One of the reasons I worry a bit about your motor turning backwards, is the mechanical leverage. When the Ram is driven by a follower with a 5:1 leverage, something could break. It's better to have the leverage low to reduce the possibility of damage.
 
EXACTLY what I meant! With that info, a tape measure, and a calculator, you can figure out the size pulley that you should have, for the motor speed you are using.

AND, close enough, really is! :)

I counted my strokes per minute. I got exactly 70 which is what the manual says it should be. The belts are at the second lowest speed and the pulley on the motor is a 2" pulley. That tells me that it was intended to be used with a 2".

In a way, that's too bad. I had hoped to get a link belt for it but they are not recommended at 2".

I must admit I'm not real thrilled with the tool chest stand. It moves around more than I'd like.
 
I did have one little mishap getting the motor installed. I decided to drill and tap the mounts instead of just drilling for bolts with nuts.

As luck would have it, I broke one of my really old Craftsman taps. At first, I contemplated abandoning that hole and just going with 3. But after the 3 were done, I set my mind to removing the old tap. It took a while, but constant back and forth with the Wilton tap remover did the trick. Slow and steady is the order of the day for them. Then I finished that hole with a better quality dormer tap.
 
Yes I agree, the return looks faster, maybe have to fill that tool chest stand with some tools, or a bag of concrete. Maybe the epoxy kind, I hear it’s popular.
My unit is definitely turning backwards, kinda fits in at the moment, the faster I go, the behinder I get. Sometime a good reason to get slower.
Will definitely need to get that motor running the other way, or change it to one that will.
Now you need/have to do a project!!
 
But first chips first.

Beautiful finish. Camara lens makes it look ugly, but it's gorgeous......

20250429_102440.jpg

But, I need some shaper advice here....

20250429_103902.jpg

Look at the leading edge. Looks like it digs in a wee bit deeper when it first connects and then bounces out to finish the cut. And what's with the wee bit of shatter as it leaves the cut on the left side? What is going on?
 
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