Shaper Lesson Learned and a Newbie Question

MetalMonkey

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OK, so I'm still a rookie (complete!) at the shaper, and still getting the hang of it. I wanted to just try out a different tool bit on a scrap piece of aluminum. Keep in mind this is probably the 4th time I've actually applied power to my new (to me ) SB7. So I put the bit in the holder, the holder in the tool post and squared everything up. put my little scrap in the vise and got a good chip from each stroke, all was well. The tool was a bit too pointed, so I got this nice textured (ribbed?) finish that I actually kinda like. Not that I'll stick with that, but it was interesting.

Anyway, I had once clean surface now, so I figure, lather rinse repeat. Loosen vice, rotate stock 90* and clamp er up again. This side has a 1/4" hole drilled through the middle, but I figure what the heck, its just scrap, lets see what happens. And this side goes through without a problem... Im kinda liking this! rotate the scrap and lets do it again.

This side had two separate openings along one side where a previous couple of screw holes had met the saw blade when this side was cut. But again, lets see what it does. So liner up and let her go!.. the slots were on the far side so the first 3/4's went without a hitch. It even made it about two thirds of the way through the slots when there was suddenly movement I didn't expect. And before I could really react, the shaper had taken about 3 more strokes making a pretty different banging sound...

Long story short, I had never checked the vice's anchor bolt. Everything seemed solid, and certainly the last guy hadn't used it with it lose! right!?!? Well, Im sure not! But apparently the interrupted cuts had been enough to loosen it up and allow the vice to rotate to about 35* counter clockwise from its intended position.

So Lesson Learned! Always check the vise. And your first reaction to anything unexpected should be to reach for the power switch!!
 
SO... Now for my question.

Is there any other specific abnormalities to watch for when you are making an interrupted cut on a shaper?
Is there possible deflection, or ????? anything else?

Thanks for any replies, I am learning a lot from this group even just as a lurker!
 
Ah yes, the old pivoting vise trick! If we could do things like that on cue it would be magical.

Here's a little scrap (well, it's scrap now anyways) that sits beside my shaper. You'll notice it's a bit wonky, eh? Like the hole by my thumb is kinda squished-looking, and the angles are oddly off of square somehow.

What happened was I had it clamped up in the vise to take a cleanup cut on the upper edge. The ram would be coming from the right side of this photo and cutting towards where my thumb is. It wasn't a heavy cut, and this piece is aluminum and also not very big, but partly because of the large hole at the one corner and partly because of the way I had it oriented in the vise, this went sideways. The cutter caught on the leading edge of the part, lifted it up and out of the jaws, all the while trapping it underneath the still charging ram.

In some ways I suppose the hole by my thumb where the part pivoted acted as a bit of a crush zone and saved damage, I don't know. But I kicked myself immediately for not orienting the part with the "leg" pointing the other direction and away from the ram. It may still have caught, and the part may have still rotated, but the leg would have rotated down and away rather than up and into the tool.

image.jpeg


My point I guess is in addition to checking and double checking your clamps and hold down bolts, think about whether you have the best orientation of the part should something go wrong. Could the setup be better, will a part fall away or get drawn in if things go sideways. And I've also become a big fan of using paper (non glossy, no clay content) in my vise jaws. It's mentioned many times in the old books, and it does help with keeping parts from sliding in the jaws or on a table.

So far cheap lessons, I want to keep it that way if I can!

-frank
 
....I've also become a big fan of using paper (non glossy, no clay content) in my vise jaws.


Would regular computer printer papaw fit this bill, or are you talking the brown grocery bag type stuff?
 
I like to ensure that my workhead givs are fairly tight. Otherwise the cut will take up the backlash in the downfeed causing a ramping action every time the tool enters the work. This makes for a weird looking cat, and is also hard on the machine.
 
Metalmonkey,
You should also have your clapper box angled towards the direction of feed by an amount. That way when the tool kicks up it moves away from the shoulder of the work.

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Cheers Phil
 
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