Reverse rotation

J

Jim Huel

H-M Supporter - Silver Member
H-M Supporter - Silver Member
Joined
Mar 1, 2018
Messages
22
I have no machining background and had not even heard of shapers until last year. But, I just got a South Bend . I have some work to do, but it functions and I started experimenting by cleaning up the edges of some home-made face spanners.

While researching in the past weeks I saw a number of comments warning not to run them in reverse using a rpc. But, my SB came stock with a reverse switch, so SB thought there must be some value. I've seen other comments about clappers that cut on the pull stroke, so is that what SB had in mind? I dont intend to do that, but am curious.


And,,,,,photo taken in driveway, prior to unloading.
20180809_130253.jpg
The homemade vice is my biggest concern so far, but it at least handles light cuts. A stock vise would be nice but I understand those don't come up often.
 
No, shapers are never run in reverse for any reason. I do not see a reversing switch, and the starting switch does not look original to me, neither does the cradle mounted motor; I'm guessing that it too is not original and is single phase. I do not see anything particularly wrong with that vice, it appears to be a shaper vise. I made one very similar to it in my high school machine shop class back in the 1960s.
That is a nice looking machine! The only shaper that I have any knowledge of that cut on the back stroke was the Morton Draw Cut, big machines used in shipyard and railroad work, I could not quite feature a machine that aims the chips towards the operator instead of away from him!
 
Stefan Gotteswinter shows cutting on the Pull stroke with his Gack HE20 shaper (ie in Reverse).


He also has prints of the Gack Pull Stroke Clapper box on his webpage.

Gack HE20 reversed shaper head

I believe the main reason people say not to use a shaper on the Pull stroke is given the mechanical action, the Pull stoke is faster than the push...... That is on a non-reversible shaper. Since your shaper motor can be run in reverse, then in reverse the Pull stroke would the slower of the strokes and the Push would be the faster.

Here's a Tubacain video showing the Whitworth Quick Reverse Mechanism, which shows how the shaper return stroke is faster than the cutting stroke.

 
Hi Jim,
I don't know if that switch is standard or not as I don't have an Southbend. There are a few occasions when you might want to run in reverse though such as cutting a keyway. It is pretty rare and you would usually lock the clapper or fit a solid bar.
The big danger in running in reverse and cutting normally is that the feed if engaged takes place during what is then the high speed part of the stroke putting strange stresses into the machine.
You and me both would love a genuine vise for our machines. I'm sure you will have much fun with it but be aware that shapers are a love or loth machine, I'm in the love camp and find they really compliment a mill. For surfacing within its capabilities a shaper with a shear tool gives a finish hard to beat definitely better than a mill.
 
Where reverse cutting would be an advantage would be when cutting to an irregular line on the front end of a workpiece, something seldom done with ordinary shop work, it would indeed keep chips out of the operator's face, but for ordinary flat work the operator stands to the right of the machine away from the most likely path of the chips, And yes, I like shapers as well, having owned three during my career in machine work, first a cone drive Queen City 16", then a 24" Gould & Eberhardt, and now, a 20-24 Gould & Eberhardt Universal Industrial from 1967.
 
The switch looks just like the one on the cover of " How to run a metal working shaper" by South Bend, so I am confident it is a SB switch. You can see the toggle switch in that photo, and all it does on my machine is change the fast-slow sequence....as least that's the only change I see.

The parts list just calls it a toggle switch, and I don't see anything in the manual about the switch or running in reverse.
 
I was referring to the push button switch in the picture that is mounted in the rain tight enclosure as not looking original.
 
I suppose the reverse switch might be useful to jog for repositioning the ram for accessing the work, and of course for cutting on the pull stroke, which is more rigid on a lighter machine, and which also helps to keep the chips on the floor near to the machine.
 
Sorry, user error. That push button switch, box and toggle switch are the same as on the SB booklet.
 
You must log in or register to reply here.
Back
Top