Fellows #7 gear shaper questions
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  1. #1
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    Default Fellows #7 gear shaper questions

    I have been tasked with operating a rebuilt Fellows #7 shaper that my shop recently purchased. I have no one with experience running anything like this to learn from. Thankfully we run only one part on it so I don’t have to learn all about the changeovers. You guys can keep that.

    I do have a couple questions for you old timers that have experience running these.

    First: is the whole machine supposed to lurch so hard it moves 1/8” at the end of every cycle? Seriously, I have to pull this thing back into place with a forklift every shift. The boss is afraid if we bolt it down it will crack the cast iron base.

    Second: I am cutting a straight 15 tooth 1” OD spline in aluminum. 1.1100-1.1118 over 2 .120 pins. We can not get these done in one cycle. It always takes at least two. Sometimes more. I would think it could handle it in one from the videos I’ve seen. And when I do get a good part, there is taper in the gear. Up to .0010” from top to bottom of the 1” tall spline. I know this old girl is from the early 60’s. Are we asking too much from it as far as tolerances go or should it be better?

    Thanks for you help guys.

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    Who did the rebuild? How was the accuracy of the rebuild qualified? Have you talked with the rebuilder about how it's operating, including the excess movement on the floor?

    How does the spline cutting fail (why more than one op)? How are your cutters, what's your sharpening process and scheduling?

    There's others here with experience on Fellows gear cutters, but the more information you supply the easier it is for them to make recommendations.

  3. #3
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    Quote Originally Posted by Cchas View Post
    I have been tasked with operating a rebuilt Fellows #7 shaper that my shop recently purchased.

    First: is the whole machine supposed to lurch so hard it moves 1/8” at the end of every cycle? Seriously, I have to pull this thing back into place with a forklift every shift. The boss is afraid if we bolt it down it will crack the cast iron base.
    First, get the manual. Easy to find them. Tells you everything.

    You can bolt it down if you like, you're boss isn't very bright, the base is an inch thick ... but : there's two types of dropoff systems, one is a spring and the other a weight. Some have a hydraulic cylinder that regulates the backout, which you can play with. They do tend to pull away in a rush but not that bad. Adjust it. (I thought it was rebuilt ?)


    Second: I am cutting a straight 15 tooth 1” OD spline in aluminum. 1.1100-1.1118 over 2 .120 pins. We can not get these done in one cycle. It always takes at least two. Sometimes more.
    The feed cam is under the door on your left that covers the stroking mechanism. It should be marked. Otherwise, put an indicator on the cutting head. Crank the infeed cam. The cutterhead will move in steps. Do you have a one-cut, a two-cut or a three-cut cam ? I personally prefer the two-cut but doing a spline in aluminum, one-cut should work.

    And when I do get a good part, there is taper in the gear. Up to .0010” from top to bottom of the 1” tall spline.
    Put an indicator on the spindle against a right-angle on the table to check. Otherwise can be your fixture, cutter sharpening, any number of things. Nicest would be if the cutterhead is off a touch, it's adjustable.

    All you should have to do is put the blank in, crank the head in two turns (or up close to the part when you get more confident), push the start button, and take the part off in a couple minutes. Measure every tenth part or so ...

    I know this old girl is from the early 60’s. Are we asking too much from it as far as tolerances go or should it be better?
    No, those guys cut millions of parts in their lifetimes, they work good and are still viable for small shops. Something is off with your "rebuilt" machine. Just have to fix it. There is a maintenance manual too, which will take you through all the adjustments necessary to make it cut good parts.

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    I would try and reach '10 fingers' (he is a member of this forum) https://www.practicalmachinist.com/v...rs/10-fingers/ is a link. I don't know how often he checks in to the orum so you might want to contact him directly: Gear Works, Inc - Contact Us He probably knows as much or more about Fellows gear shapers than anyone else on the planet.

    -DU-

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    -DU-, thank you for the kind words. There's a few of us left that cut our teeth at Fellows, still keeping the brand alive. Hope you visit again.
    I rarely check in here anymore, with this evening being an opportunity for us to pay it forward.
    The roller follower in contact with the depth feed cam is held in thrust by a counter weight at rear of machine. At end of cycle, the roller follower drops off the high dwell into a .75 deep pocket causing the cutter to retract from the work piece. There is supposed to be a hydraulic damper integral with the counter weight so it doesn't hammer into the pocket. It can hammer enough to move the entire, 3200lb machine. Fair chance the damper is out of fluid. Is tagged to use brake fluid. We purge the damper and fill with ATF. On my machines, set the roller chain position on the sprocket so the cam roller follower never reaches the bottom of the cam pocket. On very early models, there is no hydraulic damper. Only an extension spring between the roller chain and suspended weight. Never operate these machines without ample, Vactra 2 oil. A guide can seize in 2 or 3 minutes. Upper and lower worms will scuff and destroy the indexing wheels. Absolutely never use an air hose to clear chips. As suggested, buy and read the God damn manual. Long ago lost patience for people that don't try to help themselves. Believe it or not, these machines were productively employed long before Al Gore invented the internet.

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    Few more questions- whats the whole depth of your spline tooth and or the cutter d+F?? 2nd question- what feed cam is on the machine? Is it a one, two or 3 cut cam, and what is its feed depth. The cam information is etched on the face of the cam. Listen to what 10 Fingers said about oil-. There is an oil reservoir on the top of the cutter spindle under the cover that the cutter spindle return spring pokes up thru. Lift that cover off and fill the reservoir. I always squirt oil down the oil wick holes if the machine has set for a few days to make sure the guide and worm wheel always have lubrication. oh yea RTFM. then come back and ask more questions.

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    The part where you said "it won't cut a good part except in two or three tries" bothers me. Even with everything else wrong, it should cut a good part (AGMA 7 anyhow).

    There is a possibility that the "rebuild" is crap. Get the maintenance manual and check that the relieving mechanism is timed correctly. If the saddle is not solidly in four-points when the cutter comes down, I can imagine it cutting a taper and also making unpredictably bad parts.

    It's also possible for the top half to be out of square with the bottom half. That's how they used to make tapered teeth. If the "rebuilder" took the machine apart, it's possible he did not put it back together square. Shouldn't be but it is possible.

    Get the maintenance manual. You need it. It shows you how to do everything you need to check.


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