Fellows 6A Help

I have recently purchased a Fellows 6A Gear shaper. I have never ran one and am needing help. I believe I have followed the operators manual and am ready to use it but I just don't under stand the feed operation nor feed process. I'm from eastern Ky and know of no one in the area to get help from so I am really hoping to get help from the forum. Thanks
Jerry

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Catalog Record: Instructions for setting-up and operating the... | Hathi Trust Digital Library

So what do you want to know? Do you have a cutter and a gear blank? Did you get any change gears with the machine. Do you have a work arbor? Probably 1st thing to do is study how to determine what the change gears need to be based on the # of teeth in your cutter and the # of teeth in your gear to be cut. Then go out to your machine and get friendly with it, and try to mount the change gears on the correct shafts per the manual.

Thanks this is going to be a lot of help. I never had this book. I am studying it now

I got 25 change gears with the machine. I intend to make more, I have got software CPC-Ratio from rush gear to help with the change gears. I have changes gears in it now that came in it. A cutter is in it that came with the machine. It has a hollow spindle , I have a arber in it now. It has a 5.75 Id in the chuck. I was just trying to get the basics down. #1 I don’t understand setting the dept of cut by the pitch being cut. This seems way sloppy to me. I am use to lathes and mills, setting things up and finishing in a thousandth or so. It seems to want to only cut the depth fully automatic. I think I understand how to set it up for external gears and get it cutting at least cutting air. I see pitches up to 20 for stetting depth of cut. This is my questions so far. #1 how would I cut axles splines with it like car axles that are so shallow, I don’t see a depth pitch that shallow? #2 when I cut id splines, how do I make it feed into the cut instead or away from the material, do I start on the offside of center and let it feed in the same direction as and od gear? The manual says I have to cut Id’s with a idler. Is this in stone? Why? # 3 It says the worm ratio is 10 to 3. I assume this is figured in with my change gear formula to get the correct gear tooth count. Is this correct?

#1 I don’t understand setting the dept of cut by the pitch being cut.

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Ebay listing has great photo of markings on cutter that may clarify. The depth (D+F) for a 6 pitch tooth in this case is .375

FELLOWS GEAR CUTTER DISC SHAPER FINISHING NON TOPPING 6 DP 14.5 PA 24 T 3.85 BC | eBay

retrofit said:

I got 25 change gears with the machine. I intend to make more.

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I have extra 6A gears, let me know what you have or what you need and I'll see if I can help you fill out a full set.

It has a hollow spindle , I have a arber in it now. It has a 5.75 Id in the chuck. I was just trying to get the basics down. #1

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That's good to have sounds like you might have a 645A machine.

I don’t understand setting the dept of cut by the pitch being cut. This seems way sloppy to me. I am use to lathes and mills, setting things up and finishing in a thousandth or so. It seems to want to only cut the depth fully automatic.

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It is crude. a cutter with a different whole depth or addendum will give you incorrect results. I start by leaving that feed at zero, and sneaking up on the feed at the head with the machine running slowly. When the cutter scrapes the blank, I stop the machine, back off the automatic feed past the appropriate pitch mark for clearance, then crank in the amount of depth I want for the first cut at the feed on the head, being shallow for the first trial cut. Then I start it up and let the auto feed feed it in while it's stroking until it kicks out, let it cut a full pass, adjust to suit at the head for the next pass, allowing it to feed in aotomatically if it's a significant amount.

#2 when I cut id splines, how do I make it feed into the cut instead or away from the material, do I start on the offside of center and let it feed in the same direction as and od gear?

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Correct, you cut on the left side of the apron so the relieving motion is in the correct direction, and so the apron is locked on the downstroke.

The manual says I have to cut Id’s with a idler. Is this in stone? Why?

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Yes, both the cutter and the work have to turn the same direction,

# 3 It says the worm ratio is 10 to 3. I assume this is figured in with my change gear formula to get the correct gear tooth count. Is this correct?

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Yes. Do you have the big page of change gear combinations from the fellows manual?

Thanks for the help. I will get a list of the change gears I have and let you know. Yes, it’s a 645A. As for the feed question, I will play with the feed and try to figure out how you do this. Are you saying at the end of the day, you are feeding the cutter into the work by hand until your desired depth is met and then moving the auto feed again to kick it out?
As for change gear set up, I have the charts in the manual, but I don’t see how this will help much, If I am thinking correctly the number of teeth on the cutter comes into this equation . That would make a to many combinations for a chart wouldn’t it. I know I a missing something here. Bear with me , I know it pretty frustrating to try to help someone with very limited knowledge of the subject.
One more question, could and how would I cut a keyway with this machine?
Thanks
JB

retrofit said:

. Are you saying at the end of the day, you are feeding the cutter into the work by hand until your desired depth is met and then moving the auto feed again to kick it out?

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Leave the auto feed in the full depth position, and place the cutter in contact with a known diameter of the workpiece by the adjustment on the head - like touching off on a lathe. Then you can back the auto feed off to retract the head. Then adjust the crank on the head to set the depth of cut according to the dial on the pinion on the head. The auto feed can then feed the head in to the depth you just set on the head. Clear yet? Alternately you can slowly feed the head in by hand as the machine strokes until you get to full depth, then leave it set there and back off the auto feed and use the auto feed for infeed on the next part.

As for change gear set up, I have the charts in the manual, but I don’t see how this will help much, If I am thinking correctly the number of teeth on the cutter comes into this equation . That would make a to many combinations for a chart wouldn’t it. I know I a missing something here. Bear with me , I know it pretty frustrating to try to help someone with very limited knowledge of the subject.

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The chart is enough to do 99% of the combinations you'll need. So far I've only needed a program to calculate one combination for a 79T workpiece. The chart uses conventions like (2Xcutter teeth) to indicate the number of teeth in a particular gear in the train to allow you to select from several combinations to find one that fits the machine.

One more question, could and how would I cut a keyway with this machine?
Thanks
JB

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I think you can use it like a slotter by disengaging the feed gears, but I haven't tried it.

If you are going to cut keyways, You have to disengage the feed gears by disengaging them at the feed select tumbler by lifting the tumbler arm and not engaging it. If you don't do this, the upper worm will continue to rotate the cutter spindle.

Fellows made a work arbor adapter that fits in that 5.75 diameter hole in the work table. If you don't have one, I think I have an extra one if you're interested.

The change gear table in the manual works just fine for figuring out the index gears- not sure why you think its not a good solution.

The pitch markings on the feed drum do not set the depth of cut- those are only reference for manually retracting the head after your gear is cut. The head will feed to the same stop every time, then trip the clutch to shut off the stroking.

The depth of cut is set using the graduated collar on the face of the cutter head.
As Mud said- with the feed drum all the way at zero and the cutter backed off from the blank, start the machine and manually move the cutter head in until the cutter kisses the blank, or use a piece of paper like touching off a milling cutter. Stop the machine and raise the cutter above the blank. Now use the graduated collar on the head to move the head in the desired depth.

Now use the hand crank on the right side of the machine and crank the cutter head out a little past the DP mark on the feed drum- ex: for a 10 DP gear the cutter D+f is .225. Moving the feed drum past the 10 dp mark will move the cutter head out that much past the blank.

To cut a gear, pull the clutch in and then engage the feed by dropping the feed pawl onto the feed ratchet. The cutter head will feed in until the cam trips in the feed drum, the blank will make one revolution and the clutch will trip.

Now manualy crank the feed drum past the 10 DP mark and measure your gear. Rinse and repeat.

One thing I strongly suggest is make a block to mount on the top rail that guides the rail and mount a 1" travel dial indicator so the plungr rests against the head.
Make the block so you can unclamp it and move it along the rail for different positions of the head. It helps a lot keeping track of head position.

Everything you need to know to run that machine is in the manual. Take the time to sit down and read it from cover to cover.

You don't need any stinkiin software to figure out the change gears for that machine- its all in the table. Hope ths helps

Thanks I will save my money on the change gear software. I will post a picture of the work set up I have, then tell me if its the one from fellows.

You are talking about lifting the arm that has six slots and sets the feeds and not letting it seat in any of them. Then it don't matter what change gears I have in, the work nor cutter will rotate, Correct?

I also know I don't have a idler gear or shaft, do you have one of these?

SeaMoss, what can of disasters to I have to be on guard for with my 6a , can't get a 7, its not big enough to make the gears in my wrist watch. LOL.

SeaMoss said:

You guys done good but neither one of you said, if you do it manually (better, imo) then make sure you touch off on the down stroke (unless you are up-cutting, which I bet op is not). Otherwise he's in for a nasty surprise. 6'es are a pain in the ass, get a 7

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I posted to do it with the machine running slowly so yes it would logically be on the downstroke.

Since you are the expert, you can take over from here.

Here are some pictures of the factory Fellows work spindle adapter for a 645 with a 5 7/8" hole in the spindle. This adapter has the Fellows reverse taper in the bore. You can also bolt fixtures / arbors to the adapter using the 4 ea ½-13 tapped holes in the top surface. The top if this one is a kind of dinged up but it stoned flat enough. Also including a poor photo of the adapter from the op manual for reference. I hope this helps somewhat.
Dan

Here is a picture of a Fellows reverse taper adapter, the reverse idler and bracket you need for cutting internal gears and the indicator mount for the head. You should have a round stud in the upper right corner of your change gear area (near the 4 point) that the reverse idler arm slips over. This reverses the table rotation for cutting internal gears.

Mud

Thanks for the help so far. I need quite a few change gears, my cabinet has a slot and numbers for 55. Some of mine were not on that chart and I had some doubles that the chart didn't call for. so this is the ones I need according to the slots. 30 32 37 36 38 39 40 41 42 42 43 44 48 48 49 54 54 56 56 52 58 64 68 69 69 70 80 80 81 82 84 84 86 90 96 96 100 120 PM me and let me know what you have and price. Thanks JB

OK, I'll look for the list of what I have and let you know - give me a few days.
Do me a favor and PM me your email address so I can send it that way, the mailboxes here fill up awfully fast.

Don't know about a 645 but 7-type change gears fit on a weird triangular shaft. The apexes (apices?) were cylindrical, so you could use stock Browning or Boston spur gears with the right diameter round bore and just weld a flat in one segment. As long as the round part fits, the gear will stay centered and will drive off the weld interference. Much cheaper than horse-trading for actual Fellows gears.

Thanks for that ideal. I did not think of that. I could get them with a pilot hole and cnc mill the three sided bore in them.

What is the pitch and pressure angle on these gears?
I believe 6A and 7 gears are interchangeable.