MadModder
Gallery, Projects and General => Neat Stuff => Topic started by: NeoTech on September 19, 2012, 10:17:59 AM
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has any1 tried this.. does it work?!
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Neo,
There is no reason this approach would not work so long as (A) you have enough power to make the cut and (B) you can make the cutter with sufficient rake & clearance. It is conceptually simple, but the details are likely to be more fun than rational to develop. There is another approach that someone here posted (relatively) recently where you would use a drive spud that was the pitch diameter of the gear driven by a friction feed such that a single point tool would progressively hob a tooth. You still have to (manually) increment your blank for each tooth, but the variables of manufacture are much simpler to control.
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Interesting idea, but the bigger the gear, the longer cutter required
Indexing the gear would surely be easier?
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correct me if I am wrong but wouldnt you only be able to make gears with the same number of teeth as the pattern?
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There is a, maybe, better technique which uses a single cutter and the work is rotated by a taut wire that is wound around a wheel of the required pitch circle diameter.
http://neme-s.org/Shaper%20Books/Michael_Moore/shaper%20gear%20cut.pdf (http://neme-s.org/Shaper%20Books/Michael_Moore/shaper%20gear%20cut.pdf)
Gear cutting on a shaper is something that might have potential for an electronic solution?
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yeah, the only problem i see with cutting gears on a shaper is that you u need several different setups for gears.. But you should be able to produce gears that are up to the size of your rack and all the below that matches the pitch/diameter i guess. =)
i have no idea.. i dont got a shaper.. (yet) ;)
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Is that not the motion of a 'Sunderland Gear Planer' ?
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On a rotational basis for a planer it would be a sunderland gear planer,
the exact type of planer that is demonstrated in that video is a
sykes gear planer.
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A cutter plate like that wouldn't be very stiff. The more teeth the longer the span. A lot of tool steel to get adequate stiffness in a full stationary rack compared to indexing the blank during clearance without rolling it laterally.
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As commented by others, as shown it is a Sunderland or Sykes gear cutter, depending on the details. Here's a real one:
But for home use, a 5 ton machine is probably a bit much so I favour this approach:
http://neme-s.org/Shaper%20Books/Michael_Moore/shaper%20gear%20cut.pdf
The article was originally in in ME in the '50's, but gear geometry hasn't changed so all you need is a single point tool of the appropriate angle depending on 14-1/2 or 20 deg gear contact angle and a 'drive drum' appropriate for the PCD. Any and alll DP's and modules taken care of automatically, just set the PCD and tooth depth as necessary. I've not made one yet, but it's on the list............ somewhere
Richard
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Here is a solution my late father came up with to use a slotting head on the milling machine for shaping gears.
He made a set of Myford change wheels on it which go up in increments of one tooth, the stack of gears is pretty impressive.
(http://i456.photobucket.com/albums/qq286/pgp001/Model%20Engineering/Various%20Tooling/Alexander%20Mill/StackofGears_zpsf87f18ac.jpg) (http://s456.photobucket.com/user/pgp001/media/Model%20Engineering/Various%20Tooling/Alexander%20Mill/StackofGears_zpsf87f18ac.jpg.html)
(http://i456.photobucket.com/albums/qq286/pgp001/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping01_zps64d8a467.jpg) (http://s456.photobucket.com/user/pgp001/media/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping01_zps64d8a467.jpg.html)
(http://i456.photobucket.com/albums/qq286/pgp001/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping02_zpsa8464f23.jpg) (http://s456.photobucket.com/user/pgp001/media/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping02_zpsa8464f23.jpg.html)
(http://i456.photobucket.com/albums/qq286/pgp001/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping03_zpsa216c761.jpg) (http://s456.photobucket.com/user/pgp001/media/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping03_zpsa216c761.jpg.html)
(http://i456.photobucket.com/albums/qq286/pgp001/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping05_zpsa9385131.jpg) (http://s456.photobucket.com/user/pgp001/media/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping05_zpsa9385131.jpg.html)
(http://i456.photobucket.com/albums/qq286/pgp001/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping04_zps6032ac45.jpg) (http://s456.photobucket.com/user/pgp001/media/Model%20Engineering/Various%20Tooling/Alexander%20Mill/AlexanderMillerSetUpForGearShaping04_zps6032ac45.jpg.html)
Phil
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Welcome aboard Phil, that's an impressive gear making set up.
Is that what preceded your Mikron Hobber, or was it replaced by it?
Andrew
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Phil,
More details on that set-up please!
Regards,
Steve
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Thats a really interesting gear setup, i cant stop wondering if that would work with my slotting head on the Aciera. =)
Not to mention that slotting head tool.. Could we have a closeup on that? =)
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Welcome aboard Phil, that's an impressive gear making set up.
Is that what preceded your Mikron Hobber, or was it replaced by it?
Andrew
Hi Andrew
I still have both machines, the Mikron came first and then I inherited the Alexander Master Toolmaker when my dad passed away ten years ago. I remember your visit to me with a box of hobs when I lived in Harrogate.
I do have a hand written sheet my dad did on how to set the machine up for different tooth counts, the cutters are genuine Sunderland ones and I have about half a dozen different sizes, the cutter is held in a home made clapper box in a similar way to a shaping machine tool.
The idea is you make one pass and do a few teeth, then shift the table back and index the blank round part of a turn and make the next pass. The number of teeth per pass depends on the number of teeth on the wheel and there is a formula for working it out.
My dad was a bit of a genius when it came to working out compound gear trains, I dont think your average model engineer would have come up with a set up like that.
Phil
Phil
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I remember when I was younger, the next door factory had scaled up versions of that machine cutting big chain sprockets all day long.
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Hi
A robust dividing head can be set up on the shaper to replace the vice, and a single point cutter ground to the shape of the tooth form. A fine lubricated feed and slow machine speed will be required. Always use trial cuts on a test piece unless you are very experienced.
Good Luck David
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Very impressive all around!