JasonGGI
Plastic
- Joined
- Mar 23, 2020
Hi everyone,
I am currently cutting a 3 tooth helical gear with a high helix angle on a Barber Colman 6-10 gear hobber. So far, I have successfully cut several dozen of these gears, but I have shattered the teeth on two hobs in the process. I suspect feed speed is my issue, but I only have two hobs left, and I absolutely must cut these gears, so I'm reaching out for opinions before I try something else.
My gear has the following specs:
3 Teeth
81.1° Helix Angle
Left Handed Gear & Hob
38 NDP
.01” feed per revolution of work (is this too high?)
Cut: Conventional
Hob Rotation: CCW
Direction of Feed: Left
Work Rotation: Top Going
Depth of Cut: .0592
Outer Diameter: .5629
Blank Size: .57
Hob Spindle RPM: 412.5
I have adjusted my worksheet to have a feed speed of .002" per revolution of work, but this is currently untested. Here is a link to the Excel workbook I have designed to make my gears: https://drive.google.com/open?id=121CY2ybP1aT4VrN4IuPPHumwk5vwE5dX
Does anyone have any ideas why my hob keeps chipping teeth off? Am I correct that my feed is too high? Is the hob spindle RPM off? I'm very open to any ideas or wisdom you might have as to why I'm having issues. I'm a novice at this, so I can't help but feel that I'm missing something obvious.
Thanks again; I really appreciate any help!
I am currently cutting a 3 tooth helical gear with a high helix angle on a Barber Colman 6-10 gear hobber. So far, I have successfully cut several dozen of these gears, but I have shattered the teeth on two hobs in the process. I suspect feed speed is my issue, but I only have two hobs left, and I absolutely must cut these gears, so I'm reaching out for opinions before I try something else.
My gear has the following specs:
3 Teeth
81.1° Helix Angle
Left Handed Gear & Hob
38 NDP
.01” feed per revolution of work (is this too high?)
Cut: Conventional
Hob Rotation: CCW
Direction of Feed: Left
Work Rotation: Top Going
Depth of Cut: .0592
Outer Diameter: .5629
Blank Size: .57
Hob Spindle RPM: 412.5
I have adjusted my worksheet to have a feed speed of .002" per revolution of work, but this is currently untested. Here is a link to the Excel workbook I have designed to make my gears: https://drive.google.com/open?id=121CY2ybP1aT4VrN4IuPPHumwk5vwE5dX
Does anyone have any ideas why my hob keeps chipping teeth off? Am I correct that my feed is too high? Is the hob spindle RPM off? I'm very open to any ideas or wisdom you might have as to why I'm having issues. I'm a novice at this, so I can't help but feel that I'm missing something obvious.
Thanks again; I really appreciate any help!