Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Fri, 24 Jul 2020 at 22:26, Matthew Herd  wrote:

> In your second video you mention that the step generator for the rotary axis 
> is tied to the spindle motion.  What HAL pins need to be connected?  Do you 
> have an interface with a selectable ratio or do you just change the ratio in 
> the HAL file?

There is some info here: http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Hobbing

But currently I use a custom HAL component too. This allows me to also
jog the A axis (useful for re-cutting a gear)

component hobbing "synchronise a rotary axis to the spindle";

pin in float teeth;
pin in float starts = 1;
pin in float spindle-pos;
pin in float spindle-vel;
pin in float A-pos-cmd;
pin in float gear-pos-fb;

pin out float gear-pos;
pin out float gear-vel;
pin out float A-pos-fb;

author "andypugh";
license "GPL v2+";

function _;

;;

FUNCTION(_){
static double pos_ref;
static double spindle_ref;
static int old_teeth;

if (old_teeth != teeth){
pos_ref = gear_pos_fb;
spindle_ref = spindle_pos;
old_teeth = teeth;
}
if (teeth != 0) {
gear_pos = pos_ref + 360*starts*(spindle_pos -
spindle_ref)/teeth + A_pos_cmd;
gear_vel = spindle_vel / teeth;
A_pos_fb = gear_pos_fb - pos_ref - 360*starts*(spindle_pos -
spindle_ref)/teeth;
} else {
gear_pos = pos_ref + A_pos_cmd;
gear_vel = 0;
A_pos_fb = gear_pos_fb - pos_ref;
}
}


-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Matthew Herd]

Hi Andy,

In your second video you mention that the step generator for the rotary axis is 
tied to the spindle motion.  What HAL pins need to be connected?  Do you have 
an interface with a selectable ratio or do you just change the ratio in the HAL 
file?

Matt

> On Jul 24, 2020, at 5:17 PM, andy pugh  wrote:
> 
> On Fri, 24 Jul 2020 at 21:43, andrew beck  wrote:
> 
>> How hard is it to set up the hobbing and is it something I can just change
>> in and out as needed.  My cnc mill would be perfect.
> 
> Yes, my milling machine can be a vertical mill, a horizontal mill or a
> gear hobbing machine depending only on which INI file I pick to start
> LinuxCNC with.
> Some HAL files are shared, some are config-dependent, but they all
> share a tool table.
> 
> -- 
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1912
> 
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Fri, 24 Jul 2020 at 21:43, andrew beck  wrote:

> How hard is it to set up the hobbing and is it something I can just change
> in and out as needed.  My cnc mill would be perfect.

Yes, my milling machine can be a vertical mill, a horizontal mill or a
gear hobbing machine depending only on which INI file I pick to start
LinuxCNC with.
Some HAL files are shared, some are config-dependent, but they all
share a tool table.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andrew beck]

Hey Andy I like it.

How hard is it to set up the hobbing and is it something I can just change
in and out as needed.  My cnc mill would be perfect.

On Sat, Jul 25, 2020, 4:42 AM Chris Albertson 
wrote:

> On Fri, Jul 24, 2020 at 9:01 AM Jon Elson  wrote:
>
> > On 07/24/2020 02:09 AM, andrew beck wrote:
> > > Greg can you educate me on what what gear cutters are enough for most
> > gear
> > > cutting needs?
>
>
> I think the answer depends on if you are a job-shop accepting any and all
> orders from customers or if you are building parts of your own design.   If
> you are designing your own parts you can standardize on just a few gear
> sizes, perhaps modulo 0.5, 1.0 and 1.5 are enough for any machine you'd
> ever design and build.   Then for each size you need a full set of cutters
> and an arbor to mount the cutters
>
> You can find a full set of 8 for one size for about $100 more or less.  You
> can even find them on Amazon.  Search for "involute cutter".
>
> Here is an example .amazon.com/8PCS-Milling-Gear-Cutters-HSS
> <
> https://www.amazon.com/8PCS-Milling-Gear-Cutters-HSS/dp/B07VFSQVJ5/ref=sr_1_9?dchild=1=involute+gear+cutter=1595608530=8-9
> >
>
> But to buy every size cutter you might ever need in US and Metric size
> would be quite an investment but buying just a few and then limiting you
> designs to just those sizes in not bad.
> --
>
> Chris Albertson
> Redondo Beach, California
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Chris Albertson]

On Fri, Jul 24, 2020 at 9:01 AM Jon Elson  wrote:

> On 07/24/2020 02:09 AM, andrew beck wrote:
> > Greg can you educate me on what what gear cutters are enough for most
> gear
> > cutting needs?


I think the answer depends on if you are a job-shop accepting any and all
orders from customers or if you are building parts of your own design.   If
you are designing your own parts you can standardize on just a few gear
sizes, perhaps modulo 0.5, 1.0 and 1.5 are enough for any machine you'd
ever design and build.   Then for each size you need a full set of cutters
and an arbor to mount the cutters

You can find a full set of 8 for one size for about $100 more or less.  You
can even find them on Amazon.  Search for "involute cutter".

Here is an example .amazon.com/8PCS-Milling-Gear-Cutters-HSS


But to buy every size cutter you might ever need in US and Metric size
would be quite an investment but buying just a few and then limiting you
designs to just those sizes in not bad.
-- 

Chris Albertson
Redondo Beach, California

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[John Dammeyer]

> From: andy pugh [mailto:bodge...@gmail.com]
> On Fri, 24 Jul 2020 at 12:14, Gene Heskett  wrote:
> 
> > > Did my list of suppliers of involute gear cutters make it to the list?
> > > The conversation continued round it as if the question remained
> > > unanswered.
> >
> > I don't recall seeing it Andy.
> 
> 
> https://www.amazon.com/s?k=involute+gear+cutter
> https://www.ebay.com/sch/i.html?_from=R40&_nkw=involute+gear+cutter
> https://www.mcmaster.com/involute-spur-gear-cutters
> 

I bought sets like that a year or two ago.  I haven't used them yet.  Not even 
to play for two reasons.   Although I have a rotary table controlled by an ELS 
I don't have any specific application that needs gears.  At that time the CNC 
wasn't complete.  And finally , the big Harmonic Drive is still sitting in the 
3D printed version of what the cast housing will look like.  I can make it turn 
via LInuxCNC but no faceplate for it either.

Maybe once I'm retired I'll have more time

John




___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Jon Elson]

On 07/24/2020 02:09 AM, andrew beck wrote:

Greg can you educate me on what what gear cutters are enough for most gear
cutting needs?  Fusion 360 has a nice gear profile generator I can use.
But I'll have to model all the cutters after that I think...  Thinking keep
them pretty simple with no helix angle or anything.  And maybe plan to cut
most of it out with a endmill straight down the middle before putting the
gear cutter through the cut


Well, the traditional horizontal mill gear cutters usually 
come in a set of 6 for each gear tooth pitch.
You use each cutter for a range of tooth counts for that 
tooth pitch.  And, there are 14.5 degree and 20 degree 
pressure angles. So, there end up being a LOT of gear 
cutters that one could possibly need.


Jon


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Fri, 24 Jul 2020 at 14:58, Matthew Herd  wrote:

> Let’s say I were to purchase a hob like this one:
>
> https://www.ebay.com/itm/DP16-PA14-5-Gear-Hob-Cutter/302306779664
>
> How do I determine the lead angle?

It is always engraved on the hob.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Matthew Herd]

Hi Andy,

Let’s say I were to purchase a hob like this one:

https://www.ebay.com/itm/DP16-PA14-5-Gear-Hob-Cutter/302306779664?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D227672%26meid%3Dd1b784222bed4e2a9a9180c0104f7f6c%26pid%3D15%26rk%3D1%26rkt%3D12%26mehot%3Dpf%26sd%3D331272003959%26itm%3D302306779664%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV2bDemotionZeroArw%26brand%3DUnbranded&_trksid=p2047675.c15.m1851
 


How do I determine the lead angle?  Is a standard lead angle used for certain 
DP/Module sizes?  Or do I need to make some measurements to determine the lead 
angle of that particular hob.

Matt

> On Jul 24, 2020, at 8:50 AM, andy pugh  wrote:
> 
> On Fri, 24 Jul 2020 at 12:23, andrew beck  wrote:
>> 
>> Oops sorry Andy yep I missed it.  Just had a look now.  Sounds like I need
>> to set up one of my cnc mills as a gear hobber
> 
> Those are zero-lead profiled cutters. You can use those on any mill
> (or lathe, in many cases)
> 
> You can also use the rack-form cutter from those sets to generate
> teeth one-by-one on a CNC milling machine:
> https://youtu.be/SJQtx80euGM?t=172
> (or, as shown in that video, a single-point tool)
> 
> Or you can go the whole way and hob on your CNC mill, with spiral
> hobs. If you can set the work and spindle at the required angle.
> Vertical mill, poor video:
> https://youtu.be/ZhICrb0Tbn4
> Horizontal mill, better video
> https://youtu.be/xdE46yvckbM
> 
> Your ball-nose mill approach,  though, is the only easy way I know of
> to make bevels, especially spiral bevels, without a specialised
> machine.
> 
> -- 
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1912
> 
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Fri, 24 Jul 2020 at 12:23, andrew beck  wrote:
>
> Oops sorry Andy yep I missed it.  Just had a look now.  Sounds like I need
> to set up one of my cnc mills as a gear hobber

Those are zero-lead profiled cutters. You can use those on any mill
(or lathe, in many cases)

You can also use the rack-form cutter from those sets to generate
teeth one-by-one on a CNC milling machine:
https://youtu.be/SJQtx80euGM?t=172
(or, as shown in that video, a single-point tool)

Or you can go the whole way and hob on your CNC mill, with spiral
hobs. If you can set the work and spindle at the required angle.
Vertical mill, poor video:
https://youtu.be/ZhICrb0Tbn4
Horizontal mill, better video
https://youtu.be/xdE46yvckbM

Your ball-nose mill approach,  though, is the only easy way I know of
to make bevels, especially spiral bevels, without a specialised
machine.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gene Heskett]

On Friday 24 July 2020 07:17:36 andy pugh wrote:

> On Fri, 24 Jul 2020 at 12:14, Gene Heskett  
wrote:
> > > Did my list of suppliers of involute gear cutters make it to the
> > > list? The conversation continued round it as if the question
> > > remained unanswered.
> >
> > I don't recall seeing it Andy.
>
> https://www.amazon.com/s?k=involute+gear+cutter
> https://www.ebay.com/sch/i.html?_from=R40&_nkw=involute+gear+cutter
> https://www.mcmaster.com/involute-spur-gear-cutters

Got it, marked it, thanks Andy.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andrew beck]

Oops sorry Andy yep I missed it.  Just had a look now.  Sounds like I need
to set up one of my cnc mills as a gear hobber

On Fri, Jul 24, 2020, 8:30 PM andy pugh  wrote:

> On Fri, 24 Jul 2020 at 08:33, Gregg Eshelman via Emc-users
>  wrote:
> >
> > For gear cutting every pitch or module has either one hob that cuts any
> number of teeth, which requires a machine able to synchronize rotation of
> the hob and blank, or a set of 8 different single tooth cutters, each of
> them marked with a range of the number of teeth on a gear they're suitable
> for. For Diametral Pitch gears there are also two different Pressure
> Angles, 14.5 or 20 degrees. Thus a complete DP set has 2x the number of
> cutters than there are for metric Module or Mod gears.
>
> Not all Module (metric) gears are 20 degrees PA, sometimes you find 14.5.
> (And, technically you could quote metric DP or imperial Module. A 14DP
> inch gear is a 0.071428571428571 inch Module gear)
>
> Did my list of suppliers of involute gear cutters make it to the list?
> The conversation continued round it as if the question remained
> unanswered.
>
> --
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1912
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Fri, 24 Jul 2020 at 12:14, Gene Heskett  wrote:

> > Did my list of suppliers of involute gear cutters make it to the list?
> > The conversation continued round it as if the question remained
> > unanswered.
>
> I don't recall seeing it Andy.


https://www.amazon.com/s?k=involute+gear+cutter
https://www.ebay.com/sch/i.html?_from=R40&_nkw=involute+gear+cutter
https://www.mcmaster.com/involute-spur-gear-cutters


-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gene Heskett]

On Friday 24 July 2020 04:26:47 andy pugh wrote:

> On Fri, 24 Jul 2020 at 08:33, Gregg Eshelman via Emc-users
>
>  wrote:
> > For gear cutting every pitch or module has either one hob that cuts
> > any number of teeth, which requires a machine able to synchronize
> > rotation of the hob and blank, or a set of 8 different single tooth
> > cutters, each of them marked with a range of the number of teeth on
> > a gear they're suitable for. For Diametral Pitch gears there are
> > also two different Pressure Angles, 14.5 or 20 degrees. Thus a
> > complete DP set has 2x the number of cutters than there are for
> > metric Module or Mod gears.
>
> Not all Module (metric) gears are 20 degrees PA, sometimes you find
> 14.5. (And, technically you could quote metric DP or imperial Module.
> A 14DP inch gear is a 0.071428571428571 inch Module gear)
>
> Did my list of suppliers of involute gear cutters make it to the list?
> The conversation continued round it as if the question remained
> unanswered.

I don't recall seeing it Andy.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Fri, 24 Jul 2020 at 08:33, Gregg Eshelman via Emc-users
 wrote:
>
> For gear cutting every pitch or module has either one hob that cuts any 
> number of teeth, which requires a machine able to synchronize rotation of the 
> hob and blank, or a set of 8 different single tooth cutters, each of them 
> marked with a range of the number of teeth on a gear they're suitable for. 
> For Diametral Pitch gears there are also two different Pressure Angles, 14.5 
> or 20 degrees. Thus a complete DP set has 2x the number of cutters than there 
> are for metric Module or Mod gears.

Not all Module (metric) gears are 20 degrees PA, sometimes you find 14.5.
(And, technically you could quote metric DP or imperial Module. A 14DP
inch gear is a 0.071428571428571 inch Module gear)

Did my list of suppliers of involute gear cutters make it to the list?
The conversation continued round it as if the question remained
unanswered.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gregg Eshelman via Emc-users]

For gear cutting every pitch or module has either one hob that cuts any number 
of teeth, which requires a machine able to synchronize rotation of the hob and 
blank, or a set of 8 different single tooth cutters, each of them marked with a 
range of the number of teeth on a gear they're suitable for. For Diametral 
Pitch gears there are also two different Pressure Angles, 14.5 or 20 degrees. 
Thus a complete DP set has 2x the number of cutters than there are for metric 
Module or Mod gears.
Cutter #8 in the sets has straight sides, made for cutting some large 
(somewhere over 100) number of teeth to a flat rack ("infinite" teeth). Hobs 
also have straight sides on their cutting edges. It's the rotation of the gear 
being cut which forms the involute curves.
An in-between measure often used by hobbyists is a straight hob instead of a 
spiral hob. With 3 or more rows of cutting teeth (larger gears will need more 
rows on the hob) and the center row aligned with the axis of the gear being 
cut, the flanks of the cutters above and below center will cut facets on the 
teeth above and below the gullet being cut in the middle. This also works with 
a straight hob with an even number of rows, cutting with a tooth on center 
matching a groove in the hob. Dunno if after finishing a gear with gullet on 
center then switching to tooth on center with the hob moved then doing a 
cleanup pass would make the teeth smoother by cutting facets in slightly 
different places on the teeth.

The same manual setups work with straight hobs and single tooth gear cutters, 
in a vertical or horizontal mill.

On Friday, July 24, 2020, 1:11:39 AM MDT, andrew beck 
 wrote:  
 Greg can you educate me on what what gear cutters are enough for most gear
cutting needs?  Fusion 360 has a nice gear profile generator I can use.
But I'll have to model all the cutters after that I think...  Thinking keep
them pretty simple with no helix angle or anything.  And maybe plan to cut
most of it out with a endmill straight down the middle before putting the
gear cutter through the cut

I will have to model this I think.  Otherwise they will say it's to hard.
But if I can send them the model then it's all go  
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andrew beck]

Greg can you educate me on what what gear cutters are enough for most gear
cutting needs?  Fusion 360 has a nice gear profile generator I can use.
But I'll have to model all the cutters after that I think...  Thinking keep
them pretty simple with no helix angle or anything.  And maybe plan to cut
most of it out with a endmill straight down the middle before putting the
gear cutter through the cut

I will have to model this I think.  Otherwise they will say it's to hard.
But if I can send them the model then it's all go

Regards

Andrew

On Fri, Jul 24, 2020, 6:43 PM Gregg Eshelman via Emc-users <
emc-users@lists.sourceforge.net> wrote:

>  Gear tooth shaped end mills would be real handy in many situations,
> especially where you need two different sized spur gears on one part, and
> the smaller one is too close to the larger one for any conventional sort of
> rotating gear tooth cutting tool. In olden times those had to be cut with a
> linear tool like a shaper or vertical slotting attachment for a mill. A CNC
> mill with a 4th axis can do such work with a ball end mill of diameter
> smaller than the smallest width between two teeth, but it's slow, requiring
> multiple passes to cut both flanks of each tooth.
>
> An end mill with the full profile could cut in a few straight passes and
> be done. Could make a multi-diameter cluster gear from a solid piece by
> turning the diameters then milling the teeth up close on each step.
>
> I suggest duplicating the 8 profiles that come with single tooth rotary
> gear cutters. Don't leave out 14 DP (especially in 14.5 PA) and 2.5 Module.
> People who work on 1940's American and 1980's Asian (especially Indian)
> equipment would like those sets.
> After WW2 there was apparently some consensus in the machine tool industry
> that *nobody* was ever again going to use 14 DP gears. Look on any site
> selling stock gears and you'll see they skip 14 DP, except one place in the
> UK that claims to have them, but only in 20 PA. If you want 14 DP it's a
> custom order, if they'll do it at all. Same goes for 2.5 Module. Somewhere
> around the late 70's into the 80's, some Asian and Indian companies must
> have decided 14 DP was ideal for some of their gears, but they had to keep
> in Metric and created 2.5 Module. It's >thisclose< to 14 DP 14.5 PA. That
> seems to have lasted around a decade before the industry said "No more of
> this!" and everyone using 2.5 Mod gears stopped. Nobody anywhere has stock
> 2.5 Mod gears but some places can make them to order. Takang is an Indian
> company that used 2.5 Mod gears in the drive to the gearbox on their manual
> lathes. Currently they only make CNC machines and don't acknowledge ever
> making manual machines, despite having been one of the best selling brands
> in India, with a healthy export business.
>
> On Thursday, July 23, 2020, 2:07:21 PM MDT, andrew beck <
> andrewbeck0...@gmail.com> wrote:
>  Gene I can get. Custom shaped endmills made in china easy as which is what
> I will probably do soon.  I might just get some gear tooth shaped endmills
> made..  I get custom tools all the time for my tooling company
> Regards
>
> Andrew
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gregg Eshelman via Emc-users]

 Gear tooth shaped end mills would be real handy in many situations, especially 
where you need two different sized spur gears on one part, and the smaller one 
is too close to the larger one for any conventional sort of rotating gear tooth 
cutting tool. In olden times those had to be cut with a linear tool like a 
shaper or vertical slotting attachment for a mill. A CNC mill with a 4th axis 
can do such work with a ball end mill of diameter smaller than the smallest 
width between two teeth, but it's slow, requiring multiple passes to cut both 
flanks of each tooth.

An end mill with the full profile could cut in a few straight passes and be 
done. Could make a multi-diameter cluster gear from a solid piece by turning 
the diameters then milling the teeth up close on each step.

I suggest duplicating the 8 profiles that come with single tooth rotary gear 
cutters. Don't leave out 14 DP (especially in 14.5 PA) and 2.5 Module. People 
who work on 1940's American and 1980's Asian (especially Indian) equipment 
would like those sets.
After WW2 there was apparently some consensus in the machine tool industry that 
*nobody* was ever again going to use 14 DP gears. Look on any site selling 
stock gears and you'll see they skip 14 DP, except one place in the UK that 
claims to have them, but only in 20 PA. If you want 14 DP it's a custom order, 
if they'll do it at all. Same goes for 2.5 Module. Somewhere around the late 
70's into the 80's, some Asian and Indian companies must have decided 14 DP was 
ideal for some of their gears, but they had to keep in Metric and created 2.5 
Module. It's >thisclose< to 14 DP 14.5 PA. That seems to have lasted around a 
decade before the industry said "No more of this!" and everyone using 2.5 Mod 
gears stopped. Nobody anywhere has stock 2.5 Mod gears but some places can make 
them to order. Takang is an Indian company that used 2.5 Mod gears in the drive 
to the gearbox on their manual lathes. Currently they only make CNC machines 
and don't acknowledge ever making manual machines, despite having been one of 
the best selling brands in India, with a healthy export business.

On Thursday, July 23, 2020, 2:07:21 PM MDT, andrew beck 
 wrote:  
 Gene I can get. Custom shaped endmills made in china easy as which is what
I will probably do soon.  I might just get some gear tooth shaped endmills
made..  I get custom tools all the time for my tooling company
Regards

Andrew  
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gregg Eshelman via Emc-users]

Could get the same effect as cutting teeth with a multi tooth straight hob. As 
the gear is turned, the involute curves are formed as a series of facets. With 
a 4th axis under CNC control you can have as many facets as you want. After 
milling I'd want to run gears together for a bit with some lapping compound to 
smooth the facet edges.

https://www.youtube.com/watch?v=K785jfrsKQU
For two small double gears in the gearbox output drive for a LeBlond 13" light 
duty "trainer" lathe from the 1940's, using a very small end mill and CNC, or a 
shaper, are the only ways to do the smaller gear on each one. The larger gears 
could be cut with a conventional spiral hob but the small one is too close to 
hob. The small gear could be hobbed if one would want to redesign the double 
gears to be assembled from at least two pieces.

On Thursday, July 23, 2020, 4:24:26 AM MDT, andy pugh  
wrote:  
 On Thu, 23 Jul 2020 at 03:41, andrew beck  wrote:

> https://youtu.be/3u1bZxd-KCk

With a 4th axis (which I realise you don't have) you would be able to
generate a tooth form using the flank of the cutter in just the same
way as you can with a shaper.
(Ideally you would use a conical tool bit ground to the required
pressure angle)  
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gene Heskett]

On Thursday 23 July 2020 19:56:37 andrew beck wrote:

> Hey Gene depends on size.  And there are often MOQ or 10 pics.  We
> just try work it out between us.
>
> Price wise 12mm cutter might be 25 usd.
>
> Small 5mm cutter might cost 8usd.
>
> Off the shelf  6mm endmills for stainless steel.  (they are really
> good quality.  Almost as good as a sandvic one). Cost like 4usd each
>
Sounds better that the box of assorted ones I just bought off ebay.  That 
hurt.

> On Fri, Jul 24, 2020, 8:46 AM Gene Heskett  
wrote:
> > On Thursday 23 July 2020 16:04:46 andrew beck wrote:
> > > Gene I can get. Custom shaped endmills made in china easy as which
> > > is what I will probably do soon.  I might just get some gear tooth
> > > shaped endmills made..   I get custom tools all the time for my
> > > tooling company Regards
> > >
> > > Andrew
> >
> > SWAG on pricing?
> >
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law
> > respectable. - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gene Heskett]

On Thursday 23 July 2020 19:02:47 Chris Albertson wrote:

> Gene,
>
> Better to just use a standard (replaceable at a reasonable cost) ball
> mill and let your CAM software generate the toolpath.  No math
> involved.

Yes there is. I know very llittle about CAM so I'd have to write my own. 
And its an even bet that I could do it in 150 lines of code, or less. 
I'm a huge fan of LCNC's ability to do loops.  Several years ago I 
needed to sharpen a 10" table saw blade. 90 lines of code, 3 days to run 
with a dremel hand cable clamped to my toy hf.  Took 3 days to run and 
took maybe 5 thou off the face of each carbide tooth. That blade did all 
the cutting for the next 6 pieces of funiture I built before it left the 
first burn on some cherry. Cleaned it off with some easy off oven 
cleaner and used it another 2 years includung cutting up the 1/8" alu 
panel out of the side of a wrecked UPS van to make the box the GO704's 
electronics is in. Its got another $400 worth of 1x12 mahogany to cut 
before I'll call it finished. Or I may see if I can rig the dremel to 
the GO704 and sharpen it again. Depends on how much of me is left then.

> If I am making gears I'd not want to have to depend on a steady supply
> of hen's teeth.  If your part depends on one-off tooling you might
> never be able to make another part or what if the tool breaks when you
> are halfway done?

All to be considered. The ball nose and some good code sounds like the 
better choice.
> On Thu, Jul 23, 2020 at 4:27 AM Gene Heskett  
wrote:
> >  my driving impetus to but a motor on this BS-1. But I'd need help
> > with the math using a ball nosed tool, or a flat faced with a corner
> > and very small steps radius.  Otherwise I suspect one would have to
> > buy a tool grinder too, and make ones own tools.  I have spent
> > considerable time looking for shaped tools/mills for such gear
> > cutting and either didn't recognize it from the description or came
> > up empty.

Stay safe and well Chris.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andrew beck]

Hey Gene depends on size.  And there are often MOQ or 10 pics.  We just try
work it out between us.

Price wise 12mm cutter might be 25 usd.

Small 5mm cutter might cost 8usd.

Off the shelf  6mm endmills for stainless steel.  (they are really good
quality.  Almost as good as a sandvic one). Cost like 4usd each



On Fri, Jul 24, 2020, 8:46 AM Gene Heskett  wrote:

> On Thursday 23 July 2020 16:04:46 andrew beck wrote:
>
> > Gene I can get. Custom shaped endmills made in china easy as which is
> > what I will probably do soon.  I might just get some gear tooth shaped
> > endmills made..   I get custom tools all the time for my tooling
> > company Regards
> >
> > Andrew
> >
> SWAG on pricing?
>
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Chris Albertson]

Gene,

Better to just use a standard (replaceable at a reasonable cost) ball mill
and let your CAM software generate the toolpath.  No math involved.

If I am making gears I'd not want to have to depend on a steady supply of
hen's teeth.  If your part depends on one-off tooling you might never be
able to make another part or what if the tool breaks when you are halfway
done?

On Thu, Jul 23, 2020 at 4:27 AM Gene Heskett  wrote:

>  my driving impetus to but a motor on this BS-1. But I'd need help
> with the math using a ball nosed tool, or a flat faced with a corner and
> very small steps radius.  Otherwise I suspect one would have to buy a
> tool grinder too, and make ones own tools.  I have spent considerable
> time looking for shaped tools/mills for such gear cutting and either
> didn't recognize it from the description or came up empty.
>

-- 

Chris Albertson
Redondo Beach, California

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Chris Albertson]

I hope to be able to do the same but on a MUCH smaller mill.   I think you
can even cut helical bevel gears this same way.

One thing, I think this would go faster if you made the first pass with a
larger end mill that could cut faster then do the finish pass using the
tiny end mill.

On Wed, Jul 22, 2020 at 7:41 PM andrew beck 
wrote:

> Hey everyone just a quick video here.  Might interest people.
>
> https://youtu.be/3u1bZxd-KCk
>
> Regards
>
> Andrew
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gene Heskett]

On Thursday 23 July 2020 16:04:46 andrew beck wrote:

> Gene I can get. Custom shaped endmills made in china easy as which is
> what I will probably do soon.  I might just get some gear tooth shaped
> endmills made..   I get custom tools all the time for my tooling
> company Regards
>
> Andrew
>
SWAG on pricing?


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andrew beck]

Gene I can get. Custom shaped endmills made in china easy as which is what
I will probably do soon.  I might just get some gear tooth shaped endmills
made..   I get custom tools all the time for my tooling company
Regards

Andrew

On Thu, Jul 23, 2020, 11:27 PM Gene Heskett  wrote:

> On Thursday 23 July 2020 06:33:08 Matthew Herd wrote:
>
> > That’s a fascinating idea.  I was pondering CNC’ing my shaper, but a
> > fourth axis would be much easier.  Even if you don’t have a conical
> > tool bit.  Albeit the surface finish might be a little rougher, it
> > should work well enough for most applications.
> >
> And is my driving impetus to but a motor on this BS-1. But I'd need help
> with the math using a ball nosed tool, or a flat faced with a corner and
> very small steps radius.  Otherwise I suspect one would have to buy a
> tool grinder too, and make ones own tools.  I have spent considerable
> time looking for shaped tools/mills for such gear cutting and either
> didn't recognize it from the description or came up empty.
>
> If anyone knows of a stateside purveyor of such hens teeth, throw me a
> url plz.
>
> Thanks.
>
> > > On Jul 23, 2020, at 6:20 AM, andy pugh  wrote:
> > >
> > > On Thu, 23 Jul 2020 at 03:41, andrew beck 
> wrote:
> > >> https://youtu.be/3u1bZxd-KCk
> > >
> > > With a 4th axis (which I realise you don't have) you would be able
> > > to generate a tooth form using the flank of the cutter in just the
> > > same way as you can with a shaper.
> > > (Ideally you would use a conical tool bit ground to the required
> > > pressure angle)
> > >
> > > --
> > > atp
> > > "A motorcycle is a bicycle with a pandemonium attachment and is
> > > designed for the especial use of mechanical geniuses, daredevils and
> > > lunatics."
> > > — George Fitch, Atlanta Constitution Newspaper, 1912
> > >
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Thu, 23 Jul 2020 at 12:27, Gene Heskett  wrote:

> I have spent considerable
> time looking for shaped tools/mills for such gear cutting and either
> didn't recognize it from the description or came up empty.

https://www.amazon.com/s?k=involute+gear+cutter
https://www.ebay.com/sch/i.html?_from=R40&_nkw=involute+gear+cutter
https://www.mcmaster.com/involute-spur-gear-cutters

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Gene Heskett]

On Thursday 23 July 2020 06:33:08 Matthew Herd wrote:

> That’s a fascinating idea.  I was pondering CNC’ing my shaper, but a
> fourth axis would be much easier.  Even if you don’t have a conical
> tool bit.  Albeit the surface finish might be a little rougher, it
> should work well enough for most applications.
>
And is my driving impetus to but a motor on this BS-1. But I'd need help 
with the math using a ball nosed tool, or a flat faced with a corner and 
very small steps radius.  Otherwise I suspect one would have to buy a 
tool grinder too, and make ones own tools.  I have spent considerable 
time looking for shaped tools/mills for such gear cutting and either 
didn't recognize it from the description or came up empty.

If anyone knows of a stateside purveyor of such hens teeth, throw me a 
url plz.

Thanks.

> > On Jul 23, 2020, at 6:20 AM, andy pugh  wrote:
> >
> > On Thu, 23 Jul 2020 at 03:41, andrew beck  
wrote:
> >> https://youtu.be/3u1bZxd-KCk
> >
> > With a 4th axis (which I realise you don't have) you would be able
> > to generate a tooth form using the flank of the cutter in just the
> > same way as you can with a shaper.
> > (Ideally you would use a conical tool bit ground to the required
> > pressure angle)
> >
> > --
> > atp
> > "A motorcycle is a bicycle with a pandemonium attachment and is
> > designed for the especial use of mechanical geniuses, daredevils and
> > lunatics."
> > — George Fitch, Atlanta Constitution Newspaper, 1912
> >

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Matthew Herd]

That’s a fascinating idea.  I was pondering CNC’ing my shaper, but a fourth 
axis would be much easier.  Even if you don’t have a conical tool bit.  Albeit 
the surface finish might be a little rougher, it should work well enough for 
most applications. 

> On Jul 23, 2020, at 6:20 AM, andy pugh  wrote:
> 
> On Thu, 23 Jul 2020 at 03:41, andrew beck  wrote:
> 
>> https://youtu.be/3u1bZxd-KCk
> 
> With a 4th axis (which I realise you don't have) you would be able to
> generate a tooth form using the flank of the cutter in just the same
> way as you can with a shaper.
> (Ideally you would use a conical tool bit ground to the required
> pressure angle)
> 
> -- 
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1912
> 
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[andy pugh]

On Thu, 23 Jul 2020 at 03:41, andrew beck  wrote:

> https://youtu.be/3u1bZxd-KCk

With a 4th axis (which I realise you don't have) you would be able to
generate a tooth form using the flank of the cutter in just the same
way as you can with a shaper.
(Ideally you would use a conical tool bit ground to the required
pressure angle)

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Little gear I'm cutting. Thought it may interest people.

[Matthew Herd]

Great work!  Seems like a nice way to maek a gear if you’re patient.

> On Jul 22, 2020, at 10:39 PM, andrew beck  wrote:
> 
> Hey everyone just a quick video here.  Might interest people.
> 
> https://youtu.be/3u1bZxd-KCk
> 
> Regards
> 
> Andrew
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Little gear I'm cutting. Thought it may interest people.

[andrew beck]

Hey everyone just a quick video here.  Might interest people.

https://youtu.be/3u1bZxd-KCk

Regards

Andrew

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users