Hi all, hope your all ahving a good new year so far and managing to get those extra pounds back off after christmas, I think I'm almost back to my pre christmas racing snake figure

Anyway, today I'm on with cutting some gears.
Got my rotary setup and machined the blanks to size, fitted the gear cutter and fired up the new fangled wizards, selected the gear cutting one and selected the behind right (slight interferance on the left so for this A's on the right) told it the blank dia, feed clearance cut depth, etc, all in mm, I then pressed the preview code and there was nothing, no code at all.
So I rechecked, still nothing.
I then posted the code to see what came out and there was some code but no angles etc and a very bizar Y move that took the Y over the soft limits, way over the 2.28mm cut depth and no X code for the 50mm move to cut the teeth.

So just to see what it did I clicked run and got the softlimit warning and then after that I couldn't move the mill at all, I tried reset, checked the diagnostic screen and there was still communication with the limit switches.
I then shut down to restart mach and the computer locked up with a softlimit warning that just stayed there flashing with the pc speaker bipping at me.
I had to turn off the computer and it took another restart to get mach communicating with the driver.

I also tried the normal wizards with no luck and no code generated

So has anyone else had this problem with the nf wizards?

Steve

Hi

Now decided to use a sub to do this so I would like to know of you experts if this is right.
18 tooth gear with the A on the left of teh table and the cutter will be climb milling on the front of the blank from right to left, this part is right for how I want it to cut.
I can't check this on mach as I've got to look after the kids so can't get out to the workshop tonight.

M06 T57 G43 H57 (TOOL/MILL,gear cutter 24 dp)

O1 (tooth cut routine)
G0 Y-3
G0 X0
G0 Y-0.1
G1 Y2.28 F75
G1 X-40 F200
G0 Y-3
G0 X0
M99

G0 A0
M98 P1
G0 A20
M98 P1
G0 A40
M98 P1
G0 A60
M98 P1
G0 A80
M98 P1
G0 A100
M98 P1
G0 120
M98 P1
G0 A140
M98 P1
G0 A160
M98 P1
G0 A180
M98 P1
G0 A200
M98 P1
G0 A220
M98 P1
G0 A240
M98 P1
G0 A260
M98 P1
G0 A280
M98 P1
G0 A300
M98 P1
G0 A320
M98 P1
G0 A340
M98 P1
G0 A360
M05 M30

I'm far, far from an expert but what I see looks good. (I even checked your math!)

I have a hobbing machine that I built years ago (castings from the UK) that I must show here. I use commercial hobbs found on 'that auction site' but have also attempted to make them. (ever heard of a "Eclipse" cutter relief tool?) I doubt if I will ever use the 4th axis on my NC machine to make gears....

Bill C.

Hi Bill

I've used the 4th axis a few times but not that much.
I've got some gears to make for a radial engine so after trying to make the cutter I ended up buying some but I've seen photo's of the eclipse tool, I think it's the eurica tool used in Ivan Law's gears and gear cutting book.

But I've seen an easier way that doesn't require a complicated machine. You form profile then offset it in a 4 jaw chuck and use the profile tool again so that nearly 1/4 is recut and then repeat for the other 3 sides. You then cut out to make 4 teeth with form relief so they can be resharpened.

Steve

That sounds better than all the cams and spring action going on. Small snips in a lathe are so easy to get into trouble with, too fast, too much feed - time. You are wise to purchase cutters.

Too bad there isn't a cutter exchange or cutter borrow system. I happen to have a set of 24DP cutters that are sitting in a drawer used so little that they are still in new profile.

Yes; "THE EUREKA   A continuous form reliving tool for gear cutters  by I. R. Law". I just dug the drawings out. I must stop relying on memory for names.... Now I must look about this "Eclipes" brought up to 'refresh'.

Regards,

Bill C.

Steve,
I know the NFS gear cutting works since a friend has used it many times to cut gears. You need to purchase a license for the NFS wizards.

You can use a single profiled cutter in a fly cutter. If super precision is not required a  home made one will do the trick. I posted how i made gear cutters in the show and tell, but there are easier ways.I think i posted my spread sheet that calcualtes all the dimensions, then you just select the best fit end mill and shape the single cutter. My friend makes his owne gears for RC helicopters because they are better and last longer than what you buy. Beats $25 or more every time you need a cutter.
 
RICH

Rich,

With most high regard and not trying to make anyone angry or attempting to pick a fight; do you know what a "THE EUREKA   A continuous form reliving tool for gear cutters  by I. R. Law" is?

Bill C.

Here is a quick how to on using the spread sheet for making a spur gear.
One advantage i have is i can take an old end mill and resharpen it to the diameter i want.
But in many cases there is no need too for model work and non critical stuff.

RICH

Bill,
No I do not but will take look and educate myself. In the mean time above post may be of value or interest.
 Rich

Rich,

Isn't your spread sheet for making a cutter for a specific gear?